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Risk factors and seroprevalence of Mycoplasma synoviae infection in broiler breeder farms in Mazandaran province, North Iran
Abstract
This study conducted from May 2002 to October 2008 aimed to determine the risk factors (age, sex, strains, seasons, flock size and premises) affecting seroprevalence of Mycoplasma gallisepticum (MG) in broiler breeders in Mazandaran province, north of Iran. In addition, correlation between seroprevalence in breeders and chronic respiratory disease (air sacculitis) in their progeny was analyzed at slaughterhouses. Serological analyses were based on serum plate agglutination (SPA) and enzyme linked immunosorbent assay (ELISA) tests. Positive agreement score between the 2 methods was 33%. The highest (21.4%) and lowest (0%) seroprevalences were found in 2003 and 2008, respectively and the infection rates appeared more elevated in winter (18.5%) than in the other seasons. The flock size has not significantly affected the infection prevalence. Among breeder strains, the Ross strain and the Hubbard strain at a lesser extent were the more susceptible to MG infection (23.2% and 14%, respectively). Furthermore, young (10-20 weeks old) and female chickens were more frequently infected. No significant correlation was found between MG seroprevalence in breeders and occurrence of air sacculitis in progeny. These results emphasize a relatively high MG prevalence in Iran until approximately 2005 as well as the particular susceptibility of young, females and some strains of broiler chickens.
... [27][28][29] A high prevalence of MG infection in broiler has been reported by Seifi and Shirzad in this area. 30 There were only two positive commercial farms (11.11%) in central parts of Iran (Isfahan province) which is probably due to proximity of multiage layer MG positive farms to turkey flocks. Prevalence of MG in layer flocks in central part of Iran has been reported. ...
... 32 In the same way, the MG seroprevalence was slightly higher in the foothills (9.40%) than in coastal area (7.20%) in which humidity was greater. 30 The results showed that two positive commercial farms (belonged to Isfahan and Tehran provinces), were suffering from respiratory distress, decreased feed intake, weight loss and increased mortality at the same time. Roussan et al. 33 reported that all MG positive flocks were suffering from other respiratory disease(s) such as APV, MPV or NDV at the same time. ...
Mycoplasma gallisepticum (MG) is economically important pathogen of poultry causes airsacculitis and frequently infraorbital sinusitis in turkeys. Infections may remain without clinical signs, but they can make birds susceptible to secondary infections. This study was carried out for molecular detection and phylogenetic analysis of MG infections in commercial and backyard turkey flocks in some parts of Iran. A total number of 600 swab samples were collected from 18 commercial and 31 backyard turkey flocks. The PCR technique was performed for detecting 16S rRNA gene in the samples. Positive sample were subjected for sequencing of mgc2 gene. The results showed that 48.38% of backyard and 16.66% of commercial farms were positive for MG. These findings suggested the presence of MG in the commercial and backyard turkeys' farms of Iran. The molecular analysis indicated high sequence similarity between some Iranian turkeys isolates with Indian and Pakistanian MG isolates. Furthermore, substitutions of MG nucleic acids and correlated amino acids sequences may lead to some antigenic modifications.
... On the other hand, Lower prevalence was recorded in Iran (33%) [38], and also in Nakompathion [39] ranged from 18-40%. It was found that Low seroprevalence was recorded in broilers of 6 weeks old compared with those obtained from broilers examined at five or those tested in younger ages of 4 weeks. ...
... Cold weather depress the natural resistance of birds, leading to more susceptibility to infection due to cold stress on the birds. In the same way, the infection is slightly higher in the Foothills than in coastal area, in which humidity is greater [16,[17][18][19][20][21][22][23][24]. ...
Avian species are suffered with many infectious and non-infectious diseases in which Mycoplasma gallisepticum is one of vital
importance. Infected chickens can be diagnosed on the basis of clinical signs including coughing, sneezing, nasal discharge, foamy
secretions in the eye, open mouth breathing, tracheal rales, reduced feed intake, drop in egg production in layers and decrease in
weight gain. It is transmitted by both ways that is horizontal and vertical. Its prevalence is different in several regions of the country
and current status is described in this paper. Diagnosis of Mycoplasma can be done by different serological tests including Serum
plate agglutination test, Hemagglutination inhibition test and Enzyme linked Immunosorbent assay, whereas molecular detection
can be done by Polymerase chain reaction. Serological tests are used for initial screening of flocks while confirmatory diagnosis can
be done by molecular methods. Infection can be controlled by screening the breeder flock, vaccination of layer chicks and culling of
infected flocks because if flock is infected, it remains for full life, so whole flock should be destroyed to avoid the further transmission
from parent flock to offspring.
Mycoplasma gallisepticum (MG) is regarded as finest bacteria can replicate independently and they one of the illustrious pathogens for chickens cause body retardation and losing weight thereby it considered as one of the costliest worldwide significant pathogens for poultry. Mycoplasma detection using traditional culture method is not adequate procedure because it has several strains also the difficulty of cultivation technique and the obstructs that faced, current study was considered culture method and conventional Pcr assay for direct diagnosis of MG using 16S rRNA and mgc1(GapA) gene. Out of 20 commercial broiler farms at Al-dewaniyah province, Iraq, 150 tissue specimens were assembled wherever manifestation of respiratory infections was demonstrative. Whereas 16 out of 150 samples (10.66 %) were recognized as positive via conventional cultivation based on morphology of growing colonies, Diene's staining and some biochemical, however confirmed by amplification of 16S rRNA gene of polymerase chain reaction technique of suspected colonies, while cloning of direct tissue samples by 16S rRNA amplification exhibit 36/150 (24%) corresponding to the genus of Mycoplasma, the 16S rRNA amplification product was 1500 base pair. The inference of the findings of current study, is that, the PCR revealed greater sensitivity and viable reliability, quality and precision than bacterial culture techniques and therefore might be very suggestive for the supervision of flock's health imperviousness against MG and to enable application of effective preventative and control measures. all 16 cultured isolates that affirmative as Mycoplasma spp by 16S rRNA amplification were undergo by PCR analysis of GapA gene in addition to sequence analysis of 16S rRNA, the outcomes of 16 isolated Mycoplasma spp. colonies showed that 8 isolates were belongs to Mycoplasma gallisepticum out of 150 total tested samples with percent of (5.33%), this result provided by virulence GapA (mgc1) gene analysis data, however positive tissue samples by cloning assay was 22/150 (14.66%) were belongs to M. gallisepticum. Based on results of 16S rRNA sequencing, we detect other Mycoplasma spp. and other unrelated bacteria not showed in the current article. The results of Mycoplasma isolates approval through amplification of the GapA gene showed a bands of 332 bp for M. gallisepticum, the16S rRNA gene was directed to Soul University (Korea) for sequence analysis. The available data are presented in Gene bank database of 16S rRNA for documentation.
Mycoplasma gallisepticum (MG) is regarded as finest bacteria can replicate independently and they one of the illustrious pathogens for chickens cause body retardation and losing weight thereby it considered as one of the costliest worldwide significant pathogens for poultry. Mycoplasma detection using traditional culture method is not adequate procedure because it has several strains also the difficulty of cultivation technique and the obstructs that faced, current study was considered culture method and conventional Pcr assay for direct diagnosis of MG using 16S rRNA and mgc1(GapA) gene. Out of 20 commercial broiler farms at Al-dewaniyah province, Iraq, 150 tissue specimens were assembled wherever manifestation of respiratory infections was demonstrative. Whereas 16 out of 150 samples (10.66 %) were recognized as positive via conventional cultivation based on morphology of growing colonies, Diene's staining and some biochemical, however confirmed by amplification of 16S rRNA gene of polymerase chain reaction technique of suspected colonies, while cloning of direct tissue samples by 16S rRNA amplification exhibit 36/150 (24%) corresponding to the genus of Mycoplasma, the 16S rRNA amplification product was 1500 base pair. The inference of the findings of current study, is that, the PCR revealed greater sensitivity and viable reliability, quality and precision than bacterial culture techniques and therefore might be very suggestive for the supervision of flock's health imperviousness against MG and to enable application of effective preventative and control measures. all 16 cultured isolates that affirmative as Mycoplasma spp by 16S rRNA amplification were undergo by PCR analysis of GapA gene in addition to sequence analysis of 16S rRNA, the outcomes of 16 isolated Mycoplasma spp. colonies showed that 8 isolates were belongs to Mycoplasma gallisepticum out of 150 total tested samples with percent of (5.33%), this result provided by virulence GapA (mgc1) gene analysis data, however positive tissue samples by cloning assay was 22/150 (14.66%) were belongs to M. gallisepticum. Based on results of 16S rRNA sequencing, we detect other Mycoplasma spp. and other unrelated bacteria not showed in the current article. The results of Mycoplasma isolates approval through amplification of the GapA gene showed a bands of 332 bp for M. gallisepticum, the16S rRNA gene was directed to Soul University (Korea) for sequence analysis. The available data are presented in Gene bank database of 16S rRNA for documentation.
Chickens are suffered with several diseases in which Mycoplasma gallisepticum diseases is one of great importance. Infected
chickens can be diagnosed on the basis of history, clinical signs, postmortem and microscopic examination and diagnostic methods.
After observation of clinical signs, necropsy practice is the best tool to differentiate the disease on the basis of type of lesions. On
postmortem examination airsacculitis is regarded as characteristic lesion. Microscopic changes can be observed in trachea, lungs and
air sacs. Diagnosis of Mycoplasma can be done by several tests including serological tests and molecular tests. Serological tests are
used for early diagnosis of the disease. Different disease status was observed in various countries like Bangladesh, India, Iran, Egypt,
China and some other countries. Infection can be controlled by proper screening the breeder flock, vaccination of layer chicks and
culling of infected flocks because if flock is infected, it remains for whole life, so eliminate all the flock to avoid the further losses due
to Mycoplasma.
BACKGROUND: Mycoplasmosis is an infectious disease of poultry and a major cause of economic losses due to decline in growth, egg production, reduction in egg hatching and exacerbation of viral and bacterial respiratory diseases. OBJECTIVES: The purpose of this study was detection of serological prevalence of Mycoplasma gallisepticum infection in broiler breeders of Mazandaran province and to suggest control strategies against mycoplasmosis. METHODS: All breeder farms that were in production period in Mazandaran province were sampled (74 farms in 14 cities); blood samples were collected from 45 birds in each farm. Sera samples were examined by RSPA and ELISA tests based on the instructions of OIE. RESULTS: In this study, by the RSPA test, 3 out of 74 farms (4%), 15 out of 553 houses (2/7%) were positive. From 5626 collected sera samples, 139 samples (2.5%) were positive in RSPA and 124 samples (2.2%) in ELISA. CONCLUSIONS: Seroprevalence of MG infection was 4% during the selected period and zone of study. Statistical analysis showed that biosecurity situations were significantly better in negative farms (p=0.04). There are some deficiencies in quality of biosecurity situations despite implementing biosecurity principles in farms. Establishing of farms near villages or the development of villages, keeping backyard birds close to the farms and employees living in villages are some of the biosecurity principles that were not followed in infected farms.
Aim: The study was conducted to determine seroprevalence of the five diseases influenza, Newcastle, Mycoplasma gallisepticum, Mycoplasma synoviae and salmonella, among around native hens of Eghlid in Iran, on spring 2011. Materials and Methods: On the basis of native Hens distribution, this region divided into four parts of Eghlid, Doskord, Sedeh and Hasan-abad. Fifty unvaccinated native Hens randomly selected from each part. Blood samples were aseptically collected from the wing veins using 5-ml sterile syringe. Serum from hens was tested for detection and titration for Mycoplasma and Salmonella by the rapid slide agglutination method, and was tested for influenza and Newcastle by the Hemagglutination Inhibition Assay. The data was analyzed completely in randomized design with four treatments, 50 repetitions for each disease. Results: 34 out of 200 samples (17%) were positive for influenza. There were significant differences between regions (p <0.01). 38 out of 200 samples (19%) were positive for Newcastle. The maximum infectious rate obtained from Eghlid. There were significant differences between regions (p <0.05). 170 out of 200 samples (85%) were positive for Mycoplasma gallisepticum. 4 from 200 samples (2%) were positive for Mycoplasma synoviae. The results do not show a significant difference for salmonella (p <0.05). Conclusion: Contamination of Influenza, Newcastle and Mycoplasma gallisepticum was high, and the highest contamination rate was related to Mycoplasma gallisepticum. It is usually recommended that preventive strategies, such as appropriate husbandry and hygiene, sanitary handling of chicks and eggs, routine health monitoring and vaccination of Native hens should be emphasized.
A serological survey on the prevalence of antibodies against Salmonella and Mycoplasma gallisepticum (MG) was carried out in layer chickens in Rajshahi and surrounding districts of Bangladesh. A total of 605 sera samples were examined by rapid plate agglutination (RPA) test using commercial Salmonella and MG antigens to determine the Salmonella and MG specific antibody. Out of 605 sera samples 14.1% showed single Salmonella, 45.1% showed single MG and 11.2% showed their concurrent infection. Prevalence of Salmonella was recorded the highest (37.6%) in adult compared to young (16.7%). On the contrary, MG and concurrent infections were recorded the highest (71.7% and 13.3%) in young compared to adult (50.4% and 10.4%). The prevalence of Salmonella, MG and concurrent infections were recorded the highest (34.3%, 68.6% and 17.1%) in large flocks compared to small flocks (21.3%, 50.0% and 8.8%). The prevalence of Salmonella infection was the highest (30.4%) in summer followed by winter (23.7%), rainy (25.0%) and autumn (23.3%). The prevalence of MG infection was the highest (61.6%) in winter followed by autumn (56.9%), rainy (55.0%) and summer (49.6%). Whereas, their concurrent infection was the highest (12.1%) in winter followed by summer (11.9%), rainy (10.8%) and autumn (10.0%).
Avian mycoplasmosis is infectious and contagious disease which affects chicken and turkey as well as many other species with many economics losses. The absence of data on avian mycoplasmosis in Algeria and the importance of the poultry breeding in Batna encouraged us to undertake the prevalence of the most pathogenic mycoplasmas in broiler and layer chickens in this area, Mycoplasma gallisepticum (MG). 143 Mycoplasmas were isolate from 237 samples, at a rate of 60.33%. MG was isolate at a rate of 21.67% (2.09% in layer hens and 19.58% in broiler chickens). The serological screening using of breedings showed a sensitivity of 83.10%. This study shows that mycoplasmosis and in particular MG infection, represent a serious problem in chickens in Algeria in the absence of hygiene conditions and vaccination especially. [Vet. World 2011; 4(3.000): 101-105]
Mycoplasma gallisepticum (MG) is a persistent, highly transmissible chicken and turkey pathogen. Infections of the organism can yield significant
losses in performance and associated economics to all sectors of the poultry industry. In this paper, potential and realized
effects of MG on the poultry industry are discussed along with currently available and developing control methods. Available
methods of MG control largely include stringent biosecurity and biosurveillance practices within the turkey and broiler sectors
of the poultry industry and live attenuated MG vaccine strains that are approved for use only within the commercial egg layer
industry. Although largely effective, MG breaks within these industries still occur, demonstrating that further means of control
are required. Alternative means for consideration include bacterins and subunit vaccines, although their applicability may
be limited by associated vaccination protocols. Further means under consideration include novel live attenuated MG strains
and recombinant bacterial and viral species. Optimally, control methods would be applicable to all poultry and be safe, cost
effective, and efficacious. Current research regarding novel MG vaccines is addressed herein.
Sensitivity and specificity of two commercial Mycoplasma gallisepticum (MG) enzyme-linked immunosorbent assay (ELISA) kits, rapid slide agglutination (SA) and haemagglutination inhibition (HI) tests were compared using sera from specific pathogen free chickens, turkeys or ducks which had been inoculated with various avian mycoplasmas, bacteria or with a reovirus. Results show that sensitivity of SA was superior to ELISA and HI tests in the ability to detect antibodies formed in early response to MG infection. However, both ELISA kits and HI tests had a higher degree of specificity.
Six isolates of Mycoplasma synoviae, identified as WVU 1853, K1968, K1858, 92D8034, F10-2AS, and FMT, were compared for pathogenicity in broiler chickens. Specific-pathogen-free chickens were inoculated, in two groups of 20, with each isolate by footpad or eyedrop inoculation at 1 day of age and were examined at necropsy 7, 14, 28, and 42 days postinoculation. Specimens were taken for histopathology, culture, polymerase chain reaction assay, and hemagglutination-inhibition serology. Isolates were grouped according to pathogenicity on the basis of differences in lesion development and tissue distribution in the respiratory system, other viscera, and the skeletal system. K1968 (pathogenic) induced lesions in all sites examined in both the footpad and eyedrop inoculation groups. It was detected in all sites following footpad inoculation and in all sites except viscera following eyedrop inoculation. WVU 1853, K1858, and 92D8034 (moderately pathogenic) induced lesions and were detected in all sites following footpad inoculation. With eyedrop inoculation, lesions were identified only in upper and lower respiratory sites, and organisms were detected only in upper respiratory sites. F10-2AS (moderately pathogenic) was similar; however, footpad inoculation failed to induce visceral lesions or permit organism detection in any site. F10-2AS was detected in upper and lower respiratory tissues following eyedrop inoculation. FMT (mildly pathogenic) induced only upper respiratory lesions when either footpad or eyedrop inoculation was used, and detection was restricted to upper respiratory sites following eyedrop inoculation. These results are useful in comparative evaluations of the virulence of other M. synoviae isolates and form a basis for characterization of virulence factors of M. synoviae.
A retrospective longitudinal study was conducted to identify risk factors associated with Salmonella enterica serovar typhimurium (S. typhimurium) infection in Danish broiler flocks. The data included all broiler flocks slaughtered in 1995, and the epidemiological unit was the individual broiler flock. The S. typhimurium status was determined by microbiological examination of 60 fresh fecal samples. This procedure should detect an infected flock with a probability above 95%, if the prevalence is above 5%, and given that the sensitivity of the test is 100%. Nineteen variables were selected for analysis. Five factors and an interaction term were found significant by multivariate logistic regression analysis. An increased risk for S. typhimurium infection was associated with two parent flocks, one confirmed infected and one suspected of being infected with S. typhimurium, with two of the hatcheries, and with five houses on the farm. An interaction between season and the previously mentioned hatcheries, and a random effect at farm level was also found to be statistically significant. Twelve variables were not found to be associated with S. typhimurium infection: medication, growth promoters, breed of the laying flock, animal density, size of the flock, area of the house, age of the house, geographical location of the farm, observation of beetles, number of days between disinfection and replacement, visual appearance of the bedding, and age of the chickens when they were tested for Salmonella. Three variables (feed mill, slaughterhouse, and Salmonella status of the preceding flock) were not evaluated in the multivariate analysis due to collinearity with other included variables.
Mycoplasmosis avium is a highly infectious disease, which has been diagnosed mainly on commercial poultry farms. It usually occurs in meat-type flocks of hens, turkeys, and also in ducks and geese. The purpose of the study was to define the level of dissemination of infections caused by mycoplasmas in flocks of reproduction meat-type hens and broilers. The experiment covered 142 reproduction meat-type flocks (1 day-65 week-old birds) and 136 broiler flocks (1-7 weeks old birds). The materials used in the studies were blood samples collected from the farm birds in 1998-1999 (until August). Blood samples were collected once in layers and in 109 broiler flocks, and twice in the other 27 broiler flocks. i.e. in one-day chicks and in the 6th week of rearing. Moreover, additional 15 broiler farms were included in the serological monitoring (tests performed on 1st day, 2nd - 3rd and 6th - 7th week of rearing). The level of M. gallisepticum and M. synoviae antibodies in serum was determine by ELISA (Idexx kit with MG/MS antigen) and additionally by RPA test (MG and MS antigen by Intervet) on 15 farms. The presence of specific Mycoplasma antibodies was found in 54.9% of the layer flocks monitored. However, the highest percentage of serologically positive flocks was recorded in the laying period (65.2%) and the lowest in one-day old chickens (30.8%). Infection with Mycoplasmosis in broilers reached 44.1%, and in these cases the occurrence of MG/MS antibodies was observed more often in one-day old chicks (55.1%) than in 6-7 week old chickens (32.1%). The flocks of broilers demonstrated more infections with M. synoviae than with M. gallisepticum (25.9% and 7.4%, respectively in the 6th week).
Seroprevalences to three infectious agents were studied in rural poultry farms in three different ecological regions in Benin. Of 260 sera, 65% were seropositive for Newcastle disease virus, 10% for Salmonella pullorum and 62% for Mycoplasma gallisepticum.
The sero-prevalence of Mycoplasma gallisepticum (MG) infection of chickens in selected Model Breeder Poultry Farms was determined during the period January to May, 2004. To conduct this study a total of 382 sera samples were collected. Rapid Serum Plate Agglutination (SPA) test was performed using commercial MG antigen (Nobilis® MG) to detect the presence of antibodies against MG. The over all sero-prevalence of MG infection was 58.90% in the study area. The highest prevalence (62.44 %) of MG infection was found in winter season followed by summer season (53.10%). The result further revealed that the infection was higher (59.94%) in female birds than in male birds (48.57%). It was also demonstrated that the infection was higher (62.80%) in Feni sadar than in Chhagoalnaiya thana (53.45%).
The present study was undertaken to know the seroprevalence of Salmonella and Mycoplasma gallisepticum (MG) infection in six model breeder poultry farms (MBPFs) located at kalapara Upazilla under Patuakhali district, Bangladesh. A total of 364 sera samples were collected from chickens belonging to six MBPFs. All sera samples were examined by rapid serum plate agglutination (SPA) test using commercial Salmonella (SP) and MG antigens to determine the presence of Salmonella and MG specific antibodies in different age and sex of birds belonging to MBPFs. In addition to that prevalence of Salmonella and Mycoplasma infection in MBPFs during rainy and winter seasons were also recorded. The results of serological tests were analyzed statistically. The overall prevalence of Salmonella and Mycoplasma infection in six MBPFs were recorded as 23.46% and 46.88% respectively. Prevalence of salmonella was recorded highest in rainy season (25.00%) than the winter season (21.88). On the contrary, Mycoplasma infection was recorded highest in winter season (61.45%) than the rainy season (51.74%). Both Salmonella and Mycoplasma infections were recorded highest in female birds (24.10%) than the male birds (15.62%). The prevalence of MG infection decreased with the increase of age. MG infection recorded highest 71.42% at 18 weeks of age and lowest 50% at 22 weeks of age. On the other hand, the prevalence Salmonella infection was increased with the increase age. Salmonella infection was found highest 30.76% at 39 weeks of age and lowest 13.33% at 32 weeks of age. It was concluded from the present study that both Salmonella and MG infection were significantly present in all six MBPFs and SPA test could be used as a tool for quick detection of Salmonella and MG infection.
Before the year 2000, Mycoplasma synoviae was associated mainly with subclinical respiratory infections in broilers in the Netherlands and was considered to have low clinical and economic impact. The subsequent occurrence of M. synoviae arthritis and amyloid arthropathy, and of eggshell apex abnormalities, has resulted in an increasing demand for M. synoviae-free poultry. Therefore, a cross-sectional seroprevalence study was carried out over a 12-month period during 2005 and 2006. Ten blood samples per farm were generally used because M. synoviae was expected to spread quickly. However, for grandparent and layer breeder stock, 24 to 60 blood samples per house were available from a voluntary M. synoviae monitoring programme. Sera were tested by means of the rapid plate agglutination test (agglutination at dilution > or =1:8 was considered positive). The numbers of farms sampled out of the national total were: broiler grandparent, 53/53; broiler parent rearing, 34/150; broiler parent, 114/300; broiler, 185/800; layer grandparent, 13/13; layer parent, 40/50; layer, 173/1250; and meat turkey, 50/75. The seroprevalence of M. synoviae in commercial poultry was high, especially in commercial layers where it was 73% (95% confidence interval (CI)=67 to 80); in layer and broiler grandparent stock, the seroprevalence was 0% and 10%, respectively, based on sample sizes equal to the population size. In layer and broiler parent farms, the seroprevalence was 25% (95% CI=19 to 31) and 35% (95% CI=28 to 44); in both broiler parent rearing and broiler farms it was 6% (95% CI=0 to 13 and 95% CI=3 to 9); and in meat turkey, the seroprevalence was 16% (95% CI=10 to 22).
Chicken flocks hatched together but reared under different management systems were examined for mycoplasmas over a two‐year period. On the farm A multiple‐age flocks were reared in close contact. This farm had not been depopulated for over 15 years. On farms B, C and D single‐age flocks were reared and the farms were depopulated every year.
On farm A 218 birds from 20 flocks were tested: mycoplasmas were isolated from 202 (92.7%). On farms B, C and D 289 birds from seven flocks were tested: mycoplasmas were recovered from 55 (19.0%).
On farm A the following mycoplasmas were identified: M. gallisepticum (46.9% of isolates), M. gallinarum (47.8%), M. pullorum (46.3%), M. gallinaceum (43.2%),M. iners (10.9%), M. iowae (8.3%),M. synoviae (51.7%), M. lipofaciens (23.8%) and M. glycophilum (16.7%). Furthermore, mycoplasma strains which do not belong to recognised species of avian mycoplasmas, Acholeplasma laidlawii and an unidentified Acholeplasma strain were also isolated.
On farms B, C and D the isolates were identified as M. gallisepticum or M. synoviae. The only exception was one culture from which M. gallinarum was recovered. The differences between farm A and farms B, C and D regarding total mycoplasma isolation yields and incidence of their species are significant (/K0.01) and are attributed to the different management systems.
The prevalence of Mycoplasma gallisepticum (MG) and M. synoviae (MS) in commercial pullet and layer flocks in Southern and Central California was estimated by testing serum and egg-yolk samples from 360 sample flocks in Southern California and 41 sample flocks in Central California. Data relating to potential risk factors associated with MG and MS infections were collected. The estimated true prevalence rate of MG was 73% in Southern California and 3% in Central California. The estimated true prevalence rate of MS was 91% in Southern California and 32% in Central California. Compared with uninfected flocks, MG-infected flocks in Southern California were significantly older and were medicated less (P less than 0.05). More managements were under a multiple-age system, more flocks had molted, more were vaccinated with F-strain, and more had concurrent infection with MS (P less than 0.05). Only one sample flock in Central California was MG-infected; none were vaccinated with F-strain. In Southern California, MS-infected flocks were older than uninfected flocks, more had molted, more were medicated, and more had concurrent infection with MG (P less than 0.05). In Central California, MS-infected flocks did not differ significantly from uninfected flocks in any factor examined; the lack of statistical significance may be due to small sample size.
In a control scheme for enzootic-pneumonia-free herds, run by the Pig Health Control Association, a detailed study was made of 55 herds that developed enzootic pneumonia without a simple explanation. These herds were compared with 57 herds that were still free from enzootic pneumonia in mid-1984. A high standard of precautions against the risk of infection being transferred by people and fomites seemed to confer no obvious benefit. This observation was in keeping with in vitro studies which showed that, although Mycoplasma hyopneumoniae could survive for a long time in favourable liquid medium, it could not be recovered from material such as cloth, once the culture had become dry. Under field conditions, the organism would probably cease to be infective within 48 hours. The organism survived particularly well in rain water at lower temperatures, however, and transmission via moist cold air seemed a possibility. There was a tendency for breakdowns to start in the autumn and winter, particularly in highly secure units, and several farmers associated colder misty conditions with the arrival of infection. One herd was probably infected by an imported boar and the very close proximity of foreign pigs, such as in slaughterhouse transport, seemed the most likely explanation in 15 other herds. One herd was replaced without this danger being attended to and it soon broke down again, whereas the three herds in this category that have survived after replacement all had this risk eliminated. Data was available on 37 of the 39 remaining herds to compare them with the 57 surviving herds, using a risk index based on the proximity of other pig units.(ABSTRACT TRUNCATED AT 250 WORDS)
To gather information on backyard chicken flocks in Chitungwiza, an urban center in Zimbabwe, 85 flock owners were interviewed. The mean flock size was 53 birds (range 1-650), and most birds were kept for meat, for either domestic consumption or local sale. Mean age at slaughter was 12.4 weeks (range 8-24). None of the owners vaccinated their birds, and reported mortality rates were high (mean 25%), most commonly being associated with diseases causing eye and respiratory problems. Most owners complained of a lack of technical and veterinary advice. Commercial enzyme-linked immunosorbent assays on sera from 460 birds in 52 flocks showed that the birds had been exposed to avian reovirus (3%), avian leukosis virus (9%), avian encephalomyelitis virus (11%), Newcastle disease virus (27%), Mycoplasma gallisepticum and M. synoviae (33%), Pasteurella multocida (52%), infectious bursal disease virus (55%), reticuloendotheliosis virus (65%), and infectious bronchitis virus (86%). Parasite infections were detected only rarely.
Sera from 5325 chickens representing 71 commercial poultry flocks were tested for Mycoplasma synoviae (MS) using standard National Poultry Improvement Program (NPIP) testing guidelines. Based on the NPIP guidelines, only sera (N = 195) from flocks that test positive by specific plate agglutination (SPA) were submitted for additional confirmatory tests. Flocks from three multihouse farms were identified as seropositive for MS and confirmed by culture and polymerase chain reaction (PCR). Serum samples (N = 195) from these seropositive flocks were compared by SPA, enzyme-linked immunoassay (ELISA), and hemagglutination-inhibition (HI). Of the 195 sera tested for MS from these flocks, 145 (74%) sera were positive by SPA. Of the 145 SPA-positive sera, the HI test was positive for 127 samples (90.2%), whereas the ELISA was positive for 141 samples (98.6%). This difference between the two tests was significant (P = 0.0006). Significant differences (P = 0.0002) in titer were obtained from paired serum samples that were submitted to three different laboratories for HI analysis. Both the SPA and HI tests failed to detect early infection in newly introduced flocks following depopulation of MS-positive facilities. Both ELISA and PCR detected new infections on these farms. In the MS outbreak described in this study, SPA was not adequate as the sole screening test and HI was not adequate for confirmation of flock infection status. Continued reliance on the same or a similar type of testing could result in missed infections. Confirmation of infection by PCR was preferable to HI and also may be used in place of culture. The findings of this study suggest that ELISA should be considered as a serologic screen in lieu of SPA, screening with SPA may miss MS-infected flocks, and PCR should be considered as a confirmatory test.
The most important mycoplasmas isolated from domestic avian species include Mycoplasma gallisepticum (MG), M. synoviae (MS), M. meleagridis (MM) and M. iowae (MI). MG causes chronic respiratory disease of chickens and infectious sinusitis in turkeys, resulting in economic losses. MS causes infectious synovitis or mild upper respiratory disease. MM infects only turkeys, causing airsacculitis and sub-optimal production and hatchability. MI is associated with reduced hatchability in turkey flocks. Transmission is either direct, from bird to bird or through the egg, or indirect. Diagnosis is based on isolation and identification of mycoplasmas, according to biochemical, serological or molecular biology tests, or serological examination of host sera by slide agglutination, haemagglutination inhibition or enzyme-linked immunosorbent assay (ELISA) tests. Antibiotics (i.e. tetracyclines, macrolides, quinolones and tiamulin) may be used for therapeutic treatment or prophylactic medication. The eradication of mycoplasma infection can be achieved through improvements in hygiene and management practices, therapeutic treatment of breeder layers and/or of hatching eggs and better monitoring procedures.
Specific pathogen free hens and males were experimentally infected with Mycoplasma gallisepticum. Eggs were then collected, and a part was incubated and set for hatching. Mycoplasma cultures were performed on infected adults and antibodies to MG were analysed by use of slide agglutination (SA) test and commercial ELISA tests on adults and chicks sera and on yolks from non incubated eggs. Both ELISA tests could detect antibodies in yolks from non incubated eggs laid three weeks after infection. SA and the three ELISA tests revealed positive sera in chicks hatched from eggs laid as soon as one week after infection.
Our objectives were to identify risk factors for contamination of French broiler flocks by Campylobacter. We used 75 broiler farms in western France. A questionnaire was administered to the farmers and samples of fresh droppings were taken to assess the Campylobacter status of the broiler flocks. 42.7% of the flocks were positive for Campylobacter spp. The risk of contamination of the broiler flocks by Campylobacter was increased in summer/autumn, in houses with static air distribution, when two or more people took care of the flock, in poultry farms with three or more houses and when the drinking water for the chickens was acidified. The presence of litter-beetles in the change room also increased the risk of contamination. The administration of an antibiotic treatment following a disease decreased the risk of a flock being contaminated by Campylobacter.
The frequency of Mycoplasma synoviae exposure in a convenience sample of commercial layers was established by the presence of antibody in eggs. Chloroform-extracted egg yolks were found to be more suitable than saline-extracted yolks, and were used with a commercial enzyme-linked immunosorbent assay kit, having first established the sensitivity and specificity of the kit with eggs from known M. synoviae-positive and M. synoviae-negative flocks. For the prevalence study, pooled yolks from 12 eggs were obtained from each of 56 randomly selected laying farms in possession of a packing station number in the east of England. This number allowed 95% confidence of detection of antibody in one egg if present in 50% of the flock. Eggs were taken from the oldest flock on each site and were returned with a completed questionnaire. The prevalence of egg antibody to M. synoviae was 78.6% (95% confidence interval, 65.6, 88.4). This study has confirmed that chloroform extraction of yolk antibody is a suitable approach for assessing the flock prevalence of M. synoviae infection in layer hens.
In this study, the technical performance of culture, two commercially available polymerase chain reaction (PCR) tests, rapid plate agglutination (RPA) test, hemagglutination inhibition (HI) test, and eight commercially available enzyme-linked immunosorbent assays (ELISAs) were compared for the detection of avian mycoplasma infections from 3 days postinfection (d.p.i.) through 35 d.p.i. The tests were carried out on samples from specified pathogen-free layers that were infected at 66 wk of age with recent Mycoplasma synoviae (MS) and Mycoplasma gallisepticum (MG) field strains, MS and MG ATCC strains, and Mycoplasma imitans (MIM), respectively. Results showed a high percentage of positive samples in the homologous infected groups and a high percentage of negative samples (100%) in the uninfected and heterologous infected groups during 35 d.p.i. of both culture and PCR tests. For the group infected with the MG 15302 ATCC strain, serology was more sensitive than bacteriology. All MG and MS tests, with the exception of MG ELISA kit D showed a lower percentage of positive samples during 35 d.p.i. for the detection of the MG and MS ATCC strain infection compared with that of the field strains. Also, the number of cross-reactions (false positives) in the serologic tests was lower after infection with an ATCC strain than after an infection with the MG or MS field strain. Contradictory to other studies, the ELISAs and the RPA test using undiluted serum showed a relatively high number of false-positive results. The MG ELISAs (except ELISA kit D) showed more false-positive results (up to 37%) in the MIM-infected group than in the MS-infected groups. This was not unexpected, as MIM and MG have a close antigenic relationship. The results of the serologic tests in this study showed that a certain level of false-positive results can be expected in about any serologic test. Although the level of false-positive results varied between several serologic tests, this study showed that it is not advisable to rely completely on one test (system) only.
Mycoplasma synoviae infection occurs worldwide in commercial poultry flocks and may result in severe economic losses. The prevalence of this mycoplasma in standard layers older than 60 weeks was studied in a French department and the characteristics of infected or free flocks were compared. The genomic profiles of isolates from 36 infected flocks were studied by pulsed-field gel electrophoresis and random amplified polymorphic DNA methods in order to investigate possible routes of transmission. The minimum inhibitory concentrations of antibiotics were determined. Results showed that infection was more frequent in multi-age farms. Egg production and mortality of infected flocks were respectively lower and higher than in non-infected flocks but the differences were not statistically significant. The genomic profiles of isolates were quite homogeneous, a feature which does not facilitate the understanding of routes of transmission. All isolates were susceptible to tetracyclines, macrolides (except erythromycin), spectinomycin and fluoroquinolones.
Mycoplasmosis A laboratory manual for the isolation and identification of avian pathogens
- Sh Kleven
- De Swayne
- Jr Glisson
- Mw Jackwood
- Je Pearson
- Wm Reed
Kleven SH, 1998, Mycoplasmosis. In: Swayne DE, Glisson JR, Jackwood MW, Pearson JE, Reed
WM, editors, A laboratory manual for the isolation and identification of avian pathogens, 4.ed.
American Association of avian pathologists, 74-80.
Mycoplasma synoviae infection
- S H Kleven
- N Ferguson-Noeln
- Y M Saif
- A M Fadly
- J R Glisson
- L R Mcdougald
- L K Nolan
- D E Swayne
Kleven SH, Ferguson-Noeln N, 2008, Mycoplasma synoviae infection. In: Saif YM, Fadly AM,
Glisson JR, McDougald LR, Nolan LK, Swayne DE, editors, Diseases of Poultry, 12.ed.
Blackwell Publishing, Iowa State University Press, USA, Ames: Iowa, 845-56.
- A Feberwee
- De Vries
- T S Landman
Feberwee A, De Vries TS, Landman WJM, 2008, Seroprevalence of Mycoplasma synoviae in Dutch
commercial poultry farms, Avian Pathol, 37, 6, 629-33.