Publications

the presence of listeria spp. in raw milk in ontario.	raw milk samples from bulk tanks in ontario were analyzed for the presence of listeria species. the overall incidence of listeria species in raw milk was 12.4%. listeria innocua was most frequently isolated and was found in 9.7% (43/445) of the raw milk samples, while l. monocytogenes and l. welshimeri were each found in 1.3% (6/445) of the samples. no other species of listeria was found. of five regions in ontario that were examined, the eastern region had a significantly higher incidence rate ...	1988	3135930
listeria monocytogenes infections in canada.	between 1951 and january 1972 listeriosis was diagnosed bacteriologically in 101 canadian patients. this study adds 80 cases to the 21 reported from metropolitan toronto by sepp and roy in 1963. the laboratory centre for disease control, ottawa, collated epidemiological and clinical data. serotypes of listeria monocytogenes included 4b (53), 1 (15), 1b (6), 1a (2), 2 and 3. clinically, 54 patients had meningitis and 23 septicemia. the mortality rate was 30%.between 1954 and january 1972 listerio ...	1973	4198595
isolation of listeria monocytogenes from brain specimens of domestic animals in ontario.		1971	5005795
listeria monocytogenes infections in canada.	since its first isolation by murray in 1926 listeria monocytogenes has become recognized as a significant pathogen occurring worldwide and involving a wide range of wild and domestic animals including man. the first confirmed human listeriosis case in canada was published by stoot in 1951. a later survey based on records maintained at the laboratory centre for disease control, ottawa showed 101 cases detected over a 21 year period in nine provinces. the overall mortality was 30%. the most freque ...	1984	6442654
distribution and characteristics of listeria monocytogenes isolates from surface waters of the south nation river watershed, ontario, canada.	listeria monocytogenes is a facultative intracellular pathogen thought to be widely distributed in the environment. we investigated the prevalence and characteristics of l. monocytogenes isolates from surface waters derived from catchments within the south nation river watershed (ontario, canada). this watershed is dominated by urban and rural development, livestock and crop production, and wildlife habitats. from june to november 2005, a total of 314 surface water samples were collected biweekl ...	2007	17630309
seasonal relationships among indicator bacteria, pathogenic bacteria, cryptosporidium oocysts, giardia cysts, and hydrological indices for surface waters within an agricultural landscape.	the south nation river basin in eastern ontario, canada is characterized by mixed agriculture. over 1600 water samples were collected on a bi-weekly basis from up to 24 discrete sampling sites on river tributaries of varying stream order within the river basin between 2004 and 2006. water samples were analyzed for: densities of indicator bacteria (escherichia coli, clostridium perfringens, enterococci, total and fecal coliforms), the presence of pathogenic bacteria (listeria monocytogenes, e. co ...	2009	19339033
occurrence of salmonella, campylobacter, yersinia enterocolitica, escherichia coli o157 and listeria monocytogenes in swine.	the objective of this study was to investigate the occurrence of major bacterial foodborne pathogens in swine. in total, 359 samples from manure storage tanks (91) and fresh pooled faeces (268) obtained from finisher (110), sows (78) and weanlings (80) were collected and tested. campylobacter, salmonella, yersinia enterocolitica, escherichia coli o157 and listeria monocytogenes were isolated from 36.5%, 31.5%, 5.8%, 3.3% and 3.3% of samples respectively. all e. coli o157 isolates found on 10 far ...	2010	19638163
associations among pathogenic bacteria, parasites, and environmental and land use factors in multiple mixed-use watersheds.	over a five year period (2004-08), 1171 surface water samples were collected from up to 24 sampling locations representing a wide range of stream orders, in a river basin in eastern ontario, canada. water was analyzed for cryptosporidium oocysts and giardia cyst densities, the presence of salmonella enterica subspecies enterica, campylobacter spp., listeria monocytogenes, and escherichia coli o157:h7. the study objective was to explore associations among pathogen densities/occurrence and objecti ...	2011	21889781
a comparison of enrichment and direct-plating methods for isolation of listeria monocytogenes from surface water.	listeria monocytogenes is a facultative intracellular pathogen distributed in the environment. reference isolation methods include an enrichment step. we compared 2 protocols: one based on enrichment and the other on direct plating, with respect to the efficiency of isolation of l. monocytogenes from surface water samples. from march to may 2006, 126 surface water samples were collected biweekly from 24 discrete sampling sites located in the south nation river basin (ontario). presumptive lister ...	2012	23210998
subtyping of a large collection of historical listeria monocytogenes strains from ontario, canada, by an improved multilocus variable-number tandem-repeat analysis (mlva).	listeria monocytogenes is responsible for severe and often fatal food-borne infections in humans. a collection of 2,421 l. monocytogenes isolates originating from ontario's food chain between 1993 and 2010, along with ontario clinical isolates collected from 2004 to 2010, was characterized using an improved multilocus variable-number tandem-repeat analysis (mlva). the mlva method was established based on eight primer pairs targeting seven variable-number tandem-repeat (vntr) loci in two 4-plex f ...	2013	23956391