Inferences about the Global Population Structures of Cryptosporidium parvum and Cryptosporidium hominis

Abstract

Cryptosporidium parvum and Cryptosporidium hominis are two related species of apicomplexan protozoa responsible for the majority of human cases of cryptosporidiosis. In spite of their considerable public health impact, little is known about the population structures of these species. In this study, a battery of C. parvum and C. hominis isolates from seven countries was genotyped using a nine-locus DNA subtyping scheme. To assess the existence of geographical partitions, the multilocus genotype data were mined using a cluster analysis based on the nearest-neighbor principle. Within each country, the population genetic structures were explored by combining diversity statistical tests, linkage disequilibrium, and eBURST analysis. For both parasite species, a quasi-complete phylogenetic segregation was observed among the countries. Cluster analysis accurately identified recently introduced isolates. Rather than conforming to a strict paradigm of either a clonal or a panmictic population structure, data are consistent with a flexible reproductive strategy characterized by the cooccurrence of both propagation patterns. The relative contribution of each pattern appears to vary between the regions, perhaps dependent on the prevailing ecological determinants of transmission.

Identification and Immunological Characterization of Three Potential Vaccinogens against Cryptosporidium Species

“…Cp15 has been identified as an immunodominant antigen (19,29,30,33,34,39), and we are exploring its apparent role in the invasion of mammalian cells by C. parvum sporozoites (Manque et al unpublished). Bioinformatics analysis of the selected vaccine candidates did not reveal any consequential polymorphism between these genes in C. hominis, which is essentially an exclusively human pathogen, and C. parvum, which infects humans but is primarily responsible for veterinary cryptosporidiosis (37). Thus, these antigens may have utility in both human and veterinary vaccines.…”

Long-term Cryptosporidium typing reveals the aetiology and species-specific epidemiology of human cryptosporidiosis in England and Wales, 2000 to 2003

“…The disadvantage of any PCR-based system using common primers is the probable under-ascertainment of dual or multiple alleles within a sample. However, a subset of our isolates have been tested using separate species-specific primers and by multi-locus typing and showed little evidence of mixed infection [37]. The likelihood of dual infections is also driven by the endemicity of the parasite and exposure, as higher proportions have been detected in high-prevalence regions of the UK [38].…”

Is Predominant Clonal Evolution a Common Evolutionary Adaptation to Parasitism in Pathogenic Parasitic Protozoa, Fungi, Bacteria, and Viruses?

“…Smith (2009) b Su et al (2003) a,b Su et al (2006Su et al ( e , 2010 b , 2012 c ) Takumi et al (2012) b,e Tanriverdi et al (2008) b,e Thompson et al (2011) b,c Tomasini et al (2014) e Volkman et al (2007Volkman et al ( e , 2012a e , 2012b b,c,e ) Wang et al (2012) b,e Weedall and Hall (2014) c,e Weir et al (2016) d,e Wendte et al (2010Wendte et al ( c , 2011 synonymous terms (Hanage et al, 2006;Holmes, 2013). Including selfing/ inbreeding in the general frame of clonality or distinguishing 'true' clonality (mitotic reproduction) from selfing/inbreeding is a matter of definition.…”