Scielo RSS <![CDATA[Journal of Venomous Animals and Toxins including Tropical Diseases]]> vol. 22 num. lang. es <![CDATA[SciELO Logo]]> <![CDATA[The 6<sup>th</sup> international conference on envenomation by Snakebites and Scorpion Stings in Africa: a crucial step for the management of envenomation]]> Abstract During the 6th International Conference on Envenomation by Snakebites and Scorpion Stings in Africa held in Abidjan, from 1 to 5 June 2015, the measures for the management of envenomation were discussed and new recommendations were adopted by the participants. The high incidence and severity of this affliction were confirmed by several studies conducted in African countries. The poor availability of antivenom, particularly because of the cost, was also highlighted. Some experiences have been reported, mainly those regarding the financial support of antivenom in Burkina Faso (more than 90 %) and Togo (up to 60 %) or the mandatory reporting of cases in Cameroon. Key recommendations concerned: improvement of epidemiological information based on case collection; training of health workers in the management of envenomation; policy to promote the use of effective and safe antivenom; and antivenom funding by sharing its costs with stakeholders in order to improve antivenom accessibility for low-income patients. <![CDATA[Paths to the discovery of antivenom serotherapy in France]]> Abstract The current study presents a descriptive chronological survey of the articles published by Césaire Auguste Phisalix and Albert Calmette on snake poison, with the aim of shedding a light on the areas of research and reasoning followed by these scientists, leading up to their simultaneous discovery of antivenom serotherapy in 1894. The path taken by Phisalix is revealed in 15 articles that demonstrate the motivation of a naturalist and the way he confronted the puzzle of immunity against snake venom. In the case of Calmette, two articles preceded the discovery; microbiology was his theoretical base and the Pasteurian spirit of solving health problems his driving force. These two researchers followed distinct paths, mobilized by different motivations, but produced one single result. It is incontestable that the discovery of antivenom serotherapy was the work of two groups of researchers who deserve equal recognition, but who, in fact, did not receive it. Following the discovery both Calmette and Phisalix returned to their previous motivations. Calmette put the discovery into practice and began to produce antivenom serum in Lille. He came to be generally considered as the sole discoverer of antivenom serotherapy and was the recipient of a number of prestigious prizes. Phisalix, on the other hand, received little recognition and returned to his original interests, devoting himself to research on natural immunity. In Brazil, the discovery of antivenom serum therapy had a profound impact on the work of Vital Brazil Mineiro da Campanha, a researcher known worldwide for his scientific discoveries and for the evidence of the specificity of antivenom serums. <![CDATA[Melittin induces in vitro death of <em>Leishmania (Leishmania) infantum</em> by triggering the cellular innate immune response]]> Abstract Background Apis mellifera venom, which has already been recommended as an alternative anti-inflammatory treatment, may be also considered an important source of candidate molecules for biotechnological and biomedical uses, such as the treatment of parasitic diseases. Methods Africanized honeybee venom from Apis mellifera was fractionated by RP-C18-HPLC and the obtained melittin was incubated with promastigotes and intracellular amastigotes of Leishmania (L.) infantum. Cytotoxicity to mice peritoneal macrophages was evaluated through mitochondrial oxidative activity. The production of anti- and pro-inflammatory cytokines, NO and H2O2 by macrophages was determined. Results Promastigotes and intracellular amastigotes were susceptible to melittin (IC50 28.3 μg.mL−1 and 1.4 μg.mL−1, respectively), but also showed mammalian cell cytotoxicity with an IC50 value of 5.7 μg.mL−1. Uninfected macrophages treated with melittin increased the production of IL-10, TNF-α, NO and H2O2. Infected melittin-treated macrophages increased IL-12 production, but decreased the levels of IL-10, TNF-α, NO and H2O2. Conclusions The results showed that melittin acts in vitro against promastigotes and intracellular amastigotes of Leishmania (L.) infantum. Furthermore, they can act indirectly on intracellular amastigotes through a macrophage immunomodulatory effect. <![CDATA[FabAV antivenin use after copperhead snakebite: clinically indicated or knee-jerk reaction?]]> Abstract Background Crotalidae Polyvalent Immune Fab (Ovine) (FabAV) antivenin is commonly recommended after pit viper snakebites. Because copperhead envenomations are usually self-limited, some physicians are reluctant to use this costly treatment routinely, while others follow a more liberal approach. We hypothesized that, in practice, only patients with evidence of significant (moderate or severe) copperhead envenomation [those with snakebite severity score (SSS) &gt; 3] receive FabAV and examined a large cohort to determine the relationship between clinical findings and FabAV administration. Methods All data from patients evaluated for copperhead snakebite at a rural tertiary referral center from 5/2002 to 10/2013 were compiled. Demographics, transfer status, antivenin use, and clinical findings were collected; SSS was calculated. The relationships among FabAV use, clinical findings, and SSS were analyzed using t-test, chi-square, and Pearson’s coefficient (p &lt; 0.05 was significant). Results During the study period, 318 patients were treated for copperhead snakebite; 44 (13.8 %) received antivenin. Median dose was four vials (range: 1–10; IQR: 4,6). There were no deaths. Most patients receiving FabAV (63.6 %) were admitted. With regard to demographics and symptoms, only the degree of swelling (moderate vs. none/mild; p &lt; 0.01) and bite location (hand/arm vs. leg: p &lt; 0.0001) were associated with FabAV use. A SSS &gt; 3, indicating moderate or severe envenomation, was only very weakly correlated with antivenin use (r = 0.217;p &lt; 0.0001). The majority of patients with SSS &gt; 3 (65.8 %) did not receive antivenin while most patients who did receive antivenin (70.5 %) had SSS ≤ 3 (indicating mild envenomation). Conclusions Considerable variation occurs in antivenin administration after copperhead snakebite. Use of FabAV appears poorly correlated with patients’ symptoms. This practice may expose patients to the risks of antivenin and increasing costs of medical care without improving outcomes. Guidelines used for treating other pit viper strikes, such as rattlesnake or cottonmouth snakebite may be too liberal for copperhead envenomations. Our data suggests that most patients with mild or moderate envenomation appear to do well independent of FabAV use. We suggest, for patients with copperhead snakebite, that consideration be given to withholding FabAV for those without clinical evidence of severe envenomation until prospective randomized data are available. <![CDATA[Cloning and purification of the first termicin-like peptide from the cockroach <em>Eupolyphaga sinensis</em>]]> Abstract Background Termicin is an antimicrobial peptide with six cysteines forming three disulfide bridges that was firstly isolated from the salivary glands and hemocytes of the termite Pseudacanthotermes spiniger. In contrast to many broad-spectrum antimicrobial peptides, termicin is most active against filamentous fungi. Although more than one hundred complementary DNAs (cDNAs) encoding termicin-like peptides have been reported to date, all these termicin-like peptides were obtained from Isoptera insects. Methods The cDNA was cloned by combination of cDNA library construction kit and DNA sequencing. The polypeptide was purified by gel filtration and reversed-phase high performance liquid chromatography (RP-HPLC). Its amino acid sequence was determined by Edman degradation and mass spectrometry. Antimicrobial activity was tested against several bacterial and fungal strains. The minimum inhibitory concentration (MIC) was determined by microdilution tests. Results A novel termicin-like peptide with primary structure ACDFQQCWVTCQRQYSINFISARCNGDSCVCTFRT was purified from extracts of the cockroach Eupolyphaga sinensis (Insecta: Blattodea). The cDNA encoding Es-termicin was cloned by cDNA library screening. This cDNA encoded a 60 amino acid precursor which included a 25 amino acid signal peptide. Amino acid sequence deduced from the cDNA matched well with the result of protein Edman degradation. Susceptibility test indicated that Es-termicin showed strong ability to kill fungi with a MIC of 25 μg/mL against Candida albicans ATCC 90028. It only showed limited potency to affect the growth of Gram-positive bacteria with a MIC of 200 μg/mL against Enterococcus faecalis ATCC 29212. It was inactive against gram-negative bacteria at the highest concentration tested (400 μg/mL). Es-termicin showed high sequence similarity with termicins from many species of termites (Insecta: Isoptera). Conclusions This is the first report of a termicin-like peptide isolated from E. sinensis that belongs to the insect order Blattodea. Our results demonstrate the diversity of termicin-like peptides, as well as antimicrobial peptides in insects. <![CDATA[Anti-leptospirosis agglutinins in Brazilian capybaras (<em>hydrochoerus hydrochaeris</em>)]]> Abstract Background The interest in commercial use of wild animals is increasing, especially regarding raising of capybaras. Although this wild species is potentially lucrative for the production of meat, oil and leather, it is suggested as a probable reservoir of leptospires. Methods Due to the economic importance of this species and the lack of studies concerning leptospirosis, the presence of anti-leptospirosis agglutinins was assayed in 55 serum samples of capybaras (Hydrochoerus hydrochaeris) from commercial and experimental breeding flocks located in São Paulo state, Paraná state, and Rio Grande do Sul state, Brazil. Samples were obtained through cephalic or femoral venipunction (5 to 10 mL). Microscopic agglutination test was used according to the Brazilian Health Ministry considering as cut-off titer of 100. Results Out of the 55 samples analyzed, 23 (41.82 %) tested positive. The most prevalent serovar was Icterohaemorrhagiae (56.52 %) in 13 samples, followed by Copenhageni in nine samples (39.13 %), Pomona in four samples (17.39 %), Djasiman and Castellonis in three samples each (13.04 %), Grippotyphosa, Hardjo, Canicola, and Cynopteri in two samples each (8.7 %), and Andamana and Bratislava in one sample each (4.34 %). Conclusions These results suggest the evidence of exposure toLeptospira spp. and the need of new studies to evaluate a higher number of capybaras from different regions to better understand the importance of leptospirosis infection in these animals and verify the zoonotic role of this species as a possible source of infection to humans and other animals. <![CDATA[Anticancer properties of phospholipase A<sub>2</sub> from<em>Daboia siamensis</em> venom on human skin melanoma cells]]> Abstract Background Phospholipase A2 (PLA2) is a major component of theDaboia siamensis venom, which is able to hydrolyse the membrane of various cells. For this reason, the activity of PLA2was investigated regarding its pharmaceutical properties. This study was conducted to explore the pharmacological properties of a PLA2from Daboia siamensis (dssPLA2) venom on human skin melanoma cell line (SK-MEL-28). Methods dssPLA2 was isolated by ion exchange and gel filtration columns. Various concentrations of dssPLA2were investigated for cytotoxic activity and inhibition of migration on SK-MEL-28 cells. Cell death analysis, mRNA expression levels of Notch I-III and BRAF V600E genes were also determined. Results dssPLA2 exhibited cytotoxicity on SK-MEL-28 for 24 and 72 h as compared with untreated cells. However, it had no toxic effects on CCD-1064sk cells under the same conditions. dssPLA2 (0.25 and 0.5 μg/mL) induced 17.16 and 30.60 % of apoptosis, while activated 6.53 and 7.05 % of necrotic cells. dssPLA2 at 0.25, 0.5, 1 and 2 μg/mL could inhibit migration on SK-MEL-28 cells for 24 h by 31.06, 41.66, 50 and 68.75 %, respectively. The action of dssPLA2 significantly reduced the levels of Notch I and BRAF V600E genes expression on SK-MEL-28 cells compared with untreated cells at 72 h. Conclusions This study indicates that dssPLA2 had potential effects of apoptosis, necrosis, cytotoxicity and inhibition of migration on SK-MEL-28 cells. dssPLA2 could possibly be a selective agent that targets cancer cells without affecting normal cells. <![CDATA[Contribution of ultrasonography to the diagnosis of internal bleeding in snakebite envenomation]]> Abstract Background In Africa, snakebite envenomations are frequently complicated by life-threatening hemorrhagic syndromes. The authors of the present study conducted a prospective analysis at the University Hospital of Parakou (north of Benin) for seven months (January 1 to July 31, 2014) to assess the contribution of ultrasonography to the diagnosis of internal bleedings and management of envenomation. Methods An ultrasound examination was performed in all patients with clinical envenomation regardless of its severity. The study involved 32 patients admitted to the ICU of the University Hospital of Parakou. Results The average age was 27 ± 13.9 years. The main signs of severity were: prolongation of clotting time (88 %), severe anemia (41 %), clinical hemorrhage (47 %), and shock (19 %). The ultrasound imaging showed internal hemorrhage in 18 patients (56 %). There were hematomas (22 %), hemoperitoneum (13 %) or a combination of both (22 %). The occurrence of internal bleeding and hemoperitoneum were mainly related to the delay of hospital presentation (p = 0.007) and the existence of external bleeding (p = 0.04). Thirty patients (94 %) received antivenom. Case fatality rate was 3.1 %. Conclusion Ultrasonography may help in diagnosing internal bleeding, even in patients that did not show external hemorrhages, and evaluating its importance. As a consequence, the management of snakebite victims may be significantly improved. <![CDATA[Epidemiology of snakebites in Kédougou region (eastern Senegal): comparison of various methods for assessment of incidence and mortality]]> Abstract Background Although considered a public health issue in Senegal, the actual incidence and mortality from snakebite are not known. In the present study, an epidemiological survey was carried out in Kédougou region, southeastern Senegal, where envenomations, particularly by Echisocellatus, are frequent and severe. Methods Three sources of data were used: records from health centers and reports by health professionals; traditional healers; and household surveys. Results The annual incidence and mortality provided by health centers were 24.4 envenomations and 0.24 deaths per 100,000 population, respectively. The annual incidence recorded by traditional healers was 250 bites per 100,000 inhabitants, but the number of deaths was unknown. Finally, the household surveys reported an annual incidence of 92.8 bites per 100,000 inhabitants and an annual mortality rate of 2.2 deaths per 100,000 inhabitants. The differences in incidence and mortality between the different methods were explained by significant bias, resulting in particular from the complex patient's healthcare-seeking behavior. The incidence provided by health records should be used to specify the immediate quantitative requirements of antivenoms and places where they should be available first. Conclusion Mandatory reporting of cases would improve the management of envenomation by simplifying epidemiological surveys. Patients' preference for traditional medicine should prompt health authorities to urge traditional healers to refer patients to health centers according to defined clinical criteria (mainly edema and bleeding or neurotoxic symptoms). Finally, household surveys were likely to reflect the actual epidemiological situation. Poison Control Center of Senegal should continue its work to sensitize stakeholders and train health staff. <![CDATA[Snakebites notified to the poison control center of Morocco between 2009 and 2013]]> Abstract Background Snakebites cause considerable death and injury throughout the globe, particularly in tropical regions, and pose an important yet neglected threat to public health. In 2008, the Centre Anti Poison et de Parmacovigilance du Maroc (CAPM) started to set up a specific strategy for the control of snakebites that was formalized in 2012. The aim of the present study is to describe and update the epidemiological characteristics of snakebites notified to CAPM between 2009 and 2013. Methods This retrospective five-year study included all cases of snakebites notified to CAPM by mail or phone. Results During the study period, 873 snakebite cases were reported to CAPM, an average incidence of 2.65 cases per 100,000 inhabitants with 218 cases each year. The highest incidence was found in Tangier-Tetouan region with 357 cases (40.9 %) followed by Souss Massa Draa region with 128 cases (14.6 %). The average age of patients was 26.8 ± 17.2 years. The male to female sex ratio was 1.67:1 and 77 % of cases occurred in rural areas. The bites occurred mainly in spring (44 %) followed by summer (42 %). Snake species was identified in 54 cases (6.2 %): colubrids represented 31 % (n = 18) and vipers 67 % (n = 36), mainly Daboia mauritanica, Bitis arietans and Cerastes cerastes. In 311 cases (35.6 %), the patients showed viper syndrome. Thrombocytopenia was observed in 23.5 % of viper syndrome cases, whereas, compartment syndrome was observed in 7.6 % patients. FAV-Afrique® was administered in 41 patients (5 %). In patients treated with antivenom, 38 patients recovered and three died. Twenty-seven deaths were reported (3.9 %). Conclusion Despite specific efforts to better understand the epidemiology of snakebites in Morocco (incidence, severity, snake species involved), it remains underestimated. Therefore, further work is still necessary to ensure accessibility of appropriate antivenom against venomous species and to improve the management of envenomation in Morocco. <![CDATA[Retrospective study on the incidence of envenomation and accessibility to antivenom in Burkina Faso]]> Abstract Background Snakebite is a common neglected public health issue, especially in poor rural areas of sub-Saharan Africa, Asia and Latin America. Passive immunotherapy with safe and effective antivenom is the only approved treatment for it. This study aimed to determine the incidence of snakebites, and to assess the availability and accessibility of antivenoms, from 2010 to 2014, in Burkina Faso. Methods The assessment of snakebite cases managed in all health facilities from 2010 to 2014 was performed from the Statistical Yearbook of the Ministry of Health. Antivenom consumption data were collected from the drug wholesalers established in Burkina Faso. Results Snakebites are among the five leading causes of consultations in health districts. From 2010 to 2014, 114,126 envenomation cases occurred in Burkina Faso, out of which 62,293 (54.6 %) victims have been hospitalized resulting in 1,362 (2 %) deaths. The annual incidence and mortality were respectively 130 bites and 1.75 deaths per 100,000 inhabitants. The amount of antivenom sold by wholesalers were 5,738 vials with a total cost of US$ 539,055 (annual average = US$ 107,811). The high cost of these antivenoms (between US$ 42 and 170 per dose according to brand) limited their use by rural people, the main victims of snakebites, whose income is insufficient. Thus, only 4 % of patients received antivenom treatment over the past five years. The price of antivenom was reduced in 2015 to US$ 3.4 by a public drug wholesaler. Conclusion The study confirmed the high burden of snakebites in Burkina Faso. To better manage envenomation, Burkina Faso implemented a strategy consisting in seeking affordable sources of antivenom supply of good quality and innovative mechanisms of subsidy. <![CDATA[Experimental <em>Lachesis muta rhombeata</em> envenomation and effects of soursop <em>(Annona muricata)</em> as natural antivenom]]> Abstract Background In the Atlantic forest of the North and Northeast regions of Brazil, local population often uses the fruit juice and the aqueous extract of leaves of soursop (Annona muricata L.) to treat Lachesis muta rhombeata envenomation. Envenomation is a relevant health issue in these areas, especially due to its severity and because the production and distribution of antivenom is limited in these regions. The aim of the present study was to evaluate the relevance of the use of soursop leaf extract and its juice against envenomation by Lachesis muta rhombeata. Methods We evaluated the biochemical, hematological and hemostatic parameters, the blood pressure, the inflammation process and the lethality induced by Lachesis muta rhombeata snake venom. We also assessed the action of the aqueous extract of leaves (AmL) and juice (AmJ) from A. muricata on the animal organism injected with L. m. rhombeata venom (LmrV) in the laboratory environment. Results LmrV induced a decrease of total protein, albumin and glucose; and increase of creatine kinase, aspartate aminotransferase, and urea concentrations. It provoked hemoconcentration followed by reduction of hematocrit, an increase in prothrombin time and partial thromboplastin time and a decrease of the blood pressure. LmrV induced the release of interleukin-6, an increase in neutrophils and changes in the serum protein profile, characteristic of the acute inflammatory process. LD50 values were similar for the groups injected with LmrV and treated or untreated with AmJ and AmL. Both treatments play a role on the maintenance of blood glucose, urea and coagulation parameters and exert a protective action against the myotoxicity. However, they seem to worsen the hypotension caused by LmrV. Conclusion The treatments with AmJ and AmL present some beneficial actions, but they might intensify some effects of the venom. Therefore, additional studies on A. muricata are necessary to enable its use as natural antivenom for bushmaster snakebite. <![CDATA[Canine visceral leishmaniasis in the Northeast Region of Brazil]]> Abstract Background Visceral leishmaniasis (VL) is a zoonosis that affects dogs and other mammals, including humans. Contact with dogs is a major risk factor for humans. This disease is endemic in several regions of Brazil. The aim of this study was to determine the prevalence of Leishmania spp. infection in dogs and to correlate it with possible risk factors. Methods Blood samples were collected from 391 dogs of different ages, breeds, and both genders, coming from Campina Grande, Paraíba state, Brazil. An epidemiological questionnaire was employed in order to identify risk factors associated with the disease. Serological tests were performed using indirect immunofluorescence, enzyme-linked immunosorbent assay (ELISA S7®) and polymerase chain reaction. Results Leishmania spp. antibodies were detected in 33 (8.4 %) and 17 (4.3 %) dogs according to the indirect immunofluorescence test (IFAT) and enzyme-linked immunosorbent assay (ELISA S7®), respectively. PCR results indicated the presence of L. chagasi DNA in only eight (2 %) blood samples. There was a significant association between reactive animals and contact with animals from different houses (OR = 4.1; p= 0.02). Conclusions It is suggested that CVL may occur in urban areas. Moreover, it is demonstrated that the association among different diagnostic tests may lead to a more accurate identification of positive animals, which might help to improve the disease control and prevent euthanasia in false-positive results. <![CDATA[Synthesis and antimicrobial evaluation of two peptide LyeTx I derivatives modified with the chelating agent HYNIC for radiolabeling with technetium-99m]]> Abstract Background Current diagnostic methods and imaging techniques are not able to differentiate septic and aseptic inflammation. Thus, reliable methods are sought to provide this distinction and scintigraphic imaging is an interesting option, since it is based on physiological changes. In this context, radiolabeled antimicrobial peptides have been investigated as they accumulate in infectious sites instead of aseptic inflammation. The peptide LyeTx I, from the venom of Lycosa erythrognatha, has potent antimicrobial activity. Therefore, this study aimed to synthesize LyeTx I derivatives with the chelating compound HYNIC, to evaluate their antimicrobial activity and to radiolabel them with 99mTc. Methods Two LyeTx I derivatives, HYNIC-LyeTx I (N-terminal modification) and LyeTx I-K-HYNIC (C-terminal modification), were synthesized by Fmoc strategy and purified by RP-HPLC. The purified products were assessed by RP-HPLC and MALDI-ToF-MS analysis. Microbiological assays were performed against S. aureus (ATCC® 6538) and E. coli (ATCC® 10536) in liquid medium to calculate the MIC. The radiolabeling procedure of LyeTx I-K-HYNIC with 99mTc was performed in the presence of co-ligands (tricine and EDDA) and reducing agent (SnCl2. 2H2O), and standardized taking into account the amount of peptide, reducing agent, pH and heating. Radiochemical purity analysis was performed by thin-layer chromatography on silica gel strips and the radiolabeled compound was assessed by RP-HPLC and radioactivity measurement of the collected fractions. Data were analyzed by ANOVA, followed by Tukey test (p-values &lt; 0.05). Results Both LyeTx I derivatives were suitably synthesized and purified, as shown by RP-HPLC and MALDI-ToF-MS analysis. The microbiological test showed that HYNIC-LyeTx I (N-terminal modification) did not inhibit bacterial growth, whereas LyeTx I-K-HYNIC (C-terminal modification) showed a MIC of 5.05 μmol.L−1 (S. aureus) and 10.10 μmol.L−1 (E. coli). Thus, only the latter was radiolabeled with 99mTc. The radiochemical purity analysis of LyeTx I-K-HYNIC-99mTc showed that the optimal radiolabeling conditions (10 μg of LyeTx I-K-HYNIC; 250 μg of SnCl2. 2H2O; pH = 7; heating for 15 min) yielded a radiochemical purity of 87 ± 1 % (n= 3). However, RP-HPLC data suggested 99mTc transchelation from LyeTx I-K-HYNIC to the co-ligands (tricine and EDDA). Conclusions The binding of HYNIC to the N-terminal portion of LyeTx I seems to affect its activity against bacteria. Nevertheless, the radiolabeling of the C-terminal derivative, LyeTx I-K-HYNIC, must be better investigated to optimize the radiolabeled compound, in order to use it as a specific imaging agent to distinguish septic and aseptic inflammation. <![CDATA[Initial peptidomic profiling of Brazilian sea urchins: <em>Arbacia lixula</em>, <em>Lytechinus variegatus</em> and <em>Echinometra lucunter</em>]]> Abstract Background Sea urchins can be found throughout the Brazilian coast and are reported to be one of the major causes of marine accidents on the shoreline. Although not lethal, these accidents are reported to be extremely painful. In order to understand the toxinology of the Brazilian urchins, a peptidomic approach was performed aiming to characterize the naturally occurring peptides in both the coelomic fluid and the spine. Methods Animals were collected without gender distinction and samples of the coelomic fluid and spines extracted were analyzed by RP-HPLC and mass spectrometry for peptide de novo sequencing. Results Several peptides were identified either in the coelomic fluid or the spine extract (except for E. lucunter). The peptide sequences were aligned with public deposited sequences and possible functions were inferred. Moreover, some peptides can be cryptides, since their sequences were identified within functional proteins, for example thymosin from Strongylocentrotus purpuratus. Conclusions Although preliminary, the peptidomic approach presented here reports, for the first time, the abundance of novel biological molecules derived from these animals. The discovery of such molecules may be of potential biotechnological application, as described for other organisms; nevertheless, further studies are required. <![CDATA[Behavioral alterations induced by repeated saxitoxin exposure in drinking water]]> Abstract Background Blooms of the saxitoxin-producing cyanobacterium Cylindrospermopsis raciborskii have been contaminating drinking water reservoirs in Brazil for many years. Although acute effects of saxitoxin intoxication are well known, chronic deleterious outcomes caused by repeated saxitoxin exposure still require further investigation. The aim of the present work is to investigate the effects of consumption of drinking water contaminated with C. raciborskii for 30 days on learning and memory processes in rats. Methods The effects of saxitoxin (3 or 9 μg/L STX equivalents) or cyanobacteria on behavior was determined using the open field habituation task, elevated plus maze anxiety model task, inhibitory avoidance task, and referential Morris water maze task. Results No effects of saxitoxin consumption was observed on anxiety and motor exploratory parameters in the elevated plus maze and open field habituation tasks, respectively. However, groups treated with 9 μg/L STX equivalents displayed a decreased memory performance in the inhibitory avoidance and Morris water maze tasks. Conclusions These results suggest an amnesic effect of saxitoxin on aversive and spatial memories. <![CDATA[On frogs, toxins and true friendship: an atypical case report]]> Abstract The authors report a series of events including the scientific interest for poisonous dendrobates of French Guiana, the human confrontation with the immensity of the evergreen rainforest, the fragility of the best-prepared individuals to a rough life, and the unique and very special manifestation of a solid friendship between two experts and enthusiasts of outdoor life. In the evergreen forest of South America, as in many other scientific field expeditions, everything may suddenly go wrong, and nothing can prepare researchers to accidents that may occur in a succession of uncontrollable errors once the first mistake is done. This is what happened during an expedition in search for dendrobates by an experienced forest guide and naturalist. The authors decided to report the story, considering that it deserved to be brought to the attention of those interested in venomous animals and toxins, in order to illustrate the potential danger of dealing with these organisms. <![CDATA[Survival of a newborn from a pregnant woman with rabies infection]]> Abstract Background Rabies is very common in People’s Republic of China. Each year thousands of people die because of this disease, but rabies diagnosed in pregnancy is very rare. Case Presentation In this study, we report the case of a pregnant woman who was infected with the rabies virus after a dog bite. The symptoms of rabies appeared in labor and she died after pregnancy. Her baby and husband did not develop the disease. Conclusion The phenomenon that the newborn infant was healthy may be related to the protective role of placenta in resisting the invasion of the rabies virus or the absence of systemic viremia. The prompt administration of vaccines and anti-rabies immunoglobulin to the infant may have also contributed to his survival. <![CDATA[Fatal neurotoxic envenomation following the bite of a greater black krait (<em>Bungarus niger</em>) in Nepal: a case report]]> Abstract Background Neurotoxic envenomation following bites by kraits (Bungarus species) is a leading cause of snakebite mortality in South Asia. Over a long time, this had been attributed only to one species, the common krait (Bungarus caeruleus). However, recent research has provided increasing evidence of the involvement of several krait species. Here, we report a fatal case of neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal. Case presentation A 33-year-old man was bitten in the outdoor corridor of his home in the eastern hills of Ilam district while handling a snake he thought to be non-venomous. He subsequently developed severe abdominal pain, frequent vomiting, and signs of neurotoxic envenomation leading to respiratory paralysis. The patient did not respond to Indian polyvalent antivenom given 4 h after the bite and died under treatment 8 h after the bite. This is the second time that a B. niger was observed in Nepal, the first documented case of envenomation by this species in the country and the sixth reported case worldwide. Conclusions Previous distribution records – from eastern India and western Nepal, from western hills in Nepal, and from lowland localities in India and Bangladesh – indicate risk of envenomation by B. niger throughout the low and intermediate elevations of Nepal up to at least 1,500 m above sea level. As very few people in Nepal bring killed snakes to healthcare centers and because there is a general belief among local people that there are no kraits in the hills, bites by B. niger are likely to be misdiagnosed and underreported. <![CDATA[Reviewer acknowledgement 2015]]> Abstract Background Neurotoxic envenomation following bites by kraits (Bungarus species) is a leading cause of snakebite mortality in South Asia. Over a long time, this had been attributed only to one species, the common krait (Bungarus caeruleus). However, recent research has provided increasing evidence of the involvement of several krait species. Here, we report a fatal case of neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal. Case presentation A 33-year-old man was bitten in the outdoor corridor of his home in the eastern hills of Ilam district while handling a snake he thought to be non-venomous. He subsequently developed severe abdominal pain, frequent vomiting, and signs of neurotoxic envenomation leading to respiratory paralysis. The patient did not respond to Indian polyvalent antivenom given 4 h after the bite and died under treatment 8 h after the bite. This is the second time that a B. niger was observed in Nepal, the first documented case of envenomation by this species in the country and the sixth reported case worldwide. Conclusions Previous distribution records – from eastern India and western Nepal, from western hills in Nepal, and from lowland localities in India and Bangladesh – indicate risk of envenomation by B. niger throughout the low and intermediate elevations of Nepal up to at least 1,500 m above sea level. As very few people in Nepal bring killed snakes to healthcare centers and because there is a general belief among local people that there are no kraits in the hills, bites by B. niger are likely to be misdiagnosed and underreported.