Genotyping and antimicrobial resistance patterns of Escherichia coli O157 originating from cattle farms

During a Escherichia coli O157 prevalence study on cattle farms, 324 E. coli O157 isolates were collected from 68 out of 180 cattle farms. All isolates harbored the eaeA gene and the enterohemolysin (ehxA) gene. The majority of the strains only contained vtx2 (245 isolates), the combination of vtx1 and vtx2 was detected in 50 isolates, and in 29 isolates none of the vtx genes was present. Pulsed-field gel electrophoresis (PFGE) revealed that at a similarity level of 98% the isolates grouped into 83 different genotypes, 76 of which were only detected on one farm. Twenty-two out of the 68 positive farms harbored isolates belonging to more than one PFGE type, with a maximum of four different PFGE types. Minimal inhibitory concentrations of 10 antimicrobial agents were determined on a subset of 116 isolates, that is, one isolate per positive age category per farm. Acquired resistance to at least one antimicrobial agent was detected in 18 isolates and within a farm, only one resistance pattern was observed. All these 18 isolates were resistant toward streptomycin, and 16 of them also showed resistance toward sulfisoxazole. Six isolates were resistant to three or more antimicrobial agents

Occurrence of non-sorbitol fermenting, verocytotoxin-lacking Escherichia coli O157 on cattle farms

International audienceis often associated with hemorrhagic colitis and the hemolytic uremic syndrome (HUS). The verocytotoxins are considered to be the major virulence determinants. However, -negative O157 were recently isolated from patients with HUS. Several transmission routes to humans are described, but cattle feces are the primary source from which both the food supply and the environment become contaminated with O157

Escherichia coli O157 prevalence in different cattle farm types and identification of potential risk factors

Although the prevalence of Escherichia coli 0157 on cattle farms has been examined extensively, the relationship between this pathogen and farm type has been established only rarely. A large-scale study was designed to determine the prevalence of E. coli 0 157 in the Flemish region of Belgium on farms of dairy cattle, beef cattle, mixed dairy and beef cattle, and veal calves. The effect of various factors on the occurrence at the pen level also was evaluated. In 2007, 180 farms were randomly selected based on region, farm size, and number of animals purchased and were examined using the overshoe sampling method. When possible, overshoes used in areas containing animals in three different age categories (30 months) were sampled on each farm. In total, 820 different pens were sampled and analyzed for the presence of E. coli 0157 by enrichment, immunomagnetic separation, and plating on selective agar. Presumptive E. coli 0157 colonies were identified using a multiplex PCR assay for the presence of the rfb(O157) and fliC(H7) genes. The statistical analysis was carried out with Stata SE/10.0 using a generalized linear regression model with a log it link function and a binomial error distribution. The overall farm prevalence of E. coli 0157 was 37.8% (68 of 180 farms). The highest prevalence was found on dairy cattle farms (61.2%, 30 of 49 farms). The prevalences on beef, mixed dairy and beef, and veal calf farms were 22.7% (17 of 75 farms), 44.4% (20 of 45 farms), and 9.1% (I of I I farms), respectively. A significant positive correlation between age category and E. coli 0157 prevalence was found only on mixed dairy and beef farms and dairy farms. No influence of farm size or introduction of new animals was demonstrated

Alternative sampling to establish the Escherichia coli O157 status on beef cattle farms

Prevalence of Escherichia coli O157 in cattle at the farm level is mostly determined by taking individually rectal samples. From the animal welfare point of view the collection of such samples on the farm is not advisable. The present study evaluated alternative sample types to assess the E. coli O157 status of cattle farms. Twelve closed cattle farms were visited twice with a time interval of 6-8 months. Rectal and hide surface samples (the nose, the neck, the shoulder, the flank, and the round) were collected from beef cattle within the period of 5 months before slaughter and from their environment (overshoes from the pen bedding, swabs from the pen barrier, feed and water). Statistical analysis revealed that from all samples taken only the "overshoe method" might be a good sampling technique to substitute the collection of individual fecal samples to establish the E. coli O157 status of a farm and even a pen. Characterization of the isolates, using pulsed field gel electrophoresis, revealed that on each positive farm only one genotype was presented, even after a period of more than 6 months

Can the use of bread waste decrease the environmental impact of beer? Case-specific evaluation and advice using an LCA approach

Yearly, 25% of total bread and bakery products in Flanders is lost or wasted[1]. Bread is also one of the most important contributors to the environmental impact of food waste in supermarkets[2]. Therefore, valorization of bread waste in new food products could reduce food waste in terms of mass, but also in terms of environmental impact. The aim of this study is to explore the valorization potential of bread waste as an input in beer brewing. Beer production using bread waste is technically feasible and several bread-based beers are already on the market. But, can the use of bread waste decrease the environmental impact of these beers? Or in other words, is beer production a beneficial valorization route for bread waste from an environmental viewpoint? To answer these questions, we perform a life cycle assessment (LCA) and develop a LCA-model to calculate the environmental impact of beer produced either with or without bread waste as an input. Several LCA-studies of beer have been published, but results vary widely, due to the type of beer studied (e.g. ale or lager), the packaging materials used, the brewery size and assumptions made concerning system boundaries. Therefore, a case-specific approach and detailed LCA tool using primary data is needed to evaluate the full case-specific environmental potential of using bread waste in beer brewing. Our LCA-model is intended to be used not only to calculate the potential environmental benefits of using bread waste in beer brewing, but also to give case-specific advice to brewers concerning alternative production options for including bread waste, and concerning the environmental impact of their activities in genera