Frequency and molecular characterisation of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, and Entamoeba hartmanni in the context of water scarcity in northeastern Brazil

This study aimed to estimate the frequency, associated factors, and molecular characterisation of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, andEntamoeba hartmanni infections. We performed a survey (n = 213 subjects) to obtain parasitological, sanitation, and sociodemographic data. Faecal samples were processed through flotation and centrifugation methods.E. histolytica, E. dispar, E. moshkovskii, and E. hartmanni were identified by nested-polymerase chain reaction (PCR). The overall prevalence of infection was 22/213 (10.3%). The infection rate among subjects who drink rainwater collected from roofs in tanks was higher than the rate in subjects who drink desalinated water pumped from wells; similarly, the infection rate among subjects who practice open defecation was significantly higher than that of subjects with latrines. Out of the 22 samples positive for morphologically indistinguishableEntamoeba species, the differentiation by PCR was successful for 21. The species distribution was as follows: 57.1% to E. dispar, 23.8% to E. histolytica, 14.3% toE. histolytica and E. dispar, and 4.8% E. dispar and E. hartmanni. These data suggest a high prevalence of asymptomatic infection by the group of morphologically indistinguishable Entamoeba histolytica/dispar/moshkovskiicomplex and E. hartmanni species. In this context of water scarcity, the sanitary and socioenvironmental characteristics of the region appear to favour transmission.

Parasitological and immunological diagnoses from feces of captive-bred snakes at Vital Brazil Institute / Diagnóstico parasitológico e imunológico em fezes de serpentes cativas do Instituto Vital Brazil

Fecal samples from 56 snakes at the Vital Brazil Institute, in the city of Niterói, Rio de Janeiro, were tested using the sedimentation and flotation techniques to investigate the evolutionary forms of parasites such as helminths and protozoa, and using enzyme immunoassay techniques to detect antigens of Cryptosporidium sp. and Giardia sp. Among the animals tested, 80.3% were positive for parasites. Out of these, there were 16 Bothrops jararaca, 16 B. jararacussu and 13 Crotalus durissus. The prevalence of parasitic nematodes was 41.1%, and nematodes were found in all three snake species. Among these, the most frequent finding was eggs of Kalicephalus sp., which were diagnosed in 25% of the snakes. The positivity for protozoa detected using parasite concentration techniques was 75%, including oocysts of Caryospora sp. in 75%, cysts with morphology similar to Giardia sp. 3.6%, amoeboid cysts in 41.1% and unsporulated coccidia oocysts in 8.9%. Immunoassays for Cryptosporidium sp. antigens produced positive findings in 60.7%. Pseudoparasites were detected in 64.3%. These results show that there is a need to improve the sanitary handling of captive-bred snakes, and also for the animal house that supplies rodents to feed them. The results also highlight that diagnostic tests should be performed periodically on stool specimens from captive-bred snakes.

Foram analisadas amostras fecais de 56 serpentes do Instituto Vital Brazil, Niterói, Rio de Janeiro, por técnicas de sedimentação e flutuação, para pesquisa de formas evolutivas de parasitos como helmintos e protozoários, e imunoenzimáticas para detecção de antígenos de Cryptosporidium sp. e Giardia sp. Dos animais estudados, 80,3% foram positivos para parasitos, dos quais 16 pertenciam à espécie Bothrops jararaca, 16 à B. jararacussu e 13 à Crotalus durissus. A prevalência de nematódeos parasitos foi de 41,1%, sendo evidenciados nas três espécies de serpentes. Dentre estes, o mais frequente foi o encontro de ovos de Kalicephalus sp., diagnosticado em 25% das serpentes. A positividade para protozoários detectados pelas técnicas de concentração foi de 75%, nas quais oocistos de Caryospora sp. foram detectados em 75%, cistos com morfologia similar a Giardia sp. em 3,6%, cistos de amebídeos em 41,1% e oocistos não esporulados de coccídios em 8,9%. Obteve-se positividade para antígenos de Cryptosporidium sp. por imunoensaio em 60,7%. Pseudoparasitos foram detectados em 64,3%. Estes resultados apontam para a necessidade de aprimoramento do manejo sanitário das serpentes cativas, bem como no biotério que fornece roedores para sua alimentação, destacando a realização periódica de diagnóstico nas amostras fecais de serpentes cativas.