Molecular characterizations of Cryptosporidium spp. and Enterocytozoon bieneusi in brown rats (Rattus norvegicus) from Heilongjiang Province, China

Abstract

BackgroundCryptosporidium spp. and Enterocytozoon bieneusi are prevalent zoonotic pathogens responsible for the high burden of diarrheal diseases worldwide. Rodents are globally overpopulated and are known as reservoirs or carriers of a variety of zoonotic pathogens including Cryptosporidium spp. and E. bieneusi. However, few data are available on genetic characterizations of both pathogens in rodents in China. The aim of the present work was to determine the prevalence and genetic characterizations of Cryptosporidium spp. and E. bieneusi in brown rats (Rattus norvegicus) from Heilongjiang, China.MethodsA total of 242 wild brown rats were captured in Heilongjiang Province of China. A fresh fecal specimen was collected directly from the intestinal and rectal content of each brown rat. All the fecal specimens were examined for the presence of Cryptosporidium spp. and E. bieneusi by PCR and sequencing of the partial small subunit (SSU) rRNA gene and the internal transcribed spacer (ITS) region of the rRNA gene of the two pathogens, respectively.ResultsThe infection rate was 9.1% (22/242) for Cryptosporidium spp. and 7.9% (19/242) for E. bieneusi. Sequence analysis confirmed the presence of C. ubiquitum (1/22, 4.5%) and three genotypes of Cryptosporidium, including Cryptosporidium rat genotype I (14/22, 63.6%), Cryptosporidium rat genotype IV (6/22, 27.3%) and Cryptosporidium suis-like genotype (1/22, 4.5%). Meanwhile, two E. bieneusi genotypes were identified, including D (17/19, 89.5%) and Peru6 (2/19, 10.5%).ConclusionsTo the best of our knowledge, Enterocytozoon bieneusi genotype Peru6 was identified in rodents for the first time globally and Cryptosporidium rat genotype I and Cryptosporidium rat genotype IV were found in rats in China for the first time. The finding of zoonotic C. ubiquitum and C. suis-like genotype, as well as E. bieneusi genotypes, suggests that brown rats pose a threat to human health. It is necessary to control brown rat population in the investigated areas and improve local people’s awareness of the transmission risk of the two pathogens from brown rats to humans.

Occurrence and genetic characteristics of Cryptosporidium spp. and Enterocytozoon bieneusi in pet red squirrels (Sciurus vulgaris) in China

“…The prevalence of E. bieneusi was 19.4%, which was similar to that in two recent studies in Sichuan province for E. bieneusi infection rates in red-bellied tree squirrels (16.7%, 24/144) 18 and chipmunks (17.6%, 49/279) 17 . The prevalence of E. bieneusi in rodents ranged from 1.1% to 100% (Table 4) 12,19,[28][29][30] . As proposed in other studies, factors contributing to the prevalence of these pathogens may include the examination method, age, sex, season, host health status, feeding density, sample size, geo-ecological conditions, and living conditions [31][32][33] .…”

“…Previous studies have indicated that five Cryptosporidium species and nine Cryptosporidium genotypes exist in various rodents in China (Table 3) 12,22,23 . In this study, five different Cryptosporidium species/genotypes were identified, including Cryptosporidium rat genotypes I and II, Cryptosporidium ferret genotype, Cryptosporidium chipmunk genotype III, and C. parvum.…”

“…rats (89.5%, 17/19) and red-bellied tree squirrels (75%, 18/24) in China 12,18 . In China, genotype D has been identified in humans and various animals, such as nonhuman primates, cattle, sheep, horses, pigs, dogs, cats, and in wastewater 14,[47][48][49] .…”

“…have been described 11 . Among them, 11 Cryptosporidium species have been identified in rodents, Cryptosporidium parvum and C. muris are the most common 12 . For E. bieneusi, more than 474 genotypes have been identified based on the internal transcribed spacer (ITS) region of the rRNA gene 13 , and more than 35 genotypes have been determined in rodents 14 .…”

“…www.nature.com/scientificreports www.nature.com/scientificreports/ rodents (Table 3)12,25,27 . In addition, C. parvum has also been found in other animals, such as cattle, sheep, goats, deer, alpacas, horses, dogs, gray wolves, raccoon dogs, cats, and pigs43,44 .…”