Monitoring water quality is an essential component of the delivery of safe drinking water.
However, current microbial evaluation techniques are neither time-efficient nor cost-effective.
Standard techniques monitor for innocuous indicator bacteria, which often do not correlate with
pathogen concentrations, and bacterial attachment and survival in biofilms are rarely examined.
The presence of pathogens protected in the biofilm matrix is compounded in rural agricultural
areas, where both faecal contamination of water sources and the potential of exposure are very
high. This research attempts to improve the understanding of pathogen behavior in
agricultural watersheds and evaluate substrate surfaces that could be used for standard protocols
to monitor for the presence of pathogens that cause disease and economic losses in rural Canadian
water systems and around the world. To do so, the authors monitored the presence of faecal
contamination indicators (Heterotrophic plate counts, faecal coliforms, enterococci, and E. coli)
and particular pathogens (Pathogenic E. coli 0157 and Salmonella sp.) in water, sediment, and in
biofilms on river and slate rock, wood, sandpaper, and Lexan™ in Elk Creek (Fraser Valley,
British Columbia, Canada) from December 2005 to December 2006. Faecal indicator
concentrations and pathogen presence were evaluated using standard culturing and isolation
methods. Results showed that monitoring for bacterial indicator concentrations in water column
grab samples greatly underestimated the number of indicator bacteria and pathogens present at
each site. The results also showed that water column grab samples, especially during the dry
season, were not representative of pathogens present in the watershed. This indicates that biofilms
might be the main reservoir of Salmonella sp. and pathogenic E. coli O157 during the summer
time when rainfall and manure application is low. Includes 38 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 950 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 38 |
| Published : | 06/01/2007 |
