The testis-specific isoform of angiotensin-converting enzyme (tACE) is exclusively expressed in germ cells during spermatogenesis. Although the exact role of tACE in male fertility is unknown, it clearly plays a critical function in spermatogenesis. The dipeptidase domain of tACE is identical to the C-terminal catalytic domain of somatic ACE (sACE). Bradykinin potentiating peptides (BPPs) from snake venoms are the first natural sACE inhibitors described and their structure--activity relationship studies were the basis for the development of antihypertensive drugs such as captopril. In recent years, it has been showed that a number of BPPs -- including BPP-10c -- are able to distinguish between the N- and C-active sites of sACE, what is not applicable to captopril. Considering the similarity between tACE and sACE (and since BPPs are able to distinguish between the two active sites of sACE), the effects of the BPP-10c and captopril on the structure and function of the seminiferous epithelium were characterized in the present study. BPP-10c and captopril were administered in male Swiss mice by intraperitoneal injection (4.7 mumol/kg for 15 days) and histological sections of testes were analyzed. Classification of seminiferous tubules and stage analysis were carried out for quantitative evaluation of germ cells of the seminiferous epithelium. The blood-testis barrier (BTB) permeability and distribution of claudin-1 in the seminiferous epithelium were analyzed by hypertonic fixative method and immunohistochemical analyses of testes, respectively.
The morphology of seminiferous tubules from animals treated with BPP-10c showed an intense disruption of the epithelium, presence of atypical multinucleated cells in the lumen and degenerated germ cells in the adluminal compartment. BPP-10c led to an increase in the number of round spermatids and total support capacity of Sertoli cell in stages I, V, VII/VIII of the seminiferous epithelium cycle, without affecting BTB permeability and the distribution of claudin-1 in the seminiferous epithelium. Interestingly, no morphological or morphometric alterations were observed in animals treated with captopril.
The major finding of the present study was that BPP-10c, and not captopril, modifies spermatogenesis by causing hyperplasia of round spermatids in stages I, V, and VII/VIII of the spermatogenic cycle.
Hematology and plasma biochemistry parameters are useful in the assessment and management of snake physiological status. Although reference ranges are readily available for many snake species, they are lacking for most venomous ophidians. We determined hematology and plasma biochemistry reference ranges for the wild-caught Indian cobra, Naja naja.
Blood samples, taken from the ventral tail vein, were assessed for erythrocyte count, total leukocyte count, hemoglobin concentration, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration, considering the sex of snakes. Results revealed the erythrocyte numbers (male, 390000 +/- 12503.33/mm3 and female, 347500 +/- 7505.55/mm3), shapes and the centrally located oval nuclei. Leukocytes were round, circular or disk-shaped, and the mean size was larger in male than female snakes. The maximum number of leukocytes was found to be 11700 +/- 100/mm3 in male and 12100 +/- 200/mm3 in female snakes, and mean values of differential leukocyte count differed statistically between male and female snakes. The total leukocyte levels were found to be higher in female snakes, but the levels of hemoglobin, hematocrit, and MCV values were higher in male snakes. However, the MCH and MCHC values remained higher in female snakes throughout the study period. Mean protein and cholesterol contents differed significantly between male (45.32 +/- 1.76 and 3.76 +/- 0.06 mg/mL) and female (12.47 +/- 0.82 and 4.72 +/- 0.2 mg/mL) snakes.
In conclusion, monitoring snake hematological and biochemical parameters can serve as a means to evaluate the physiological and health status of N. naja populations, which may be a useful indicator of their environmental status.
Scorpion envenomations are a major public health problem in Brazil, whose most dangerous cases are attributable to the genus Tityus. This study was designed to compare the clinical and demographic features of envenomations by Tityus obscurus in two areas of the state of Para located in the Amazon basin.Were compared demographic findings, local and systemic signs and symptoms of human envenomations caused by T. obscurus that occurred in western and eastern areas of the state.
Forty-eight patients with confirmed envenomation by T. obscurus were evaluated from January 2008 to July 2011. Most of them came from the eastern region, where male and female patients were present in similar numbers, while males predominated in the west. Median age groups were also similar in both areas. Most scorpion stings took place during the day and occurred significantly more frequently on the upper limbs. The time between the sting and admission to the health center was less than three hours in both areas. Most eastern patients had local manifestations while in the west, systemic manifestations predominated. Local symptoms were similar in both areas, but systemic signs and symptoms were more common in the west. Symptoms frequently observed at the sting site were local and radiating pain, paresthesia, edema, erythema, sweating, piloerection and burning. The systemic manifestations were significantly higher in patients from the west. Futhermore, neurological symptoms such as general paresthesia, ataxia, dysarthria, myoclonus, dysmetria, and electric shock-like sensations throughout the body were reported only by patients from the west.
The present study shows that two regions of Para state differ in the clinical manifestations and severity of confirmed envenomation by T. obscurus which suggests a toxicity variation resulting from the diversity of T. obscurus venom in different areas of the Brazilian Amazon basin, and that T. serrulatus antivenom can be successfully used against T. obscurus.
Scorpions, mainly those belonging to the genus Tityus cause many deaths and injuries in Brazil, with tens of thousands of envenomations notified every year. However, injuries involving other scorpion species are scarcely registered. Among the sixteen species of the genus Rhopalurus, Thorell, 1876, described up to date, nine are found in this country, with only a confirmed case of human envenomation provoked by R. agamemnon Koch, 1839. The present case reports, for the first time, a case of scorpion sting in a human victim involving Rhopalurus amazonicus, endemic species of the west region of the Pará state, Amazon, Brazil. The symptoms of envenomation were local pain and paresthesia. This study contributes to develop the knowledge on venomous scorpions, particularly those that may cause envenomations in this region.
This work provides historical context about scorpion studies from the end of the 19th century to the present day. The content is mainly addressed to non-zoologists, working in research fields that embrace scorpion biology, notably to those working with venoms and toxins. The historical aspects described include academic professional scholars who worked on scorpion classification and general distribution patterns; and to a lesser extent, on studies of ecology and natural history. The aim is not to provide an exhaustive description of all scholars who in one way or another became involved with scorpions, but rather of those who greatly contributed during a given period to the research of these organisms. No critical analysis of the work of previous researchers is undertaken, but some comments are proposed to bring clarification on 'who's who'. Since a global consensus in relation to classification and/or distribution patterns has not been reached among modern experts, these different approaches are also presented without judgment. Consequently, distinct approaches remain open for discussion.
Scorpion venoms are rich bioactive peptide libraries that offer promising molecules that may lead to the discovery and development of new drugs. Leiurus abdullahbayrami produces one of the most potent venoms among Turkish scorpions that provokes severe symptoms in envenomated victims.
In the present study, the peptide profile of the venom was investigated by electrophoretic methods, size-exclusion and reversed-phase chromatography and mass spectroscopy. Cytotoxic and antimicrobial effects were evaluated on a breast cancer cell line (MCF-7) and various bacterial and fungal species.
Proteins make up approximately half of the dry weight of L. abdullahbayrami crude venom. Microfluidic capillary electrophoresis indicated the presence of 6 to 7 kDa peptides and proved to be a highly practical peptidomics tool with better resolution when compared to conventional polyacrylamide gel electrophoresis. Mass spectroscopy analysis helped us to identify 45 unique peptide masses between 1 to 7 kDa with a bimodal mass distribution peaking between molecular weights of 1 to 2 kDa (29%) and 3 to 4 kDa (31%). L. abdullahbayrami crude venom had a proliferative effect on MCF-7 cells, which may be explained by the high concentration of polyamines as well as potassium and calcium ions in the arachnid venoms. Antimicrobial effect was stronger on gram-negative bacteria.
This work represents the first peptidomic characterization of L. abdullahbayrami venom. Considering the molecular weight-function relationship of previously identified venom peptides, future bioactivity studies may lead to the discovery of novel potassium and chloride ion channel inhibitors as well as new antimicrobial peptides from L. abdullahbayrami venom.
The crown-of-thorns starfish Acanthaster planci is a venomous species from Taiwan whose venom provokes strong hemolytic activity. To understand the hemolytic properties of A. planci venom, samples were collected from A. planci spines in the Penghu Islands, dialyzed with distilled water, and lyophilized into A. planci spine venom (ASV) powder.
Both crude venom and ASV cause 50% hemolysis at a concentration of 20 mug/mL. The highest hemolytic activity of ASV was measured at pH 7.0-7.4; ASV-dependent hemolysis was sharply reduced when the pH was lower than 3 or greater than 8. There was almost no hemolytic activity when the Cu2+ concentration was increased to 10 mM. Furthermore, incubation at 100[degree sign]C for 30 to 60 minutes sharply decreased the hemolytic activity of ASV. After treatment with the protease alpha-chymotrypsin, the glycoside hydrolase cellulase, and the membrane component cholesterin, the hemolytic activity of ASV was significantly inhibited.
The results of this study provide fundamental information about A. planci spine venom. The hemolytic activity was affected by pH, temperature, metal ions, EDTA, cholesterin, proteases, and glycoside hydrolases. ASV hemolysis was inhibited by Cu2+, cholesterin, alpha-chymotrypsin, and cellulose, factors that might prevent the hemolytic activity of venom and provide the medical treatment for sting.
Although honeybee venom (BV) has been reported to induce apoptosis in different types of cancerous cells, its synergistic effects with customary anti-cancer drugs remain largely unknown. In the present study, we evaluated the cytotoxic effect of BV alone (as a natural product) and the synergistic cytological effects of this component in combination with [Pd (bpy) (Pi-Pydtc)]NO3 -- a novel palladium complex on human T-cell lymphoblastic leukemia cells. To investigate the cytotoxic effect of the BV alone and in combination with palladium complex on MOLT-4 cells MTT assay was performed. In order to determine the apoptotic effects of BV separately and in combination with Pd (II) complex on these cells and its ability to induce apoptosis, morphological examination, flowcytometric analysis and caspase-3 colorimetric assay were done.
We found that BV induced morphological changes, namely nuclear shrinkage, and inhibited MOLT-4 cell proliferation; both effects were dose- and time-dependent. Flow cytometry by Annexin-V antibody demonstrated that BV induced apoptosis in MOLT-4 cells. Furthermore, BV induced apoptosis independently of caspase-3 in these cells. In addition, we proved a clear synergistic effect of BV on [Pd (bpy) (Pi-Pydtc)]NO3. The apoptotic pathway activated by BV in combination with Pd complex was caspase-3-dependent.
These observations provide an explanation for the anti-proliferative properties of BV, and suggest that this agent may be useful for treating lymphoblastic leukemia alone or in combination with chemotherapy drugs pending further investigations on animal models as preclinical tests.
The venom of Centruroides limpidus limpidus (Cll) is a mixture of pharmacologically active principles. The most important of these are toxic proteins that interact both selectively and specifically with different cellular targets such as ion channels. Recently, anticancer properties of the venom from other scorpion species have been described. Studies in vitro have shown that scorpion venom induces cell death, inhibits proliferation and triggers the apoptotic pathway in different cancer cell lines. Herein, after treating human cervical adenocarcinoma (HeLa) cells with Cll crude venom, their cytotoxic activity and apoptosis induction were assessed.
Cll crude venom induced cell death in normal macrophages in a dose-dependent manner. However, through viability assays, HeLa cells showed high survival rates after exposure to Cll venom. Also, Cll venom did not induce apoptosis after performing ethidium bromide/acridine orange assays, nor was there any evidence of chromatin condensation or DNA fragmentation.
Crude Cll venom exposure was not detrimental to HeLa cell cultures. This may be partially attributable to the absence of specific HeLa cell membrane targets for molecules present in the venom of Centruroides limpidus limpidus. Although these results might discourage additional studies exploring the potential of Cll venom to treat human papilloma cervical cancer, further research is required to explore positive effects of crude Cll venom on other cancer cell lines.
In Guinea Elapids are responsible for 20% of envenomations. The associated case fatality rate (CFR) ranged 15-27%, irrespective of treatment.
We studied 77 neurotoxic envenomations divided in 3 groups: a set of patients that received only traditional or symptomatic treatments, and two other groups that received either 2 or 4 initial vials of Antivipmyn® Africa renewed as necessary. CFR was 27.3%, 15.4% and 17.6%, respectively. Although antivenom treatment was likely to reduce CFR, it didn't seem to have an obvious clinical benefit for the patients, suggesting a low treatment efficacy. Mean delay to treatment or clinical stages were not significantly different between the patients who recovered and the patients who died, or between groups. Interpretation of these results is complicated by the lack of systematic studies under comparable conditions. Of particular importance is the absence of assisted ventilation, available to patients in all the other clinical studies of neurotoxic envenomation.
The apparent lack of clinical benefit may have several causes. The hypothesis of a limited therapeutic window, i.e. an insufficient formation of antigen-antibody complexes once toxins are bound to their targets and/or distributed beyond the reach of antivenom, should be explored.
The tremendous outbreak of Ebola virus disease occurring in West Africa since the end of 2013 surprises by its remoteness from previous epidemics and dramatic extent. This review aims to describe the 27 manifestations of Ebola virus that arose after its discovery in 1976. It provides an update on research on the ecology of Ebola viruses, modes of contamination and human transmission of the disease that are mainly linked to close contact with an infected animal or a patient suffering from the disease. The recommendations to contain the epidemic and challenges to achieve it are reminded.
Snakebite envenoming is a major public health problem among rural communities of the Nigerian savanna. The saw-scaled or carpet viper (Echis ocellatus) and, to a lesser extent, the African cobras (Naja spp.) and puff adders (Bitis arietans) have proved to be the most important cause of mortality and morbidity. The main clinical features of E. ocellatus envenoming are systemic hemorrhage, incoagulable blood, shock, local swelling, bleeding and, occasionally, necrosis. Bites may be complicated by amputation, blindness, disability, disfigurement, mutilation, tissue destruction and psychological consequences. Antivenom remains the hallmark and mainstay of envenoming management while studies in Nigeria confirm its protection of over 80% against mortality from carpet-viper bites. However, the availability, distribution and utilization of antivenom remain challenging although two new antivenoms (monospecific EchiTab G and trispecific EchiTab ICP-Plus) derived from Nigerian snake venoms have proven very effective and safe in clinical trials. A hub-and-spoke strategy is suggested for broadening antivenom access to endemic rural areas together with instituting quality assurance, standardization and manpower training. With the advent of antivenomics, national health authorities must be aided in selecting and purchasing antivenoms appropriate to their national needs while manufacturers should be helped in practical ways to improve the safety, efficacy and potential coverage against snake venoms and pricing of their products.
Apis mellifera stings are a problem for public health worldwide, particularly in Latin America due to the aggressiveness of its Africanized honeybees. Massive poisoning by A. mellifera venom (AmV) affects mainly the cardiovascular system, and several works have described its actions on heart muscle. Nevertheless, no work on the pharmacological action mechanisms of the AmV in isolated aorta has been reported. Thus, the present work aimed to investigate the actions of AmV and its main fractions, phospholipase A2 (PLA2) and melittin, on isolated aorta rings and a probable action mechanism.
AmV and the complex PLA2 + melittin (0.1-50 mug/mL) caused contraction in endothelium-containing aorta rings, but neither isolated PLA2 nor melittin were able to reproduce the effect. Endothelium removal did not change the maximum vasoconstrictor effect elicited by AmV. Ca2+-free medium, as well as treatment with phentolamine (5 muM), verapamil (10 muM), losartan (100 muM), and U-73122 (10 muM, a phospholipase C inhibitor), eliminated the AmV-induced contractile effects.
In conclusion, AmV caused contractile effect in aorta rings probably through the involvement of voltage-operated calcium channels, AT1 and alpha-adrenergic receptors via the downstream activation of phospholipase C. The protein complex, PLA2 + melittin, was also able to induce vasoconstriction, whereas the isolated proteins were not.
We report three cases of stings by Africanized bees in cattle in the state of Rio de Janeiro, Brazil. Erythema, subcutaneous edema, necrosis accompanied by skin detachment, and subsequent skin regeneration were observed, especially on the head and dewlap. Histopathological examinations performed 45 days later revealed complete skin reepithelialization with moderate dermal fibrosis. The clinical picture and differential diagnosis are discussed in the present manuscript, with a focus on photosensitization, which causes cutaneous lesions on the head (sequela) with cicatricial curving of the ears and can be very similar to what is observed in cattle attacked by swarms of bees. The distinction between photosensitization and bee sting lesions can be made with a focus on history and clinical and pathological aspects.
Hepatitis B virus (HBV) infects from 6 to 14% of HIV-infected individuals. Concurrent HIV/HBV infection occurs due to the overlapping routes of transmission, particularly sexual and parenteral. HIV-infected patients that have acute hepatitis B have six times greater risk of developing chronic hepatitis B, with higher viral replication, rapid progression to end-stage liver disease and shorter survival. The coinfection is also associated with poor response to hepatitis B treatment with interferon-alpha and increased liver toxicity to the antiretroviral therapy. Herein, we describe the case of a 35-year-old man who engages in sex with men and presented with newly diagnosed HIV-1, serological markers for acute hepatitis B and progression to chronic hepatitis B infection (HBsAg+ > 6 months, high alanine aminotransferase levels and moderate hepatitis as indicated by liver biopsy). Lacking indication of antiretroviral treatment (CD4 768 cells/mm3), he was treated with pegylated-interferon alpha2b (1.5 mg/kg/week) by subcutaneous injection for 48 weeks. Twelve weeks after treatment, the patient presented HBeAg seroconversion to anti-HBe. At the end of 48 weeks, he presented HBsAg seroconversion to anti-HBs. One year after treatment, the patient maintained sustained virological response (undetectable HBV-DNA). The initiation of antiretroviral therapy with nucleosides and nucleotides is recommended earlier for coinfected individuals. However, this report emphasizes that pegylated interferon remains an important therapeutic strategy to be considered for selected patients, in whom the initiation of HAART may be delayed.
The state of Para encompasses 26% of Brazilian Amazon where an enormous diversity of arboviruses has been found. This study aimed to assess the prevalence and distribution of hemagglutination-inhibition antibodies against antigens of six Flavivirus (yellow fever virus, Ilheus virus, Saint Louis encephalitis virus, Cacipacore virus, Bussuquara virus and Rocio virus) in water buffaloes in Para state, Brazil. The prevalence of antibodies in these farm animals is important to determine the circulating arboviruses.
All investigated arboviruses were detected in the species studied and our results indicate that water buffaloes are susceptible to Flavivirus infection. Furthermore, there is solid evidence of active circulation of these viruses in the Brazilian Amazon.
Water buffaloes showed higher prevalence of heterotypic antibody reactions and we hypothesized that they can serve as sentinels to detect the movement of such arboviruses in the Brazilian Amazon.
Snakebite envenoming is a serious public health problem in Central America, where approximately 5,500 cases occur every year. Panama has the highest incidence and El Salvador the lowest. The majority, and most severe, cases are inflicted by the pit viper Bothrops asper (family Viperidae), locally known as 'terciopelo', 'barba amarilla' or 'equis'. About 1% of the bites are caused by coral snakes of the genus Micrurus (family Elapidae). Despite significant and successful efforts in Central America regarding snakebite envenomings in the areas of research, antivenom manufacture and quality control, training of health professionals in the diagnosis and clinical management of bites, and prevention of snakebites, much remains to be done in order to further reduce the impact of this medical condition. This essay presents seven challenges for improving the confrontation of snakebite envenoming in Central America. Overcoming these challenges demands a coordinated partnership of highly diverse stakeholders though inter-sectorial and inter-programmatic interventions.
Asian slow lorises (Nycticebus spp.) are one of few known venomous mammals, yet until now only one published case report has documented the impact of their venomous bite on humans. We describe the reaction of a patient to the bite of a subadult Nycticebus kayan, which occurred in the Mulu District of Sarawak in 2012.
Within minutes of the bite, the patient experienced paraesthesia in the right side of the jaw, ear and right foot. By 40 minutes, swelling of the face was pronounced. The patient was admitted to Mulu National Park Health Clinic/Klinik Kesihatan Taman Mulu Tarikh, at which time he was experiencing: swollen mouth, chest pain, mild abdominal pain, nausea, numbness of the lips and mouth, shortness of breath, weakness, agitation and the sensation of pressure in the ears due to swelling. The blood pressure was 110/76, the heart ratio was 116 and oxygen saturation was 96%. The patient was treated intramuscularly with adrenaline (0.5 mL), followed by intravenous injection of hydrocortisone (400 mg) and then intravenous fluid therapy of normal saline (500 mg). By 8 h10 the next day, the patient’s condition had significantly improved with no nausea, and with blood pressure and pulse rate stable.
A handful of anecdotes further support the real danger that slow loris bites pose to humans. As the illegal pet trade is a major factor in the decline of these threatened species, we hope that by reporting on the danger of handling these animals it may help to reduce their desirability as a pet.
Among the tropical parasitic diseases, those caused by protozoans are considered a challenge to public health, being represented by leishmaniasis and Chagas disease. In view of the low effectiveness and toxicity of the current therapy, animal venoms such as amphibian secretions have been used as a promising source of new drug prototypes. The present work aimed to achieve bioguided fractionation of metabolites present in a cutaneous secretion of the caecilian Siphonops annulatus (Amphibia: Gymnophiona: Siphonopidae) with antileishmanial and antitrypanosomal activity.
Through liquid-liquid partition and chromatographic techniques, the secretion was fractionated using bioguided assays. The 50% inhibitory concentration (IC50) of the main fraction (SaFr1) was studied against Leishmania (L.) infantum promastigotes and intracellular amastigotes, trypomastigotes of Trypanosoma cruzi and mammalian cells; viability was detected by the colorimetric MTT assay. By using a spectrofluorimetric assay with the probe SYTOX® Green and transmission electron microscopy (TEM), we also investigated the potential damage caused by SaFr1 in the plasma membrane and mitochondria of Leishmania.
The bioguided assay enabled isolation of a highly purified fraction (SaFr1) with an IC50 of 0.065 μg/mL against promastigotes and 2.75 μg/mL against trypomastigotes. Due to its high toxicity to peritoneal macrophages, SaFr1 showed no selectivity towards the intracellular forms of Leishmania. Ultrastructural studies with Leishmania demonstrated severe mitochondrial damage and the formation of large cytoplasmic vacuoles, leading to the parasite's death within a few hours. Nevertheless, it caused no alteration in the plasma membrane permeability as detected by the fluorescent probe and TEM.
The present study demonstrated for the first time the antiparasitic activity of the skin secretion of the caecilian S. annulatus against Leishmania and T. cruzi, confirming that skin secretions of these amphibians, similarly to those of anurans and salamanders, are also potential tools for the development of new drug candidates against neglected diseases.
Despite the high importance of Helicobacter pylori, the origin and transmission of this bacterium has not been clearly determined. According to controversial theories and results of previous studies, animal source foods - especially milk - play an important role in the transmission of H. pylori to humans. The aim of the present study was to determine the distribution of vacA, cagA, iceA and oipA virulence factors in H. pylori strains isolated from milk and dairy products and study their antimicrobial resistance properties.
A total of 520 raw milk and 400 traditional dairy product samples were cultured and tested. Those that were H. pylori-positive were analyzed for the presence of vacA, cagA, iceA and oipA virulence factors. Antimicrobial susceptibility testing was performed by the disk diffusion method.
One hundred and three out of 520 milk samples (19.8%) and 77 out of 400 dairy products samples (19.2%) were contaminated with H. pylori. The most frequently contaminated samples were ovine milk (35%) and traditional cheese (30%). Total prevalence of vacA, cagA, iceA and oipA factors were 75%, 76.6%, 41.6% and 25%, respectively. H. pylori strains of milk and dairy products harbored high levels of resistance to ampicillin (84.4%), tetracycline (76.6%), erythromycin (70.5%) and metronidazole (70%).
High presence of antibiotic-resistant strains of H. pylori suggest that milk and dairy samples may be the sources of bacteria that can cause severe infection. Our findings should raise awareness about antibiotic resistance in H. pylori strains in Iran.
This study aimed to evaluate the occurrence of Leishmania spp. in dogs and cats from Botucatu, Sao Paulo state, and Campo Grande, Mato Grosso do Sul state, Brazil, by the association of three diagnostic tests: blood culture in liver infusion tryptose medium, immunofluorescent antibody test and polymerase chain reaction. Fifty blood samples of dogs and cats from the Center for Zoonosis Control in Campo Grande, an area endemic for canine visceral leishmaniasis, were collected randomly, as well as canine and feline blood samples from the Municipal Kennel and Animal Protection Association in Botucatu, currently considered a transmission-free, non-endemic area.
Of the 50 dog blood cultures from Botucatu, three (6%) were positive and of the 50 cats, two (4%) were positive. In Campo Grande, 29 dog blood cultures (58%) were positive and all (100%) cats negative by this test. Polymerase chain reaction detected Leishmania spp. in 100% of dog and cat samples from Botucatu but found all the cats from Campo Grande to be negative. On the other hand, 36 dogs from Campo Grande were positive (72%) by the same technique. Immunofluorescent antibody test in Botucatu found 100% of dogs and cats non-reactive, while in Campo Grande, it detected positivity in 32 dogs (64%) and 15 cats (30%).
The results show the importance of not only continuous epidemiological surveillance in areas not endemic for leishmaniasis, but also research for accurate diagnosis of this zoonosis.
The present work aimed to evaluate the antimycobacterial activity and cytotoxicity of Microcystis aeruginosa toxins, the MC-LR variant and purified extract of [D-Leu(1)] microcystin-LR.
The antimicrobial activity of M. aeruginosa extract and microcystin was evaluated by resazurin microtiter assay against Mycobacterium tuberculosis, M. terrae, M. chelonae and M. kansasii. The cytotoxicity assay was performed by trypan blue exclusion against the HTC cell line.
Antimicrobial activity was observed in the hexanic extract of M. aeruginosa (RST 9501 strain) against M. tuberculosis, including sensitive and resistant strains with minimal inhibitory concentrations (MIC) between 1.93 μM and 0.06 μM. The high activity of M. aeruginosa hexanic extract could be attributed to the major presence of the toxins MC-LR and [D-Leu(1)] MC-LR that showed activity at MIC between 53 and 0.42 μM against tested mycobacterial strains. Even at the highest concentration tested, no toxicity of M. aeruginosa extracts was identified against HTC cells.
These preliminary results suggest that [D-Leu(1)] MC-LR is a promising candidate for the development of a new antimycobacterial agent.
Snakebites are considered a neglected tropical disease that affects thousands of people worldwide. Although antivenom is the only treatment available, it is associated with several side effects. As an alternative, plants have been extensively studied in order to obtain an alternative treatment. In folk medicine, Azima tetracantha Lam. is usually used to treat snakebites. The present study aims to provide a scientific explanation for the use of this plant against snakebite. The extracts of shade dried leaves of A. tetracantha were tested for in vitro inhibitory activity on toxic venom enzymes like phosphomonoesterase, phosphodiesterase, acetylcholinesterase, hyaluronidase etc. from Bungarus caeruleus and Vipera russelli venoms.
The ethylacetate extract rendered a significant inhibitory effect on the phosphomonoesterase, phosphodiesterase, phospholipase A2 andacetylcholinesterase enzymes.
The present study suggests that ethylacetate extract of A. tetracantha leaves possesses compounds that inhibit the activity of toxic enzymes from Bungarus caeruleus and Vipera russelli venom. Further pharmacological in vivo studies would provide evidence that this substance may be lead to a potential treatment against these venoms.
Millepora complanata is a plate-like fire coral common throughout the Caribbean. Contact with this species usually provokes burning pain, erythema and urticariform lesions. Our previous study suggested that the aqueous extract of M. complanata contains non-protein hemolysins that are soluble in water and ethanol. In general, the local damage induced by cnidarian venoms has been associated with hemolysins. The characterization of the effects of these components is important for the understanding of the defense mechanisms of fire corals. In addition, this information could lead to better care for victims of envenomation accidents.
An ethanolic extract from the lyophilized aqueous extract was prepared and its hemolytic activity was compared with the hemolysis induced by the denatured aqueous extract. Based on the finding that ethanol failed to induce nematocyst discharge, ethanolic extracts were prepared from artificially bleached and normal M. complanata fragments and their hemolytic activity was tested in order to obtain information about the source of the heat-stable hemolysins.
Rodent erythrocytes were more susceptible to the aqueous extract than chicken and human erythrocytes. Hemolytic activity started at ten minutes of incubation and was relatively stable within the range of 28-50°C. When the aqueous extract was preincubated at temperatures over 60°C, hemolytic activity was significantly reduced. The denatured extract induced a slow hemolytic activity (HU50 = 1,050.00 ± 45.85 μg/mL), detectable four hours after incubation, which was similar to that induced by the ethanolic extract prepared from the aqueous extract (HU50 = 1,167.00 ± 54.95 μg/mL). No significant differences were observed between hemolysis induced by ethanolic extracts from bleached and normal fragments, although both activities were more potent than hemolysis induced by the denatured extract.
The results showed that the aqueous extract of M. complanata possesses one or more powerful heat-labile hemolytic proteins that are slightly more resistant to temperature than jellyfish venoms. This extract also contains slow thermostable hemolysins highly soluble in ethanol that are probably derived from the body tissues of the hydrozoan.
Venom hyaluronidase (Hyase) contributes to the diffusion of venom from the inoculation site. In this work, we purified and characterized Hyase from the venom of Vitalius dubius (Araneae, Theraphosidae), a large theraphosid found in southeastern Brazil. Venom obtained by electrical stimulation of adult male and female V. dubius was initially fractionated by gel filtration on a Superdex® 75 column. Active fractions were pooled and applied to a heparin-sepharose affinity column. The proteins were eluted with a linear NaCl gradient.
Active fractions were pooled and assessed for purity by SDS-PAGE and RP-HPLC. The physicochemical tests included optimum pH, heat stability, presence of isoforms, neutralization by flavonoids and assessment of commercial antivenoms. Hyase was purified and presented a specific activity of 148 turbidity-reducing units (TRU)/mg (venom: 36 TRU/mg; purification factor of ~4). Hyase displayed a molecular mass of 43 kDa by SDS-PAGE. Zymography in hyaluronic-acid-containing gels indicated an absence of enzyme isoforms. The optimum pH was 4-5, with highest activity at 37°C. Hyase was stable up to 60°C; but its activity was lost at higher temperatures and maintained after several freeze-thaw cycles. The NaCl concentration (up to 1 M) did not influence activity. Hyase had greater action towards hyaluronic acid compared to chondroitin sulfate, and was completely neutralized by polyvalent antiarachnid sera, but not by caterpillar, scorpion or snakes antivenoms.
The neutralization by arachnid but not scorpion antivenom indicates that this enzyme shares antigenic epitopes with similar enzymes in other spider venoms. The biochemical properties of this Hyase are comparable to others described.
Septic arthritis is an inflammatory disease of the joints that is started by an infection whose most common agent is Staphylococcus aureus. In this review we discuss some of the most arthritogenic bacterial factors and the contribution of innate and specific immune mechanisms to joint destruction. Special emphasis is given to the induction of experimental arthritis by S. aureus in mice. The improvement of therapy by association of antibiotics with down-modulation of immunity is also included.
It is estimated that venoms of marine cone snails (genus Conus) contain more than 100,000 different small peptides with a wide range of pharmacological and biological actions. Some of these peptides were developed into potential therapeutic agents and as molecular tools to understand biological functions of nervous and cardiovascular systems. In this study we examined the cytotoxic and anticancer properties of the marine vermivorous cone snail Conus vexillum (collected from Hurgada and Sharm El-Shaikh, Red Sea, Egypt) and suggest the possible mechanisms involved. The in vitro cytotoxic effects of Conus venom were assessed against Ehrlich's ascites carcinoma (EAC) cells.
Conus venom treatment resulted in concentration-dependent cytotoxicity as indicated by a lactate dehydrogenase leakage assay. Apoptotic effects were measured in vivo by measuring levels of reactive oxygen species and oxidative defense agents in albino mice injected with EAC cells. Conus venom (1.25 mg/kg) induced a significant increase (p < 0.05) in several oxidative stress biomarkers (lipid peroxidation, protein carbonyl content and reactive nitrogen intermediates) of EAC cells after 3, 6, 9 and 12 hours of venom injection. Conus venom significantly reduced (p < 0.05) the activities of oxidative defense enzymes (catalase and superoxide dismutase) as well as the total antioxidant capacity of EAC cells, as evidenced by lowered levels of reduced glutathione.
These results demonstrate the cytotoxic potential of C. vexillum venom by inducing oxidative stress mediated mechanisms in tumor cells and suggest that the venom contains novel molecules with potential anticancer activity.
Stingrays are a group of rays -- cartilaginous fish related to sharks -- that have whiplike tails with barbed, usually venomous spines and are found around the world, especially the marine species. Despite recent reports of accidents involving these fish, they are not aggressive, reacting only when stepped on or improperly handled. Injuries by stingrays are seldom mentioned by historians, although they have always been present in riverine communities of inland waters and in South American coasts. Indeed, envenomations by stingrays are quite common in freshwater and marine fishing communities. Although having high morbidity, such injuries are neglected because they have low lethality and usually occur in remote areas, which favor the use of folk remedies. In the present review article, historical aspects of injuries caused by stingrays in Brazil and their distribution on the coast of Sao Paulo state and riverine communities of the North, Midwest and Southeast regions were studied. In addition, other aspects were analyzed such as clinical features, therapeutic methods, preventive measures and trends in occurrence of these accidents in the country, particularly in areas in which freshwater stingrays had not been previously registered, being introduced after breaching of natural barriers.
Only a few Helicobacter pylori-infected individuals develop severe gastric diseases and virulence factors of H. pylori appear to be involved in such clinical outcomes. Duodenal ulcer promoting gene A (dupA) is a novel virulence factor of Helicobacter pylori that is associated with duodenal ulcer development and reduced risk for gastric carcinoma in some populations. The aims of the present study were to determine the presence of dupA gene and evaluate the association among dupA and other virulence factors including cagA and vacA in Brazilian patients. Gastric biopsies were obtained from 205 dyspeptic patients (100 children and 105 adults). DNA was extracted and analyzed for the presence of H. pylori and its virulence factors using the polymerase chain reaction method.
Patients with gastritis tested positive for H. pylori more frequently. The dupA gene was detected in 41.5% of them (85/205); cagA gene was found in 98 isolates (47.8%) and vacA genotype s1/m1 in 50.2%, s1/m2 in 8.3%, s2/m2 in 36.6%, s2/m1 in 0.5% and s1/s2/m1/m2 in 4.4%. We also verified a significant association between cagA and dupA genes [p = 0.0003, relative risk (RR) 1.73 and confidence interval [CI] = 1.3-2.3]. The genotypes s1/m1 were also associated with dupA gene (p = 0.0001, RR: 1.72 and CI: 1.3-2.2). The same associations were found when analyzing pediatric and adult groups of patients individually.
Ours results suggest that dupA is highly frequent in Brazilian patients and is associated with cagA gene and vacA s1/m1 genotype, and it may be considered an important virulence factor in the development of gastric diseases in adults or children.
Previous works had shown that scorpion venom induced neurotransmitter elevation and an inflammatory response associated with various anatomo-pathological modifications. The most dangerous scorpions species in Algeria responsible for these effects are Androctonus australis hector (Aah) and Androctonus amoreuxi (Aam).
Comparison of the physiopathological effects induced by the two venoms showed differences in the kinetic of cytokine release and in lung injury.The lung edema was only observed in response to Aah venom and it was correlated with cell infiltration. In order to better understand the involved mechanism in inflammatory response, we used two antagonists, atropine (non-selective muscarinic antagonist) and propranolol (β adrenergic antagonist), which lead to a decrease of cell infiltration but has no effect on edema forming.
These results suggest another pathway in the development of lung injury following envenomation with Aam or Aah venom.
Numerous spider toxins are of interest as tools for neurophysiological research or as lead molecules for the development of pharmaceuticals and insecticides. Direct detection and identification of the interacting proteins of a spider toxin are helpful for its action-mechanism analysis and practical application. The present study employed a combinative strategy for the analysis of interacting proteins of huwentoxin-IV (HWTX-IV), a peptidic neurotoxin from the venom of the spider Selenocosmia huwena.
HWTX-IV was first lightly labeled with biotin under the optimized mild experimental conditions and the toxin labeled with a single biotin group (monobiotinylated HWTX-IV) was demonstrated by electrophysiological experiments to retain its original bioactivity and was used in combination with far-western blotting to detect its interacting proteins. Comparative experiments indicated that some membrane proteins from rat neuromuscular junction preparations bind to monobiotinylated HWTX-IV after being transferred onto a PVDF membrane from the SDS-gel. With capillary high performance liquid chromatography-tandem mass spectrometry, several membrane proteins with which HWTX-IV potentially interacted were identified from the preparations and then bioinformatically analyzed.
This work has provided not only a new insight into the action mechanism of HWTX-IV but also a reference technology for the relevant researches.
Toxic cyanobacterial blooms are recurrent in Patos Lagoon, in southern Brazil. Among cyanotoxins, [D-Leu(1)] microcystin-LR is the predominant variant whose natural cycle involves water and sediment compartments. This study aimed to identify and isolate from sediment a bacterial strain capable of growing on [D-Leu(1)] microcystin-LR. Sediment and water samples were collected at two distinct aquatic spots: close to the Oceanographic Museum (P1), in Rio Grande City, and on São Lourenço Beach (P2), in São Lourenço do Sul City, southern Brazil.
[D-Leu(1)] microcystin-LR was isolated and purified from batch cultures of Microcystis aeruginosa strain RST9501. Samples of water and sediment from Rio Grande and São Lourenço do Sul were collected. Bacteria from the samples were allowed to grow in flasks containing solely [D-Leu(1)] microcystin-LR. This strain named DMSX was isolated on agar MSM with 8 g L(-1) glucose and further purified on a cyanotoxin basis growth. Microcystin concentration was obtained by using the ELISA immunoassay for microcystins whereas bacterial count was performed by epifluorescence microscopy. The genus Pseudomonas was identified by DNA techniques.
Although several bacterial strains were isolated from the samples, only one, DMXS, was capable of growing on [D-Leu(1)] microcystin-LR. The phylogenetic analysis of the 16S rRNA gene from DMXS strain classified the organism as Pseudomonas aeruginosa. DMXS strain incubated with [D-Leu(1)] microcystin-LR lowered the amount of toxin from 1 μg.L(-1) to < 0.05 μg.L(-1). Besides, an increase in the bacterial count-from 71 × 10(5) bacteria.mL(-1) to 117 × 10(5) bacteria.mL(-1)-was observed along the incubation.
The use of bacteria isolated from sediment for technological applications to remove toxic compounds is viable. Studies have shown that sediment plays an important role as a source of bacteria capable of degrading cyanobacterial toxins. This is the first Brazilian report on a bacterium-of the genus Pseudomonas-that can degrade [D-Leu(1)] microcystin-LR, the most frequent microcystin variant in Brazilian freshwaters.
Only seven types of mammals are known to be venomous, including slow lorises (Nycticebus spp.). Despite the evolutionary significance of this unique adaptation amongst Nycticebus, the structure and function of slow loris venom is only just beginning to be understood. Here we review what is known about the chemical structure of slow loris venom. Research on a handful of captive samples from three of eight slow loris species reveals that the protein within slow loris venom resembles the disulphide-bridged heterodimeric structure of Fel-d1, more commonly known as cat allergen. In a comparison of N. pygmaeus and N. coucang, 212 and 68 compounds were found, respectively. Venom is activated by combining the oil from the brachial arm gland with saliva, and can cause death in small mammals and anaphylactic shock and death in humans. We examine four hypotheses for the function of slow loris venom. The least evidence is found for the hypothesis that loris venom evolved to kill prey. Although the venom's primary function in nature seems to be as a defense against parasites and conspecifics, it may also serve to thwart olfactory-orientated predators. Combined with numerous other serpentine features of slow lorises, including extra vertebra in the spine leading to snake-like movement, serpentine aggressive vocalisations, a long dark dorsal stripe and the venom itself, we propose that venom may have evolved to mimic cobras (Naja sp.). During the Miocene when both slow lorises and cobras migrated throughout Southeast Asia, the evolution of venom may have been an adaptive strategy against predators used by slow lorises as a form of Mullerian mimicry with spectacled cobras.
Scorpion envenoming is a public health problem in Brazil, where Tityus serrulatus and T. bahiensis are considered the most dangerous scorpions. They are well adapted to urbanized environments, and there is an increasing probability of human exposure to these venoms, including during pregnancy. Not much is known about the effects of prenatal exposure to the venom, and no information is available to aid in the rational treatment of victims stung during pregnancy. Thus, this study aimed to investigate whether venom from the scorpion T. bahiensis administered once to pregnant female rats at a dose that causes a moderate envenomation may lead to deleterious effects on the reproductive performance of the dams and on the development of their offspring. This is the first work demonstrating that T. bahiensis venom, when administered experimentally to rats, alters maternal reproductive performance and the morphological development of fetuses. The venom was given to dams on the 5th (GD5) or on the 10th (GD10) gestational day. After laparotomy, on GD21, fetuses and placentas were counted, weighed and externally analyzed. The corpora lutea were counted. The sex and vitality of fetuses were evaluated, and each litter was then randomly divided for visceral or skeletal analyses. Data were analyzed by ANOVA followed by the Tukey-Kramer test and Fisher's exact test. The significance level for all tests was set at p < 0.05.
GD5 group presented an increased number of pre-implantation losses. Weight gains in fetuses and placentas were observed in the GD5 and GD10 groups. Weights of the heart and lungs were elevated in GD5 and GD10 and liver weight in GD10.
Moderate envenomation by T. bahiensis scorpion venom alters maternal reproductive performance and fetal development. However, these are preliminary results whose causes should be investigated more carefully in future studies.
Polycystic ovarian syndrome (PCOS) is a low-grade inflammatory disease characterized by hyperandrogenemia, hirsutism, chronic anovulation and vascular disorder. Interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) are triggered by inflammatory stimuli and lead to angiogenesis and pathogenesis of the ovary. Honeybee venom (HBV) contains an array of biologically active components possessing various pharmaceutical properties. This study was designed to assess the possibility of HBV application as an anti-inflammatory therapeutic agent to suppress levels of the main inflammatory mediators IL-6, COX-2 and VEGF.To induce PCOS, 1 mg of estradiol valerate (EV) per 100 g of body weight was subcutaneously (SC) injected into eight-week-old rats. After 60 days, 0.5 mg/kg of HBV was administered SC for 14 consecutive days, and the results of PCOS treatment were investigated. Rats were then anesthetized with chloroform, and the ovaries were surgically removed. Serum IL-6 was detected by the ELISA kit. Immunoexpression of COX-2 and VEGF were examined in three groups: EV-induced PCOS, HBV-treated PCOS and control animals.
Thickness of theca layer, number and diameter of cysts and levels of IL-6 significantly decreased in HBV group relative to PCOS group. The immunohistochemical analysis showed an increase in COX-2 and VEGF expression in PCOS group whereas HBV-treated rats presented weak and irregular immunostaining.
Our results suggest that the beneficial effect of HBV may be mediated through its inhibitory effect on serum IL-6 level and ovarian COX-2 and VEGF expression.
The present study aims to investigate the clinical-epidemiological characteristics of bee sting cases recorded between 2007 and 2012 in the city of Campina Grande, Paraiba state, Brazil. Data were collected from the database of the Injury Notification Information System of the Brazilian Ministry of Health.
A total of 459 bee sting cases were retrospectively analyzed. The average annual incidence was 19 cases per 100,000 inhabitants. Cases were distributed in all months of the year, with higher prevalence in September and February. Most victims were men aged between 20 and 29 years. The highest incidence of cases was recorded in urban areas. Victims were stung mainly on the head and torso and received medical assistance predominantly 1 to 3 hours after being stung. The most frequent clinical manifestations were pain, edema and itching. Most cases were classified as mild, and three deaths were reported.
The high incidence of envenomations provoked by bees in Campina Grande suggests that it may be an important risk area for accidents. Since several medical records lacked information, clinical-epidemiological profile of bee sting cases in the studied region could not be accurately determined.The current study provides relevant data for the development of strategies to promote control and prevention of bee stings in this area. Further training for health professionals seems to be necessary to improve their skills in recording clinical-epidemiological information as well as in treating bee sting victims.
Biomolecules from Cerastes cerastes venom have been purified and characterized. Two phospholipases isolated from Cerastes cerastes venom share 51% of homology. CC2-PLA2 exhibits antiplatelet activity that blocks coagulation. CCSV-MPase, a non-hemorrhagic Zn2+-metalloproteinase, significantly reduced the plasmatic fibrinogen level and hydrolyzes only its Bβ chain. Serine proteinases such as RP34, afaâcytin and CC3-SPase hydrolyze the fibrinogen and are respectively α, αβ and αβ fibrinogenases. In deficient human plasma, afaâcytin replaces the missing factors VIII and IX, and activates purified human factor X into factor Xa. It releases serotonin from platelets and directly aggregates human (but not rabbit) blood platelets. RP34 proteinase also had no effect on both human and rabbit blood platelet aggregation. CC3-SPase revealed a pro-coagulant activity. However, the insolubility of the obtained clot indicates that CC3-SPase does not activate factor XIII. In addition, CC3-SPase clotting activity was carried out with human plasmas from volunteer patients deficient in clotting factors. Results showed that CC3-SPase shortens clotting time of plasma deficient in factors II and VII but with weaker clotting than normal plasma. The clotting time of plasma deficient in factor II is similar to that obtained with normal plasma; suggesting that CC3-SPase is able to replace both factors IIa and VII in the coagulation cascade and thus could be involved in the blood clotting process via an extrinsic pathway. These results imply that CC3-SPase and afaâcytin could repair hemostatic abnormalities and may replace some factors missing in pathological deficiency. Afaâcytin also exhibits α fibrinase property similar to a plasmin-like proteinase. Despite its thrombin-like characteristics, afaâcytin is not inhibited by plasmatic thrombin inhibitors. The procoagulant properties of afaâcytin might have potential clinical applications.
The study of the distribution and ecology of sandfly species is essential for epidemiological surveillance and estimation of the transmission risk of Leishmania spp. infection.
In the present study, sandflies were captured in native fragmented forest areas in Rubião Júnior district, Botucatu municipality, São Paulo state, Brazil, between September 2001 and January 2005. A minimum of two automatic light traps were installed per night from 6 pm to 8 am, in different months, resulting in approximately 900 collecting hours. During this period, 216 sandfly specimens of sixteen species were captured. Pintomyia monticola and Brumptomyia guimaraesi were the most abundant with 56 specimens (25.93%) captured per species, followed by Pintomyia fischeri 28 (12.96%) and Psathyromyia pascalei 18 (8.33%). Other captured species were Lutzomyia amarali, Sciopemyia sordellii, Psathyromyia aragaoi, Nyssomyia whitmani, Migonemyia migonei, Pintomyia bianchigalatiae, Pintomyia misionensis, Brumptomyia carvalheiroi, Brumptomyia cardosoi, Brumptomyia cunhai, Brumptomyia nitzulescui, Brumptomyia brumpti and Brumptomyia spp. represented by 58 (26.85%) specimens.
Although less frequently found, the presence of Pintomyia fischeri, Nyssomyia whitmani and Migonemyia migonei, known vectors of Leishmania braziliensis, indicates risk of American cutaneous leishmaniasis occurrence. Moreover, the absence of Lutzomyia longipalpis-the main vector of Leishmania infantum chagasi, which is the agent of American visceral leishmaniasis-suggests that there is no risk of introduction and establishment of this disease in the studied area.
Leptospirosis, toxoplasmosis and brucellosis are diseases with worldwide distribution. Among stray dogs, these zoonoses are facilitated by direct contact with other animal species, by the habit of scavenging garbage and hunting in search of food, drinking standing water, smelling other animals' urine, licking female genitalia and the sexual act itself.
The objective of this study was to detect antibodies anti-Toxoplasma gondii, anti-Leptospira spp., anti-Brucella canis and anti-Brucella abortus in stray dogs housed in shelters at Umuarama city, Parana, Brazil. In order to detect toxoplasmosis, indirect immunofluorescence assay (IFA) was performed, agglutination microscopic (MAT) test for leptospirosis and agar gel immunodiffusion (AGID) and buffered acidified antigen (BAA) tests for brucellosis.
Of the 175 serum samples analyzed, 70.85% were considered positive for toxoplasmosis by IFA, 20% by MAT for leptospirosis and 2.85% by AGID for Brucella canis.
The serological results of this study showed that stray dogs housed at the private shelter are potential carriers of these three different zoonoses and contribute to the spread and maintenance of these etiologic agents in the urban area of Umuarama (PR), Brazil.
Crotalus durissus are found from Mexico to northern Argentina in a highly disjunct distribution. According to some studies, this species is prone to occupy areas disturbed by human activities and floods comprise a plausible method of dispersal as inferred for some North American rattlesnakes. Based on the literature, it seems plausible that Crotalus durissus expanded their natural distribution in Brazil due to floods, but only in a few municipalities in Rio de Janeiro State. Data entries of Butantan Institute, in Sao Paulo, Brazil, from 1998 to 2012 show a declining tendency of snakes brought by donors. In addition, research shows no evidence of Crotalus durissus being an expanding species in the Brazilian territory.
Being distant from Brazil's great natural diversity, from its long tradition in the study of snakebites and from the fact that it is one of the few countries which has a national information system for monitoring incidents involving venomous animals, non-Brazilian researchers face risks when estimating the incidence of these accidents in the country. The present work offers a critical review of the main estimates undertaken since 1954. It is interesting to note contradictions between textual and graphic information within the same article, variations over time in the work of a same researcher and differences among distinct authors, and that all these issues remain unmentioned or undiscussed. Comparison among such estimates and the data available at the Brazilian Information System on Diseases of Compulsory Declaration (Sistema de Informacao de Agravos de Notificacao -- SINAN) creates an opportunity to identify the degree of imprecision present in those articles, and draws attention to the need for the production of studies at both the regional and national levels, based on concrete data collected at national, state and municipal levels, which has been available on the internet since 2001.
With the aim of studying Leptospira spp. infection in sheep herds, blood samples and respective kidney and liver fragments were collected from 100 animals from twenty different properties during slaughter at a meat company in the Sorocaba region, São Paulo state, southeast Brazil. The microscopic agglutination test (MAT) was performed with 29 strains of Leptospira spp. To identify the agent in the liver and kidney, 100 samples of each tissue were submitted to culture in Fletcher medium and analyzed by the polymerase chain reaction (PCR) for Leptospira spp.
MAT detected 23 samples serologically positive for one or more Leptospira spp. serovars and significantly more for Autumnalis. Eight (4%) samples were positive in culture (four kidneys and four livers), corresponding to five animals with positive serology (one animal simultaneously positive for both kidney and liver) and two negatives. PCR detected Leptospira spp. in 14 samples (seven kidneys and seven livers) corresponding to 12 positive animals (two animals simultaneously positive for kidney and liver), of which ten were serologically positive and two negative.
PCR was faster, more practical and more sensitive than culture for detecting leptospires. The results reinforce the importance of sheep in the epidemiological context of leptospirosis.
The aim of the present study was to estimate hepatitis B virus seroprevalence among first-time blood donors in the city of Campo Grande, Mato Grosso do Sul State, in the central-western region of Brazil.
A retrospective analysis of first-time voluntary blood donor records, from January 2010 to December 2010, was conducted at the Hematology Center of Mato Grosso do Sul. The prevalence of the HBsAg and anti-HBc serological markers and their respective 95% confidence intervals were calculated. Chi-square analysis was performed between the seroprevalence previously found in 2001 and the one determined by the current study. Results were considered statistically significant if p < 0.05. Among 8,840 subjects, 269 (3.04%, 95% CI: 2.7-3.4) were positive for HBV markers. The prevalence rate of HBsAg was 0.19% (95% CI: 0.1-0.3) and anti-HBc alone was 2.85% (95% CI: 2.5-3.2).
There was no statistically significant difference regarding gender. However, an important association was observed between HBV infection and older age (p < 0.01). The seroprevalence of HBV infection in first-time blood donors diminished from 2001 to 2010 (p < 0.01). Such decrease suggests an improvement in the recruitment of safe donors, the positive impact of vaccination programs and the decreasing of HBV infection prevalence in the general population.
The reintroduction of sylvatic yellow fever in the state of São Paulo after about six decades was confirmed in the Northwestern region in 2000, where in 2008 there also occurred an important epizootic. The purpose of this study was to investigate the feeding habits of culicids potentially involved in the sylvatic transmission of the virus in this region.
Specimens were collected in 24 forested localities at ground level with hand nets and mouth aspirators. Collections were made quarterly between October 2006 and July 2008 during daylight hours. Blood-meal identification was carried out in mosquitoes of the tribes Aedini, Mansoniini and Sabethini. The biotin/avidin sandwich ELISA was employed to determine six source types: bird, bovine, equine, rat, human and monkey.
A total of 24,879 females of the three tribes were obtained, 245 (0.98%) of which were engorged. The presence of three different blood sources per engorged female was the predominant situation, and included 35.10% of the total of samples processed. Samples with two or four different sources were represented by 25.31% and 25.71%, of the specimens, respectively, while just 9.39% had only one type and 1.22%, five different sources. Aedes scapularis, Ae. serratus (Group), Psorophora albigenu and Ps. ferox were the most abundant species and accounted for about 95% of the engorged specimens. Of the principal vector species, Haemagogus janthinomys/capricornii was found with bird, bovine and primate blood. These sources were predominant and alternated top ranking as the most frequent source according to the mosquito species and collection site. In general, primate blood was the most prevalent source.
The human population of the region visits this ecotone frequently, which indicates the need for the periodical assessment of vaccination coverage against yellow fever. The frequency of non-human primate blood source in mosquito species that show minor vector importance in yellow fever virus transmission deserves attention. The eclectic feeding habits and some aspects of the interactions between potential vectors and reservoirs of yellow fever may be associated with the habitat fragmentation characteristic of the region. We recommend that further studies on the capacity and vector competence be performed on secondary vectors in extra-Amazonian region.
Brazil holds annual nationwide public campaigns to vaccinate dogs and cats against rabies. The presence of rabies antibodies in these animals, which are among the main transmitters of rabies to humans, is a good indicator that they are immunized and protected.
In the present study we analyzed 834 serum samples from dogs and cats from the Southeast of Brazil (Presidente Prudente and Dracena cities), 12 months after the 2009 vaccination campaign. We used the technique known as rapid fluorescent focus inhibition test (RFFIT) and considered reactant those sera with values higher 0.5 IU/mL.
Results and discussion
Reactant sample results in Presidente Prudente were 153 (51.0%) for dogs and 59 (32.6%) for cats, and in Dracena 110 (52.1%) for dogs and 71 (50.0%) for cats. We discussed vaccine coverage of animals involved in this experiment, and observed low titers < 0.5 IU/mL, especially in cats from Presidente Prudente.
According to the results presented in our experiment, we suggest that titers below 0.5 IU/mL are worrisome and that, for multiple reasons, animals should be immunized against rabies in the period between public vaccination campaigns. Hence, the desired vaccine coverage was not accomplished, especially among cats from Presidente Prudente.
The venom of the Cuban scorpion Rhopalurus junceus is poorly study from the point of view of their components at molecular level and the functions associated. The purpose of this article was to conduct a proteomic analysis of venom components from scorpions collected in different geographical areas of the country.
Venom from the blue scorpion, as it is called, was collected separately from specimens of five distinct Cuban towns (Moa, La Poa, Limonar, El Chote and Farallones) of the Nipe-Sagua-Baracoa mountain massif and fractionated by high performance liquid chromatography (HPLC); the molecular masses of each fraction were ascertained by mass spectrometry analysis. At least 153 different molecular mass components were identified among the five samples analyzed. Molecular masses varied from 466 to 19755 Da. Scorpion HPLC profiles differed among these different geographical locations and the predominant molecular masses of their components. The most evident differences are in the relative concentration of the venom components. The most abundant components presented molecular weights around 4 kDa, known to be K+-channel specific peptides, and 7 kDa, known to be Na+-channel specific peptides, but with small molecular weight differences. Approximately 30 peptides found in venom samples from the different geographical areas are identical, supporting the idea that they all probably belong to the same species, with some interpopulational variations. Differences were also found in the presence of phospholipase, found in venoms from the Poa area (molecular weights on the order of 14 to 19 kDa). The only ubiquitous enzyme identified in the venoms from all five localities studied (hyaluronidase) presented the same 45 kD molecular mass, identified by gel electrophoresis analysis.
The venom of these scorpions from different geographical areas seem to be similar, and are rich in peptides that have of the same molecular masses of the peptides purified from other scorpions that affect ion-channel functions.
The venom of the family Viperidae, including the saw-scaled viper, is rich in serine proteinases and metalloproteinases, which affect the nervous system, complementary system, blood coagulation, platelet aggregation and blood pressure. One of the most prominent effects of the snake venom of Echis carinatus (Ec) is its coagulation activity, used for killing prey.
Subfractions F1A and F1B were isolated from Ec crude venom by a combination of gel chromatography (Sephadex G-75) and ion exchange chromatography on a DEAE-Sepharose (DE-52). These subfractions were then intravenously (IV) injected into NIH male mice. Blood samples were taken before and after the administration of these subfractions. Times for prothrombin, partial thromboplastin and fibrinogen were recorded.
Comparison of the prothrombin time before and after F1A and F1B administrations showed that time for blood coagulation after injection is shorter than that of normal blood coagulation and also reduced coagulation time after Ec crude venom injection. This difference in coagulation time shows the intense coagulation activity of these subfractions that significantly increase the coagulation cascade rate and Causes to quick blood coagulation. The LD50 of the Ec crude venom was also determined to be 11.1 μg/mouse. Different crude venom doses were prepared with physiological serum and injected into four mice. Comparison of the prothrombin times after injection of subfractions F1A and F1B showed that the rate of mouse blood coagulation increases considerably. Comparing the partial thromboplastin times after injecting these subfractions with this normal test time showed that the activity rate of intrinsic blood coagulation system rose sharply in mice. Finally, by comparing the fibrinogen time after subfraction injections and normal test time, we can infer intense activation of coagulation cascade and fibrin production.
Erucism is a skin reaction to envenomation from certain poisonous caterpillar bristles. In Brazil, most reports of erucism provoked by Lonomia caterpillars are from the southern region. Most manifestations of erucism are local and include burning pain, itching, local hyperthermia and, rarely, blisters (benign symptoms with spontaneous regression in a few hours). General symptoms such as nausea and vomiting, headache, fever, myalgia, abdominal pain and conjunctivitis may also occur. Uncommon symptoms include arthritis, coagulation disorders (manifested as bruising and bleeding), intracerebral hemorrhage and acute renal failure, which comprise serious complications. The present study reports the case of 60-year-old patient from Rio de Janeiro state, Brazil, who came into contact with a caterpillar and developed, a few days later, chronic renal disease.
Echinometra lucunter is a common American sea urchin responsible for the majority of the marine accidents in Brazil. Although not lethal, these accidents are reported to be extremely painful. Recently, our group described the presence of toxins in its spines that contribute to the pathological reactions. Additionally, we have observed that the E. lucunter spines can regenerate when broken. In the present work we evaluated the enzymatic activities of sea urchin spine extracts in order to identify an enzyme that could contribute not only to the toxicity, but also participate in the spine growth and regeneration.
The spine aqueous extract was tested for peptidase activity, with synthetic substrates, in the presence and absence of inhibitors and activators. For proper enzyme classification, the FRET-substrate cleavage pattern, pH-dependency activity and Western-blot analyses were performed. The spine extract was able to cleave Z-R-MCA and Abz-GIVRAK(Dnp)-OH following pre-incubation with DTT, and was inhibited by E-64. Furthermore, the double-peaked pH curve (5 and 7) and the cleavage site proportion (4:6, R[downwards arrow]A:A[downwards arrow]K) indicate the presence of both mono and dicarboxypeptidase activities. Moreover, in Western-blot analysis, the spine extract was positive for anti-cathepsin B antibody.
E. lucunter spines extracts presented a cysteine peptidase activity that was identified as cathepsin B/X that would participate in the remodeling and growth processes of the spine, as well as in the inflammatory response to the accident.
Journal of Venomous Animals and Toxins including Tropical Diseases Center for the Study of Venoms and Venomous Animals (CEVAP) Sao Paulo State University (UNESP), Fazenda Experimental Lageado, Caixa Postal 577, Rua Jose Barbosa de Barros, 1780, Botucatu, SP, 18610-307