Frequency of rhabdiasid nematodes in wild Crotalus durissus terrificus (Serpentes, Viperidae) from Botucatu region, São Paulo State, Brazil

The aim of the present study was to evaluate the frequency of rhabdiasid nematodes in recently captured Crotalus durissus terrificus snakes from São Paulo State, Brazil. Fifty snakes (34 males and 16 females) were studied and each one was evaluated for the presence of that nematode at the moment of receipt at the Institution and after 90 days of quarantine inside individual cages. Tracheopulmonary washes were examined. Snakes that died during quarantine underwent necropsy and lung examination. Analysis of the results obtained at the two evaluation times (0 and 90 days), in addition to the data obtained during necropsies, showed that 44% (18 males and 4 females) of the C. d. terrificus snakes were naturally infected by rhabdiasid nematodes. These data demonstrate the parasitism level in natural conditions and are important for the sanitary handling of these reptiles in captivity.

Experimental envenomation with Crotalus durissus terrificus venom in dogs treated with antiophidic serum - Part I: Clinical evaluation, hematology and myelogram

The present study aimed at evaluating clinical and laboratory aspects during experimental envenomation by Crotalus durissus terrificus in dogs treated with antiophidic serum. Twenty-one dogs were divided into three groups of seven animals each. Group I received 1mg/kg venom (sc); Group II received 1mg/kg venom (sc), 50mg antiophidic serum (iv), and fluid therapy including 0.9% NaCl solution (iv); and Group III received 1mg/kg venom (sc), 50mg antiophidic serum (iv), and fluid therapy including 0.9% NaCl solution containing sodium bicarbonate diluted to the dose of 4mEq/kg. The clinical signs of ataxia, sedation, flaccid paralysis, mydriasis, eyeball paralysis, mandible ptosis, sialorrhea, vomiting and diarrhea observed in the dogs were very similar to those observed in humans. The decrease in hemoglobin, hematocrit, erythrocyte, platelet and fibrinogen levels, prolongation of clotting time, prothrombin time (PT) and activated partial thromboplastin time (APTT), as well as hypocellularity in the bone marrow characterized anemia, thrombocytopenia and blood incoagulability, as well as hypofibrinogenemia and decreased bone-marrow activity. Important bleeding was not observed. Increased numbers of leukocytes and neutrophils and decreased numbers of lymphocytes and eosinophils characterized an acute inflammatory response and stress caused by generalized pain. The employed antiophidic serum was effective and all animals survived.

Experimental envenomation with Crotalus durissus terrificus venom in dogs treated with antiophidic serum - Part II: Laboratory aspects, electrocardiogram and histopathology

The present work shows laboratory aspects, electrocardiogram and histopathology results during experimental envenomation by Crotalus durissus terrificus in dogs treated with antiophidic serum. Twenty-one dogs were divided into three groups of seven animals each. Group I received 1mg/kg venom (sc); Group II received 1mg/kg venom (sc), 50mg antiophidic serum (iv) and fluid therapy including 0.9% NaCl solution (iv); and Group III received 1mg/kg venom (sc), 50mg antiophidic serum (iv) and fluid therapy including 0.9% NaCl solution containing sodium bicarbonate diluted to the dose of 4mEq/kg. Urinalysis showed brown urine, proteinuria, occult blood and myoglobinuria. Respiratory acidosis and hypotension were also observed. At the venom inoculation site, there was discreet edema, popliteal lymph node response, musculature presenting whitish areas and necrotic myositis with myoregenerative activity. There was not evidence of electrocardiographical and biochemical alterations.

Resposta imune e capacidade de neutralização de anticorpos produzidos em ovinos jovens imunizados com veneno de Crotalus durissus terrificus nativo e irradiado com Cobalto 60

The ELISA technique was used to evaluate and compare young ovine humoral immune response during crotalic antiserum production. Animals were clinically evaluated throughout this process, and the neutralizing capacity of antisera raised against natural (NV) and Cobalt-60 irradiated (IrV) venoms of Crotalus durissus terrificus (C.d.t.) was verified by means of in vitro challenges. Three groups of six animals each were used: G1 received NV; G2 was inoculated with IrV; and G3 was used as control. Animals received six immunizations during 84 days at 14-day intervals. ELISA of antibody profile showed significant difference (p<5%) between experimental groups (G1Crotalus durissus terrificus venom like alternative to antiserum production. The neutralizing capacity of antiserum raised against IrV was fivefold higher than that of antiserum raised against NV. Results showed a new possibility of using ovines to produce commercial crotalic antiserum, which may be employed in the treatment of human and animal envenomation. Production cost might be reduced by the subsequent utilization of hyperimmunized ovines as food.

Ablation of the ability to control the right-to-left cardiac shunt does not affect oxygen uptake, specific dynamic action or growth in the rattlesnake Crotalus durissus

The morphologically undivided ventricle of the heart in non-crocodilian reptiles permits the mixing of oxygen-rich blood returning from the lungs and oxygen-poor blood from the systemic circulation. A possible functional significance for this intra-cardiac shunt has been debated for almost a century. Unilateral left vagotomy rendered the single effective pulmonary artery of the South American rattlesnake, Crotalus durissus, unable to adjust the magnitude of blood flow to the lung. The higher constant perfusion of the lung circulation and the incapability of adjusting the right-left shunt in left-denervated snakes persisted over time, providing a unique model for investigation of the long-term consequences of cardiac shunting in a squamate. Oxygen uptake recorded at rest and during spontaneous and forced activity was not affected by removing control of the cardiac shunt. Furthermore, metabolic rate and energetic balance during the post-prandial metabolic increment, plus the food conversion efficiency and growth rate, were all similarly unaffected. These results show that control of cardiac shunting is not associated with a clear functional advantage in adjusting metabolic rate, effectiveness of digestion or growth rates. © 2013. Published by The Company of Biologists Ltd.

Biochemical, functional, structural and phylogenetic studies on Intercro, a new isoform phospholipase A2 from Crotalus durissus terrificus snake venom

Crotoxin is a neurotoxin from Crotalus durissus terrificus venom that shows immunomodulatory, anti-inflammatory, antimicrobial, antitumor and analgesic activities. Structurally, this toxin is a heterodimeric complex composed by a toxic basic PLA2 (Crotoxin B or CB) non-covalently linked to an atoxic non-enzymatic and acidic component (Crotapotin, Crotoxin A or CA). Several CA and CB isoforms have been isolated and characterized, showing that the crotoxin venom fraction is, in fact, a mixture of different molecules derived from the combination of distinct subunit isoforms. Intercro (IC) is a protein from the same snake venom which presents high similarity in primary structure to CB, indicating that it could be an another isoform of this toxin. In this work, we compare IC to the crotoxin complex (CA/CB) and/or CB in order to understand its functional aspects. The experiments with IC revealed that it is a new toxin with different biological activities from CB, keeping its catalytic activity but presenting low myotoxicity and absence of neurotoxic activity. The results also indicated that IC is structurally similar to CB isoforms, but probably it is not able to form a neurotoxic active complex with crotoxin A as observed for CB. Moreover, structural and phylogenetic data suggest that IC is a new toxin with possible toxic effects not related to the typical CB neurotoxin. © 2013.

Description of three new species of Hepatozoon (Apicomplexa, Hepatozoidae) from Rattlesnakes (Crotalus durissus terrificus) based on molecular, morphometric and morphologic characters

Hepatozoon spp. are commonly found infecting snakes. Since the latter are parasitized by diverse forms and data in the literature show divergence, we studied Hepatozoon spp. diversity on Crotalus durissus terrificus snakes using both molecular and morphological approaches. Naturally infected animals were employed. Blood was collected, blood smears were prepared and an aliquot was stored at -20. °C for DNA extraction. Five specimens of C. durissus terrificus were selected, each of them infected with one gamont type. Morphological and morphometric analyses of the found gamonts led to their grouping into three populations. For molecular characterization, seven oligonucleotide pairs that amplify distinct regions of rDNA gene were tested by adopting the PCR technique. Only the oligonucleotide pairs HepF300/Hep900 and HEMO1/HEMO2 were efficient in amplifying and distinguishing different isolates of Hepatozoon spp. from snakes. The better results were obtained when both oligonucleotide pairs were used in association. Based on the molecular and morphologic differences, three new species were proposed: Hepatozoon cuestensis sp. nov.; Hepatozoon cevapii sp. nov. and Hepatozoon massardii sp. nov. This is the first description of new Hepatozoon species from snakes, based on molecular characterization and morphological data, in South America. © 2013 Elsevier Inc.

Avaliação da resposta humoral e da capacidade de neutralização do soro de camundongos Swiss inoculados com venenos nativo e irradiado com cobalto-60 de serpentes Crotalus durissus terrificus, Bothrops jararaca, Bothrops jararacussu e Bothrops moojeni

Pós-graduação em Doenças Tropicais - FMB

Avaliação dos efeitos dos polissacarídeos sulfatados de macroalgas marinhas sobre a Fosfolipase A2 de Crotalus durissus terrificus

Pós-graduação em Biologia Geral e Aplicada - IBB

Avaliação dos efeitos da crotoxina isolada do veneno de serpente Crotalus durissus terrificus sobre a transecção do nervo ciático de ratos: avaliação histológica da formação do neuroma e capacidade de interferir com a condutividade nervosa (dor)

Pós-graduação em Medicina Veterinária - FMVZ

Aspectos clínico, laboratorial e histopatológico da intoxicação experimental pelos venenos das serpentes Bothrops jararaca e Crotalus durissus terrificus em ratos Wistar tratados com antiveneno e Mikania glomerata

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Implicações do parasitismo por nematódeos do gênero Rhabdias(Nematoda, Rhabdiasidae) em Crotalus durissus terrificus (Serpentes, Viperidae): alterações pulmonares, microbiológicas e hematológicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Histórico alimentar das serpentes Crotalus durissus terrificus pela análise do isótopo do carbona-13(δ13C) no guizo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Purificação, caracterização, cristalização e modelagem molecular teórica da fração giroxina do veneno de Crotalus durissus terrificus (Laurenti 1768)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atividade coagulante e da toxidade da giroxina nativa e irradiada com Cobalto-60 isolada do veneno de Crotalus durissus terrificus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)