Previous Article | Next Article ![]()
Applied and Environmental Microbiology, July 2004, p. 4035-4039, Vol. 70, No. 7
0099-2240/04/$08.00+0 DOI: 10.1128/AEM.70.7.4035-4039.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
Laboratoire de Parasitologie-Mycologie, CHU Maison Blanche, UFR Médecine,1 EA 2070, IFR 53, Université de Reims Champagne-Ardenne, 51092 Reims,2 Communauté de Communes de I'Agglomération de Reims (CCAR), 51096 Reims,3 Direction Régionale des Affaires Sanitaires et Sociales, Service Santé Environnement, 51037 ChÂlons en Champagne, France4
Received 8 October 2003/ Accepted 6 April 2004
Several recent outbreaks of toxoplasmosis were related to drinking water. We propose a strategy for Toxoplasma oocyst detection as part of an approach to detecting multiple waterborne parasites, including Giardia and Cryptosporidium spp., by the U.S. Environmental Protection Agency method with the same sample. Water samples are filtered to recover Toxoplasma oocysts and purified on a sucrose density gradient. Detection is based on PCR and mouse inoculation (bioassay) to determine the presence and infectivity of recovered oocysts. In an experimental seeding assay with 100 liters of deionized water, a parasite density of 1 oocyst/liter was successfully detected by PCR in 60% of cases and a density of 10 oocysts/liter was detected in 100% of cases. The sensitivity of the PCR assay varied from less than 10 to more than 1000 oocysts/liter, depending on the sample source. PCR was always more sensitive than mouse inoculation. This detection strategy was then applied to 139 environmental water samples collected over a 20-month period. Fifty-three samples contained PCR inhibitors, which were overcome in 39 cases by bovine serum albumin addition. Among 125 interpretable samples, we detected Toxoplasma DNA in 10 cases (8%). None of the samples were positive by mouse inoculation. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method.
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»