Correlation between markers of strain variation in Cryptosporidium parvum: Evidence of clonality

Molecular epidemiology of cryptosporidiosis outbreaks and transmission in British Columbia, Canada.

“…This is consistent with data from other molecular typing studies [12][13][14][15][16][17]23,24 in which these two genotypes have been referred to as animal and human genotypes. The TRAP-C2 gene sequence analysis of oocyst specimens from several North American outbreaks, including an isolate from the Cranbrook outbreak, demonstrated that these two major genotypes could be associated with two different cycles of transmission, i.e., either zoonotic transmission, which has been mainly bovine-to-human, 4,5 or person-to-person transmission.…”

“…Previous animal infectivity studies 25 have shown that human isolates exhibit biological differences by their varying abilities to infect mouse or calf models and that this could be correlated with genetic differences. 26 By combining the multi-locus gene analysis data that we obtained on the animal genotype isolates, we have shown that these isolates can be characterized as a group of C. parvum parasites with ITS1 loci that were amplified by the cry7/cryITS1 primer pair, as well as had either animal DHFR gene sequences 23 and/or genotype 2 TRAP-C2 segregating sites (Table 1). 12 In addition, isolates from sporadic cases with the animal genotype were more likely to be found in patients residing in less densely populated rural or farming communities.…”

“…12 This is consistent with previous studies using these polymorphic gene loci where the animal genotype was identified in both human and animal isolates, in particular cattle isolates. 12,23 In comparison, multi-locus gene analysis of human genotype isolates showed that the ITS1 loci of these isolates amplified with the cry7/cry21 primer pair and had either genotype 1 TRAP-C2 segregating sites or human DHFR gene sequences, as well as human 18S rRNA sequences. Also, isolates with the human genotype were significantly more likely (P Ͻ 0.005) to be found in patients residing in more densely populated urban communities.…”

“…The PCR amplification and sequence analyses of other polymorphic gene loci such as the TRAP-C2 gene, which codes for a cell-surface protein, 12 the DHFR gene, which codes for a metabolic enzyme, 16,23 and the 18S rRNA gene 14 were performed on a number of patient isolates using previously published methods. 12,14,23 Data analysis. Data was analyzed statistically using the chi-square test and analysis of variance with Epi-Info software (Centers for Disease Control and Prevention, Atlanta, GA and World Health Organization, Geneva, Switzerland).…”

Cryptosporidiosis in Goats: a Review

“…The PCR protocols so far described could detect as few as 10-50 Cryptosporidium oocysts per sample, while the most sensitive PCR assays can detect as low as 1 oocyst per sample (Gibbons et al, 1998;Xiao et al, 1999;Coupe et al, 2005). One of the drawbacks of these PCR assays is that they demand preparatory DNA purification protocols, which are time consuming and tedious.…”