In Silico Analysis of Shiga Toxin-Producing O157:H7 Strains from Presumptive Super- and Low-Shedder Cattle.

Cattle are the primary reservoir for STEC O157, with some shedding >10 CFU/g in feces, a phenomenon known as super-shedding (SS). The mechanism(s) responsible for SS are not understood but have been attributed to the environment, host, and pathogen. This study aimed to compare genetic characteristics of STEC O157 strains from cattle in the same commercial feedlot pens with SS or low-shedding (LS) status.

The Isolation and Characterization of Bacteriophages Infecting Avian Pathogenic O1, O2 and O78 Strains.

Avian pathogenic (APEC), such as O1, O2 and O78, are important serogroups relating to chicken health, being responsible for colibacillosis. In this study, we isolated and characterized bacteriophages (phages) from hen feces and human sewage in Alberta with the potential for controlling colibacillosis in laying hens. The lytic profile, host range, pH tolerance and morphology of seven APEC-infecting phages (ASO1A, ASO1B, ASO2A, ASO78A, ASO2B, AVIO78A and ASO78B) were assessed using a microplate phage virulence assay and transmission electron microscopy (TEM).

Bacteriophages for the Targeted Control of Foodborne Pathogens.

Foodborne illness is exacerbated by novel and emerging pathotypes, persistent contamination, antimicrobial resistance, an ever-changing environment, and the complexity of food production systems. Sporadic and outbreak events of common foodborne pathogens like Shiga toxigenic . (STEC), , , and are increasingly identified.

Genomic Analysis of Shiga Toxin-Producing O157 Cattle and Clinical Isolates from Alberta, Canada.

Shiga toxin () is the principal virulence factor of the foodborne pathogen, Shiga toxin-producing (STEC) O157:H7 and is associated with various lambdoid bacterio (phages). A comparative genomic analysis was performed on STEC O157 isolates from cattle ( = 125) and clinical ( = 127) samples to characterize virulence genes, -phage insertion sites and antimicrobial resistance genes that may segregate strains circulating in the same geographic region. In silico analyses revealed that O157 isolates harboured the toxin subtypes and Most cattle (76.

Activity of Bacteriophage and Complex Tannins against Biofilm-Forming Shiga Toxin-Producing from Canada and South Africa.

Bacteriophages, natural killers of bacteria, and plant secondary metabolites, such as condensed tannins, are potential agents for the control of foodborne pathogens. The first objective of this study evaluated the efficacy of a bacteriophage SA21RB in reducing pre-formed biofilms on stainless-steel produced by two Shiga toxin-producing (STEC) strains, one from South Africa and the other from Canada. The second objective examined the anti-bacterial and anti-biofilm activity of condensed tannin (CT) from purple prairie clover and phlorotannins (PT) from brown seaweed against these strains.

Biofilm formation by South African non-O157 Shiga toxigenic on stainless steel coupons.

This study examined the biofilm-forming ability of six non-O157 Shiga-toxin-producing (STEC) strains: O116:H21, wzx-Onovel5:H19, O129:H21, O129:H23, O26:H11, and O154:H10 on stainless steel coupons after 24, 48, and 72 h of incubation at 22 °C and after 168 h at 10 °C. The results of crystal violet staining revealed that strains O129:H23 and O154:H10 were able to form biofilms on both the submerged surface and the air-liquid interface of coupons, whereas strains O116:H21, wzx-Onovel5:H19, O129:H21, and O26:H11 formed biofilm only at the air-liquid interface. Viable cell counts and scanning electron microscopy showed that biofilm formation increased ( < 0.

Characterization of Non-O157 STEC Infecting Bacteriophages Isolated from Cattle Faeces in North-West South Africa.

Non-O157 Shiga toxin-producing (STEC) are emerging pathotypes that are frequently associated with diseases in humans around the world. The consequences of these serogroups for public health is a concern given the lack of effective prevention and treatment measures. In this study, ten bacteriophages (phages; SA20RB, SA79RD, SA126VB, SA30RD, SA32RD, SA35RD, SA21RB, SA80RD, SA12KD and SA91KD) isolated from cattle faeces collected in the North-West of South Africa were characterized.

Biofilm Formation by Shiga Toxin-Producing on Stainless Steel Coupons as Affected by Temperature and Incubation Time.

Forming biofilm is a strategy utilized by Shiga toxin-producing Escherichia coli (STEC) to survive and persist in food processing environments. We investigated the biofilm-forming potential of STEC strains from 10 clinically important serogroups on stainless steel at 22 °C or 13 °C after 24, 48, and 72 h of incubation. Results from crystal violet staining, plate counts, and scanning electron microscopy (SEM) identified a single isolate from each of the O113, O145, O91, O157, and O121 serogroups that was capable of forming strong or moderate biofilms on stainless steel at 22 °C.