The objective of this work was to evaluate culture-based and quantitative polymerase
chain reaction (PCR)-based methods for the detection of Yersinia spp. in water, by examining its
occurrence in the Grand River watershed in Southwestern Ontario, Canada. This watershed is
used as a drinking water source for up to 500,000 people, as well as for recreational purposes. It
is also one of the most heavily impacted watersheds in Canada and receives inputs from both
agricultural and urban activities. Five sampling locations were selected along the Grand River in
the area surrounding the cities of Kitchener and Waterloo. Surface water was collected from each
of these sites every other week. In this study, culture-based work involved comparing four different enrichment broths as
well as examining the effect of an alkaline treatment of cultures grown in each enrichment broth.
The methods were selected from the literature and were originally developed for and are
commonly used for isolating Y. enterocolitica from food and clinical samples. These methods
have not been tested extensively on water. Results showed that one of the enrichment broths
tested, modified tryptic soy broth (mTSB), appeared to have more potential for recovery of Y.
enterocolitica than the others. Additionally, an alkaline treatment was found to be effective.
Consequently, the mTSB enrichment broth with and without an alkaline treatment followed by
growth on Cefsulodin-Irgasan-Novobiocin (CIN) agar, a commonly used selective agar for Y.
enterocolitica, was used to isolate Yersinia from surface water samples from the Grand River.
Presumptive Yersinia isolates were confirmed with a series of biochemical tests. Confirmed
Yersinia strains were isolated from 39 out of 154 (25%) surface water samples collected between
April 2006 and May 2007. Isolated strains were then sub-typed to determine their species and
biotype. None of the strains isolated were Y. enterocolitica. Species that were isolated included
Y. aldovae, Y. bercovieri, Y. frederiksenii and Y. intermedia, all typically considered to be nonpathogenic
species. Non-pathogenic Yersinia species have previously been found in aquatic
environments. Strains isolated in 2006 were also screened for the two virulence genes
targeted in the molecular-based methods and the surface water isolates did not
contain either gene. Includes 9 references.
| Edition : | Vol. - No. |
| File Size : | 1
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| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 4 |
| Published : | 11/01/2007 |
