During the winter of 2000 to 2001, an outbreak due to Salmonella Enteritidis (SE) phage type 30 (PT30), a rare strain, was detected in Canada. The ensuing investigation involved Canadian and American public health and food regulatory agencies and an academic research laboratory. Enhanced laboratory surveillance, including phage typing and pulsed-field gel electrophoresis, was used to identify cases. Case questionnaires were administered to collect information about food and environmental exposures. A case-control study with 16 matched case-control pairs was conducted to test the hypothesis of an association between raw whole almond consumption and infection. Almond samples were collected from case homes, retail outlets, and the implicated processor, and environmental samples were collected from processing equipment and associated farms for microbiological testing. One hundred sixty-eight laboratory-confirmed cases of SE PT30 infection (157 in Canada, 11 in the United States) were identified between October 2000 and July 2001. The case-control study identified raw whole almonds as the source of infection (odds ration, 21.1; 95% confidence interval, 3.6 to infinity). SE PT30 was detected in raw whole natural almonds collected from home, retail, distribution, and warehouse sources and from environmental swabs of processing equipment and associated farmers' orchards. The frequent and prolonged recovery of this specific organism from a large agricultural area was an unexpected finding and may indicate significant diffuse contamination on these farms. Identification of almonds as the source of a foodborne outbreak is a previously undocumented finding, leading to a North American recall of this product and a review of current industry practices.

In order to assess the health risk associated with a given source of fecal contamination using bacterial source tracking (BST), it is important to know the occurrence of potential pathogens as a function of host. Escherichia coli isolates (n ‫؍‬ 593) from the feces of diverse animals were screened for various virulence genes: stx 1 and stx 2 (Shiga toxin-producing E. Eleven hosts were positive for only the eae (10.11%) gene, representing atypical EPEC, while two hosts were positive for both eae and EAF (1.3%), representing typical EPEC. stx 1 , stx 2 , or both stx 1 and stx 2 were present in 1 (0.1%,) 10 (5.56%), and 2 (1.51%) hosts, respectively, and confirmed as non-O157 by using a E. coli O157 rfb (rfb O157 ) TaqMan assay. STh and STp were carried by 2 hosts (2.33%) and 1 host (0.33%), respectively, while none of the hosts were positive for LT and ipaH. The repetitive element palindromic PCR (rep-PCR) fingerprint analysis identified 221 unique fingerprints with a Shannon diversity index of 2.67. Multivariate analysis of variance revealed that majority of the isolates clustered according to the year of sampling. The higher prevalence of atypical EPEC and non-O157 STEC observed in different animal hosts indicates that they can be a reservoir of these pathogens with the potential to contaminate surface water and impact human health. Therefore, we suggest that E. coli from these sources must be included while constructing known source fingerprint libraries for tracking purposes. However, the observed genetic diversity and temporal variation need to be considered since these factors can influence the accuracy of BST results.

Microcosm studies have been carried out to find out the relative survival of Escherichia coli and Salmonella typhimurium in a tropical estuary. Survival has been assessed in relation to the important self-purifying parameters such as biotic factors contained in the estuarine water, toxicity due to the dissolved organic and antibiotic substances in the water and the sunlight. The results revealed that sunlight is the most important inactivating factor on the survival of E. coli and S. typhimurium in the estuarine water. While the biological factors contained in the estuarine water such as protozoans and bacteriophages also exerted considerable inactivation of these organisms, the composition of the water with all its dissolved organic and inorganic substances was not damaging to the test organisms. Results also indicated better survival capacity of E. coli cells under all test conditions when compared to S. typhimurium.

Aims:  The survival of Escherichia coli, Salmonella enterica serovar Typhimurium, Enterococcus faecalis and coliphage MS2 was studied in stored, fresh and diluted (1 : 1) human urine at 15 and 30°C. Methods and Results:  Survival rate was studied by the plate count method. All the organisms showed rapid inactivation in stored urine, but they survived better in diluted and fresh urine. The high pH level and temperature were the major factors found to influence the survival of the micro‐organisms with the survival rate being higher at 15°C than at 30°C. Conclusions:  The destruction of all micro‐organisms in stored urine required <1 week at 30°C. Thus, the storage of urine is a useful way to reduce the risk of contamination while using urine as a fertilizer. Significance and Impact of the Study:  The urine fertilization is aimed for the developing countries and the high temperatures in these countries may hasten the destruction of micro‐organisms in urine. On the contrary, a higher survival rate of these organisms in fresh and diluted urine is a public health concern because the dilution of urine with water is likely to happen during flushing.

Escherichia coli isolates (n ‫؍‬ 658) obtained from drinking water intakes of Comox Lake (2011 to 2013) were screened for the following virulence genes (VGs): stx 1 and stx 2 (Shiga toxin-producing E. coli [STEC]), eae and the adherence factor (EAF) gene (enteropathogenic E. coli [EPEC]), heat-stable (ST) enterotoxin (variants STh and STp) and heat-labile enterotoxin (LT) genes (enterotoxigenic E. coli [ETEC]), and ipaH (enteroinvasive E. coli [EIEC]). The only genes detected were eae and stx 2 , which were carried by 37.69% (n ‫؍‬ 248) of the isolates. Only eae was harbored by 26.74% (n ‫؍‬ 176) of the isolates, representing potential atypical EPEC strains, while only stx 2 was detected in 10.33% (n ‫؍‬ 68) of the isolates, indicating potential STEC strains. Moreover, four isolates were positive for both the stx 2 and eae genes, representing potential EHEC strains. The prevalence of VGs (eae or stx 2 ) was significantly (P < 0.0001) higher in the fall season, and multiple genes (eae plus stx 2 ) were detected only in fall. Repetitive element palindromic PCR (rep-PCR) fingerprint analysis of 658 E. coli isolates identified 335 unique fingerprints, with an overall Shannon diversity (H=) index of 3.653. Diversity varied among seasons over the years, with relatively higher diversity during fall. Multivariate analysis of variance (MANOVA) revealed that the majority of the fingerprints showed a tendency to cluster according to year, season, and month. Taken together, the results indicated that the diversity and population structure of E. coli fluctuate on a temporal scale, reflecting the presence of diverse host sources and their behavior over time in the watershed. Furthermore, the occurrence of potentially pathogenic E. coli strains in the drinking water intakes highlights the risk to human health associated with direct and indirect consumption of untreated surface water. F ecal contamination is the primary contributor of pathogens to surface water and constitutes a significant public health risk. In Canada, the estimated rate of acute gastrointestinal illness attributable to water is 0.11 cases per person per year, which poses a substantial economic burden (1). Traditionally, the safety of water used for drinking and recreation as required by regulation is assessed in terms of the concentration of Escherichia coli, a dominant intestinal inhabitant of humans and warm-blooded animals, whose presence in water indicates fecal contamination and the potential presence of enteric pathogens (2). The sources of E. coli in the aquatic environment can originate from runoff from land applied with animal wastes or animal feeding operations, urban runoff, inadequate or failing septic or sewer systems, and wildlife (3). Identification of the source of fecal pollution is a high priority in order to protect and manage source water quality and also to assess the potential public health risk associated with fecal contamination from a given host source (4). To this end, many advances have been made in recent years to develop various ...