A new restriction fragment length polymorphism from Cryptosporidium parvum identifies genetically heterogeneous parasite populations and genotypic changes following transmission from bovine to human hosts.
Length and restriction site polymorphism within a 2.8-kb threonine-rich open reading frame from Cryptosporidium parvum was identified and used to determine the genotypes of isolates from calves and humans. In agreement with observations of other genetic loci, all calf isolates were identical at this locus. In contrast, human isolates showed two profiles, one found exclusively in humans and one a superposition of both profiles, which were indicative of heterogeneous parasite populations. PCR fingerprints were consistent with a change in the genetic profile of C. parvum isolates following transmission from bovine to human hosts.
Carraway
M
M
Tufts University School of Veterinary Medicine, Department of Comparative Medicine, North Grafton, Massachusetts 01536, USA.
Tzipori
S
S
Widmer
G
G
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D016785:Cryptosporidium parvum / Q000235:genetics*; D016054:DNA, Protozoan / Q000235:genetics; D006801:Humans; D051379:Mice; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D013912:Threonine
D016054:DNA, Protozoan; D013912:Threonine