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Analysis of the genetic diversity within Cryptosporidium hominis and Cryptosporidium parvum from imported and autochtonous cases of human cryptosporidiosis by mutation scanning
Author(s) -
Jex Aaron R.,
Gasser Robin B.
Publication year - 2008
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200800422
Subject(s) - biology , genotype , cryptosporidium parvum , cryptosporidium , genetic diversity , phylogenetic tree , genetic variation , genetics , virology , microbiology and biotechnology , gene , feces , population , medicine , environmental health
The present study investigated sequence variation in part of the 60 kilodalton glycoprotein (p gp60 ) gene among Cryptosporidium hominis and Cryptosporidium parvum isolates ( n =115) from citizens of the UK inferred to have been infected whilst travelling abroad (to 25 countries) or in the UK. The genomic DNA samples from these isolates were subjected to PCR‐coupled single‐strand conformation polymorphism analysis, followed by targeted sequencing of p gp60 . Individual samples were classified to the genotypic and subgenotypic levels based on phylogenetic analysis (Bayesian inference) of p gp60 data, including published sequences for comparison. Based on this analysis, five C. hominis (Ia–If) and four C. parvum (IIa, IIc–IIe) genotypes were identified, equating to 16 and 10 subgenotypes, respectively. Of these genotypes, C. hominis Ib was predominant ( n =82). Interestingly, one subgenotype ( C. hominis Ib A10G2R2) accounted for the majority of the samples examined and was identified in travellers to 14 countries; the examination of published records suggested that C. hominis Ib A10G2R2 has a global distribution. Numerous new and seemingly rare subgenotypes (eight for C. hominis and six for C. parvum ) were also discovered. In conclusion, the present study revealed substantial genetic variation in p gp60 within both C. hominis and C. parvum and emphasizes the need to undertake investigations of human and animal populations in countries for which there is no information on the genetic make‐up of Cryptosporidium infecting humans.