| epidemiology of hemolytic-uremic syndrome in canadian children from 1986 to 1988. the canadian pediatric kidney disease reference centre. | to define the epidemiologic features of childhood hemolytic-uremic syndrome (hus) on a national level in canada, to determine the proportion of patients in whom escherichia coli o157:h7 was isolated from stools, and to examine risk factors for more severe hus. | 1991 | 1861207 |
| risk factors for escherichia coli o157:h7 infection in an urban community. | outbreaks of escherichia coli o157:h7 have been attributed to meat or meat products, particularly ground meat, and to unpasteurized dairy products. however, the risk factors for sporadic cases have not been clearly delineated. study data were collected by using a self-administered dietary and historical questionnaire on all patients whose history included bloody diarrhea and who attended one of the participating emergency departments. designation as "case" or "control" occurred after stool cultu ... | 1989 | 2681437 |
| sporadic cases of hemorrhagic colitis associated with escherichia coli o157:h7. clinical, epidemiologic, and bacteriologic features. | during a 6-month period in 1983, escherichia coli o157:h7 was isolated from 19 (15%) of 125 patients with grossly bloody diarrhea and 1 sibling with non-bloody diarrhea in the calgary area. there was no clustering of the cases geographically or in time. all but 1 had clinical manifestations typical of hemorrhagic colitis associated with e. coli o157:h7. the illness appeared to be associated with consumption of hamburgers by 15 patients. the diarrheal illness was usually self-limited, but 3 child ... | 1984 | 6388450 |
| impact of free verotoxin testing on epidemiology of diarrhea caused by verotoxin-producing escherichia coli. | during a 10-week period in the summer of 1990, an epidemiologic investigation of the prevalence of verotoxin (vt)-producing escherichia coli infection was conducted in calgary, alberta, canada. consecutive stool specimens (n = 3,577) were cultured for e. coli o157:h7, and fecal filtrates were tested for free vts (fvts). e. coli o157:h7 was recovered from 22 specimens (0.6%), but vt was detected in 74 specimens (2.1%). sixty-nine stool specimens positive for fvts or e. coli o157:h7 were probed fo ... | 1995 | 7615714 |
| infection caused by escherichia coli o157:h7 in alberta, canada, and in scotland: a five-year review, 1987-1991. | infections and life-threatening complications due to verotoxin-producing escherichia coli (vtec) have been increasingly recognized as a public health problem in recent years. through enhanced surveillance in alberta, canada, and in scotland, 1,993 cases of vtec infection and 115 cases of hemolytic-uremic syndrome (hus) were detected in 1987-1991 in a combined population of more than 7.5 million; there were 24 deaths. the mean annual rates of vtec infection were 12.1/100,000 and 2.0/100,000 for a ... | 1994 | 7893866 |
| risk of hemolytic uremic syndrome after sporadic escherichia coli o157:h7 infection: results of a canadian collaborative study. investigators of the canadian pediatric kidney disease research center. | the objectives of this study were to better estimate the age-specific risks of hemolytic uremic syndrome (hus) and hemolytic anemia after escherichia coli o157:h7 infection among a representative cohort of both referred and nonreferred children with documented illness from the province of alberta and to compare this with the rates in children evaluated at referral centers in the rest of canada. | 1998 | 9602185 |
| the prevalence of verotoxins, escherichia coli o157:h7, and salmonella in the feces and rumen of cattle at processing. | fecal samples collected from cattle at processing during a 1-year period were tested for verotoxins (vt1, vt2), escherichia coli o157:h7, and salmonella. verotoxins were detected in 42.6% (95% ci, 39.8% to 45.4%), e. coli o157:h7 in 7.5% (95% ci, 6.1% to 9.1%), and salmonella in 0.08% (95% ci, 0.004% to 0.5%) of the fecal samples. in yearling cattle, the median within-lot prevalence (percentage of positive samples within a lot) was 40% (range, 0% to 100%) for verotoxins and 0% for e. coli o157:h ... | 1999 | 10340094 |
| environmental sources and transmission of escherichia coli o157 in feedlot cattle. | a study was conducted in 2 feedlots in southern alberta to identify environmental sources and management factors associated with the prevalence and transmission of escherichia coli o157:h7. escherichia coli o157:h7 was isolated in preslaughter pens of cattle from feces (0.8%), feedbunks (1.7%), water troughs (12%), and incoming water supplies (4.5%), but not from fresh total mixed rations. fresh total mixed rations did not support the growth of e. coli o157:h7 and e. coli from bovine feces follo ... | 2001 | 11565371 |
| investigation of an e. coli o157:h7 outbreak in brooks, alberta, june-july 2002: the role of occult cases in the spread of infection within a daycare setting. | | 2003 | 12629877 |
| prevalence of escherichia coli o157:h7 and salmonella spp. in surface waters of southern alberta and its relation to manure sources. | the oldman river watershed in southern alberta, canada, is an extensively irrigated region in which intensive agricultural practices have flourished. concern over water quality in the basin has been expressed because of high levels of enteric disease indigenous to the region. to address these concerns, we conducted a 2-year study to estimate the prevalence of escherichia coli o157:h7 and salmonella spp. in surface water within the basin. this study is the first of its kind to identify e. coli o1 ... | 2003 | 12897826 |
| shiga toxin-producing escherichia coli in the feces of alberta feedlot cattle. | shiga toxin-producing escherichia coli (stec) are a public health concern. bacterial culture techniques commonly used to detect e. coli o157:h7 will not detect other stec serotypes. feces from cattle and other animals are a source of o157:h7 and other pathogenic serotypes of stec. the objective of this study was to estimate the pen-level prevalence of shiga toxins and selected stec serotypes in pre-slaughter feedlot cattle. composite fecal samples were cultured and a polymerase chain reaction (p ... | 2004 | 15188961 |
| bacterial pathogens in rural water supplies in southern alberta, canada. | raw river and irrigation water in the oldman river basin in southern alberta was tested for the presence of two bacterial pathogens, escherichia coli o157:h7 and salmonella spp., over the last 2 yr (2000-2001). the number of e. coli o157:h7 and salmonella spp. isolated from raw water peaked during the summer months. while e. coli o157:h7 was only isolated from 11/802 (1.35%) of raw water samples over the entire sampling season in 2000 and from 16/806 (2.05%) of the samples in 2001, the pathogen ... | 2004 | 15371206 |
| monitoring escherichia coli o157:h7 in inoculated and naturally colonized feedlot cattle and their environment. | on-farm methods of monitoring escherichia coli o157:h7 were assessed in 30 experimentally inoculated steers housed in four pens over a 12-week period and in 202,878 naturally colonized feedlot cattle housed in 1,160 pens on four commercial alberta feedlots over a 1-year period. in the challenge study, yearling steers were experimentally inoculated with 10(10) cfu of a four-strain mixture of nalidixic acid-resistant e. coli o157:h7. after inoculation, shedding of e. coli o157:h7 was monitored wee ... | 2005 | 15690800 |
| an outbreak of e. coli o157:h7 hemorrhagic colitis associated with unpasteurized gouda cheese. | a cluster of e. coli o157:h7 hemorrhagic colitis was identified in metro edmonton, alberta through notifiable disease surveillance in late 2002. | 2005 | 15913080 |
| escherichia coli o157:h7 vaccine field trial in 9 feedlots in alberta and saskatchewan. | a feedlot trial was conducted to assess the efficacy of an escherichia coli o157:h7 vaccine in reducing fecal shedding of e. coli o157:h7 in 218 pens of feedlot cattle in 9 feedlots in alberta and saskatchewan. pens of cattle were vaccinated once at arrival processing and again at reimplanting with either the e. coli o157:h7 vaccine or a placebo. the e. coli o157:h7 vaccine included 50 microg of type iii secreted proteins. fecal samples were collected from 30 fresh manure patties within each fee ... | 2005 | 16187717 |
| ecology of escherichia coli o157:h7 in commercial dairies in southern alberta. | shedding of escherichia coli o157:h7 was monitored monthly over a 1-yr period by collecting pooled fecal pats (fecal) and manila ropes orally accessed for 4 h (rope) from multiple pens of cattle in 5 commercial dairies in southern alberta, canada. using immunomagnetic separation, e. coli o157:h7 was isolated from cows on 4 of the dairies and from 13.5% of fecal and 1.1% of rope samples. pulsed-field gel electrophoresis of xbai- and spei-digested bacterial dna of the 65 isolates produced 23 uniqu ... | 2005 | 16291636 |
| outbreak of escherichia coli o157:h7 gastroenteritis associated with consumption of beef donairs, edmonton, alberta, may-june 2006. | | 2007 | 17233124 |
| genotypic characterization and prevalence of virulence factors among canadian escherichia coli o157:h7 strains. | in this study, the association between genotypic and selected phenotypic characteristics was examined in a collection of canadian escherichia coli o157:h7 strains isolated from humans and cattle in the provinces of alberta, ontario, saskatchewan, and quebec. in a subset of 69 strains selected on the basis of specific phage types (pts), a strong correlation between the lineage-specific polymorphism assay (lspa6) genotype and pt was observed with all strains of pts 4, 14, 21, 31, 33, and 87 belong ... | 2008 | 18487402 |
| detection and determinants of escherichia coil o157:h7 in alberta feedlot pens immediately prior to slaughter. | food safety risks due to escherichia coli o157:h7 may be affected by variability in prevalence in or on live cattle at slaughter. our objectives were to assess the prevalence and risk factors associated with e. coli o157:h7 in feedlot pens immediately prior to slaughter, and assess relationships among methods of monitoring the e. coli o157:h7 status of pre-harvest pens. we studied 84 pens containing a total of nearly 27,000 head of cattle in commercial feedlots in alberta during 2003 and 2004. s ... | 2008 | 18505184 |
| prevalence and impact of bacteriophages on the presence of escherichia coli o157:h7 in feedlot cattle and their environment. | the relationship between endemic bacteriophages infecting e. coli o157:h7 (referred to as "phage") and levels of shedding of e. coli o157:h7 by cattle was investigated in two commercial feedlots in southern alberta, canada. between may and november 2007, 10 pens of cattle were monitored by collection of pooled fecal pats, water with sediment from troughs, manure slurry from the pen floor, and rectal fecal samples from individual animals (20 per pen) at two separate times. bacteriophages infectin ... | 2009 | 19139243 |
| differences between notifiable and administrative health information in the spatial-temporal surveillance of enteric infections. | the purpose of this study is to compare the spatial and temporal information generated from two distinct health data sources available for the surveillance of intestinal infections associated with escherichia coli o157:h7. | 2009 | 19195926 |
| host range and lytic capability of four bacteriophages against bovine and clinical human isolates of shiga toxin-producing escherichia coli o157:h7. | to evaluate host range and lytic capability of four bacteriophages (rv5, wv7, wv8 and wv11) against escherichia coli o157:h7 (stec o157:h7) from cattle and humans. | 2009 | 19302306 |
| escherichia coli o157:h7 lineages in healthy beef and dairy cattle and clinical human cases in alberta, canada. | the aim of this study was to examine the prevalence and distribution of escherichia coli o157:h7 lineage-specific polymorphism assay (lspa) 6 genotypes from cattle (n = 313) and clinical human (n = 203) isolates from northern and southern alberta, canada, to understand possible associations of genotypes with host and geographic location. the majority of cattle isolates (feedlot and dairy) typed as lspa-6 111111 (72.2%), with proportionately higher lspa-6 222222 (19.4%) than other lspa-6 genotype ... | 2009 | 19343950 |
| a microbiological survey of selected alberta-grown fresh produce from farmers' markets in alberta, canada. | previously there was no available information on the levels of indicator bacteria and the prevalence of pathogens in fresh produce grown in alberta, canada. baseline information on the occurrence and levels of escherichia coli and the prevalence of foodborne pathogens in selected produce items available to consumers from farmers' and public markets in two large urban centers and surrounding areas in alberta was obtained. a total of 10 large markets with between 1 and 12 produce vendors and 26 sm ... | 2009 | 19350990 |
| characterization of antimicrobial resistance and seasonal prevalence of escherichia coli o157:h7 recovered from commercial feedlots in alberta, canada. | to characterize antimicrobial resistance (amr) and determine the seasonal prevalence of escherichia coli o157:h7 isolated from commercial feedlots. | 2010 | 20102509 |
| molecular subtypes of campylobacter spp., salmonella enterica, and escherichia coli o157:h7 isolated from faecal and surface water samples in the oldman river watershed, alberta, canada. | campylobacter spp., salmonella enterica, and escherichia coli o157:h7 isolated from 898 faecal, 43 sewage, and 342 surface water samples from the oldman river were characterized using bacterial subtyping methods in order to investigate potential sources of contamination of the watershed. among these pathogens, campylobacter spp. were the most frequently isolated from faecal, sewage, and surface water samples (266/895, 11/43, and 91/342, respectively), followed by salmonella (67/898, 8/43, and 29 ... | 2011 | 20971491 |
| prevalence of staphylococcus aureus and methicillin-resistant s. aureus (mrsa) in food samples associated with foodborne illness in alberta, canada from 2007 to 2010. | consumption of foods containing staphylococcus aureus can cause severe gastro-intestinal illness. given the fact that over the past decade, canada has seen increasing rates of methicillin-resistant s. aureus (mrsa) carriage and infection, the objective of this study was to investigate the impact of methicillin-susceptible s. aureus (mssa) and mrsa on foodborne illness in alberta, canada. between january 2007 and december 2010, there were 693 food samples associated with foodborne investigations ... | 2012 | 22850394 |
| spatial and temporal drivers of zoonotic pathogen contamination of an agricultural watershed. | in regions where animal agriculture is prominent, such as southern alberta, higher rates of gastrointestinal illness have been reported when compared with nonagricultural regions. this difference in the rate of illness is thought to be a result of increased zoonotic pathogen exposure through environmental sources such as water. in this study, temporal and spatial factors associated with bacterial pathogen contamination of the oldman river, which transverses this region, were analyzed using class ... | 2015 | 22218192 |
| molecular profiling of escherichia coli o157:h7 and non-o157 strains isolated from humans and cattle in alberta, canada. | virulence markers in shiga toxin-producing escherichia coli (stec) and their association with diseases remain largely unknown. this study determines the importance of 44 genetic markers for stec (o157 and non-o157) from human clinical cases and their correlation to disease outcome. stec isolated from a cattle surveillance program were also included. the virulence genes tested were present in almost all o157:h7 isolates but highly variable in non-o157 stec isolates. patient age was a significant ... | 2015 | 25540392 |
| differing populations of endemic bacteriophages in cattle shedding high and low numbers of escherichia coli o157:h7 bacteria in feces. | the objectives of this study were to identify endemic bacteriophages (phages) in the feedlot environment and determine relationships of these phages to escherichia coli o157:h7 from cattle shedding high and low numbers of naturally occurring e. coli o157:h7. angus crossbred steers were purchased from a southern alberta (canada) feedlot where cattle excreting ≥ 10(4) cfu · g(-1) of e. coli o157:h7 in feces at a single time point were identified as supershedders (ss; n = 6), and cattle excreting < ... | 2014 | 24747892 |
| genetic diversity and antimicrobial resistance among isolates of escherichia coli o157: h7 from feces and hides of super-shedders and low-shedding pen-mates in two commercial beef feedlots. | cattle shedding at least 104 cfu escherichia coli o157:h7/g feces are described as super-shedders and have been shown to increase transmission of e. coli o157:h7 to other cattle in feedlots. this study investigated relationships among fecal isolates from super-shedders (n = 162), perineal hide swab isolates (ps) from super-shedders (n = 137) and fecal isolates from low-shedder (< 104 cfu/g feces) pen-mates (n = 496) using pulsed-field gel electrophoresis (pfge). a subsample of these fecal isolat ... | 2012 | 23014060 |
| escherichia coli o157:h7 infections associated with contaminated pork products - alberta, canada, july-october 2014. | during july-october 2014, an outbreak of 119 escherichia coli o157:h7 infections in alberta, canada was identified through notifiable disease surveillance and investigated by local, provincial, and federal public health and food regulatory agencies. twenty-three (19%) patients were hospitalized, six of whom developed hemolytic uremic syndrome; no deaths were reported. informed by case interviews, seven potential food sources were identified and investigated. the majority of patients reported hav ... | 2017 | 28056011 |
| the utility of multiple molecular methods including whole genome sequencing as tools to differentiate escherichia coli o157:h7 outbreaks. | a standardised method for determining escherichia coli o157:h7 strain relatedness using whole genome sequencing or virulence gene profiling is not yet established. we sought to assess the capacity of either high-throughput polymerase chain reaction (pcr) of 49 virulence genes, core-genome single nt variants (snvs) or k-mer clustering to discriminate between outbreak-associated and sporadic e. coli o157:h7 isolates. three outbreaks and multiple sporadic isolates from the province of alberta, cana ... | 2015 | 26625187 |
| relationship between the numbers of escherichia coli and the prevalence of escherichia coli o157:h7 on hides of carcasses at a large beef packing plant. | due to the expense of monitoring multiple serotypes of escherichia coli at slaughter, a study was conducted at a beef abattoir in southern alberta to determine relationships between e. coli and e. coli o157:h7 on hides. swab samples were collected from carcasses immediately prior to hide removal over 8 weeks in summer (n = 591) and winter (n = 686). detection of e. coli was highest in summer (p < 0.05), although detection of e. coli o157:h7 did not differ by season. numbers of e. coli did not va ... | 2013 | 23834801 |
| spatio-temporal scan statistics for the detection of outbreaks involving common molecular subtypes: using human cases of escherichia coli o157:h7 provincial pfge pattern 8 (national designation ecxai.0001) in alberta as an example. | molecular typing methods have become a common part of the surveillance of foodborne pathogens. in particular, pulsed-field gel electrophoresis (pfge) has been used successfully to identify outbreaks of escherichia coli o157:h7 in humans from a variety of food and environmental sources. however, some pfge patterns appear commonly in surveillance systems, making it more difficult to distinguish between outbreak and sporadic cases based on molecular data alone. in addition, it is unknown whether th ... | 2013 | 22958357 |