Zoonotic Cryptosporidium Species in Animals Inhabiting Sydney Water Catchments

Abstract

Cryptosporidium is one of the most common zoonotic waterborne parasitic diseases worldwide and represents a major public health concern of water utilities in developed nations. As animals in catchments can shed human-infectious Cryptosporidium oocysts, determining the potential role of animals in dissemination of zoonotic Cryptosporidium to drinking water sources is crucial. In the present study, a total of 952 animal faecal samples from four dominant species (kangaroos, rabbits, cattle and sheep) inhabiting Sydney’s drinking water catchments were screened for the presence of Cryptosporidium using a quantitative PCR (qPCR) and positives sequenced at multiple loci. Cryptosporidium species were detected in 3.6% (21/576) of kangaroos, 7.0% (10/142) of cattle, 2.3% (3/128) of sheep and 13.2% (14/106) of rabbit samples screened. Sequence analysis of a region of the 18S rRNA locus identified C. macropodum and C. hominis in 4 and 17 isolates from kangaroos respectively, C. hominis and C. parvum in 6 and 4 isolates respectively each from cattle, C. ubiquitum in 3 isolates from sheep and C. cuniculus in 14 isolates from rabbits. All the Cryptosporidium species identified were zoonotic species with the exception of C. macropodum. Subtyping using the 5’ half of gp60 identified C. hominis IbA10G2 (n = 12) and IdA15G1 (n = 2) in kangaroo faecal samples; C. hominis IbA10G2 (n = 4) and C. parvum IIaA18G3R1 (n = 4) in cattle faecal samples, C. ubiquitum subtype XIIa (n = 1) in sheep and C. cuniculus VbA23 (n = 9) in rabbits. Additional analysis of a subset of samples using primers targeting conserved regions of the MIC1 gene and the 3’ end of gp60 suggests that the C. hominis detected in these animals represent substantial variants that failed to amplify as expected. The significance of this finding requires further investigation but might be reflective of the ability of this C. hominis variant to infect animals. The finding of zoonotic Cryptosporidium species in these animals may have important implications for the management of drinking water catchments to minimize risk to public health.

Detection and prevalence of protozoan parasites in ready-to-eat packaged salads on sale in Italy

“…The presence of two additional species of protozoans i.e. B. hominis and D. fragilis -responsible for several gastrointestinal symptoms in humans, and both recognized as responsible or co-responsible for Irritable Bowel Syndrome (Garcia, 2016;Yakoob et al, 2010) -cannot be considered as completely unexpected, since these pathogens are frequently detected in humans worldwide (Garcia, 2016;Wawrzyniak et al, 2013). This includes Italy (Lacasella et al, 2013;Manganelli et al, 2012), where both D. fragilis (Cacciò et al, 2012;Crotti et al, 2007) and B. hominis (Zanzani et al, 2016) have also been detected in animals, thus hypotizing their zoonotic role.…”

“…ubiquitum is considered an emerging zoonotic species (Li et al, 2014;Zahedi et al, 2016), of which, sheep and wild rodents are suspected to be the key source of transmission to humans (Li et al, 2014). The detection of this species of Cryptosporidium requires further studies on its diffusion in Europe and the related risks.…”

Anti-parasitic activity of polyether ionophores

“…Cryptosporidiosis in farm and wild animals is associated with weight loss and mortality, but may also cause zoonotic infections in humans [167][168][169]. It is one of the most common waterborne diseases in humans, and can be found worldwide in both recreational and drinking water [170]. The disease is transmitted by ingestion of food or water contaminated with oocysts shed by infected animals or humans, or by smear infections [171].…”

Molecular characterisation and risk factor analysis of Cryptosporidium spp. in calves from Italy

“…C. parvum is also an important zoonotic species because together with C. hominis, it is involved in most cases of cryptosporidiosis in humans (Xiao 2010). Given that some recent investigations suggest an increasing importance of C. hominis in bovines (Zahedi et al 2016;Razakandrainibe et al 2018), cattle may play an important role as reservoirs of Cryptosporidium species causing human cryptosporidiosis. Cryptosporidial infection is transmitted by the faecal-oral route, and the majority of human cases are waterborne (Fayer et al 2000;Olson et al 2004).…”