Molecular Survey of Toxoplasma gondii in Wild Mammals of Southern Italy

Abstract

Systematic wildlife surveillance is important to aid the prevention of zoonotic infections that jeopardize human health and undermine biodiversity. Toxoplasma gondii is an opportunistic zoonotic protozoan that can infect all endothermic vertebrates, causing severe disease in immunocompromised humans and cases of congenital transmission. Humans can be infected by ingestion of raw meat containing bradyzoites or water contaminated by oocysts. In our study, we assessed the potential circulation of Toxoplasma gondii in wild mammals by performing surveillance in the Campania region (southern Italy) and surveyed its presence from 2020 to 2022 within the framework of the Regional Plans for Wildlife Surveillance. In detail, 211 individuals belonging to five wild mammals (wolf, fox, wild boar, badger, and roe deer) underwent necropsy and the organs were analyzed by real-time PCR for the detection of the parasite. Toxoplasma gondii was found in 21.8% (46/211) of the subjects examined. No statistically significant differences were noticed between the prevalence and the host’s trophic level or age, rejecting the hypotheses that Toxoplasma gondii will have a higher prevalence in top predators and adult individuals, respectively. Our work emphasized the high circulation of Toxoplasma gondii in wildlife and remarked on the critical role of anthropized areas where domestic cats and wildlife may come into contact, urging a systematic surveillance.

Sero-epidemiological investigation on Toxoplasma gondii infection in Apennine wolf (Canis lupus italicus) and wild boar (Sus scrofa) in Italy

“…When comparing seroprevalences between wolves and wild boars, despite wolves occupying higher trophic levels and exhibiting a higher prevalence of T. gondii , no statistically significant differences were observed between these two populations. This finding aligns with the results of Dakraub et al [ 4 ]. Reliable T. gondii seroprevalence data for wolves in European countries, including Italy, are notably scarce.…”

“…Reliable T. gondii seroprevalence data for wolves in European countries, including Italy, are notably scarce. Recent reports from Italy have indeed documented seropositivity in wolves, albeit with relatively small sample sizes: Dini et al [ 33 ] identified one positive wolf out of 5 samples, while Dakraub et al [ 4 ] reported 4 positives out of 14. In other European countries, such as Spain, a seroprevalence rate of 46.9% was observed ( n = 32 wolves sampled) [ 34 ].…”

“…In Italy, the native European wildcat ( Felis silvestris silvestris ) maintains a relatively small population size in the wild, despite beingclassified as Least Concern in the IUCN Red List of Threatened Species [ 3 ]. However, free-roaming domestic cats are prevalent in rural and peri-urban regions [ 4 ].…”

Food and Drinking Water as Sources of Pathogenic Protozoans: An Update

“…Up to 70% of the cat population is infected with T. gondii, and cats can shed millions of oocysts in their feces. Oocysts may survive for several years in the environment and infect intermediate hosts through water and food [11,[157][158][159][160][161][162]. Upon infection, the parasites differentiate into tachyzoites that rapidly divide asexually and spread in the body, causing toxoplasmosis [160,161].…”

“…Humans and animals can become infected with T. gondii also through the ingestion of the parasite in the form of tissue cysts containing slowly replicating bradyzoites [161,162] that originate from tachyzoites and can differentiate back into tachyzoites [160].…”