TY - JOUR
T1 - Genetic Polymorphism among Cryptosporidium parvum Isolates
T2 - Evidence of Two Distinct Human Transmission Cycles
AU - Peng, Michael M.
AU - Xiao, Lihua
AU - Freeman, Amanda R.
AU - Arrowood, Michael J.
AU - Escalante, Ananias A.
AU - Weltman, André C.
AU - Ong, Corinne S.L.
AU - Mac Kenzie, William R.
AU - Lal, Altaf A.
AU - Beard, Charles B.
PY - 1997
Y1 - 1997
N2 - We report the results of molecular analysis of 39 isolates of Cryptosporidium parvum from human and bovine sources in nine human outbreaks and from bovine sources from a wide geographic distribution. All 39 isolates could be divided into either of two genotypes, on the basis of genetic polymorphism observed at the thrombospondin-related adhesion protein (TRAP-C2) locus. Genotype 1 was observed only in isolates from humans. Genotype 2, however, was seen in calf isolates and in isolates from a subset of human patients who reported direct exposure to infected cattle or consumed items thought to be contaminated with cattle feces. Furthermore, experimental infection studies showed that genotype 2 isolates were infective to mice or calves under routine laboratory conditions, whereas genotype 1 isolates were not. These results support the occurrence of two distinct transmission cycles of C. parvum in humans.
AB - We report the results of molecular analysis of 39 isolates of Cryptosporidium parvum from human and bovine sources in nine human outbreaks and from bovine sources from a wide geographic distribution. All 39 isolates could be divided into either of two genotypes, on the basis of genetic polymorphism observed at the thrombospondin-related adhesion protein (TRAP-C2) locus. Genotype 1 was observed only in isolates from humans. Genotype 2, however, was seen in calf isolates and in isolates from a subset of human patients who reported direct exposure to infected cattle or consumed items thought to be contaminated with cattle feces. Furthermore, experimental infection studies showed that genotype 2 isolates were infective to mice or calves under routine laboratory conditions, whereas genotype 1 isolates were not. These results support the occurrence of two distinct transmission cycles of C. parvum in humans.
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U2 - 10.3201/eid0304.970423
DO - 10.3201/eid0304.970423
M3 - Article
C2 - 9366611
AN - SCOPUS:0031254810
SN - 1080-6040
VL - 3
SP - 567
EP - 573
JO - Emerging Infectious Diseases
JF - Emerging Infectious Diseases
IS - 4
ER -