Previous Article | Next Article ![]()
Appl. Environ. Microbiol., 05 1997, 2029-2037, Vol 63, No. 5
PA Rochelle, DM Ferguson, TJ Handojo, R De Leon, MH Stewart and RL Wolfe
The presence of Cryptosporidium in drinking water supplies is a significant
problem faced by the water industry. Although a variety of methods exist
for the detection of waterborne oocysts, water utilities currently have no
way of assessing the infectivity of detected oocysts and consequently are
unable to accurately determine the risks posed to public health by
waterborne Cryptosporidium. In this paper, the development of an
infectivity assay for waterborne Cryptosporidium parvum is described.
Oocysts were inoculated onto monolayers of Caco-2 cells and grown on
microscope slides, and infections were detected by C. parvum specific
reverse transcriptase PCR of extracted mRNA, targeting the heat shock
protein 70 (hsp70) gene. A single infectious oocyst was detected by this
experimental procedure. The use of concentrated samples obtained from 250
liters of finished water had no observable effect on the integrity of cell
monolayers or on the infectivity of oocysts seeded into the concentrate.
Intracellular developmental stages of the parasite were also detected by
using fluorescently labeled antibodies. One pair of PCR primers targeting
the hsp70 gene was specific for C. parvum, while a second pair recognized
all species of Cryptosporidium tested. The C. parvum-specific primers
amplified DNA from 1 to 10 oocysts used to seed 65 to 100 liters of
concentrated environmental water samples and were compatible with multiplex
PCR for the simultaneous detection of C. parvum and Giardia lambia. This
paper confirms the utility of PCR for the detection of waterborne C. parvum
and, most importantly, demonstrates the potential of an in vitro
infectivity assay.
Copyright © 1997, American Society for Microbiology
An assay combining cell culture with reverse transcriptase PCR to detect and determine the infectivity of waterborne Cryptosporidium parvum
Water Quality Laboratory, Metropolitan Water District of Southern California, La Verme 91750-3399, USA. prochelle@mwd.dst.ca.us
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»