Gastrointestinal Parasites in Captive Animals at the Rio de Janeiro Zoo.

BACKGROUND: Gastrointestinal parasites may determine diarrhea, dysentery or even death in captive mammals. These animals tend to be more susceptible to parasitic infections due to confinement and stress. Purpose To increase the information about these etiological agents in captive animals in Brazil, the gastrointestinal parasites of the captive mammals of the Rio de Janeiro Zoo were investigated. METHODS: From 2016 to 2018, 180 fecal samples were collected from animals housed in the Rio de Janeiro Zoo: 63 from animals of the order Primates, 26 of Carnivora, 78 of Artiodactyla, 9 of Perissodactyla and 4 of the order Rheiformes. The feces were processed by direct examination and by the techniques of Faust et al., Sheather, Ritchie, Lutz, and smears were stained with safranin. Immunoenzymatic assays were also performed to investigate antigens of Giardia duodenalis, Cryptosporidium spp., Entamoeba histolytica/Entamoeba dispar. RESULTS: Parasite positivity was identified in 68.3% of the fecal samples, with a parasite positivity rate of 68.2% among primates, 65.3% among carnivores, 69.2% among artiodactyls, 33.3% among perissodactyls, and 100% among rheiformes. The most frequently detected parasite was Entamoeba histolytica/E. dispar antigens, which showed a statistically significant positivity rate (33.3%; p = 0.000), particularly in the feces of carnivores (30.7%) and artiodactyls (53.8%). A statistically significant positivity rate of Balantioides coli (11.1%; p = 0.001) was also detected in feces from nonhuman primates, tapirs, collared peccaries and rheas. The positivity of Cryptosporidium sp. antigens in feces of the orders Carnivora, Artiodactyla and Primates was also statistically significant (7.2%, p = 0.010). Oocysts compatible with Cryptosporidium spp. were detected in 6.3% from primates. The helminths most frequently detected were thin-shelled eggs of nematodes (17.7%, p = 0.000), nematode larvae (15.5%, p = 0.000) and Trichuris trichiura eggs (6.1%, p = 0.018). CONCLUSION: The positivity rate for gastrointestinal parasites demonstrates the need for a sanitation management program to be implemented in the zoo, including routine diagnostic parasitology tests followed by specific treatment for each parasitosis.

First molecular characterization of Balantioides coli (Malmsten, 1857) isolates maintained in vitro culture and from feces of captive animals, Rio de Janeiro, Brazil.

Ciliate protozoa of the genus Balantioides can parasitize a variety of animals. The morphology of the evolutionary forms of the parasite and the host species affected have long been the only characteristics used to taxonomically identify the species of these protozoa, but these variables are not very precise. To confirm species identity, molecular biology tools are currently used. In this context, this study aimed to analyze protozoan isolates maintained in culture medium and from fecal samples from captive animals in Rio de Janeiro, Brazil, by means of molecular tools. Forty isolates maintained in Pavlova modified medium (30 were isolated from feces of pigs and 10 from feces of cynomolgus macaques) were analyzed. In addition, 34 fecal samples (8 from pigs, 8 from cynomolgus macaques and 18 from rhesus macaques) containing Balantioides coli-like cysts were analyzed. All samples were subjected to DNA extraction and the polymerase chain reaction (PCR) to amplify the fragment ITS1 - 5.8s rRNA - ITS2, and the PCR products were purified and sequenced. All samples (100%) presented sequences that were grouped in the Balantioides coli cluster. The type A0 variant predominated. These sequences were 96% to 99% identical to those deposited in GenBank, including a B. coli sequence that had been obtained from human fecal material in Bolivia. It seems that the culturing system did not select variants, because this variant was also seen in the amplified sequences of fecal samples containing cysts. The isolate sequences in the cultures showed few ambiguities and substitutions, thus generating reliable chromatograms. This was the first study to identify B. coli in captive animals in Brazil, through molecular biology. In addition, it was the first to evaluate a large panel of isolates of the parasite through culturing.