Diagnosis of endoparasite species and subtypes of Cryptosporidium spp. with one health importance, in feces from captive snakes in Rio de Janeiro, Brazil

In captivity, snakes may present chronic infections with high mortality, such as those caused by Cryptosporidium serpentis, or they may be pseudoparasitized by species that present zoonotic potential. Thus, the aim of this study was to evaluate the frequency of helminths and protozoa in the feces of captive snakes, characterize the species and subtypes of Cryptosporidium spp. and correlate the parasites detected with other information obtained from these animals. Feces were collected from 189 snakes kept at the Vital Brazil Institute, Rio de Janeiro, including samples from Bothrops jararaca, Bothrops jararacussu, Bothrops moojeni, Bothrops atrox, Bothrops leucurus, Crotalus durissus and Lachesis muta. All the samples were subjected to microscopy techniques and the polymerase chain reaction (PCR) in association with sequencing, to identify Cryptosporidium spp.. Forms of parasites infecting the snakes were identified through microscopy in 50.8% of the samples. Helminths were detected more often than protozoa in the feces of these animals, mainly comprising eggs resembling Kalicephalus sp. and oocysts of Eimeria sp.. Pseudoparasites such as Syphacia sp., Aspiculuris sp. and Hymenolepis nana were also detected. Through correlating the results obtained from parasitological staining techniques and PCR, the total frequency of Cryptosporidium sp. was found to be 19%. The species C. tyzzeri and C. parvum were identified. Characterization using the target gp60 showed subtypes with high potential for zoonotic transmission, especially IIaA15G2R1 and IIaA14G2R1 of C. parvum and IXbA8 of C. tyzzeri. This study highlighted the need for more intensive health management in the Institute's serpentarium and, especially, in its bioterium where rodents are reared as a food source for these snakes.