Article
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

The invasion of the male urogenital tract by microorganisms, and its subsequent effects on sperm fertilising ability, has not been well discussed in bucks. The present study was conducted to assess the bacterial load in fresh semen of the 2–6 years old bucks. For conducting the experiment, semen ejaculates from 18 bucks (6 from each breed namely Jakhrana, Jamunapari and Barbari) were used. We collected 5 ejaculates from each buck in each season (Summer‐April to June, Rainy‐July to Sept and Winter‐November to January). Semen was collected with the artificial vagina (AV) method, and separate AV was used for each buck every time. The semen collection frequency was once in a week. Immediately after initial evaluation, collected semen samples were transferred to the microbiology laboratory of the institute. Thereafter, the semen samples were subjected to bacteriological examination to assess the microbial load. The results of the current study indicate that the microbial load in the semen was significantly (p < 0.05) higher in the Jamunapari bucks and in aged bucks. Bacteriospermia in different seasons was not significantly varied; however, nonsignificant increase in microbial load during the rainy season was observed. Overall, the average bacterial load in the semen of Jamunapari, Barbari and Jakhrana bucks was found 540.50 ± 55.88 CFU/ml, 391.81 ± 46.33CFU/ml and 388.93 ± 44.71 CFU/ml respectively. No significant difference in bacterial counts in the subsequent ejaculates among bucks was observed. Moreover, correlation analysis revealed that the proportions of motility, viability, plasma membrane integrity and acrosomal integrity were negatively influenced by the increased bacterial contamination of buck semen.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Semen dilution and semen cryopreservation: The semen samples were diluted as described earlier by Gangwar et al. (2021). The various concentration of M. oleifera aqueous extract were added in the above extender (different groups i.e. ...
... Effect on sperm plasma membrane: The hypo-osmotic swelling test (HOST) was used to evaluate the functional integrity of the sperm plasma membrane as per the protocol used by Gangwar et al. (2021). Total of 200 spermatozoa were counted in at least five different microscopic fields. ...
... Male urogenital tract infections significantly contribute to buck infertility, with recent attention focusing on the role of infections in semen quality degradation, particularly asymptomatic bacteriospermia (Gangwar et al. 2021). These infections can deteriorate spermatogenesis, impair sperm function, and cause seminal tract obstruction (Kumaresan et al. 2022). ...
Article
Full-text available
The current investigation was planned to evaluate the effect of Moringa leaves also called Moringa oleifera (M. oleifera) aqueous extract on buck semen quality during cryopreservation, and its antimicrobial potential against the Escherichia coli (E. coli) isolated from the semen samples. Semen was collected from 8 Jakhrana bucks, and from each buck, 8 ejaculates were collected. Semen samples were subjected to bacteriological studies and pathogenic coli were isolated from semen samples. Then, various concentrations of M. oleifera extract were evaluated for its antimicrobial potential. Good quality semen samples were pooled during each collection. Pooled semen samples were then divided into 4 equal parts, and diluted in TRIS buffer containing different concentration of M. oleifera leaf aqueous extract (Different groups, i.e. T1-50 mg, T2-100 mg, T3-200 mg, C-0 mg of M. oleifera aqueous extract in 100 ml TRIS Buffer). Semen samples were evaluated for various sperm characteristics after cryopreservation. oleifera aqueous extract supplemented groups showed significant enhancement in sperm viability, sperm motility, acrosomal integrity and plasma membrane integrity. The treatment significantly reduced the lipid peroxidation in supplemented groups and M. oleifera extract shows the potent antimicrobial activity against the E. coli isolated from buck semen.
... Semen samples were collected applying separate AV in each collection that was sterilized by autoclaving and following hygienic methods as described previously. [6] Besides, all the bucks belonged to same breeding season and maintained in similar housing and microenvironmental conditions. ...
... [2] The presence of Staphylococcus in buck semen has a direct effect on the semen, as we found significant reduction in the progressive motility, acrosomal integrity, and plasma membrane integrity and significant increase in sperm abnormalities [ Table 2]. In earlier studies, it is reported that S. aureus can easily invade the reproductive tract affecting its functions [6,13] and reducing the reproductive potential of spermatozoa. [14] Most studies conducted in the past also reported that S. aureus and S. epidermidis are the most common Staphylococcus spp. reported in bull semen and the metabolic by-products secreted from these species were reported to have damaging effects on the acrosomal integrity and sperm motility. ...
Article
Full-text available
Objective Buck reproductive health is the key for breeding and production of quality semen. To assess the health of breeding bucks, in this study, we detected the presence of Staphylococcus spp in semen. Staphylococcus aureus is a common commensal and opportunistic pathogenic bacteria and is also a cause of many diseases in animals. Besides this, it can also deteriorate the semen quality. Materials and Methods In this study, we collected 48 semen ejaculates from healthy bucks of three breeds, namely, Jamunapari, Barbari, and Jakhrana to assess the presence of Staphylococcus spp. Besides bacteriological study, the semen was also assessed for semen quality parameters in infected as well as in non-infected semen samples. Results and Conclusion The semen quality was significantly deteriorated with Staphylococcus infection. The bacterial infection was initially confirmed as Staphylococcus spp. based on the Gram’s staining and growth on Mannitol salt agar. Based on this preliminary bacteriological analysis, 52.08% ( n = 25) of the samples were found positive for Staphylococcus spp. from the total 48 buck semen ejaculates belonging to three different goat breeds. The isolates were confirmed based on the basis of multiplex PCR and the species identified were S. aureus, Staphylococcus sciuri, Staphylococcus haemolyticus, Staphylococcus chromogenes, Staphylococcus epidermidis , and Staphylococcus simulans directly in the buck semen. By this study, it is evident that semen can get contamination from a buck which has the presence of staphylococcus in the reproductive tract and semen quality is adversely affected. Hence, it is important to ensure the health and hygiene of the bucks maintained for semen production for artificial insemination.
... We use the artificial vagina method to ejaculate the trained ram before semen collection to promote the production of fresh semen, ensure the quality of semen and improve the libido of the breeding ram. Finally, we recorded the amount of ejaculate [26]. ...
... The semen was diluted at a ratio of 1:100 and counted using a hemocytometer. The sperm count was observed in the five squares on the hemocytometer under a microscope, and this allowed us to calculate the sperm concentration [26]. ...
Article
Full-text available
Copy number variations (CNVs) have many forms of variation structure, and they play an important role in the research of variety diversity, biological evolution and disease correlation. Since CNVs have a greater impact on gene regulation and expression, more studies are being finalized on CNVs in important livestock and poultry species. The protein phosphatase 3 catalytic subunit alpha (PPP3CA) is a key candidate gene involved in the goat fecundity trait, and has important effects on precocious puberty, estrogen signal transduction pathways and oocyte meiosis. Additionally, PPP3CA also has a dephosphorylation effect in the process of spermatogonial stem cell meiosis and spermatogenesis. So far, there is no research on the relationship between the copy number variations of the PPP3CA gene and reproduction traits. Therefore, the purpose of this study was to determine the association between copy number variations in the goat PPP3CA gene and litter size and semen quality in Shaanbei white cashmere goats (SBWC) (n = 353) and Guizhou Heima goats (n = 64). Based on the association analysis, the results showed that only CNV1 and CNV2 within the PPP3CA gene were distinctly related to the first-birth litter size in female goats (p = 7.6802 × 10−11; p = 5.0895 × 10−9, respectively) and they were also significantly associated with the semen quality of SBWC goats (p < 0.05). In addition, individuals with Loss genotypes demonstrated better phenotypic performance compared to those with other types. Therefore, CNV1 and CNV2 of the PPP3CA gene are potentially useful for breeding, as they are linked to important goat reproduction traits.
... Moreover, the preservation of diluted semen at moderate temperatures, with nutrient-rich extenders, creates favorable conditions for considerable bacterial multiplication [4]. Bacterial proliferation leads to sperm agglutination, decreased sperm motility, viability, membrane integrity and acrosomal integrity acrosome damage [5]. ...
Article
Full-text available
This study aims to investigate the impact of carvacrol and thymol on the quality of Beni Arouss buck semen stored in skim milk at 4 • C. Ejaculates were collected from eight Beni Arouss bucks weekly for 11 weeks, pooled, and then divided into three equal parts. Samples were diluted to 400 × 10 6 sperm/mL in skim milk (control) and skim milk supplemented with a single dose of 200 µM carvacrol and thymol each. Evaluations of sperm motility, viability, abnormalities, membrane integrity, lipid peroxidation, and bacterial growth were conducted at 0, 6, 24, and 48 h of liquid storage at 4 • C. After 48 h of storage, the results indicate that the addition of carvacrol positively influences total and progressive motility and viability. However, it also leads to a decrease in lipid peroxidation and bacterial growth compared to the control group (p < 0.05). Thymol showed similar results to carvacrol, except for progressive motility (p > 0.05). Bacterial growth was negatively correlated with total and progressive motility and viability (p < 0.05), while no correlation between lipid peroxidation and these parameters was observed (p > 0.05). In conclusion, the addition of carvacrol and thymol to skim milk extender moderately improves the quality of Beni Arouss buck semen after 48 h storage at 4 • C due to its antimicrobial activity.
... Furthermore, several studies have been conducted of the microbiome of the healthy bull prepuce (Koziol et al., 2017;Wickware et al., 2020), and semen microbiota (Medo et al., 2021) and their correlation with sperm quality (Medo et al., 2021;Koziol et al., 2022) or fertility results (Cojkic et al., 2021). It has also been found that sperm quality and seminal bacterial load are affected by season in rams (Azawi and Ismaeel, 2012), goats (Gangwar et al., 2021), and buffalo (Sannat et al., 2015), as well as different breeds of cattle (Sannat et al., 2016). Identification of bacteria in these studies was done by traditional culture-dependent methods where bacteria that are difficult to culture may be missed, leaving us with an incomplete knowledge of the bull semen microbiota. ...
... Aging can cause a decrease in semen quality (Tsai et al., 2013) and impact decreasing fertility (Kidd et al., 2001). Various species have reported that age affects fertility (Pardede et al., 2020b;Gangwar et al., 2021). Aging can cause a physiological decline in the reproductive organs that can cause disturbances in spermatogenesis. ...
Article
Full-text available
This study aimed to analyze the characteristics of the HSP70 gene and protein in spermatozoa of Bali bulls of different age groups and to examine its potential as a biomarker determining bull fertility. This study used frozen semen produced from six Bali bulls divided into two groups based on age (≤ 9 years and ≥ 12 years). Parameters of frozen semen quality analyzed included sperm motility and kinetics using computer-assisted semen analysis, sperm morphological defects using Diff-Quick staining, acrosome integrity using FITC-PNA staining, and DNA fragmentation using acridine orange staining. HSP70 gene expression characterization was analyzed using qRT-PCR, and HSP70 protein abundance was analyzed using enzyme immunoassays. Fertility field data were obtained by analyzing the percentage conception rate for each bull based on the artificial insemination service data contained in the Indonesian-integrated system of the National Animal Health Information System (iSIKHNAS). The results showed significant differences (P<0.05) in total and progressive motility, morphological defects of the neck and midpiece, and tail of sperm, and acrosome integrity between the age groups of Bali bulls. HSP70 gene expression and protein abundance showed no significant differences (P>0.05) in different age groups. HSP70 gene expression correlated with fertility rate (P<0.05). Age affected several semen quality parameters but did not affect HSP70 gene expression and protein abundance. The HSP70 gene molecule could be a biomarker that determines the fertility of Bali bulls.
... ROS are also generated from semen processing steps including cryopreservation in addition to the spermatogenesis (Bucak et al. 2008(Bucak et al. , 2009) and further the freezing/thawing procedures leads to cold shock/injuries and lipid peroxidation (Bucak et al. 2012). Moreover, other environmental factors like high temperature, toxins, chemicals and microbial contamination (Gangwar et al. 2021, Kumaresan et al. 2022 attribute to ROS production thereby affecting the reproduction system. ...
Article
Full-text available
Male infertility is becoming an important untouched area that needs immediate attention due to the increasing demand for breeding strategies, keeping in view the production and increasing per animal productivity. Many additives and antioxidants have been tried for enhancing the seminal quality, but still there is no evidence of full- proof effect on the conception rates in female animals. However, herbal preparations which promise multi-factorial effect in the breeding male animals can be explored, and in turn could prove to be a better tool to encounter the problem of male infertility holistically. The herbal preparations and its effect at the cellular, molecular and metabolic level still needs to be understood. However, the advantage of using the herbal ingredients could be, use of available local herbal ingredients which are more economical, affordable, can reduce the use of hormonal therapy, have less side effects on long term usage, and have greater acceptability by the farmers. These herbal ingredients will be useful in breeding programmes for improvement of germplasm in terms of productivity. The current review covers how the herbs can be utilized in improving the semen quality and quantity, enhancing function of sertoli and leydig cells, mating behaviour, fecundity, seminal antioxidant status, hypophyseal adrenal gonadal axis cum endocrine regulation, microcirculation of testes, as well as in semen cryopreservation and post thaw quality of different species.
... A hemocytometer was used to measure sperm concentration after dilution and eosin staining [26]. Several methods exist for determining spermatozoa concentration, including estimation based on the distance between sperm heads, counting chamber, spectrophotometer, HR 5 or 6 photometer, and sperm cue [27]. ...
Article
Copy number variations (CNV) contribute significantly to genetic variations. Numerous studies have shown that CNV affects phenotypic traits in livestock. The SMAD family member 2 (SMAD2) is a leading candidate gene in reproduction and has a crucial effect on litter size. Additionally, SMAD2 is also required for male reproduction and influences male germ cell development. However, there are no reports on investigating the effect of CNVs in the SMAD2 gene on reproductive traits in goat. Therefore, the goal of this study was to explore associations between CNV of the SMAD2 gene and litter size and semen quality in Shaanbei white cashmere (SBWC) goats. In this study, two CNVs within the SMAD2 were identified in 352 SBWC goats (50 males and 302 females). The association analysis revealed that only CNV2 was significantly associated with female goat first-born litter size (P = 3.59 × 10-4), male semen concentration (P < 0.01), ejaculation volume, live sperm count, and sperm deformity rate (P < 0.05). In terms of phenotypic performance, the individuals with loss genotypes outperformed those with other genotypes. CNV1 and CNV2 genotype combinations containing their dominant genotypes were also associated with goat litter size (P = 1.7 × 10-5), but no differences in semen quality were found. In summary, CNV2 of the SMAD2 gene is useful for molecular marker-assisted selection breeding, as it is associated with essential goat reproductive traits.
... Acute and chronic infections and consequent inflammation in the male reproductive system may compromise the sperm cell function and the whole spermatogenetic process (Sanocka-Maciejewska et al. 2005). The final effect usually is poor sperm quality and hence male infertility (Gangwar et al. 2021). In the present study, we investigated the occurrence and performed molecular characterization of Staphylococcus spp. ...
Article
Full-text available
Staphylococcus aureus is one of the most prevalent pathogens, and a causative agent of a variety of infections in humans and animals. Most studies concentrated on characterization of staphylococcus isolates and its antimicrobial resistance from various illness of veterinary importance, but there is no specific study that is available on isolates from reproductive tract of small ruminants and especially its semen. Hence, in the current study, a total of 48 semen samples were collected from healthy bucks of different breeds to investigate the occurrence of S. aureus. Antimicrobial resistance and virulence of the Staphylococcus isolates were determined to assess the adverse effects of them on buck fertility. The bacterial isolates were tentatively confirmed as Staphylococcus spp. based on the Gram’s staining, growth on Mannitol salt agar and catalase test. Overall, 75% (n = 36) of the samples were positive for Staphylococcus spp. from the total 48 buck semen ejaculates from different breeds and among them 23 (63.89%) were coagulase-negative (CoNS) and 13 (36.11%) were coagulase-positive Staphylococcus (CoPS) strains. The species identified by molecular characterization are S. aureus, S. chromogenes, S. haemolyticus, S. sciuri, S. simulans, and S. epidermidis from buck semen. Further, these isolates exhibited varying degrees of multidrug resistance genotypically as well as phenotypically. The presence of antibiotic resistance and virulence genes may pose a potential threat to reproductive health of animals, the animal handlers and livestock keepers, while simultaneously highlighting the need for vigilant monitoring of these isolates at the time of semen cryopreservation.
... The effects of these conditions may be sperm damage, elevated leucocyte response, poor motility and immature sperms compromising the semen quality. Consequently it leads to compromise of sperm cell function and the whole spermatogenesis (Gangwar et al. 2021). In the present study, we investigated the prevalence and performed molecular characterization of Staphylococcus spp. ...
Preprint
Full-text available
Staphylococcus aureus is one of the most prevalent pathogens, and a causative agent of a variety of infections in humans and animals. A total of 48 semen samples were collected from healthy bucks of different breeds to investigate the prevalence of S. aureus . Antimicrobial resistance and virulence of the Staphylococcus isolates were determined to assess the adverse effects of them on buck fertility. The bacterial isolates were tentatively confirmed as Staphylococcus spp. based on the Gram’s staining, growth on Mannitol salt agar and catalase test. Overall, 75% (n = 36) of the samples were positive for Staphylococcus spp. from the total 48 buck semen ejaculates from different breeds. Out of 36 staphylococcal isolates, 23 (47.92%) were coagulase negative (CoNS) and 13 (27.08%) were coagulase positive Staphylococcus (CoPS) based on the slide coagulase test. In the current study, on the basis of molecular characterization, we identified S. aureus , S. chromogenes, S. haemolyticus, S. sciuri, S. simulans and S. epidermidis amongst the staphylococcal isolates in the buck semen. This study revealed a high prevalence of Staphylococcus species in semen of the healthy bucks. The isolates exhibited varying degrees of multidrug resistance genotypically as well as phenotypically. The presence of antibiotic resistance and virulence genes may pose a potential threat to reproductive health of animals, highlighting the need for vigilant monitoring of these isolates at the time of semen cryopreservation.
... Apart from the extender and potential supplements, other important factors affecting the shelf life of goat LS include but are not limited to the cooling rate, animal individuality, and the season: Cooling at the rate of 0.1-0.25 • C/min did not affect the values for sperm viability variables, while more rapid cooling rates of 0.6 • C/min from 30 • to 15 • C led to a reduction in goat sperm motility and membrane integrity . Concerning seasonality, results from a number of reports suggest there is a marked decrease of semen quality during the non-breeding season (Corteel et al., 1988;Ritar and Salamon, 1991;Gangwar et al., 2021). The definition of the breeding season depends on the geographic location and was defined as mid-September to mid-March (breed: Saanen and Alpine) by Corteel et al. (1988) or as March to August in the southern hemisphere (breed: Angora) by Ritar and Salamon (1991). ...
Article
This review is part of the Festschrift in honor of Dr. Duane Garner and provides an overview of current techniques in cooled storage of semen from livestock animals such as camelids, goats, and sheep. Facing worldwide environmental changes and a trend towards more conscious and healthy eating behaviors, the development of a stable animal breeding industry is a significant challenge for the near future. In the present review, factors influencing semen handling in camelids, goats and sheep are described and relevant methods as well as current trends to improve liquid-storage of cooled semen are discussed, including extenders, additives, cooling rates, and storage temperatures. The species-specific physiology and resulting challenges are taken into consideration. While the main problem for camelid semen processing is the relatively greater viscosity as compared with that of some other animals, the deciding factor for successful artificial insemination (AI) in goats and sheep is the site (i.e., cervical or vaginal) of semen placement in the reproductive tract. Due to the type of cervical anatomy, the penetration of the cervix when using AI instruments is rather difficult. Furthermore, the seminal plasma of small ruminants affects the interaction with milk-based extenders and egg yolk which results in species-specific regimens for cooled liquid-preservation. Comparing all three species, the greatest pregnancy rates were obtained by AI with goat semen after cooled liquid-storage for several days.
Preprint
Full-text available
Senescence, the deterioration of organismal function with advancing age, is a puzzling biological phenomenon. While actuarial senescence ( i.e. , age-dependent increases in mortality rates) is well described across some taxa, reproductive senescence ( i.e. age- dependent declines in reproduction) is less understood, especially in males, with mixed patterns reported across studies. To examine the evidence for male reproductive senescence, we investigated how advancing male age affects ejaculate traits across non-human animals via a meta-analysis yielding 1814 effect sizes from 379 studies. We found no evidence for a general pattern of reproductive senescence. Instead, we found high heterogeneity for how reproduction changes with male age across animals. Some of this heterogeneity (>10%) was associated with biological factors. For example, there were taxonomical differences for some ejaculate traits — sperm motility declined with male age in lab rodents and fish, whereas ejaculate size improved with male age in bulls, fish, and insects. Some methodological factors were also important in explaining this heterogeneity: studies sampling a larger proportion of a species’ lifespan were more likely to detect senescence in ejaculate traits, emphasising the need to examine the full life cycle of species to document senescence. Contrary to predictions, we reveal that the evidence for senescence in ejaculate traits is sporadic. Our findings will help generate novel hypotheses and identify more effective methodological approaches for studying male reproductive senescence.
Article
Microbiota is a cluster of physiological and pathogenic microorganisms found in many tissues and organs of living things, including such as bacteria, viruses, fungi. Microbiota has important roles on many system functions such as immune system, urinary system, digestive system. However, these microorganisms can cause obstruction in the genital tract, epididymitis and orchitis, and thus may lead to infertility. In addition, pathogenic and apathogenic microorganisms such as bacteria, viruses and fungi have negative effects on spermatology. Decreased sperm motility, disruption of membrane integrity, and acrosome damage are the most common of these negativities. Approximately 15% of male infertility in the world is associated with infection in the genital tract. The most common microorganisms found in the male genital tract and semen are Enterobacter, Lactobacillus and Staphylococci. In addition, microorganisms in semen cause infections in the female genital tract, birth of offspring with anomalies and embryonic deaths. In this study, the current literature on the microorganisms found in the male genital tract and semen in different species has been compiled.
Article
ATP is essential for mammalian sperm to maintain fertilizing capacity. Metformin (Met) can activate 5′-AMP-activated protein kinase (AMPK) to maintain energy homeostasis. Thus, the aim of the present study was to investigate whether Met can improve testis function, semen quality, antioxidant and autophagy capacity through AMPK mediation of energy metabolism in goats. Twelve adult goats were randomly divided into three dietary treatments. All goats were fed a basal diet for 3 weeks and then assigned to a Met supplementation diet containing 0, 150, or 300 mg/kg for 8 weeks. The results showed that sperm viability, sperm membranal functional integrity, and acrosome integrity increased (P < 0.05) relative to the other treatments in the 300 mg/kg Met group. Growth hormone (GH) and insulin-like growth factor (IGF-1) in the 300 mg/kg Met group significantly decreased (P < 0.05) relative to the control group. Estrogen levels (E2) in the 300 mg/kg Met group remarkably improved (P < 0.05) compared with the control group. The activities of the antioxidant enzymes catalase (CAT), glutathione peroxidase (GSH-px), and superoxide dismutase (SOD) significantly increased (P < 0.05) in the 300 mg/kg Met group relative to the control group. A significant increase in AMPK and p-AMPK protein expression in the 300 mg/kg Met group was observed relative to the control group (P < 0.05). Belicin-1 and LC3II/I protein expression was significantly increased by adding Met to the diet (P < 0.05) and reached a maximum in the 300 mg/kg Met group. In addition, differentially expressed genes (DEGs) of goat testis were confirmed by RNA-seq. GO enrichment analysis revealed that DEGs were enriched in testicular metabolism and sperm development-related functional pathways. Overall, the results indicate that Met may play an important role in the regulation of testis function, semen quality, antioxidant, and autophagy capacity. These findings will help elucidate the role of Met in goat testis development.
Article
Full-text available
Infectious diseases and etiological agents related to female reproductive systems were extensively covered compared to its male counterpart. There needs a proper study to bridge this gap, where microflora and infectious agents of both male and female reproductive are mutually intelligible. With this study, we aimed to evaluate the microbial contamination of the preputial cavity and also screened for abortion causing agents which are zoonotic as well. In goats, such types of abortions are caused by Brucella melitensis, Chlamydophila, Campylobacter and Coxiella etc. One of the major sources of contamination of semen is the preputial cavity, which is exposed to the external environment leading to spread of infection into the female via semen straws or by natural service. In the current study, good quality bucks (n=32, Barbari=12, Jamunapari=10, Jakhrana=10) which were routinely used for semen collection were screened for their preputial swabs, for the presence of the above pathogens. For detection of Brucella melitensis, OMP31 based TaqMan® probe real time PCR assay was used, and for Chlamydia, 16srRNA gene based SYBR® green real‐time PCR assay was employed for detection of Chlamydophila abortus. While for Campylobacter spp. and Coxiella burnetii, 16srRNA gene based conventional PCR and Trans‐PCR were used respectively. In the current study, of the screened preputial swabs, none of them showed positive for Brucella and Coxiella, but of the screened 32 samples 17 showed positive for Chlamydia (53.13%) and two (6.25%) showed positive for Campylobacter spp. The current study emphasises on the farms and laboratories which were regularly involved in screening of brucellosis also often overlook the other potential non‐brucella pathogens, causing abortions eventually incurring severe economic losses to the goat keepers.
Article
Full-text available
The objectives of this trial were to estimate prevalence of bacteriospermia, to determine the bacterial load, and to isolate the types of bacteria as well as to assess the association between bacterial load and sperm quality traits in cryopreserved bull semen in field conditions in the South Wollo Zone. A total of 309 cryopreserved straws of semen from the Holstein Friesian (HF)-cross bull (n = 180 straws) and pure Jersey bull (n = 129 straws) were investigated. Bacteriological assessments of the presence of aerobic bacteria, estimation of bacterial count and bacterial isolation, as well as semen quality were performed. Aerobic bacterial contamination was prevalent in 38.8% of the semen straws. No significant difference in the prevalence of bacteriospermia was observed among bulls although the HF-cross bull had a higher prevalence (40.0%). But, significant difference in prevalence of bacteriospermia was found among semen ejaculates of the same bull. The risk of bacteriospermia in the HF-cross bull was higher (Odds ratio = 1.86, 95% CI = 0.168–20.26) compared to Jersey although not significant. Overall average bacterial load of 50.38 ± 16.29 colony-forming units (CFU)/ml (from nil to 1318.20 CFU/ml) was found. No significant difference in bacterial count among bulls and their ejaculates was observed. Moreover, correlation analysis revealed that the proportions of motility, live, and normal morphology were negatively influenced by an increase in the bacterial contamination of semen. In this study, three isolates of coagualse-negative Staphylococcus species and one isolate of Corynebacterium species were found. Average percentages of sperm motility (48.35 ± 1.23), live (66.08 ± 1.0), and normal morphology (80.62 ± 1.24) were observed. It was concluded that cryopreservation does not guarantee the quality of semen from bacterial contamination. Hence, meticulous care should be adopted to prevent contamination of semen by bacteria during collection, transportation, processing, and storage times. 1. Introduction Ethiopia inhabits significant proportion of cattle population in Africa with its 56.71 million heads of cattle [1]. Indigenous cattle are the main livestock species used for dairy production in Ethiopia, which contributes around 81.2% of the total national annual milk yield [2]. Although the country has a huge potential for milk production, the genetic potential and productivity of local breeds, as a matter of fact, is very low [3]. Consequently, the direct contribution of the dairy sector to the national economy is inadequate [1]. More recently, the country has designed a dairy cattle improvement plan to enhance productivity of local breeds through genetic selection, breeding, and artificial insemination (AI) programs [4]. So as to realize this, accurate prediction of bull fertility is essential because it determines the economic success and sustainability of the dairy industry. This in turn is reliant on obtaining high conception rates after insemination of cows using frozen-thawed semen [5]. AI is the oldest and most popular assisted reproductive biotechnology allowing the use of genetically superior males from elsewhere for genetic improvement of livestock [6]. Long-term storage of semen in liquid nitrogen (−196°C), through cryopreservation, is indispensable in order to realize many of the potential advantages of AI. Cryopreservation halts the metabolic activities of spermatozoa, which allows unlimited storage without substantial loss of fertility. Hence, quality of frozen-thawed semen is an important factor that predicts bull fertility and the sustainability of AI as well as investment of bulls with high genetic merits [7]. However, quality of semen can be altered, among others, by the process of cryopreservation [8–13], types of extender used [14], and bacterial contamination [15–18]. Prevalence of bacteria within sperm “bacteriospermia” had detrimental effects on sperm cell function by reducing sperm motility, viability, and abnormal morphology as well as premature acrosome reaction. Other ways by which bacteriospermia affects fertility is by altered mitochondrial function, which provokes formation of reactive oxygen species thereby increasing DNA fragmentation [15, 19]. These effects of bacteria have been reported to negatively impact the viability and fertility of spermatozoa, thereby resulting in total breeding failure. Thus, one of the main factors contributing to AI failure is the contamination of the germplasm with pathogens, which eventually cause loss of fertility [20]. Most common microorganisms that contaminated bull semen were from species of Corynebacterium, Staphylococcus, Micrococcus, Bacillus, Escherichia, Proteus, Pseudomonas, Klebsiella, Streptococcus, Citrobacter, Enterobacter, and Stenotrophomonas [21–25]. These pathogens, in one way or other, may infect inseminated females or contribute to a rapid deterioration in sperm quality [26]. Nevertheless, scientific evidence based on published data concerning the major risk pathogens or bacterial contamination of the germplasms used in AI operations in Ethiopia has been lacking until recently. In Ethiopia, AI has been applied for over five decades to crossbred indigenous cattle with bulls of known genetic merits imported from different countries. Although AI in Ethiopia has a long history, the success rate of AI in Ethiopia has been and is generally poor. The National AI Centre (NAIC) is the chief source of semen and other consumables for the procedures of AI throughout the whole country. However, many constraints have been reported associated with the source, the selection procedures, and health status of the AI bulls at NAIC [27]. This was further revealed by the unsatisfactory success of AI in regional and district AI centres due to different factors. The major constraints have been linked to lack of infrastructure, lack of AI technician’s experience, or due to heat detection problems, management problems, and disease problems [28, 29]. These factors coupled with environmental causes, improper handling, transportation, and storage of semen that deteriorates semen quality including motility, thereby affecting subsequent fertility [30]. Nevertheless, the effects of microbiological contaminants such as bacteria in bull (fresh or frozen) semen have not been assessed in Ethiopia, yet. Thus, this research explores the prevalence of bacteriospermia and semen quality of cryopreserved semen of bulls used in AI of cows in the South Wollo Zone, Ethiopia. Moreover, bacterial load and the types of bacterial contaminants of cryopreserved semen were investigated for the first time in Ethiopia. 2. Materials and Methods 2.1. Description of Study Area For this study, cryopreserved French ministraws of bull semen were purchased from South Wollo Zonal Liquid Nitrogen Production and Semen Distribution Centre (SWLNPSDC), Dessie, Ethiopia. Dessie, the largest city in South Wollo Zone of the Amhara Region, is located in the north central part of the country at a distance of 401 km north of Addis Ababa. This city is placed at latitude of 11′8°N and longitude of 39′38°E with an altitude range of 2470 to 2550 meters above sea level. The area has an average annual rainfall of 1145 mm and a mean annual temperature of 15.2°C. A combination of crop and livestock production is the main farming system of the precinct. The total cattle population of the district was estimated at 1.75 million cattle [1]. Both natural service and artificial insemination (AI) are used for crossbreeding of dairy cows for genetic improvement of local breeds despite its low achievement. Semen and other accessories for AI is obtained from the NAIC, Kality, Ethiopia, and stored in the SWLNPSDC. Semen and liquid nitrogen from SWLNPSDC for AI are dispatched to the district AI centres located in South Wollo Zone (Figure 1).
Article
Full-text available
Abstract Background Although artificial insemination (AI) was developed as a means of controlling disease transmission, pathogens can still be transmitted to females in semen used for AI. In addition, bacteria can cause deterioration in sperm quality during storage. Semen becomes contaminated by the male’s normal bacterial flora as it passes out of the reproductive tract but potential pathogens may also contaminate the semen. Therefore, semen samples from stallions to be used for AI are tested before the breeding season to minimize transmission of pathogens to inseminated mares. In Sweden, semen samples are tested at the National Veterinary Institute, Uppsala (SVA). For the present study, a retrospective analysis was made of potentially pathogenic bacteria isolated from samples submitted to the SVA from 2007 to 2017. Results In our study, Taylorella equigenitalis was found infrequently (53 out of 25,512 samples), representing 11 out of 2308 stallions. If T. equigenitalis was detected, the stallions were treated with antibiotics and re-tested later in the same year. Klebsiella pneumoniae and beta haemolytic streptococci were the most commonly found potential pathogens, whereas Pseudomonas aeruginosa was also isolated occasionally. There were considerable differences in the number of species isolated each year. Conclusions Potential pathogens were identified in relatively few of the samples submitted to SVA during this period, with T. equigenitalis not being identified since 2015. Of the other potential pathogens, K. pneumoniae and beta haemolytic streptococci were the most common. The information is relevant for determining guidelines on the testing and treatment of stallions before breeding.
Article
Full-text available
Compared to its female counterpart, the microbiota of the male genital tract has not been studied extensively. With this study, we aimed to evaluate the bacterial composition of seminal fluid and its impact on sperm parameters. We hypothesized that a dysbiotic microbiota composition may have an influence on sperm quality. Semen samples of 26 men with normal spermiogram and 68 men with at least one abnormal spermiogram parameter were included in the study. Samples were stratified based on total sperm count, spermatozoa concentration, progressive motility, total motility and spermatozoa morphology. Microbiota profiling was performed using 16S rRNA gene amplicons sequencing and total bacterial load was determined using a panbacterial quantitative PCR. Semen samples broadly clustered into three microbiota profiles: Prevotella-enriched, Lactobacillus-enriched, and polymicrobial. Prevotella-enriched samples had the highest bacterial load (p < 0.05). Network analysis identified three main co-occurrence modules, among which two contained bacteria commonly found in the vaginal flora. Genera from the same module displayed similar oxygen requirements, arguing for the presence of different ecological niches for bacteria that colonize semen through the passage. Contrary to our hypothesis, shifts in overall microbiota composition (beta-diversity) did not correlate with spermiogram parameters. Similarly, we did not find any difference in microbial richness or diversity (alpha-diversity). Differential abundance testing, however, revealed three specific genera that were significantly enriched or depleted in some of the sperm quality groups (p < 0.05). Prevotella relative abundance was increased in samples with defective sperm motility while Staphylococcus was increased in the corresponding control group. In addition, we observed an increased relative abundance of Lactobacillus in samples with normal sperm morphology. Our study indicates that overall bacterial content of sperm might not play a major role in male infertility. Although no major shifts in microbiota composition or diversity were found, the differential abundance of specific bacterial genera in the sperm suggests that a small subset of microbes might impact the spermatozoal physiology during sperm transition, more specifically motility and morphology. Further studies are required to challenge this finding and develop potential strategies to induce the formation of a healthy seminal microbiota.
Article
Full-text available
A variety of pathogenic contaminants might be isolated from semen, processed for artificial insemination (AI) programs: prions, viruses, bacteria, yeasts or protozoa. This review will discuss the broad scale of pathogens detected in processed ram semen. Reviewed findings will be confronted with the latest knowledge related to semen contamination in other livestock species. An accent will be placed on current experience and future aspects of approaches for elimination of pathogens from processed semen (especially, from semen processed under field conditions).
Article
Full-text available
There are currently no WHO guidelines on the indications for semen culture; however, semen cultures are performed in the evaluation of male infertility and the assisted reproductive technology (ART) process. The relevance and significance of positive semen cultures is widely debated in the literature, with no current consensus on the usefulness of this test in relation to male infertility. We review the pathogenic mechanisms of potentially pathogenic bacteria, general bacteria, urethral flora, and skin flora on sperm parameters. We also present, possible routes of semen contamination, measures to reduce contamination, and the clinical significance of culture contamination. First, it is critical to distinguish round cells in semen as leukocytes from immature germ cells. Second, it is critical to distinguish leukocytospermia from infected semen in order to guide management.
Article
Full-text available
The aim of this study was to verify the influence of the degree of bacterial contamination of boar ejaculate and semen extender on the quality of semen doses. The experiment was conducted in four boar studs, from which raw semen and two semen doses from each ejaculate were collected to evaluate the number of colony-forming units (CFU), pH, sperm morphology and motility. Extender samples were also evaluated for CFU. Ejaculates that had higher levels of contamination ( > 220 CFU mL-1) resulted in semen doses with a greater degree of bacterial contamination but with no reduction in motility or alteration in pH. When the semen doses were classified according to the degree of contamination of the extender, a decrease in motility was observed after 108 and 168 h of storage (P < 0.05) in the group whose extender had ? 14,000 CFU mL-1 versus the group whose extender had ? 330 CFU mL-1. The pH remained stable during 168 h of storage in semen doses with extender that had lower contamination levels, but decreased from 7.2 to 6.0 between 24 and 168 h of storage (P < 0.05) in the group with extender that had higher levels of contamination. A higher number of abnormal acrosomes (P < 0.05) were observed after 168 h of storage in the semen doses whose extender was highly contaminated. The production of semen doses with low bacterial contamination and high sperm cell viability will only be possible with a strict hygienic control in semen processing, primarily with respect to the extender, combined with minimal contamination during collection.
Article
Full-text available
This study was designed to determine the degree and type of bacterial contamination in boar semen (79 ejaculates from Large White and Landrace boars) and its consequences for sperm quality during storage (27 extended semen samples, 16°C for five days) under practical conditions of artificial insemination (AI). The results revealed the presence of aerobic bacteria in 99% of the ejaculates (from 80 to 370 ×10⁶ colony-forming units/mL). Most of the ejaculates contained two or three bacterial contaminants, while the Staphylococcus, Streptococcus, and Pseudomonas bacterial genera were most frequently isolated. Also detected were Enterobacter spp., Bacillus spp., Proteus spp., Escherichia coli, P. fluorescens, and P. aeruginosa. In general, the growth of certain bacterial types isolated prior to semen processing (Enterobacter spp., E. coli, P. fluorescens, and P. aeruginosa) was not discovered on different days of storage, but fluctuations (with a tendency towards increases) were found in the frequencies of Bacillus spp., Pseudomonas spp., and Staphylococcus spp. isolates up to the end of storage. Semen preserved for five days exhibited decreases in sperm motility and increases in the average number of total aerobic bacteria; this was associated with sperm agglutination, plasma membrane disruption, and acrosome damage. We inferred that, due to the different degrees and types of bacterial contaminants in the boar ejaculates, the inhibitory activity of some antimicrobial agents used in swine extenders (such as gentamicin sulfate) may be limited. Because such agents can contribute to the overgrowth of certain aerobic bacteria and a reduction in the quality of stored semen, procedures with high standards of hygiene and microbiological control should be used when processing boar semen.
Article
Full-text available
Milk is considered as a universal food. Milk being a nutritious food for human being also provides an ideal environment for microbial growth; thus, microorganisms which may gain entry into milk can multiply and bring about spoilage of milk products and render them unsafe due to potential health hazards. A total of 64 raw buffalo milk samples from Indore district were screened for direct microscopic count (DMC), total viable count(TVC), methylene blue reduction time (MBRT) Test, as per the procedure described in ICMSF (1978) for mesophilic, thermophilic, psychrotrophic, coliform and yeast/mould count. The overall DMC in the milk samples was 10.553; it ranged from 0.38 to 26x10 4 per ml. The thermoduric count in the milk samples was 6.651, ranging from 0 to 80x10 3 per ml The psychrotrophic count in the milk samples was 0.452, ranging from 0 to 2x10 4 per ml. The coliform count in the milk samples was 0.68, ranging from 0 to 3x10 3 per ml. And the yeast/mould count in the milk samples was 30.429, ranging from 2 to 110x10 3 per ml. The MBRT test revealed that 50% of the milk samples from the Mhow zone were of good quality, 25% were very good quality, and the remaining 25% were of poor quality, whereas among samples from the Sanwer zone, 62.5% were of poor quality, 31.3% were of fair quality, a mong samples and only 6.2% of good quality. If we look at the results of MBRT test and DMC, Simultaneously it seems that both the tests correspond with each other very well. The DMC, TVC and MBRT of buffalo milk samples in the present study were within permissible limits as per Indian Standards. But the high levels of these test results could be pathogenic and its possible adverse effect on public health.
Article
Full-text available
Aim: To study the effect of preputial washing on bacterial load, preservability and semen quality in Murrah buffalo bulls. Materials and methods: A total of 36 collections of three Murrah buffalo bulls maintained at Artificial Breeding Research Centre, ICAR-National Dairy Research Institute, Karnal, were collected at weekly intervals from each bull without preputial washing and latter ejaculates from same bull with preputial washing by infusing normal saline (0.85%), KMnO4 (0.02%) and savlon (2.0%) to first, second and third bull, respectively. The microbial load and semen quality were evaluated during different hours of storage at refrigerated temperature (0, 24 and 48 h) and after thrawing of cryopreserved (at -196°C) semen. Results: The results of preservation of semen at refrigerated temperature showed that bacterial load was markedly lower in ejaculates of bulls subjected to preputial washing. Semen preserved at refrigerator temperature and cryopreserved, the effect of washing solution was significant for individual motility (IM), non-eosiniphilic count, hypo-osmotic swelling reactivity (HOST), total plate count (TPC) and acrosome integrity. KMnO4 was found to be the best in lowering bacterial load, sperm abnormalities and in improving semen quality such as motility, non-eosinophilic count, HOST and acrosome integrity even up to 48 h of preservation and cryopreserved semen. Effect of duration of preservation and stage of cryopreservation was also significant for IM, non-eosiniphilic count, HOST, sperm abnormalities and acrosome integrity. Conclusion: Overall the results suggested that preputial washing with KMnO4 solution improved the semen quality and reduced microbial load of Murrah buffalo bull's semen preserved at refrigerated temperature and cryopreservation.
Article
Full-text available
Aim: The present study was conducted to investigate the effect of species, breed and age on bacterial load in fresh and frozen semen of Cattle and Buffalo bull. Materials and methods: Present study covered 56 cow and 10 buffalo bulls stationed at Central Semen Station Anjora, Durg (Chhattisgarh). Impact of breeds on bacterial load in semen was assessed using six breeds of cattle viz. Sahiwal, Gir, Red Sindhi, Tharparkar, Jersey and Holstein Friesian (HF) cross. Cow bulls were categorized into four different groups based on their age (<4 years, 4-5 years, 5-6 years and > 6 years) to study variation among age groups. Bacterial load was measured in fresh and frozen semen samples from these bulls using the standard plate count (SPC) method and count was expressed as colony forming unit (CFU) per ml of semen. Results: Higher bacterial load was reported in fresh (2.36 × 10(4) ± 1943 CFU/ml) and frozen (1.00 × 10 ± 90 CFU/ml) semen of cow bulls as compared to buffalo bulls (1.95 × 10(4) ± 2882 and 7.75 × 10(2) ± 160 CFU/ml in fresh and frozen semen, respectively). Jersey bull showed significantly higher bacterial count (p < 0.05) both in fresh (4.07 × 10(4) ± 13927 CFU/ml) and frozen (1.92 × 10(3) ± 178 CFU/ml) semen followed by HF cross, Sahiwal, Gir, Red Sindhi and Tharparkar bull. Bulls aged < 4 years and more than 6 years yielded increased bacterial load in their semen. Although a minor variation was reported between species and among age groups, no significant differences were measured. Conclusion: Bacterial load in semen did not differ significantly between species and age groups; however significant variation was reported among different breeds. Bulls of Jersey breed showed significantly higher bacterial load in semen as compared to the crossbred and indigenous bull.
Article
Full-text available
The aims of the study were to identify microbial flora in boar semen under field condition in Italy. Investigate about antibiotic resistance and sensitivity of isolated bacteria and postulate the efficacy of antibiotics (amikacin vs gentamicin) as a component of semen extender. A total of 60 boars were collected in 13 pig farms. Bacteriological and mycological investigations were performed immediately on raw semen samples and then on semen diluted randomly in a new short-term modified extender (ME-S) and in a commercial one (CRONOSTM) after 48 and 120 hours. Bacterial contamination were found in 63% of raw semen samples and were isolated E.coli, Serratia marcescens, Staphylococcus epidermidis and aureus, Proteus spp., Streptococcus spp. and Pseudomonas aeruginosa. E. coli was the most contaminant isolated (53%). Pseudomonas aeruginosa, was found only in one semen sample. The analysis of variance of factors affecting contamination levels were significant for the farmof origin (P<0.05) and not significant for the breed. Antibiotic resistance of these bacteria was assessed using different antibiotics. Significant differences (P<0.05) between observed and expected frequencies of bacterial isolates resistant or not to the antibiotics contained in the extenders were found. At 48 hours of storage a reduction of aerobic contamination were found after ME-S dilution by 85.3% and after CRONOSTM by 63.8%. This paper proved the presence of pathogenic bacteria in semen, so we believe that it is highly advisable to perform a periodical microbiological screening of boar semen in swine industry to avoid the use of low sperm quality.
Article
Full-text available
Unidentified soluble factors secreted by E. coli, a frequently isolated microorganism in genitourinary infections, have been reported to inhibit mitochondrial membrane potential (ΔΨm), motility and vitality of human spermatozoa. Here we explore the mechanisms involved in the adverse impact of E. coli on sperm motility, focusing mainly on sperm mitochondrial function and possible membrane damage induced by mitochondrial-generated reactive oxygen species (ROS). Furthermore, as lactobacilli, which dominate the vaginal ecosystem of healthy women, have been shown to exert anti-oxidant protective effects on spermatozoa, we also evaluated whether soluble products from these microorganisms could protect spermatozoa against the effects of E. coli. We assessed motility (by computer-aided semen analysis), ΔΨm (with JC-1 dye by flow cytometry), mitochondrial ROS generation (with MitoSOX red dye by flow cytometry) and membrane lipid-peroxidation (with the fluorophore BODIPY C11 by flow cytometry) of sperm suspensions exposed to E. coli in the presence and in the absence of a combination of 3 selected strains of lactobacilli (L. brevis, L. salivarius, L. plantarum). A Transwell system was used to avoid direct contact between spermatozoa and microorganisms. Soluble products of E. coli induced ΔΨm loss, mitochondrial generation of ROS and membrane lipid-peroxidation, resulting in motility loss. Soluble factors of lactobacilli prevented membrane lipid-peroxidation of E. coli-exposed spermatozoa, thus preserving their motility. In conclusion, sperm motility loss by soluble products of E. coli reflects a mitochondrial dysfunction-related membrane lipid-peroxidation. Lactobacilli could protect spermatozoa in the presence of vaginal disorders, by preventing ROS-induced membrane damage.
Article
Full-text available
In an earlier work done in our laboratory, we have been able to isolate a sperm agglutinating strain of Escherichia coli from the semen sample of a male attending infertility clinic. Further, factor responsible for sperm agglutination (SAF) was isolated and purified, and, using SAF as a tool, corresponding SAF binding receptor from human spermatozoa has been purified. Characterization of SAF and SAF binding receptor using MALDI-TOF showed homology to glutamate decarboxylase and MHC class I molecule, respectively. Coincubation of SAF with spermatozoa not only resulted in spermagglutination but could also compromise other sperm parameters, namely, Mg(2+) dependent ATPase activity and apoptosis. Intravaginal administration of SAF could lead to infertility in Balb/c mice. SAF induced impairment of sperm parameters, and infertility was observed to be due to interaction of SAF with sperm surface receptor component as, when purified receptor was introduced, receptor completely inhibited all the detrimental effects induced by SAF. From these results, it could be concluded that interaction of SAF with spermatozoa is receptor mediated.
Article
Full-text available
Male infertility is a frequent medical condition, compromising approximately one in twenty men, with infections of the reproductive tract constituting a major etiological factor. Bacterial epididymo-orchitis results in acute inflammation most often caused by ascending canalicular infections from the urethra via the continuous male excurrent ductal system. Uropathogenic Escherichia coli (UPEC) represent a relevant pathogen in urogenital tract infections. To explore how bacteria can cause damage and cell loss and thus impair fertility, an in vivo epididymo-orchitis model was employed in rats by injecting UPEC strain CFT073 into the vas deference in close proximity to the epididymis. Seven days post infection bacteria were found predominantly in the testicular interstitial space. UPEC infection resulted in severe impairment of spermatogenesis by germ cell loss, damage of testicular somatic cells, a decrease in sperm numbers and a significant increase in TUNEL (+) cells. Activation of caspase-8 (extrinsic apoptotic pathway), caspase-3/-6 (intrinsic apoptotic pathway), caspase-1 (pyroptosis pathway) and the presence of 180 bp DNA fragments, all of which serve as indicators of the classical apoptotic pathway, were not observed in infected testis. Notably, electron microscopical examination revealed degenerative features of Sertoli cells (SC) in UPEC infected testis. Furthermore, the passive release of high mobility group protein B1 (HMGB1), as an indication of necrosis, was observed in vivo in infected testis. Thus, necrosis appears to be the dominant cell death pathway in UPEC infected testis. Substantial necrotic changes seen in Sertoli cells will contribute to impaired spermatogenesis by loss of function in supporting the dependent germ cells.
Article
Full-text available
To verify the prevalence of semen bacterial contamination and whether the contamination could decrease sperm quality. Spermiogram, semen culture, and sperm transmission electron microscopy (TEM) analysis were performed. TEM data were elaborated using a mathematical formula that calculates a fertility index (FI)--able to define patients as fertile or infertile--and the percentage of sperm apoptosis, immaturity and necrosis. We aligned the amino acid sequence of beta-tubulin with protein of the most frequent species isolated from semen. Patients were divided according to the contaminating species; in each group, we observed fertile individuals, in whom the semen quality was similar to that of controls and infertile men whose sperm quality was significantly decreased, in terms of motility, FI, apoptosis and necrosis. Partial homology between beta-tubulin and bacterial proteins was observed. Sperm bacterial contamination is quite frequent and could contribute to the deterioration of the sperm quality of infertile men.
Article
Full-text available
The objective of this study was to develop a relatively simple test to evaluate the functional integrity of the membranes of human spermatozoa. As in some other species, human spermatozoa 'swell' under hypo-osmotic conditions due to the influx of water and the expansion of the membranes. A mixture of equal parts of fructose and sodium citrate (150 mosmol) with calculated ionic strength of 0.15 resulted in a maximal number of clearly identifiable swollen spermatozoa. Only small variations were seen when different aliquants of the same semen samples were separately evaluated. A high correlation (r = 0.94) was obtained between expected and observed values of swollen spermatozoa when known amounts of heat-treated spermatozoa, unable to undergo swelling, were added to untreated spermatozoa. A good correlation (r = 0.90) was also observed between the % spermatozoa in a semen sample that were capable of undergoing swelling and the % of denuded hamster oocytes that were penetrated by capacitated spermatozoa from the same semen sample. By contrast, the correlations between % sperm swelling in ejaculates and % normal sperm forms, % motile spermatozoa and % spermatozoa that do not stain with eosin-Y (supravital stain) in the same ejaculates were 0.30, 0.61 and 0.52, respectively. Therefore, the hypoosmotic swelling technique to evaluate the functional integrity of the sperm membrane appears to give high repeatability and accuracy and is closely correlated to the in-vitro fertilizing ability of spermatozoa. It may be a useful addition to the standard semen analysis.
Article
The semen of different Indian goat breeds, viz. Barbari, Jamunapari, Marwari, Kutchi, Sirohi and Jakhrana was studied to find out the effect of cool (December to February), moderate (March, October and November), hot dry (April to June) and hot humid (July to September) and age on bacterial load in buck semen. Semen of Jamunapari buks showed highest bacterial load (37.48 CFU/ml) irrespective of seasons. Age has no significant effect on bacterial load. However, periods (seasons) had significant effect on bacterial load. Most of the bacterial contaminants were of non-pathogenic nature.
Article
The invasion of the male reproductive tract by microorganisms, and its subsequent consequences for sperm fertilizing potential, has been intensely discussed. The role of the bacteria that are responsible for the colonization and contamination of the male urogenital tract, rather than its infection, in diminished sperm parameters raises the most controversy. There are numerous premises suggesting that bacterial semen infection is associated with male infertility. However, the molecular mechanism by which the fertility is affected is complex and multifactorial, and still presents a puzzle. Some authors have suggested that direct interactions between bacteria and human spermatozoa facilitate sperm immobilization, affect sperm morphology, and thus weaken the ability of sperm to fertilize. On the other hand, the massive infiltration of activated leukocytes into the inflammatory site may be associated with impairment of sperm fertilizing potential, due to oxidative, apoptotic, and immune processes. This review presents current research trends and aims to summarize the present knowledge of semen inflammation and causative bacterial agents in the male urogenital tract, with its consequence on seminological parameters, and male fertility status.
Article
Definition of chronic male genital tract inflammation and its impact on male infertility is still a matter of debate. In particular, DNA integrity has been reported to be disturbed in subfertile men. Thus, the aim of this study was to investigate an association of DNA integrity to altered standard semen parameters as well as inflammatory parameters such as peroxidase-positive cells, macrophages and seminal interleukin-6 concentration. Macrophages were detected by CD18/HLA-Dr staining, and DNA integrity was analysed by acridine orange staining using flow cytometry. Interleukin-6 was detected by ELISA. Normal DNA integrity showed a significant correlation to sperm number and progressive motility. Moreover, a significant inverse correlation of DNA integrity to Interleukin-6 and macrophages could be demonstrated. Further on, seminal interleukin-6 also significantly correlated to macrophages. No association has been observed between the number of peroxidase-positive cells and normal DNA integrity. As disturbed DNA integrity has been reported to negatively influence spermatozoon-egg interaction and even fertilisation rates following ICSI, and as early miscarriages have been associated with sperm DNA damage, it should be screened very carefully for male genital tract inflammations in couples undergoing infertility treatment. Measuring Interleukin-6 seems superior to assessment of the number of leucocytes alone and additional assessment of DNA integrity into the diagnostic work-up should be considered. © 2015 Blackwell Verlag GmbH.
Article
Leukocytes contribute directly and indirectly to reactive oxygen species (ROS) production. Although leukocytospermia is defined as the presence of >=1 x 10(6) white blood cells/mL (WBC/mL) in a semen sample, the presence of less than 1x10(6) WBC/mL (low-level leukocytospermia) can still produce a detectable amount of ROS, impairing sperm function and lowering the chances of pregnancy. Our objective was to assess the effect of low-level leukocytospermia on semen quality, ROS levels, and DNA damage in infertile men. Semen samples were examined from 472 patients and divided into 3 groups: no seminal leukocytes; group 2, men with low-level leukoctyospermia (0.1-1.0 x 10(6) WBC/mL); and group 3, frank leukocytospermia, (>1.0 x 10(6). WBC/mL). Semen analysis, leukoctyospermia, reactive oxygen species and DNA fragmentation was tested. Conventional semen parameters between the 3 groups were similar. Group 2 patients had significantly higher levels of ROS and sperm DNA fragmentation (1839.65 +/- 2173.57RLU/s; DNA damage: 26.47 +/- 19.64%) compared with group 1 (ROS: 1101.09 +/- 5557.54 RLU/s; DNA damage: 19.89 +/- 17.31%) (ROS: p = 0.002; DNA damage: p = 0.047). There was no significant difference in ROS levels between groups 2 and 3. Patients presenting with low-level leukocytospermia have seminal oxidative stress. Although these patients are not categorized as leukocytospermic by current World Health Organization (WHO) guidelines, these men may benefit by treatment with antibiotics, testing for bacterial cultures, or antioxidant supplements to reduce ROS-induced sperm DNA fragmentation and improve their chances of fertility. The WHO guidelines for leukocytospermia may need to be revised accordingly.
Article
To explore the relationships between resistin, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) and semen parameters, sperm apoptosis, and necrosis in infertile patients and in control subjects with unknown reproductive potential with/without smoking habits, leukocytospermia, and varicocele. Prospective study. Sperm laboratory. A total of 110 selected men. Family history, clinical/physical examination, ELISA determination (resistin, IL-6, TNF-α), semen analysis, annexin V/propidium iodide assay. Relationships among resistin, IL-6, and TNF-α and semen parameters in the presence of smoking habits, varicocele, leukocytospermia, and in infertile subjects. Resistin level was higher in semen than in serum. Resistin semen levels showed negative correlations with sperm motility and positive correlations with apoptotic, necrotic sperm and TNF-α and IL-6 levels. Resistin, TNF-α, and IL-6 levels were higher in smokers compared with nonsmokers and in cases with leukocytospermia, in which an increase in necrotic sperm and a decrease in the number of sperm with normal morphology and motility were observed. Cytokine levels were significantly higher in infertile patients compared with control subjects with unknown reproductive potential. A total of 74.5% of infertile patients showed leukocytospermia. Semen resistin correlated with IL-6, TNF-α, and sperm quality; in cases of leukocytospermia and smoking habits, resistin concentrations were increased, suggesting that resistin may play a regulatory role in inflammation of the male reproductive system.
Article
Commercial cattle breeders produce their own herd offspring for the dairy and beef market using artificial insemination. The procedure involves sanitary risks associated with the collection and commercialization of the germplasm, and the in vitro production and transfer of the bovine embryos must be monitored by strict health surveillance. To avoid the spreading of infectious diseases, one must rely on using controlled and monitored germplasm, media, and reagents that are guaranteed free of pathogens. In this article, we investigated the use of a new mass spectrometric approach for fast and accurate identification of bacteria and fungi in bovine semen and in culture media employed in the embryo in vitro production process. The microorganisms isolated from samples obtained in a commercial bovine embryo IVP setting were identified in a few minutes by their conserved peptide/protein profile, obtained applying matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), matched against a commercial database. The successful microorganisms MS identification has been confirmed by DNA amplification and sequencing. Therefore, the MS technique seems to offer a powerful tool for rapid and accurate microorganism identification in semen and culture media samples.
Article
The aim of the study was to examine an in vitro effect of the three bacterial strains (Escherichia coli, Staphylococcus haemolyticus and Bacteroides ureolyticus) on ejaculated spermatozoa with reference to sperm membrane integrity and mitochondrial activity. The study was carried out on swim-up-separated spermatozoa from 12 normozoospermic volunteers. Sperm plasma membrane stability was evaluated by the LIVE/DEAD Sperm Viability Kit and by the merocyanine 540 test. Mitochondrial activity was evaluated using the JC-1 test as well as the NADH-dependent NBT assay. The percentage of dead cells was significantly higher in spermatozoa treated with B. ureolyticus as compared to that of control spermatozoa (P < 0.01). All the bacterial strains applied affected sperm plasma membrane architecture measured by M540 test (P < 0.01). Moreover, the presence of E. coli or B. ureolyticus was connected with significant decrease in both the number of cells with high mitochondrial transmembrane potential (ΔΨm) and the cells with normal oxidoreductive function of mitochondria (P < 0.05 as compared to untreated cells). To conclude, the contact of bacteria with ejaculated spermatozoa can be a reason for severe injury of sperm membrane stability and mitochondrial activity with potential consequences for male fertility.
Article
To determine the incidence of bacteriospermia and elevated seminal leukocytes (ESL) in a subfertile male population and correlate these results with semen parameters. Retrospective cohort study. Canadian tertiary-level male infertility clinic and university-affiliated andrology and microbiology laboratories. Four thousand nine hundred thirty-five nonazoospermic subfertile men. Analysis and concurrent culture of 7,852 semen samples. Incidence of bacteriospermia and ESL and comparison of semen parameters between these groups. The rate of bacteriospermia was 15% (22 species), and the rate of ESL was 19%, with no statistical correlation between these groups. Bacteriospermic patients (without ESL) had a statistically significant deterioration in DNA fragmentation index (DFI) only, compared with patients without bacteriospermia and ESL (24.1 vs. 21.8%). ESL alone was associated with a statistically significant deterioration in sperm concentration (20.6 vs. 55.3 × 10(6)/mL), motility (21.8 vs. 26.9%), normal morphology (12.3 vs. 17.4%), and DFI (26.5 vs. 21.8%), with no additional deterioration identified with bacteriospermia. Bacteriospermia and ESL were prevalent, but not statistically associated, in subfertile men. Bacteriospermia alone was associated with an increase in DFI only, but the presence of ESL was the dominant factor associated with deterioration in semen parameters.
Article
Contents The objectives of the present study were to determine the effects of season on some semen parameters and bacterial contamination of Awassi ram semen. Semen samples from six mature Awassi rams were used in this study. Semen collection was performed with artificial vagina every week, from September 2009 to October 2010. Volume, sperm concentration, mass motility, individual motility, percentage live sperm and sperm abnormalities were evaluated. Moreover, determination of viable bacterial count of the rams was also recorded weekly. Higher (p < 0.05) semen volume in the hot summer and spring months was observed of August (1.55 ± 0.08 ml) and March (1.27 ± 0.15 ml). Sperm concentration was highest (p < 0.05) in the breeding season (late summer to early autumn) of September (4.21 ± 0.86 × 10 ⁹ sperm/ml). Sperm individual motility and percent of live sperm observed in August (summer) and May (end of spring) when the environmental temperature started to increase were recorded highest values and differed significantly (p < 0.05) from December and January (winter). The highest value of the mean sperm acrosomal defects (13.33 ± 0.63%) was recorded in December. The highest value of the mean viable bacterial count (138.3 ± 21.6) was recorded in July (summer). A significant decrease (p < 0.01) in the mean viable bacterial count was observed from the middle of winter towards the end of spring. The lowest bacterial count was noted in January (60.5 ± 2.98). It could be concluded from the results of the present study that there is an effect of season on ram semen quality, and summer high temperature in northern Iraq has no effect on Awassi ram semen. There is a significant effect of season on bacterial count on Awassi ram semen.
Article
Contents Semen is collected and processed from a variety of animal species for use in artificial insemination breeding programmes. Because of the inherent nature of the semen collection process, bacterial contamination of the ejaculate is a common occurrence. Additionally, manipulation of the ejaculate during processing in the laboratory can expose the sample to possible introduction of bacterial contamination. If preventative measures at the stud fail to adequately control these risks, decreases in semen quality, dose longevity and fertility may occur. Multiple mammalian and non‐mammalian sources have been identified as origins of contamination in the stud. Knowledge of these sources has aided the industries in developing strategies that help in controlling the introduction of contaminant bacteria in extended semen. A primary step in minimizing contamination is in the practice of good hygiene by stud personnel. Prudent general sanitation protocols should also be followed in the laboratory, animal housing and semen collection areas. Cleanliness and attention to the actual semen collection process can also aid in reducing bacterial load originating from the stud semen donor. Attentiveness to all of these steps significantly contributes to an overall reduction in the type and amount of bacterial contamination. However, their complete elimination stills remains unavoidable. To address residual bacteria load in the sample, antimicrobials are commonly used in semen extenders intended to promote in vitro sperm longevity beyond that of a few hours. Current research by the animal industries continues in the selection and prudent use of antimicrobials that will lead to the success and sustainability of this modality in controlling bacterial contamination.
Article
This study was designed to determine the degree and type of bacterial contamination of ejaculated semen samples in fertile rams and its consequences on sperm quality during storage. In experiment 1, 68 ejaculates from 36 rams were divided into two aliquots, one of which was used for bacterial culture, while the other one was diluted, stored at 15°C and assessed for plasma membrane integrity and motility at 0, 24 and 48h after dilution. From the 68 ejaculates, 66 were positive for aerobic bacteria, including 20 species of bacteria from 14 genera. The most frequently isolated bacteria were Escherichia coli, Proteus mirabilis, Enterobacter cloacae, Staphylococcus epidermis, and Staphylococcus aureus species. These 5 bacteria were present in 97% of all contaminated samples. All contaminant bacteria were found to be sensitive to gentamicin and to ceftiofur, with variable percentages of resistance to the other antibiotics evaluated. In samples with total enterobacteria count lower than 100 colony-forming units (CFU)/ml, higher proportions of motile and progressive sperm and higher velocities of spermatozoa were observed at different times during storage. In experiment 2, pure cultures of the most frequently isolated bacteria were individually added to fresh semen samples of low contamination and tested for their effects on sperm quality during storage at 15°C. Semen with E. coli showed a drastic reduction in motility, velocity and viability during storage. This reduction was also significant, but less drastic, in semen with E. cloacae and P. mirabilis, whereas it was partial and less pronounced in the other groups (S. epidermidis and S. aureus). In conclusion, the contamination of ram semen with enterobacterial species reduced sperm quality during storage at 15°C, and the antibiotics gentamicin and ceftiofur showed the higher antimicrobial activities.
Article
The impact of chronic prostatitis resulting from Chlamydia trachomatis infection on male fertility is controversial. To investigate the correlation between C. trachomatis infection and semen quality in young male patients affected by chronic prostatitis resulting from C. trachomatis infection and to evaluate the correlation between anti-C. trachomatis immunoglobulin (Ig) A against heat shock protein 60 (HSP60), heat shock protein 70 (HSP70), and semen parameters. All patients with clinical and instrumental diagnosis of chronic prostatitis underwent microbiological cultures for common bacteria, DNA extraction, mucosal and serum antibody evaluation for C. trachomatis, and semen parameter analysis. Western blot analysis of mucosal anti-C. trachomatis IgA was performed. Subjects were split into two groups: Group A consisted of patients with chronic prostatitis resulting from common bacteria (uropathogens), and group B consisted of patients with chronic prostatitis resulting from C. trachomatis infection. The relationship between C. trachomatis infection and semen parameters as well as the correlation among IgA levels, IgA characterisation, and semen analysis were determined. We enrolled 1161 patients (mean age: 36.5 yr). Of these, 707 patients were placed in group A, and 454 were placed in group B. Significant statistical differences were reported between groups in terms of sperm concentration (p<0.001), percentage of motile sperm (p<0.001), and normal morphologic forms (p<0.001). Strong correlations between mucosal anti-C. trachomatis IgA and sperm concentration (p<0.001) and normal morphologic forms (p<0.001) were reported. Correlations among positivity to HSP60, HSP70, and sperm concentration (p<0.003) and normal morphologic forms (p<0.001) were also reported. This study demonstrated the role of chronic prostatitis resulting from C. trachomatis in male fertility decrease, highlighting probable immunomediated damage to germinal cells because of C. trachomatis infections.
Article
To investigate sperm viability, incidence of apoptosis, and intracellular basal and induced reactive oxygen species (ROS) in sperm fractions. Prospective controlled study. Center for Reproductive Medicine at a tertiary care hospital. Liquefied seminal ejaculates (n = 12) prepared by density gradient centrifugation were reconstituted to 2 mL with phosphate-buffered saline. Oxidative stress was induced by hydrogen peroxide (H(2)O(2), 100 muM). Sperm viability, intracellular ROS, and incidence of apoptosis/necrosis in neat, immature, and mature sperm fractions were assessed. Before H(2)O(2) exposure, mature spermatozoa fractions showed a significantly lower incidence of apoptotic sperm and intracellular O(2)(-*) levels but higher amounts of intracellular H(2)O(2) compared with neat semen. Higher levels of intracellular H(2)O(2) were demonstrated in immature sperm fractions compared with neat or mature fractions. In all sperm fractions, intracellular H(2)O(2) levels correlated with the intracellular concentration of O(2)(-*). After H(2)O(2) exposure, neat semen showed a significantly higher percentage of apoptosis compared with the prepared mature spermatozoa. However, no differences were observed in the incidence of apoptosis between immature and mature sperm fractions. There is a differential shift of both intracellular H(2)O(2) and O(2)(-*) in each sperm fraction that may affect sperm quality. Sperm apoptosis is related to intracellular H(2)O(2) levels, which in turn are affected by intracellular O(-*) levels. Oxidative stress was not associated with an increased incidence of apoptosis in immature or mature sperm fractions.
Article
Acrosomal structures of ram spermatozoa were prominently stained when air dried smears of diluted semen were fixed for 15 minutes in buffered formal saline and stained for 90 minutes in a 6 per cent (v/v) buffered solution of Giemsa stain. Progressive disruption of the acrosomes was demonstrated during chilling and deep-freezing of the spermatozoa, and the degree of damage was systematically scored. A rapid and repeatable estimate of the state of the acrosomes in a sample could be made from the mean score of 20 spermatozoa examined per slide.
Article
This study evaluated if the negative influence of Escherichia coli on the motility of human spermatozoa is a consequence of E. coli-induced ultrastructural alterations. Suspensions of spermatozoa were artificially infected with E. coli from a serotyped, pathogenic strain and incubated at 37 degrees C for 6 h. After incubation, spermatozoa were fixed in glutaraldehyde, stained with osmium tetroxide and ruthenium red and embedded in Spurr(R)-resin followed by ultramicrotomy. The sections were analysed subsequently by use of transmission electron microscopy. Uninfected suspensions of spermatozoa in medium and bacterial suspensions served as controls. Negative contrast technique was performed to facilitate visualization of ultrastructural details of the bacterial capsule after experimental exposure to spermatozoa. Electron microscopic evaluation revealed multiple and profound alterations in the ultrastructure of spermatozoa such as membrane defects and cytoplasmic vacuoles exclusively in spermatozoa of infected samples (> 90%). Morphological alterations involved all superficial structures of spermatozoa, in particular the plasma membrane of the mid-piece and neck as well as the inner and outer acrosomal membrane of the acrosome, indicating that morphological defects account for the immobilization of spermatozoa by E. coli. The results suggest that E. coli infection of ejaculates results in immobilization and impaired acrosomal function in human spermatozoa, findings that support the indication for antimicrobial chemotherapy in symptomatic and silent infections that affect the ejaculate.
Article
The artificial insemination (AI) industry has developed over the last 50 years to the extent that it is used in almost every country in the world. One of the main factors contributing to its success is the confidence of the farmers that germplasm is not associated with pathogens, so that AI can be performed without risks. This has been achieved as a result of a considerable amount of research based on sound scientific data that has identified the major risk pathogens. A summary of these studies, given in this section, shows that despite the large number of agents that could be transmitted via the semen, there are cost-effective means to prevent such hazards. One of the basic rules is that the males should be housed in strictly protected semen collection centres (SCCs). Such centres should be approved by the veterinary authorities based upon specific criteria, which include special housing and operating specifications. This also includes specific means of monitoring the health of individual males through regular clinical examinations, assessment of semen and testings for various diseases. Two new challenges can now be identified, one relevant to so-called emerging diseases the impact of which on the status of the semen donors should always be assessed, and the second, relates to endangered genetic resources which may become extinct without active conservation programmes. The experience gained by the AI industry over the last 50 years should help to solve those problems. Currently, the use of semen derived from approved SCCs warrants their disease-free status.
Article
Urogenital infections are considered important factors in male infertility. In this in vitro study we have evaluated the impact of leucocytes in association with an artificial infection with Escherichia coli on the motility of human spermatozoa. Ejaculates and blood samples were obtained from healthy donors with normal semen parameters. Ejaculates were prepared by swim-up technique and five fractions were isolated for incubation. Leucocyte subtypes were separated from blood samples by gradient centrifugation. Purified sperm suspensions were adjusted to a concentration of 20 x 106 ml-1 and incubated with lymphocytes/ monocytes, polymorphonuclear granulocytes (PMN), and E. coli. Samples were incubated for up to 6 h at 37 degrees C. Motility analysis was performed using a computer-assisted sperm analyzer (CASA). Spermatozoa incubated with 3 x 106 PMN ml-1 revealed a significant (P=0.003) decrease in progressive motility after 2 h. This decrease remained weakly significant (P=0.024) after 4 and 6 h. Lymphocytes and monocytes had no effect on sperm motility. Spermatozoa incubated with granulocytes and E. coli demonstrated highly significant alterations in motility after 4 and 6 h of incubation (P < 0.001). The PMN indicate an effect on motility of spermatozoa under experimental conditions. However, the results suggest that bacteria are the primary agents that interfere with sperm motility.
Article
To determine the prevalence of pathogens that cause sexually transmitted infections (STIs) in semen from asymptomatic male infertility patients with and without leukocytospermia (LCS), and associations between STIs, inflammatory markers, and other semen variables. Retrospective, controlled study. Academic Medical Center. Two hundred and forty-one male infertility patients undergoing routine semen analysis: 132 with LCS, and 109 without LCS. None. The DNA from STI pathogens (human papillomavirus [HPV], cytomegalovirus [CMV], herpes simplex virus [HSV], human herpesvirus type 6 [HHV-6], Epstein-Barr virus [EBV], hepatitis B virus [HBV], and Chlamydia trachomatis [CT]), routine semen parameters, and markers of accessory gland and epididymal function and inflammation. The DNA from STI pathogens was detected in 45/241 (18.7%) of the samples (CMV, 8.7%; HPV, 4.5%; HHV-6, 3.7%; HSV, 3.7%; CT, 2.5%; EBV, 0.4%; and HBV, 0%), with no difference in prevalence between the LCS and non-LCS groups. The DNA of STI pathogens in semen was associated with a decrease in sperm concentration, motile sperm concentration, total sperm count, and neutral alpha-glucosidase concentration, whereas LCS was associated with a decrease in total sperm count, percent normal forms, and fructose concentration. The DNA of STI pathogens was detected in semen from a high percentage of asymptomatic male infertility patients, and was associated with poor semen quality. Efforts to diagnose and treat subclinical genital-tract infections should be intensified.
Article
Infectious agents can impair various important human functions, including reproduction. Bacteria, fungi, viruses and parasites are able to interfere with the reproductive function in both sexes. Infections of male genito-urinary tract account for about 15% of the case of male infertility. Infections can affect different sites of the male reproductive tract, such as the testis, epididymis and male accessory sex glands. Spermatozoa themselves subsequently can be affected by urogenital infections at different levels of their development, maturation and transport. Among the most common microorganisms involved in sexually transmitted infections, interfering with male fertility, there are the Chlamydia trachomatis and Neisseria gonorrhoeae. Less frequently male infertility is due to non-sexually transmitted epididymo-orchitis, mostly caused by Escherichia coli. In female, the first two microorganisms are certainly involved in cervical, tubal, and peritoneal damage, while Herpes simplex cervicitis is less dangerous. The overall importance of cervical involvement is still under discussion. Tubo-peritoneal damage seems to be the foremost manner in which microorganisms interfere with human fertility. C. trachomatis is considered the most important cause of tubal lacerations and obstruction, pelvic inflammatory disease (PID) and adhesions. N. gonorrhoeae, even though its overall incidence seems to decline, is still to be considered in the same sense, while bacterial vaginosis should not be ignored, as causative agents can produce ascending infections of the female genital tract. The role of infections, particularly co-infections, as causes of the impairment of sperm quality, motility and function needs further investigation. Tropical diseases necessitate monitoring as for their diffusion or re-diffusion in the western world.
Development of an assay to assess the functional integrity of the human sperm membrane and its relationship to other semen characters
  • R S Jayendran
  • H Vander-Ven
  • M Perez-Pelaez
  • B G Crabo
  • L J D Zanevld
Jayendran, R. S., Vander-Ven, H., Perez-Pelaez, M., Crabo, B. G., & Zanevld, L. J. D. (1984). Development of an assay to assess the functional integrity of the human sperm membrane and its relationship to other semen characters. Journal of Reproduction & Infertility, 70, 219-228. https://doi.org/10.1530/jrf.0.0700219
Bacterial contamination of imported bulls frozen semen
  • H B Najee
  • A M Al-Shawii
  • L Y Rahman
Najee, H. B., Al-Shawii, A. M., & Abd-Al Rahman, L. Y. (2012). Bacterial contamination of imported bulls frozen semen. Al-Anbar Journal of Veterinary Sciences, 5, 54-62.
Bacterial contamination of imported bulls frozen semen
  • Najee H. B.