The utility of multiple molecular methods including whole genome sequencing as tools to differentiate Escherichia coli O157:H7 outbreaks.

The utility of multiple molecular methods including whole genome sequencing as tools to differentiate Escherichia coli O157:H7 outbreaks. Euro Surveill. 2015 Nov 26;20(47) Authors: Berenger BM, Berry C, Peterson T, Fach P, Delannoy S, Li V, Tschetter L, Nadon C, Honish L, Louie M, Chui L Abstract 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, Canada were included in the study. Two of the outbreaks occurred concurrently in 2014 and one occurred in 2012. Pulsed-field gel electrophoresis (PFGE) and multilocus variable-number tandem repeat analysis (MLVA) were employed as comparator typing methods. The virulence gene profiles of isolates from the 2012 and 2014 Alberta outbreak events and contemporary sporadic isolates were mostly identical; therefore the set of virulence genes chosen in this study were not discriminatory enough to distinguish between outbreak clusters. Concordant with PFGE and MLVA results, core genome SNV and k-mer phylogenies clustered isolates from the 2012 and 2014 outbreaks as distinct events. k-...
Source: Euro Surveill - Category: Infectious Diseases Authors: Tags: Euro Surveill Source Type: research

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In conclusion, using a simple, fast, and inexpensive detection method, such as LAMP, especially in endemic regions or in an outbreak to control spreading of pathogens, is very important for public health.
Source: Journal of Microbiological Methods - Category: Microbiology Source Type: research
Abstract Lettuce (Lactuca sativa), one of the most consumed leafy vegetables in the world, is frequently implicated with foodborne disease (FBD) outbreaks, with Salmonella spp. and Escherichia coli O157:H7 being the most common bacteria to cause this illness. Estimates of prevalence and levels of these pathogens on lettuce are scarce in developed or in developing countries, which hinders risk assessment attempts. In here, we present a systematic review and meta-analysis of reported prevalence and levels of Salmonella spp. and E. coli O157:H7 on lettuce using the worldwide available data. Literature was reviewed an...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
In this study, we investigated the genetic diversity, virulence factors and farm-to-table spread pattern of V. parahaemolyticus by analyzing 383 genomes of food-associated isolates. These strains were isolated from diverse sample types from six provinces of China in 2014, being classified into three tiers of the farm-to-table spread process: food production, circulation and consumption. The genetic diversity of V. parahaemolyticus in different classifications, including geographical location, sample type, source and spread tier, was similar, as the median number of pairwise SNPs within each classification was between 33,01...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
Abstract Only a few studies concerning Shiga toxin-producing E. coli (STEC) detection in bivalves and their harvesting areas have been reported, and to the best of our knowledge there are no outbreaks associated with STEC from bivalves described. The aim of the present study was to investigate the occurrence of STEC in Norwegian bivalves, and to characterize potential STEC isolated from the samples. A total of 269 samples of bivalves were screened for the presence of stx and eae genes, and markers for the serogroups O26, O103, O111, O145 and O157 by using ISO TS 13136 (2012). The screening returned 19 samples that...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
;jar S, Allende A Abstract Fresh produce causes most foodborne outbreaks in the USA, and it is also considered a hazardous food product in other areas of the world such as Europe. The outbreaks attributed to fresh produce increase the focus of producers on hygiene to minimize exposure to food hazards. The fresh produce industry has the urgent need to detect if there are production lots contaminated with pathogenic microorganisms before distribution. Although the industry is mostly using end-product testing for the detection of target microorganisms, previous studies have evaluated the suitability of different samp...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
Abstract Bacterial persistence is a form of phenotypic heterogeneity in which a subpopulation, persisters, has high tolerance to antibiotics and other stresses. Persisters of enteric pathogens may represent the subpopulations capable of surviving harsh environments and causing human infections. Here we examined the persister populations of several shiga toxin-producing Escherichia coli (STEC) outbreak strains under conditions relevant to leafy greens production. The persister fraction of STEC in exponential-phase of culture varied greatly among the strains examined, ranging from 0.00003% to 0.0002% for O157:H7 str...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research
Globally, the bacterial genus Campylobacter is one of the leading causes of human gastroenteritis, with its primary route of infection being through poultry meat. The application of biosecurity measures is currently limited by a lack of understanding of the transmission dynamics within a flock. Our work is the first to undertake a mathematical modelling approach to Campylobacter population dynamics within a flock of broilers (chickens bred specifically for meat). A system of stochastic differential equations is used to model the routes of infection between co-housed birds. The presented model displays the strong correlatio...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
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Source: Food Control - Category: Food Science Source Type: research
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Source: Food Control - Category: Food Science Source Type: research
This study aimed to characterize the resistance to antimicrobials, plasmids and virulence, as well as the serotypes and phylogenetic groups inE. coli isolated from sheep in Brazil. A total of 57 isolates were obtained and showed different antimicrobial resistance profiles. Nineteen isolates presented acquired antimicrobial resistance genes (ARGs) (blaCTX-M-Gp9,qnrB, qnrS, oqxB, oqxA, tetA, tetB, tetC, sul1 andsul2) and plasmid families (F, FIA, FIB, I1, K, HI1 and ColE-like). Thestx1,stx2 andehxA virulence genes were detected by PCR, being 50 isolates (87.7%) classified as STEC. A great diversity of serotypes was detected,...
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research
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