Occurrence and multilocus genotyping of Giardia duodenalis from post-weaned dairy calves in Sichuan province, China.

Jiaming Dan,Xueping Zhang,Junliang Deng,Xiaobin Gu,Yanchun Hu,Haifeng Liu,Ziyao Zhou,Xiaoping Ma,Zhijun Zhong,Ya Wang,Hualin Fu,Suizhong Cao,Yi Geng,Guangneng Peng,Shumin Yu,Liuhong Shen,Liqin Wang,Zhihua Ren,Zhuang Zuo ,Chao He

doi:10.1371/journal.pone.0224627

Abstract

Giardia duodenalis is a zoonotic parasitic protist and poses a threat to human and animal health. This study investigated the occurrence of G. duodenalis infection in post-weaned calves from Sichuan province, China. Faecal samples were collected from a total of 306 post-weaned calves (3–12 months old) from 10 farms, including 4 intensive feeding farms and 6 free-ranging farms. The overall infection rate of G. duodenalis was 41.2% (126/306) based on the PCR results at any of the three genetic loci: beta-giardin (bg), triose-phosphate isomerase (tpi) and glutamate dehydrogenase (gdh) genes. Giardia duodenalis assemblages E (n = 115, 91.3%), A (n = 3, 2.4%), and A mixed with E (n = 8, 6.3%) were identified among the 126 positive specimens. Multilocus sequence typing of G. duodenalis revealed 34 assemblage E multilocus genotypes (MLGs), 1 assemblage A MLG and 7 mixed assemblage (A and E) MLGs. The eBURST data showed a high degree of genetic diversity within assemblage E MLGs. The phylogenetic tree revealed that MLG E3 was the primary MLG subtype in Sichuan province and also the most widely distributed in China.

Highlights

Giardia is one of the most common parasitic protists that infects both humans and animals, poses a considerable threat to human and animal health globally [1, 2]
Based on the PCR results at any of the 3 genetic loci, 126 (41.2%) of the 306 faecal specimens tested positive for G. duodenalis, which was similar to the occurrence in Hubei (37.8%, 28/74) [16], but much higher than the majority of provinces in China
multilocus genotypes (MLGs) E3 is the primary founder of clonal complex 1, which is consistent with the results found in Shanghai [28]

Summary

Introduction

Giardia is one of the most common parasitic protists that infects both humans and animals, poses a considerable threat to human and animal health globally [1, 2]. Among the six species of Giardia, only Giardia duodenalis can infect humans and animals (domestic, farmed and wild animals) [3, 4]. The life cycle of Giardia is relatively simple; involving two developmental stages of rapid multiplying trophozoites and infectious cysts, transmitted via the faecal-oral route (i.e., faeces, contaminated water or food) [1, 5]. Humans and animals infected with Giardia usually show symptoms such as diarrhoea, abdominal cramps, weight loss, malabsorption or recessive infections without obvious clinical symptoms [5, 6].

Methods

Results

Conclusion