Cryptosporidium Species and C. parvum Subtypes in Farmed Bamboo Rats

Abstract

Bamboo rats (Rhizomys sinensis) are widely farmed in Guangdong, China, but the distribution and public health potential of Cryptosporidium spp. in them are unclear. In this study, 724 fecal specimens were collected from bamboo rats in Guangdong Province and analyzed for Cryptosporidium spp. using PCR and sequence analyses of the small subunit rRNA gene. The overall detection rate of Cryptosporidium spp. was 12.2% (88/724). By age, the detection rate in animals under 2 months (23.2% or 13/56) was significantly higher than in animals over 2 months (11.2% or 75/668; χ2 = 6.95, df = 1, p = 0.0084). By reproduction status, the detection rate of Cryptosporidium spp. in nursing animals (23.1% or 27/117) was significantly higher than in other reproduction statuses (6.8% or 4/59; χ2 = 7.18, df = 1, p = 0.0074). Five Cryptosporidium species and genotypes were detected, including Cryptosporidium bamboo rat genotype I (n = 49), C. parvum (n = 31), Cryptosporidium bamboo rat genotype III (n = 5), C. occultus (n = 2), and C. muris (n = 1). The average numbers of oocysts per gram of feces for these Cryptosporidium spp. were 14,074, 494,636, 9239, 394, and 323, respectively. The genetic uniqueness of bamboo rat genotypes I and III was confirmed by sequence analyses of the 70 kDa heat shock protein and actin genes. Subtyping C. parvum by sequence analysis of the 60 kDa glycoprotein gene identified the presence of IIoA15G1 (n = 20) and IIpA6 (n = 2) subtypes. The results of this study indicated that Cryptosporidium spp. are common in bamboo rats in Guangdong, and some of the Cryptosporidium spp. in these animals are known human pathogens.

Zoonotic parasites in farmed exotic animals in China: Implications to public health

“…As expected, young animals were reported to have higher prevalence of Cryptosporidium spp. than older animals ( Chen et al, 2019a ; Li et al, 2020a , 2020b ; Qian et al, 2020 ; Zhang et al, 2016a ; Zhao et al, 2019 ). In crab-eating macaques, animals with diarrhea had higher occurrence of Cryptosporidium infection ( Chen et al, 2019a ).…”

“…The reported infection rates varied greatly among studies for each species of the animals examined ( Table 1 ). This has been attributed to levels of hygiene in the study facilities ( Li et al, 2020b ). The highest infection rates were reported as 9.1% in crab-eating macaques, 15.9% in foxes, 20.5% in raccoon dogs, 29.4% in bamboo rats, and 29.6% in minks ( Table 1 ).…”

“…Among them, C. parvum was one of the dominant species in the a few studies conducted in southern China. Other common genotypes include Cryptosporidium bamboo rat genotypes I and IIII, which are genetically related to C. ubiquitum and C. parvum , respectively ( Li et al, 2020b ). The remaining species and genotypes ( C. occultus , C. muris , and bamboo rat genotype II) have been found in only a few animals ( Table 1 ), thus could represent native parasites of other rodents.…”

“…The intensity of oocyst shedding was higher when animals were infected with C. parvum and C. parvum -like genotype (bamboo rat genotype III) than with other Cryptosporidium spp. ( Li et al, 2020a , 2020b ).…”

“…The C. parvum subtypes found in bamboo rats belong mostly to two divergent subtype families (IIo and IIp) of C. parvum , which are genetically related to the IId subtype family and have been thus far reported only in Asia ( Li et al, 2020a ; Liu et al, 2015 ; Wei et al, 2019 ). Two subtypes of each subtype family have been identified in bamboo rats from various areas, including IIoA13G1, IIoA15G1, IIpA6 and IIpA9 ( Li et al, 2020a , 2020b ; Liu et al, 2015 ; Wei et al, 2019 ). One bamboo rat was identified as having the C. parvum IIdA15G1 subtype ( Wei et al, 2019 ).…”