Resumo em Inglês:Dogs and cats are the animals that owners most frequently seek assistance for potential poisonings, and these species are frequently involved with toxicoses due to ingestion of poisonous food. Feeding human foodstuff to pets may prove itself dangerous for their health, similarly to what is observed in Allium species toxicosis. Allium species toxicosis is reported worldwide in several animal species, and the toxic principles present in them causes the transformation of hemoglobin into methemoglobin, consequently resulting in hemolytic anemia with Heinz body formation. The aim of this review is to analyze the clinicopathologic aspects and therapeutic approach of this serious toxicosis of dogs and cats in order to give knowledge to veterinarians about Allium species toxicosis, and subsequently allow them to correctly diagnose this disease when facing it; and to educate pet owners to not feed their animals with Allium-containg food in order to better control this particular life-threatening toxicosis.
Resumo em Inglês:Antivenoms against snake and scorpion envenomations are usually equine in nature and composed mostly of F(ab')2; additionally, phenol and m-cresol are mainly employed for their preservation. Although there is no study on this subject, m-cresol is utilized by most manufacturers in a concentration that ranges from 0.15 to 0.35 g%. Decreasing the concentration of m-cresol to its minimal effective level may protect victims from its toxic effects and keep the antivenom stable during its shelf life without forming any aggregates. In the present work, different concentrations of m-cresol, ranging from 0.1 to 0.35 g%, were used with some selected batches of snake and scorpion antivenoms. A low concentration of 0.15 g% showed an acceptable preserving result that complies perfectly with antimicrobial specifications stated by the British Pharmacopoeia. Tested antivenoms (in 12 batches), when kept in a cold room for 39 months (more than their shelf life), retained their physical, chemical and microbiological activities according to the specifications of pharmacopeias. The present data demonstrated that reduction of m-cresol concentration to 0.15 g% in case of equine F(ab')2 antivenoms will improve safety of such preparations and preserve their stability during their shelf life.
Resumo em Inglês:Gyroxin, a thrombin-like enzyme isolated from Crotalus durissus terrificus venom and capable of converting fibrinogen into fibrin, presents coagulant and neurotoxic activities. The aim of the present study was to evaluate such coagulant and toxic properties. Gyroxin was isolated using only two chromatographic steps - namely gel filtration (Sephadex G-75) and affinity (Benzamidine Sepharose 6B) - resulting in a sample of high purity, as evaluated by RP-HPLC C2/C18 and electrophoretic analysis that showed a molecular mass of 30 kDa. Gyroxin hydrolyzed specific chromogenic substrates, which caused it to be classified as a serine proteinase and thrombin-like enzyme. It was stable from pH 5.5 to 8.5 and inhibited by Mn²+, Cu²+, PMSF and benzamidine. Human plasma coagulation was more efficient at pH 6.0. An in vivo toxicity test showed that only behavioral alterations occurred, with no barrel rotation. Gyroxin was not able to block neuromuscular contraction in vitro, which suggests that its action, at the studied concentrations, has no effect on the peripheral nervous system.
Resumo em Inglês:The properties and agglutination activity of acutolysin C, a hemorrhagic metalloproteinase obtained from Agkistrodon acutus venom, were studied herein. Acutolysin C is a basic glycoprotein consisting of a single polypeptide chain with a molecular weight of 23.1 kDa and pI 8.7, containing one Zn2+ and one Ca²+ per molecule. It possesses caseinolytic, weak lethal (LD50 = 7.6 mg/kg) and weak hemorrhagic (MHD = 12.0 μg) activities, but does not present fibrinolytic, fibrinogenolytic, arginine esterase and phospholipase A2 actions. In addition, it revealed agglutination activity on some animal lymphocytes, including five species of mammals, six of birds, three of reptiles and one of amphibians, but had no effect on lymphocytes from two species of reptiles, one amphibian and nine species of fish. It had no effects on the erythrocytes and platelets of all 26 animal species tested. Both leucoagglutination and caseinolytic activities were inhibited by EDTA; while cysteine, 2-mercaptoethanol, 1,4-dithiothreitol, glutathione, serum against acutolysin C and serum against homologous snake venom as well as glucose, sucrose, mannose, lactose and galactose had no effects on inhibition. The lowest concentration of acutolysin C that induced mouse lymphocyte agglutination was 2.5 μg/mL. Acutolysin C is an interesting substance since it is the first member of the hemorrhagin family to be shown to have leucoagglutination activity.
Resumo em Inglês:In the present study, the effectiveness of Mimosa pudica tannins (MPT) in neutralizing the lethality of Naja kaouthia venom was compared with commercially derived tannins. Preincubation of MPT with N. kaouthia venom maintained 100% survival of mice after 24 hours. The mouse group in which there was no preincubation, no protection against the effects of the venom was observed. M. pudica tannin was found to be more effective in neutralizing the lethality of N. kaouthia venom when compared to commercial tannic acid. Two protein spots were missing in the two-dimensional gel electrophoresis (2-DE) of the MPT treated mouse indicating the down-regulation of venom proteins. The results from this study indicated that tannins obtained from M. pudica are better than tannic acid in neutralizing the lethality of N. kaouthia venom in vitro. However, further investigations are required to establish that M. pudica has potential for treating N. kaouthia snakebites.
Resumo em Inglês:A myotoxin phospholipase A2 homologue, BmooMtx, was isolated from the venom of Bothrops moojeni by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. SDS-PAGE showed the enzyme to be a monomer with a molecular weight of 16,500. BmooMtx induced release of creatine kinase and morphological analyses indicated that it provoked an intense myonecrosis, with visible leukocyte infiltrate and damaged muscle cells 24 hours after injection. Anti-BmooMTx antibodies partially neutralized the myotoxic activity of BmooMtx and crude B. moojeni venom, as judged by determination of plasma creatine kinase levels and histological evaluation of skeletal muscle in mice. Anti-BmooMTx antibodies were effective in reducing the plasma creatine kinase levels of crude B. alternatus and B. leucurus venoms, evidencing immunological cross-reactivity between BmooMTx and other bothropic venoms. Intraplantar (i.pl.) injection of BmooMtx (1 to 15 μg/animal) caused a dose- and time-dependent hyperalgesia and edematogenic responses. Dexamethasone (0.4 mg/kg), meloxicam (2 mg/kg) and promethazine (5 mg/kg) markedly reduced the hyperalgesia. Our data suggest that these drugs may likely serve as complementary therapies in cases of accidents with Bothrops moojeni, provided that such pharmacological treatments are administered immediately after the incident.
Resumo em Inglês:Clostridium perfringens is an important pathogen in both human and veterinary medicine. Necrotic enteritis (NE) is the most clinically dramatic bacterial enteric disease of poultry induced by C. perfringens. The pathogenicity of this bacterium is associated with the production of extracellular toxins produced by some of its strains, such as beta2 toxin. The exact role of beta2 toxin in NE pathogenesis is still controversial. In the present study, C. perfringens isolates from healthy and diseased poultry flocks from different parts of Iran were analyzed by PCR assay to determine the presence of all variants of the beta2 toxin gene (cpb2). The products of two positive cpb2 PCR reactions were sequenced, compared to each other and to the cpb2 sequences published in GenBank (by multiple alignment and phylogenetic analysis). The current work represents the first study of cpb2 in poultry C. perfringens isolates in Asia, and reports the highest percentage of cpb2-positive isolates in both apparently healthy chickens (97.7%) and those afflicted with NE (94.4 %). The sequenced isolates were classified as atypical. This study did not show a direct correlation between NE occurrence and cpb2 presence.
Resumo em Inglês:Freshwater sponges are abundant in the Amazon region and they have been known to cause dermatitis (acute inflammation) since the beginning of the 20th century. To determine whether additional constituents, besides their body spicules, cause dermatological reactions in humans, an experimental study was developed and carried out using mice and Drulia uruguayensis prepared in three different forms: intact sponges (IS), macerated sponges (MS) or isolated spicules - megascleres (ISM). The cells most commonly involved in inflammatory reactions (mast cells, eosinophils and neutrophils), as well as intraepithelial lymphocytes and degranulated mast cells, were counted so that they could be used as parameters to determine which of the sponge preparations induced the greatest reaction. The effects of the sponge on the skin were then determined by histological analysis. The results obtained showed that IS caused the greatest inflammatory reaction (p = 0.000005), activating mainly mast cells (p = 0.0018). The histopathological analysis revealed a slight loss of continuity of the epidermis when ISM or IS were applied. These findings allow us to conclude that a structurally intact sponge can cause a greater inflammatory reaction in the first contact because of its ability to perforate the skin and allow inflammatory agents to enter. Other proteins present in dried sponge bodies could induce allergic but not toxic responses (in contact with the entire sponge, a large number of pharmacologically inert proteins may be introduced, with a potential allergen).
Resumo em Inglês:To evaluate scallop safety in the Guangzhou seafood market, contents of shellfish toxins in adductor muscle, mantle skirts, gills and visceral mass of scallops were examined using enzyme-linked immunosorbent assay (ELISA) and mouse unit assay. The results showed that: paralytic shellfish poisoning contents were up to 37.44 μg/100 g by ELISA and 319.99 MU/100 g by mouse unit assay, which did not exceed the limits of national standards (80 μg/100g and 400 MU/100 g); the contents of diarrhetic shellfish poisoning were 142.04 μg/100g and 0.2 MU/100 g, which exceeded the national standard limits (60 μg/100g); neurotoxic shellfish poisoning was undetectable; the contents of amnesic shellfish poisoning reached 220.12 μg/100g (no limit value could be referred to) . In addition, these poisons were present mainly in visceral mass and gills rather than adductor muscle and mantle skirts, suggesting that these toxins accumulate in a tissue-specific manner.
Resumo em Inglês:Most of the snakebites recorded in Brazil are caused by the Bothrops genus. Given that the local tissue damage caused by this genus cannot be treated by antivenom therapy, numerous studies are focusing on supplementary alternatives, such as the use of medicinal plants. Serjania erecta has already demonstrated anti-inflammatory, antiseptic and healing properties. In the current study, the aerial parts of S. erecta were extracted with methanol, then submitted to chromatographic fractionation on a Sephadex LH20 column and eluted with methanol, which resulted in four main fractions. The crude extract and fractions neutralized the toxic activities of Bothrops jararacussu snake venom and isolated myotoxins (BthTX-I and II). Results showed that phospholipase A2, fibrinogenolytic, myotoxic and hemorrhagic activities were inhibited by the extract. Moreover, the myotoxic and edematous activities induced by BthTX-I, and phospholipase A2 activity induced by BthTX-II, were inhibited by the extract of S. erecta and its fraction. The clotting time on bovine plasma was significantly prolonged by the inhibitory action of fractions SF3 and SF4. This extract is a promising source of natural inhibitors, such as flavonoids and tannins, which act by forming complexes with metal ions and proteins, inhibiting the action of serineproteases, metalloproteases and phospholipases A2.
Resumo em Inglês:In the recent years, the wild boar (Sus scrofa) trade has increased in Brazil. The present study aimed to detect Leptospira spp. infection in 308 blood samples from wild boars bred in São Paulo state, Brazil. The microscopic agglutination test (MAT) was performed using 29 serovars. Sixty three (63; 20.45%) animals tested positive against the serovars Hardjo (29/63; 46.0%), Copenhageni (11/63; 17.4%), Pomona (8/63; 12.7%), Pyrogenes (4/63; 6.3%), Wolfii (4/63; 6.3%), Autumnalis (3/63; 4.7%), Icterohaemorraghiae (2/63; 3.1%), and Hardjo-miniswajezak (1/63; 15.8%). These results indicate that captive wild boars were infected with Leptospira spp. and may represent a source of infection to humans and other animals.
Resumo em Inglês:This study aims to report the amplification of the DNA of Leishmania (V.) braziliensis, using polymerase chain reaction, obtained from the saliva of a patient with American cutaneous leishmaniasis who did not present any lesion in the oral mucosa. Amplification produced fragments of 103 bp, an estimated size employing Leishmania (V.) braziliensis primers (b1 e b2). The present results revealed, for the first time, that the in vitro amplification of Leishmania DNA using samples from the salivary fluid of a patient with American cutaneous leishmaniasis is possible. However, more studies are required with a larger number of participants to evaluate the usefulness of saliva as a non-invasive sample for PCR. The development of such non-invasive technique is necessary for the diagnosis of many diseases in the future, especially infectious and parasitic ones.
Resumo em Inglês:Enteric infections caused by the ingestion of contaminated water, especially by Escherichia coli, are important to define the virulence properties of these bacteria. Due to frequent infantile diarrhea in the city of Ouro Preto, Minas Gerais state, Brazil, the phenotypic and genotypic diarrheagenic properties of E. coli isolated from drinking water were studied. The culture supernatants of 39 (40%) among a total of 97 E. coli isolates from drinking water were positive by suckling mouse assay and induced cytotoxic effects on Vero cells. The enterotoxic and cytotoxic activities were present in the fraction with less than 10 kDa and were not lost when heated up to 60°C and 100°C for 30 minutes. PCR assays showed that among these 39 Vero cytotoxigenic E. coli, four (10.2%) were positive for ST II (estB) and two (5%) positive for αHly (hlyA). Gene amplification of SLT (stx 1, stx 2), ST I (estA), LT (eltI, eltII), EAST1 (astA), EHly (enhly) and plasmid-encoded enterotoxin (pet) were not observed. This heat-stable cytotoxic enterotoxin of E. coli is probably a new putative diarrheagenic virulence factor, as a toxin presenting these characteristics has not yet been described.
Resumo em Inglês:Acute onset of multiple organ dysfunction syndrome (MODS) is a well-known complication following multiple wasp stings. However, MODS after a single wasp sting has been rarely reported in children and acute pancreatitis have probably never been observed before. Herein we describe the case of a 12-year-old boy who had urticaria and abdominal pain after a single wasp sting. The child gradually developed MODS while his abdominal complaints were worsening. Despite aggressive supportive management, the child did not survive. Afterward, the cause of the acute abdomen was finally diagnosed as acute pancreatitis. Both MODS and pancreatitis following a single wasp sting are very unusual. Thus, although pancreatitis is rarely manifested, it should be suspected after a wasp sting if there are predominant abdominal symptoms.
Resumo em Inglês:In the present study, snakebites caused by a single Bothrops pauloensis simultaneously affecting three male adult horses are described. Whereas the first two affected horses were six years old, the third was 16 years old; they weighed respectively 555, 550 and 500 kg. All horses presented swollen muzzles. The first animal received an initial antivenom dose of 19 vials and adjuvant medication, it was also subjected to tracheostomy due to the progression of acute respiratory failure. The second and third horses respectively received 15 vials of antivenom each, in addition to adjuvant medication. Due to continuous changes in blood coagulation observed during hospitalization, the first and the second horses received five more vials of antivenom, respectively, in the second and third days of treatment. The first animal was discharged on 15th day and the other on the 8th day of hospitalization. Several factors including the main actions of Bothrops venom (coagulation, proteolytic and vasculotoxic activities), the importance of early diagnosis based on clinical history and clinical examination suggesting the diagnosis of Bothrops snakebite, the adequate doses of antivenom, and finally the immediate tracheostomy are herein discussed. The tracheostomy, required to save the life of the first horse, should only occur after the administration of antivenom and control measures for changes in blood coagulation.