Captive-bred neotropical birds diagnosed with Cryptosporidium Avian genotype III

Abstract

Currently, there are only three valid species of Cryptosporidium infecting avian hosts, namely, Cryptosporidium meleagridis, Cryptosporidium baileyi, Cryptosporidium galli and Cryptosporidium avium in addition to 12 genotypes of unknown species status. The objectives of this study were to microscopically diagnose the presence of Cryptosporidium in birds from a commercial aviary located in Rio de Janeiro, Brazil; genotypically characterize species and/or genotypes of genus Cryptosporidum; and conduct sequencing and phylogenetic analyses to compare the obtained DNA sequences with those deposited in GenBank. A total of 85 fecal samples were collected from wild captive-bred birds: 48 of family Psittacidae and 37 of family Ramphastidae. Initially, a search for the presence of Cryptosporidium sp. oocysts was conducted using the centrifugal-flotation in saturated sugar solution technique, after that, the collected samples were analyzed microscopically. Cryptosporidium infections were only detected in 24.32% of samples belonging to the family Ramphastidae. DNA was extracted from positive samples and molecular diagnostics was applied targeting the 18S rRNA gene, followed by sequencing and phylogenetic analysis. The Cryptosporidium Avian genotype III was diagnosed in this study more closely related to the gastric species. This is the first record of Cryptosporidium Avian genotype III in order Piciformes and family Ramphastidae, where three host species (Ramphastus toco, Ramphastus tucanus, and Pteroglossus bailloni) were positive for the etiologic agent. Based on the molecular data obtained, these wild birds raised in captivity do not represent a source of human cryptosporidiosis, considering that Cryptosporidium Avian genotype III does not constitute a zoonosis.