Research Publications (Food Safety)

Publication date: 15 July 2017
, Volume 227

Author(s): Rong Di, Malathi S. Vakkalanka, Chatchaya Onumpai, Hoa K. Chau, Andre White, Robert A. Rastall, Kit Yam, Arland T. Hotchkiss

Abstract

Background

INTRODUCTION

Summary

Abstract

Aims

To evaluate the performance of the IQ-Check kits and the USDA Microbiology Laboratory Guidebook (MLG) methods for detection of the top 7 Shiga toxin-producing E. coli (STEC) (O157:H7, O26, O45, O103, O111, O121, and O145) in ground beef and both STEC and Salmonella in co-inoculated samples.

Publication date: May 2017
, Volume 63

Author(s): Kaushi S.T. Kanankege, Kelly S. Anklam, Catherine M. Fick, Megan J. Kulow, Charles W. Kaspar, Barbara H. Ingham, Andrew Milkowski, Dörte Döpfer

The determination of Shiga toxin (ST) subtypes can be an important element in the risk characterization of foodborne ST-producing Escherichia coli (STEC) isolates for making risk management decisions.

Genomic antimicrobial resistance (AMR) prediction tools have the potential to support foodborne illness outbreak investigations through their application in the analysis of bacterial genomes from causative strains. The AMR marker profile of a strain of interest, initially identified in outbreak-associated clinical samples, may serve as the basis for customization of selective enrichment media, facilitating its recovery from samples in a food safety investigation.

Shiga toxin (Stx) 2e of Stx-producing Escherichia coli (STEC) is the primary virulence factor in the development of pig edema disease shortly after weaning. Stx2e binds to the globo-series glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer, Galα1-4Galβ1-4Glcβ1-1Cer) and globotetraosylceramide (Gb4Cer, GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-1Cer), the latter acting as the preferential Stx2e receptor.

Publication date: May 2017
, Volume 63

Author(s): Hana Vojkovská, Petra Myšková, Tereza Gelbíčová, Alena Skočková, Ivana Koláčková, Renáta Karpíšková

Brenda P. Murphy, Evonne McCabe, Mary Murphy, James F. Buckley, Dan Crowley, Séamus Fanning, Geraldine Duffy A 12-month longitudinal study was undertaken on two dairy herds to ascertain the Shiga-toxin producing Escherichia coli (STEC) O157 and O26 shedding status of the animals and its impact (if any) on raw milk. Cattle are a recognized reservoir for these organisms with associated public health and environmental implications. Animals shedding E.

Shiga toxin-producing Escherichia coli (STEC)-associated enteric illness is attributed to O157 and non-O157 serotypes; however, traditional culture-based methods underdetect non-O157 STEC. Labor and cost of consumables are major barriers to implementation of the CDC recommendation to test all stools for both O157 and non-O157 serotypes. We evaluated the feasibility of a pooled nucleic acid amplification test (NAAT) as an approach for screening stool specimens for STEC.

Most Shiga toxin-producing Escherichia coli (STEC) strains associated with severe disease, such as hemolytic-uremic syndrome (HUS), carry large enterohemolysin-encoding (ehxA) plasmids, e.g., pO157 and pO103, that contribute to STEC clinical manifestations. Six ehxA subtypes (A through F) exist that phylogenetically cluster into eae-positive (B, C, F), a mix of eae-positive (E) and eae-negative (A), and a third, more distantly related, cluster of eae-negative (D) STEC strains.

In 2011, one of the world's largest outbreaks of hemolytic-uremic syndrome (HUS) occurred, caused by a rare Escherichia coli serotype, O104:H4, that shared the virulence profiles of Shiga toxin-producing E. coli (STEC)/enterohemorrhagic E. coli (EHEC) and enteroaggregative E. coli (EAEC). The persistence and fitness factors of the highly virulent EHEC/EAEC O104:H4 strain, grown either in food or in vitro, were compared with those of E. coli O157 outbreak-associated strains.

More than 470 serotypes of Shiga toxin–producing Escherichia coli (STEC) have been identified, but not all cause severe illness in humans. Most STEC that cause severe diseases can adhere to epithelial cells, produce specific stx subtypes, and belong to certain serotypes; therefore, these traits appear to be critical STEC risk factors. However, testing for these traits is labor intensive, and serotyping is inadequate because of extensive variations among E. coli O and H antigen types.

Abstract

In summer 2013, an excess of paediatric cases of haemolytic uraemic syndrome (HUS) in a southern region of Italy prompted the investigation of a community-wide outbreak of Shiga toxin 2-producing Escherichia coli (STEC) O26:H11 infections. Case finding was based on testing patients with HUS or bloody diarrhoea for STEC infection by microbiological and serological methods. A case-control study was conducted to identify the source of the outbreak.

Gerardo A. Leotta, Victoria Brusa, Lucía Galli, Cristian Adriani, Luciano Linares, Analía Etcheverría, Marcelo Sanz, Adriana Sucari, Pilar Peral García, Marcelo Signorini

The U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM) Chapter 4a describes a Luminex microbead–based suspension array used to screen colonies for 11 clinically relevant Shiga toxin–producing Escherichia coli (STEC) serogroups: O26, O45, O91, O103, O104, O111, O113, O121, O128, O145, and O157. We evaluated the usefulness of this method to identify STEC-positive enrichment samples before agar plating. Twelve E.

Abstract

Aims

A batch chlorination system was optimized for onsite wastewater treatment and reuse system (OWRS) and its efficiency was evaluated for reducing viruses, protozoa, bacteria, and antimicrobial resistance in cold and warm seasons.

Publication date: 21 November 2016
, Volume 237

Author(s): Rosa Guzman-Hernandez, Araceli Contreras-Rodriguez, Rosa Hernandez-Velez, Iza Perez-Martinez, Ahide Lopez-Merino, Mussaret B. Zaidi, Teresa Estrada-Garcia

Shiga toxin-producing Escherichia coli (STEC) strains can colonize cattle for several months and may, thus, serve as gene reservoirs for the genesis of highly virulent zoonotic enterohemorrhagic E. coli (EHEC). Attempts to reduce the human risk for acquiring EHEC infections should include strategies to control such STEC strains persisting in cattle. We therefore aimed to identify genetic patterns associated with the STEC colonization type in the bovine host.

The disinfectant and antimicrobial susceptibility profiles of 138 non-O157 Shiga toxin–producing Escherichia coli strains (STECs) from food animals and humans were determined. Antimicrobial resistance (AMR) was moderate (39.1% of strains) in response to 15 antimicrobial agents. Animal strains had a lower AMR prevalence (35.6%) than did human strains (43.9%) but a higher prevalence of the resistance profile GEN-KAN-TET.

Publication date: 7 November 2016
, Volume 236

Author(s): María-Elena Álvarez-Suárez, Andrés Otero, María-Luisa García-López, Ghizlane Dahbi, Miguel Blanco, Azucena Mora, Jorge Blanco, Jesús A. Santos