Genotypes of Cryptosporidium from Sydney water catchment areas

Abstract

Aims: Currently cryptosporidiosis represents the major public health concern of water utilities in developed nations and increasingly, new species and genotypes of Cryptosporidium are being identified in which the infectivity for humans is not clear. The complicated epidemiology of Cryptosporidium and the fact that the majority of species and genotypes of Cryptosporidium cannot be distinguished morphologically makes the assessment of public health risk difficult if oocysts are detected in the raw water supplies. The aim of this study was to use molecular tools to identify sources of Cryptosporidium from the Warragamba catchment area of Sydney, Australia. Methods and Results: Both faecal and water samples from the catchment area were collected and screened using immunomagnetic separation (IMS) and immunofluorescence microscopy. Samples that contained Cryptosporidium oocysts were genotyped using sequence and phylogenetic analysis of the 18S rDNA, and the heatshock (HSP-70) gene. Analysis identified five Cryptosporidium species/genotypes including C. parvum (cattle genotype), C. suis, pig genotype II, the cervid genotype and a novel goat genotype. Conclusions: Monitoring and characterization of the sources of oocyst contamination in watersheds will aid in the development and implementation of the most appropriate watershed management policies to protect the public from the risks of waterborne Cryptosporidium. Significance and Impact of the Study: This study has shown that quantification by IMS analysis can be combined with the specificity of genotyping to provide an extremely valuable tool for assessing the human health risks from land use activities in drinking water catchments.

Cryptosporidium Genotypes and Subtypes in Lambs and Goat Kids in Spain

“…These findings are consistent with most restricted molecular studies conducted in the United Kingdom, where C. parvum was seen in specimens from both diarrheic and healthy preweaned lambs and goat kids (9,10,18,21,27). Likewise, C. parvum was identified in limited numbers of isolates from both young and adult sheep and goats from Australia, Cyprus, Spain, the Czech Republic, and Zambia (15,16,20,28). However, our results appear to contrast with those of some reports that question the role of sheep as a zoonotic reservoir for human cryptosporidiosis.…”

Occurrence and molecular characterization of Cryptosporidium sp. in sheep

“…ubiquitum has the largest number of hosts among the Cryptosporidium species . It was detected in sheep in Australia (SWEENY et al, 2011;RYAN et al, 2005;YANG et al, 2009), United States (SANTÍN;FAYER, 2007;SANTIN et al, 2007), Belgium (GEURDEN et al, 2008), China (WANG et al, 2010), Spain (DIAZ et al, 2010), Norway (ROBERTSON et al, 2010), UK (ELWIN;CHALMERS, 2008;MUELLER-DOBLIES et al, 2008), and other countries. In Brazil, this species of Cryptosporidium has been detected by Fiuza et al (2011) in the State of Rio de Janeiro and by Silva et al (2014) and Zucatto et al (2015) in São Paulo.…”

Tracking Host Sources of Cryptosporidium spp. in Raw Water for Improved Health Risk Assessment

“…only be inferred from available host-parasite information and molecular phylogeny, which can then be further supported by land use information. For example, the host source of C. parvum cannot be inferred from the single occurrence detected; however, when the known host sources of C. parvum (36,52) are combined with land use analysis, the data suggest that cattle, deer, or humans are the most probable source within the watershed. Previous studies have tried to link species and genotypes of Cryptosporidium to human, livestock, and wildlife contamination by directly characterizing potential sources of contamination (i.e., sampling animals or sewage [13,36]) rather than characterizing parasites present in natural watercourses in a watershed context.…”

“…For example, the host source of C. parvum cannot be inferred from the single occurrence detected; however, when the known host sources of C. parvum (36,52) are combined with land use analysis, the data suggest that cattle, deer, or humans are the most probable source within the watershed. Previous studies have tried to link species and genotypes of Cryptosporidium to human, livestock, and wildlife contamination by directly characterizing potential sources of contamination (i.e., sampling animals or sewage [13,36]) rather than characterizing parasites present in natural watercourses in a watershed context. Some studies have focused on identifying species and genotypes of Cryptosporidium in the watersheds (11,14) but failed to evaluate the spatial and temporal patterns of contamination.…”