ABSTRACT
Enterovirus A71 (EVA71) belongs to the Picornaviridae family and is the main etiological agent of hand, foot, and mouth disease (HFMD). There is no approved antiviral against EVA71, and therefore the search for novel anti-EVA71 therapeutics is essential. In this context, the antiviral activity of proteins isolated from snake venoms has been reported against a range of viruses. Here, the proteins CM10 and CM14 isolated from Bothrops moojeni, and Crotamin and PLA2CB isolated from Crotalus durissus terrificus were investigated for their antiviral activity against EVA71 infection. CM14 and Crotamin possessed a selective index (SI) of 170.8 and 120.4, respectively, while CM10 and PLA2CB had an SI of 67.4 and 12.5, respectively. CM14 inhibited all steps of viral replication (protective effect: 76 %; virucidal: 99 %; and post-entry: 99 %). Similarly, Crotamin inhibited up to 99 % of three steps. In contrast, CM10 and PLA2CB impaired one or two steps of EVA71 replication, respectively. Further dose-response assays using increasing titres of EVA71 were performed and CM14 and Crotamin retained functionality with high concentrations of EVA71 (up to 1000 TCID50). These data demonstrate that proteins isolated from snake venom are potent inhibitors of EVA71 and could be used as scaffolds for future development of novel antivirals.
Subject(s)
Crotalid Venoms , Enterovirus Infections , Enterovirus , Hand, Foot and Mouth Disease , Animals , Brazil , Proteins , Antiviral Agents/pharmacology , Antigens, Viral , Snakes , Phospholipases A2ABSTRACT
The aim of the present study was to verify the occurrence of hemogregarines in the colubrid snake Thamnodynastes lanei from the eastern Amazon region of Brazil. Intraerythrocytic gamonts with mean dimensions of 14.8 ± 1.8 × 4.0 ± 0.7 µm and encapsulated gamonts with mean dimensions of 15.3 ± 1.1 × 4.8 ± 0.5 µm were observed. Through morphological and molecular data based on the partial 18S rDNA gene, the parasite was identified as Hepatozoon cevapii, originally described in the viperid snake Crotalus durissus terrificus from the southeast region of Brazil. Thus, the findings of the present study extend the geographic range of H. cevapii and provide novel Hepatozoon-snake associations.
Subject(s)
Colubridae , Eucoccidiida , Animals , Brazil , Colubridae/parasitology , Eucoccidiida/isolation & purificationABSTRACT
Abstract The current study aimed to verify the relationship between the patterns of coloration, the morphometrical features and pholidosis of specimens of Philodryas patagoniensis from Brazil, with the sexual dimorphism of this species. We studied specimens of P. patagoniensis deposited in several herpetological collections from Brazil. A total of 355 specimens were analyzed, of these 145 were males (87 adults and 58 juveniles) and 210 were females (134 adults and 76 juveniles). Adult specimens exhibit sexual dimorphism in snout-vent length, tail length, head length, number of ventral shields, and number of subcaudal shields. The analysis of variance showed that the adult females are significantly longer than adult males, both at snout-vent length and tail length. Females have a greater number of ventral shields (138-210) than males (151-200). The specimens studied also exhibit two distinct patterns of coloration unrelated to geographical or sexual variations.
Resumo O presente estudo objetivou verificar a relação entre os padrões de coloração, as características morfométricas e a folidose de espécimes de Philodryas patagoniensis existentes no Brasil, com o dimorfismo sexual dessa espécie. Foram estudados espécimes de P. patagoniensis depositados em várias coleções herpetológicas do Brasil. Um total de 355 espécimes foram analisados, destes 145 eram machos (87 adultos e 58 filhotes) e 210 fêmeas (134 adultos e 76 filhotes). Espécimes adultos apresentam dimorfismo sexual no comprimento rostro-cloacal, comprimento da cauda, comprimento da cabeça, número de escudos ventrais e número de escudos subcaudais. A análise de variância mostrou que fêmeas adultas são significativamente maiores que machos adultos, tanto no comprimento rostro-cloacal quanto no comprimento da cauda. Fêmeas possuem maior número de escudos ventrais (138-210) que machos (151-200). Os espécimes estudados apresentam dois padrões distintos de coloração não relacionadas a variações geográficas ou sexuais.
