Identification of Cryptosporidium viatorum XVa subtype family in two wild rat species in China

Abstract

BackgroundCryptosporidium viatorum is a minor Cryptosporidium pathogen in humans. Currently, there is limited information regarding the prevalence and genotypes of C. viatorum in animals in China.MethodsIn this study, 228 faecal samples were collected from two wild rat species (Leopoldamys edwardsi and Berylmys bowersi) in Chongqing Municipality and Guangdong Province, China. These specimens were analyzed for C. viatorum and then subtyped it using PCR and sequence analysis of the small subunit ribosomal RNA (SSU rRNA) and 60-kilodalton glycoprotein (gp60) genes, respectively.ResultsA total of 25 (11.0%) faecal samples were tested positive for C. viatorum by SSU rRNA assay. Of these samples, 4 (3.6%) came from L. edwardsi and 21 (18.0%) from B. bowersi. Of the 25 C. viatorum-positive samples, 17 were successfully amplified at the gp60 gene locus, which represented four subtypes belonging to two subtype families, including XVa (XVaA6, XVaA3g, XVaA3h) and XVc (XVcA2G1). Phylogenetic analysis based on the gp60 amino acid sequences indicated that all of the C. viatorum isolates grouped together, supporting the conclusion that C. viatorum from the wild rats represent two subtype families.ConclusionsThese results indicate an occurrence of C. viatorum XVa subtype family from rats which is genetically identical to those found in humans. Our findings suggest that wild rats may be a potential source of human cryptosporidiosis.

Identification of Uncommon Cryptosporidiumviatorum (a Novel Subtype XVcA2G1c) and Cryptosporidium andersoni as Well as Common Giardia duodenalis Assemblages A and B in Humans in Myanmar

“…The same subtypes (XVaA3h and XVaA3g) have been identified in humans (Braima et al, 2019;Xu et al, 2020) and rats (Chen et al, 2019) (Tables 5, 6). In the present study, a novel subtype (XVcA2G1c) was identified in humans for the first time, which had the largest similarity of 99.88% (onebase difference) with that (XVcA2G1) from a Bower's whitetoothed rat in China (Chen et al, 2019). These results above indicated the large potential of zoonotic transmission of C. andersoni and C. viatorum.…”

“…C. viatorum was initially thought to occur exclusively in humans. However, it has also been detected in some rat species in Australia (Koehler et al, 2018) and China (Chen et al, 2019;Zhao et al, 2019). The same subtypes (XVaA3h and XVaA3g) have been identified in humans (Braima et al, 2019;Xu et al, 2020) and rats (Chen et al, 2019) (Tables 5, 6).…”

High Diversity of Cryptosporidium Species and Subtypes Identified in Cryptosporidiosis Acquired in Sweden and Abroad

“…This species was initially thought to be anthroponotic because only human cases had been detected until 2018, when the first non-human host, an Australian swamp rat, was identified [67,68]. This swamp rat isolate was genetically quite different from all known human isolates, but recent studies from China focusing on different rat species have found C. viatorum isolates genetically similar to human isolates, and subtyping with gp60 has demonstrated the same subtype, XVaA3g, in wild rats from China and a human from Australia [37,69].…”

Genotyping and subtyping of Cryptosporidium spp. and Giardia duodenalis isolates from two wild rodent species in Gansu Province, China

“…To date, a total of 13 Cryptosporidium spp. species and 19 genotypes have been detected in 16 studies of various rodents in China, including those obtained in this study (Table2)[19,[26][27][28][29][30][31][32][33][34][35][36][38][39][40]. Among them,11 species have been detected in humans: C. parvum, C. muris, C. ubiquitum, C. andersoni, C. occultus, C. viatorum, C. canis, C. suis, C. erinaceid, C. tyzzeri and horse genotype 4.…”

“…At the bg locus, ve assemblage B sequences shared 100% homology with squirrel monkey-derived assemblage B isolate (KJ888974) from China, one assemblage A sequence had 100% homology with humanspp. in wild rodent species in China than this study, including in house mice (3.2%, 1/31), long-tailed rats (3.6%, 4/111 and 55.3%, 21/38), brown rats (6.3%, 4/64; 9.1%, 22/242 and 28.6%, 16/56), wild plateau pikas (6.3%, 4/64), Qinghai voles (8.9%, 8/90), Asian house rats (18.0%, 21/117; 18.2%, 6/33 and 73.9%, 4/46), Brandt's voles (18.7%, 127/678), Muridae (40.0%, 4/10)[19,[26][27][28][29][30][31]. The prevalence in this study was also lower than that in some pet rodent species, including in bamboo rats (3.3%, 3/92), further identi ed as novel subtype VIbA10.…”