Assessing the genomic relatedness and evolutionary rates of persistent verotoxigenic serotypes within a closed beef herd in Canada.

Verotoxigenic (VTEC) are food- and water-borne pathogens associated with both sporadic illness and outbreaks of enteric disease. While it is known that cattle are reservoirs of VTEC, little is known about the genomic variation of VTEC in cattle, and whether the variation in genomes reported for human outbreak strains is consistent with individual animal or group/herd sources of infection. A previous study of VTEC prevalence identified serotypes carried persistently by three consecutive cohorts of heifers within a closed herd of cattle.

Plasmid Distribution among from Livestock and Associated Wastewater: Unraveling Factors That Shape the Presence of Genes Conferring Third-Generation Cephalosporin Resistance.

A key concern with agricultural wastewater storage ponds is that they may provide an environment conducive for horizontal exchange of antibiotic resistance genes (ARGs), thereby facilitating the emergence of antibiotic resistant pathogens. Central to this exchange are mobile genetic elements like plasmids; yet, the factors shaping their presence in agricultural environments remain poorly understood. Here, using as a model bacterium, we examined genetic backgrounds and plasmid profiles of generic fecal and wastewater isolates and those possessing and genes (which confer resistance to third-generation cephalosporins) to delineate factors shaping the environmental persistence of plasmid-associated ARGs in beef cattle feedlots.

Sources of generic Escherichia coli and factors impacting guideline exceedances for food safety in an irrigation reservoir outlet and two canals.

Nearly half of all cases of foodborne illness are associated with plant-based foods such as leafy greens and raw flour. An important potential source of pathogen contamination along the food-production continuum is irrigation water, which has led to the implementation of increasingly stringent agricultural irrigation water quality requirements. To better understand factors impacting irrigation water quality, we investigated sources of generic Escherichia coli and how they varied temporally among different sampling sites.

Multi-Year Persistence of Verotoxigenic (VTEC) in a Closed Canadian Beef Herd: A Cohort Study.

In this study, fecal samples were collected from a closed beef herd in Alberta, Canada from 2012 to 2015. To limit serotype bias, which was observed in enrichment broth cultures, Verotoxigenic (VTEC) were isolated directly from samples using a hydrophobic grid-membrane filter verotoxin immunoblot assay. Overall VTEC isolation rates were similar for three different cohorts of yearling heifers on both an annual (68.

Zoonotic Fecal Pathogens and Antimicrobial Resistance in Canadian Petting Zoos.

This study aimed to better understand the potential public health risk associated with zoonotic pathogens in agricultural fairs and petting zoos in Canada. Prevalence of , Shiga toxin-producing (STEC) O157:H7, and top six non-O157 STEC serogroups in feces ( = 88), hide/feather ( = 36), and hand rail samples ( = 46) was assessed, as well as distributions of antimicrobial resistant (AMR) broad and extended-spectrum β-lactamase (ESBL)-producing . Prevalence of methicillin-resistant (MRSA) in pig nasal swabs ( = 4), and , , and in feces was also assessed.

A national investigation of the prevalence and diversity of thermophilic Campylobacter species in agricultural watersheds in Canada.

The occurrence and diversity of thermophilic Campylobacter species (C. jejuni, coli, and lari) were studied in water samples from four river basins located across Canada. These basins located in Quebec (Bras d'Henri), Alberta (Oldman), Ontario (South Nation), and British Columbia (Sumas) represented some of the most intensive farming areas in Canada for hog, beef cattle, dairy cattle, and poultry, respectively.

Long-term monitoring of waterborne pathogens and microbial source tracking markers in paired agricultural watersheds under controlled and conventional tile drainage management.

Surface waters from paired agricultural watersheds under controlled tile drainage (CTD) and uncontrolled tile drainage (UCTD) were monitored over 7 years in order to determine if there was an effect of CTD (imposed during the growing season) on occurrences and loadings of bacterial and viral pathogens, coliphages, and microbial source tracking markers. There were significantly lower occurrences of human, ruminant, and livestock (ruminant plus pig) Bacteroidales markers in the CTD watershed in relation to the UCTD watershed. As for pathogens, there were significantly lower occurrences of Salmonella spp.

Using SWAT, Bacteroidales microbial source tracking markers, and fecal indicator bacteria to predict waterborne pathogen occurrence in an agricultural watershed.

Developing the capability to predict pathogens in surface water is important for reducing the risk that such organisms pose to human health. In this study, three primary data source scenarios (measured stream flow and water quality, modelled stream flow and water quality, and host-associated Bacteroidales) are investigated within a Classification and Regression Tree Analysis (CART) framework for classifying pathogen (Escherichia coli 0157:H7, Salmonella, Campylobacter, Cryptosporidium, and Giardia) presence and absence (P/A) for a 178 km(2) agricultural watershed. To provide modelled data, a Soil Water Assessment Tool (SWAT) model was developed to predict stream flow, total suspended solids (TSS), total N and total P, and fecal indicator bacteria loads; however, the model was only successful for flow and total N and total P simulations, and did not accurately simulate TSS and indicator bacteria transport.

Coherence among different microbial source tracking markers in a small agricultural stream with or without livestock exclusion practices.

Over 1,400 water samples were collected biweekly over 6 years from an intermittent stream protected and unprotected from pasturing cattle. The samples were monitored for host-specific Bacteroidales markers, Cryptosporidium species/genotypes, viruses and coliphages associated with humans or animals, and bacterial zoonotic pathogens. Ruminant Bacteroidales markers did not increase within the restricted cattle access reach of the stream, whereas the ruminant Bacteroidales marker increased significantly in the unrestricted cattle access reach.

A Canadian application of one health: integration of Salmonella data from various Canadian surveillance programs (2005-2010).

Most bacterial pathogens associated with human enteric illness have zoonotic origins and can be transmitted directly from animals to people or indirectly through food and water. This multitude of potential exposure routes and sources makes the epidemiology of these infectious agents complex. To better understand these illnesses and identify solutions to reduce human disease, an integrative approach like One Health is needed.

Quantitative multi-year elucidation of fecal sources of waterborne pathogen contamination in the South Nation River basin using bacteroidales microbial source tracking markers.

Over a seven-year period (2004-2010) 1095 water samples were obtained from the South Nation River basin at multiple watershed monitoring sites (Ontario, Canada). Real-time PCR using Bacteroidales specific markers was used to identify the origin (human (10% prevalence), ruminant (22%), pig (~2%), Canada goose (4%) and muskrat (7%)) of fecal pollution. In parallel, the distribution of fecal indicator bacteria and waterborne pathogens (Cryptosporidium oocysts, Giardia cysts, Escherichia coli O157:H7, Salmonella enterica and Campylobacter spp.

Spatiotemporal analysis of Cryptosporidium species/genotypes and relationships with other zoonotic pathogens in surface water from mixed-use watersheds.

Nearly 690 raw surface water samples were collected during a 6-year period from multiple watersheds in the South Nation River basin, Ontario, Canada. Cryptosporidium oocysts in water samples were enumerated, sequenced, and genotyped by detailed phylogenetic analysis. The resulting species and genotypes were assigned to broad, known host and human infection risk classes.

An enhanced technique combining pre-enrichment and passive filtration increases the isolation efficiency of Campylobacter jejuni and Campylobacter coli from water and animal fecal samples.

Improved isolation techniques from environmental water and animal samples are vital to understanding Campylobacter epidemiology. In this study, the efficiency of selective enrichment in Bolton Broth (BB) followed by plating on charcoal cefoperazone deoxycholate agar (CCDA) (conventional method) was compared with an approach combining BB enrichment and passive filtration (membrane method) adapted from a method previously developed for testing of broiler meat, in the isolation of thermophilic campylobacters from surface water and animal fecal samples. The conventional method led to recoveries of Campylobacter from 36.

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 classification and regression tree analysis.

Development and validation of a comparative genomic fingerprinting method for high-resolution genotyping of Campylobacter jejuni.

Campylobacter spp. are a leading cause of bacterial gastroenteritis worldwide. The need for molecular subtyping methods with enhanced discrimination in the context of surveillance- and outbreak-based epidemiologic investigations of Campylobacter spp.

The occurrence and sources of Campylobacter spp., Salmonella enterica and Escherichia coli O157:H7 in the Salmon River, British Columbia, Canada.

In this study, we wished to assess the prevalence and determine the sources of three zoonotic bacterial pathogens (Salmonella, Campylobacter, and Escherichia coli O157:H7) in the Salmon River watershed in southwestern British Columbia. Surface water, sewage, and animal faecal samples were collected from the watershed. Selective bacterial culture and PCR techniques were used to isolate these three pathogens and indicator bacteria from these samples and characterize them.

A methods comparison for the isolation and detection of thermophilic Campylobacter in agricultural watersheds.

Campylobacter species contribute to an enormous burden of enteric illnesses around the world. This study compared two different methods for detecting Campylobacter species in surface water samples from agricultural watersheds across Canada. One method was based on membrane filtration (MF) of 500 ml water samples followed by selective microaerophilic enrichment at 42 degrees C in Bolton broth, isolation of Campylobacter on CCDA, and subsequent identification confirmation by a PCR assay.

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.