title: Geographical segregation of Cryptosporidium parvum multilocus genotypes in Europe.
abstract: Cryptosporidium parvum is a common enteric protozoan pathogen of humans and livestock. Multilocus genotyping based on simple sequence repeat polymorphisms has been used extensively to identify transmission cycles and to investigate the structure of C. parvum populations and of the related pathogen Cryptosporidiumhominis. Using such methods, the zoonotic transmission of C. parvum has been shown to be epidemiologically important. Because different genetic markers have been used in different surveys, the comparison of Cryptosporidium genotypes across different laboratories is often not feasible. Therefore, few comparisons of Cryptosporidium populations across wide geographical areas have been published and our understanding of the epidemiology of cryptosporidiosis is fragmented. Here we report on the genotypic analysis of a large collection of 692 C. parvum isolates originating primarily from cattle and other ruminants from Italy, Ireland and Scotland. Because the same genotypic markers were used in these surveys, it was possible to merge the data. We found significant geographical segregation and a correlation between genetic and geographic distance, consistent with a model of isolation by distance. The presence of strong LD and positive IA(S) values in the combined MLG dataset suggest departure from panmixia, with different population structures of the parasite prevailing in each country.
authors: Istituto Superiore di Sanità, Department of Infectious, Parasitic and Immunomediated Diseases, Viale Regina Elena 299, Rome 00161, Italy. Electronic address: simone.caccio@iss.it.
authors: Simone M
authors: SM
authors: Cacciò
authors: Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerpen, Belgium.
authors: Valerie
authors: V
authors: de Waele
authors: Cummings School of Veterinary Medicine at Tufts University, Department of Infectious Disease and Global Health, North Grafton, MA 01536, United States.
authors: Giovanni
authors: G
authors: Widmer
mesh_terms: D000818:Animals; D016785:Cryptosporidium parvum / Q000145:classification* / Q000235:genetics*; D005060:Europe; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D058974:Phylogeography
chemical_list: D005819:Genetic Markers
keywords: Cryptosporidium parvum; Linkage disequilibrium; Multilocus genotypes; Population structure; Principal coordinate analysis