Contamination of river water by Cryptosporidium parvum oocysts in western Japan

Citation
K. Ono et al., Contamination of river water by Cryptosporidium parvum oocysts in western Japan, APPL ENVIR, 67(9), 2001, pp. 3832-3836
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology,Microbiology
Journal title
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
ISSN journal
0099-2240 → ACNP
Volume
67
Issue
9
Year of publication
2001
Pages
3832 - 3836
Database
ISI
SICI code
0099-2240(200109)67:9<3832:CORWBC>2.0.ZU;2-X
Abstract
In Japan, only a few rivers have been inspected for Cryptosporidium parvum contamination, and the methods used had low sensitivity. In 1998 and 1999, we used a method with higher sensitivity to examine all large rivers used a s sources of water supply in one prefecture (which we divided into four are as) in western Japan for Cryptosporidium oocysts. One sample was collected at each of 156 sites along 18 rivers, and samples were tested for Cryptospo ridium oocysts by immunomagnetic separation. Samples were classified as bei ng obtained on an island with livestock and fishing industries, a densely p opulated urban area, a western region including farming villages, or a stil l more rural northern area with agriculture and fishing. Restriction fragme nt length polymorphism analysis was used for identification of the C parvum found as the bovine or human type. C parvum was detected in at least one s ample from 13 of the 18 rivers and in 47% (74 of 156) of the samples. One-t hird to all of the samples from each area contained C parvum oocysts. The n umber of C pari,um oocysts per 20 liters of river water varied in the same pattern as the number of cattle kept in the four kinds of areas (as determi ned by the Mantel extension test). Oocysts isolated were of the bovine type ; the C. parvum detected in rivers probably came from cattle kept in that v alley. As we had expected, when tested with a more sensitive method, river water in western Japan was found to be greatly contaminated with C parvum o ocysts, as reported in other countries.