Gastrointestinal Parasites in Non-Human Primates in Zoological Gardens in Northern Italy

Non-human primates, due to their close taxonomic relationship with humans, host the highest diversity of parasites with zoonotic potential. In zoological gardens, the presence of helminths and protist parasites with a direct lifecycle is virtually unavoidable; biosecurity measures are of the utmost importance to control their spread and environmental load and avoid transmission to staff and visitors. In this study, we investigated the population of non-human primates in two zoos in Northern Italy to evaluate gastrointestinal parasite diversity and their zoonotic potential. The highest prevalence was registered for protist taxa, i.e., Giardia and Blastocystis. Proof for the transmission of parasites from synanthropic rats to the animals in the collection was also provided. Non-human primates (NHPs) host a variety of helminth and protist parasites that are able to cause infection in humans. Gastrointestinal parasites in NHPs living in two zoological gardens of Northern Italy were studied. An total of 96 faecal pools were collected from 26 groups of NHPs. The mini-Flotac method was applied to fecal samples to detect gastrointestinal helminthiases, while the detection of the protists Cryptosporidium spp., Blastocystis sp. and Giardia duodenalis was performed by targeting SSU rRNA through nested PCR and real-time PCR; they were further studied by sequencing the same gene for Blastocystis and beta giardine and triosephosphate isomerase (TPI) genes for Giardia. Twenty-two out of the 96 examined fecal pools (22.9%) were positive for one or more helminth species, including Hymenolepis diminuta, Trichurid, Capillariid and Strongylid eggs. All samples were negative for Cryptosporidium spp., while 16/26 (61.5%) animals were positive for G. duodenalis in the real-time PCR; the sequences obtained assigned them all to sub-assemblage BIV. Blastocystis sp. was detected in 22/26 of the NHPs (84.6%); molecular analyses attributed the isolates to ST 4, allele 92. Analyses of the feces of sympatric rats revealed the presence of the same allele, as well as of Hymenolepis diminuta eggs, raising concern about their role as parasite reservoirs in the facilities.