Molecular Detection and Multilocus Genotyping of Giardia duodenalis in Pigs in Fujian Province, Southeastern China

SIMPLE SUMMARY: Giardia duodenalis is a world-widely distribution intestinal protozoan parasite that can infect human and a broad range of mammals. It can cause a number of clinical symptoms including diarrhoea, abdominal pain, vomiting, severe dehydration and anemia etc. in animals and humans. Eight genetic assemblages (A to H) have been identified in G. duodenalis based on molecular analysis. In this study, the infection rates and genotypes of G. duodenalis in swine are investigated in Fujian province, southeastern China. G. duodenalis assemblages E was found in pigs in the present study. These results provide epidemiological data for giardiasis prevention, control and public health. ABSTRACT: Giardia duodenalis, an intestinal parasite, is widely distributed in humans and various animals, such as pigs, cattle and cats. The clinical symptoms of giardiasis are characterized as including abdominal pain, acute or chronic diarrhea, and bloating and weight loss in humans and animals, leading to public and veterinary health problems worldwide. However, the prevalence and genotypes of G. duodenalis in pigs in Fujian Province, southeastern China, have not been reported. In the present study, 725 fecal samples were collected from six cities (Fuqing, Putian, Nanping, Longyan, Sanming, Zhangzhou) in Fujian Province and analyzed for G. duodenalis prevalence and genotypes using nested PCR targeting the beta-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes. The results shown that total occurrence rate of G. duodenalis was 26.9% (195/725) in pigs, with significant differences in the prevalence among different regions (χ(2) = 86.508, p < 0.05) and groups (χ(2) = 12.748, p < 0.05). 195, 11 and 6 samples were detected at the bg, tpi and gdh loci, respectively. Each one belonged to a subtype of assemblage E and was analyzed using sequences obtained in this study. Based on phylogenetic analyses of sequences from the three genetic loci, only one MLG E1 was found. The results indicated that pigs may present a potential zoonotic risk of spreading G. duodenalis infection from animals to humans in this area. The findings of the present study also provide basic data for the prevention and control of G. duodenalis infection in pigs and humans in China.