Irrigation Water Sources and Time Intervals as Variables on the Presence of Campylobacter spp. and Listeria monocytogenes on Romaine Lettuce Grown in Muck Soil.

Irrigation water has been identified as a possible source of vegetable contamination by foodborne pathogens. Risk management for pathogens such as Campylobacter spp. and Listeria monocytogenes in fields can be influenced by the source of the irrigation water and the time interval between last irrigation and harvest.

Extensive characterization of Campylobacter jejuni chicken isolates to uncover genes involved in the ability to compete for gut colonization.

Background: Campylobacter jejuni is responsible for human foodborne enteritis. This bacterium is a remarkable colonizer of the chicken gut, with some strains outcompeting others for colonization. To better understand this phenomenon, the objective of this study was to extensively characterize the phenotypic performance of C.

Comparison of intestinal bacterial populations between two dairy cattle herds colonized or not by Campylobacter jejuni.

Campylobacter jejuni is an important foodborne pathogen. It can be isolated from bovine feces and its presence is influenced by farm characteristics and management practices. The impact of the bovine gut microbiota on the presence of C.

Detection and characterization of Campylobacter spp. from 40 dairy cattle herds in Quebec, Canada.

Dairy cattle are considered a Campylobacter reservoir in the epidemiology of campylobacteriosis. Currently, very little data on the prevalence of Campylobacter in dairy herds are available in the Province of Quebec, Canada. The objectives of this study were to evaluate the prevalence of Campylobacter associated with management practices in 40 dairy cattle herds as well as to characterize the bacterial genetic diversity.

Presence and characterization of Campylobacter jejuni in organically raised chickens in Quebec.

The objective of this study was to estimate the presence of the important foodborne pathogen Campylobacter jejuni in organically raised chickens in the province of Quebec. The recovered isolates were further characterized for their antimicrobial resistance profile, autoagglutination property and chemotaxis. Antimicrobial resistance was evaluated using agar dilution for: tetracycline, erythromycin, chloramphenicol, ciprofloxacin, gentamicin, nalidixic acid, clindamycin, ampicillin, azithromycin, bacitracin, and ceftiofur.

Simultaneous recovery of bacteria and viruses from contaminated water and spinach by a filtration method.

Water and leafy vegetables eaten fresh are increasingly reported as being involved in food-borne illness cases. The pathogenic agents responsible for these infections are mainly bacteria and viruses and are present in very small quantities on the contaminated food matrices. Laboratory techniques used to isolate or detect the contaminating agent differ enormously according to the type of microorganisms, generating time and economical losses.

Risk factors at slaughter associated with presence of Salmonella on hog carcasses in Canada.

Despite the application of hazard analysis and critical control point systems at slaughter and during processing, Salmonella contamination is still a significant biological hazard associated with pork products. A better understanding of risk factors in slaughterhouses and of contamination sources is therefore critical to improve control of this bacterium in the abattoirs. The objectives of this study were to identify the risk factors at slaughter that are associated with the presence of Salmonella on hog carcasses and to assess possible sources of contamination.

Genetic detection of Campylobacter lanienae in fecal matter and stored manure from swine and dairy cattle.

Tracking sources of contamination is an issue related to food safety. In a preliminary study conducted to evaluate the distribution of thermophilic Campylobacter in the environment surrounding dairy cattle and swine production, a number of Campylobacter lanienae were directly detected by PCR. The amplicons came from dairy cows and pig fecal samples, as well as from stored manure.

Antibiotic resistance in Escherichia coll and Enterococcus spp. isolates from commercial broiler chickens receiving growth-promoting doses of bacitracin or virginiamycin.

Antibacterial agents such as zinc bacitracin (ZB) and virginiamycin (VG) are used as growth promoting agents (GP) in broiler chicken production. The objective of this study was to evaluate the effect of the use of ZB and VG on the emergence of antibacterial resistance in a commercial broiler chicken farm. Three trials were conducted using 3 different diets: one without antibacterial agents, one containing VG, and one with ZB.

Comparative evaluation of new TaqMan real-time assays for the detection of hepatitis A virus.

Three novel real-time TaqMan RT-PCR assays targeting the 5'-UTR, the viral protease and the viral polymerase regions of the hepatitis A virus (HAV) were developed, evaluated and compared against a new published 5'-UTR TaqMan assay (JN) and a widely used conventional RT-PCR assay (HAVc). All conventional RT-PCR (HAV, SH-Prot and SH-Poly systems) and TaqMan (SH-Prot, SH-Poly, JN and SH-5U systems) assays evaluated were consistent for the detection of the three different HAV strains (HM-175, HAS-15 and LSH/S) used and reproducible for both RNA duplicates with the exception of two reproducibility discrepancies observed with both 5'-UTR real-time systems (JN and SH-5U). Limits of detection for conventional HAV, SH-Prot and SH-Poly RT-PCR systems were found to be equivalent when tested with serially diluted suspensions of the HM-175 strain.

Antimicrobial susceptibilities of thermophilic Campylobacter from humans, swine, and chicken broilers.

The aim of this study was to evaluate the incidence and the distribution of antimicrobial resistance, and the presence of genetic determinants of resistance, in Campylobacter recovered from swine, poultry, and human populations in Quebec. Minimum inhibitory concentrations (MICs) of 10 antimicrobial agents were determined by the agar dilution technique. Polymerase chain reaction (PCR) was used to detect the tetO determinant, and mutations in gyrA were analyzed by sequencing and by mismatch amplification mutation assay (MAMA) PCR.

Development of an extraction and concentration procedure and comparison of RT-PCR primer systems for the detection of hepatitis A virus and norovirus GII in green onions.

Vegetables can be considered as a vector of transmission for human hepatic and enteric viruses such as hepatitis A virus (HAV) and noroviruses when contaminated by spoiled irrigation water or when prepared by infected food handlers. Recently, outbreaks of HAV have been reported in the USA involving fresh green onions. A viral elution-concentration method was developed for the detection of HAV and norovirus contaminated green onions by RT-PCR.

Characterization of Campylobacter isolates recovered from clinically healthy pigs and from sporadic cases of campylobacteriosis in humans.

Campylobacter spp. were recovered from 660 (77.6%) of 850 swine cecal contents at the abattoir and from 24 (8.

Serotypes of Streptococcus agalactiae cultured from dairy milk samples in Québec.

Streptococcus agalactiae remains an important pathogen of dairy herds in Québec, but data about antigenic characteristics of this microorganism are sparse. This study was conducted to determine the variety of S. agalactiae serotypes in dairy herds in Québec.