ABSTRACT
African pygmy hedgehogs (Atelerix albiventris) are widely farmed in southern China and Japan for medicinal materials and as pets. However, little is known about the prevalence, zoonotic potential, and environmental burden of Cryptosporidium spp., Enterocytozoon bieneusi and Giardia duodenalis in these animals. In this study, 380 fecal samples were collected from farmed and pet African pygmy hedgehogs in Guangdong of China, and analyzed for these pathogens by PCR and DNA sequencing. Overall, the detection rates of Cryptosporidium spp., E. bieneusi and G. duodenalis were 35.5%, 70.0% and 0, respectively. By living condition, the highest detection rates of Cryptosporidium spp. (61.5%) and E. bieneusi (100.0%) were both obtained from animals kept in the cave, which could be due to the overcrowding and poor hygiene conditions. Two Cryptosporidium species were identified, including C. erinacei (n = 22) and Cryptosporidium horse genotype (n = 113). The C. erinacei isolates belonged to a new subtype family (XIIIb), which has been identified in a patient with cryptosporidiosis recently. The horse genotype isolates are of a known subtype VIbA13, which was previously identified in a pet store employee in care of hedgehogs with diarrhea. Eleven genotypes of the zoonotic Group 1 were identified in E. bieneusi, with the known genotype SCR05 previously detected in pet rabbits being dominant (235/266, 88.3%). In longitudinal monitoring of Cryptosporidium infection in 11 naturally infected African pygmy hedgehogs, the oocyst shedding intensity decreased gradually from the mean oocysts per gram of feces of â¼6 logs to â¼2 logs over 42 days. The high intensity and long duration of oocyst shedding could lead to heavy environmental contamination and increase the potential for zoonotic transmission of the pathogens. Results of the study suggest that zoonotic Cryptosporidium spp. and E. bieneusi are common in farmed and pet African pygmy hedgehogs. Hygiene and One Health measures should be implemented by pet owners and farmers to prevent zoonotic transmission and environmental contamination of Cryptosporidium spp. and E. bieneusi.
ABSTRACT
Calcium-dependent protein kinases (CDPKs) are important in calcium influx, triggering several biological processes in Cryptosporidium spp. As they are not present in mammals, CDPKs are considered promising drug targets. Recent studies have characterized CpCDPK1, CpCDPK3, CpCDPK4, CpCDPK5, CpCDPK6, and CpCDPK9, but the role of CpCPK2A remains unclear. In this work, we expressed recombinant CpCDPK2A encoded by the cgd2_1060 gene in Escherichia coli and characterized the biologic functions of CpCDPK2A using qRT-PCR, immunofluorescence microscopy, immuno-electron microscopy, and in vitro neutralization. The results revealed that CpCDPK2A protein was highly expressed in the apical region of sporozoites and merozoites and in macrogamonts. Monoclonal or polyclonal antibodies against CpCDPK2A failed to block the invasion of host cells. Among the 44 candidate inhibitors from molecular docking of CpCDPK2A, one inhibitor was identified as having a potential effect on both Cryptosporidium parvum growth and CpCDPK2A enzyme activities. These data suggest that CpCDPK2A may play some roles during the development of C. parvum and might be a potential drug target against cryptosporidiosis.
ABSTRACT
Diarrhoea is one of the most important syndromes in neonatal calves. In industrialized nations with intensive animal farming, Cryptosporidium spp. and rotavirus are primary causes of calf diarrhoea, but the role of these and other enteric pathogens is not clear in China. In November and December 2018, a diarrhoea outbreak was identified in over 150 pre-weaned calves on a dairy farm in Heilongjiang Province, northeast China and approximately 60 calves died. To determine the cause of the outbreak, we analyzed 131 faecal samples collected from pre-weaned calves (0-2 months) during (n = 114) and after the outbreak (n = 17). Initially, 10 diarrheic samples during the outbreak and 10 non-diarrheic samples after the outbreak were screened for rotavirus, coronavirus, Escherichia coli K99 and Cryptosporidium parvum by using an enzymatic immunoassay (EIA). In addition, 81 other samples were tested specifically for rotavirus by EIA, and all 131 samples were analyzed for Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi by PCR. The initial EIA analysis identified C. parvum (8/10) and rotavirus (5/10) as the dominant pathogens in calves during the outbreak, while both pathogens were detected at lower frequency after the outbreak (2/10 and 1/10, respectively). Further PCR analyses indicated that the occurrence of C. parvum infections in calves was significantly higher during the outbreak (75.4%, 86/114) than after the outbreak (11.8%, 2/17; odds ratio [OR] = 23.0), and was significantly associated with the occurrence of watery diarrhoea (OR = 15.7) and high oocyst shedding intensity. All C. parvum isolates were identified as subtype IIdA20G1. Among other pathogens analyzed, the overall prevalence of rotavirus, G. duodenalis and E. bieneusi was 19.8% (20/101), 38.9% (51/131) and 42.0% (55/131) in calves, respectively, without significant differences during and after the outbreak. Among the three pathogens, only the rotavirus infection was associated with diarrhoea in calves. More importantly, coinfections of C. parvum and rotavirus were significantly associated with the occurrence of watery diarrhoea in calves and were seen only during the outbreak. Thus, C. parvum subtype IIdA20G1 and rotavirus appeared to be responsible for this diarrhoea outbreak. Control measures should be implemented to effectively prevent the concurrent transmission of these enteric pathogens in pre-weaned dairy calves in China.
