Research Publications (Food Safety)

Publication date: May 2016
, Volume 63

Author(s): Jacqueline Tanury Macruz Peresi, Ivete Aparecida Zago Castanheira de Almeida, Tânia Mara Ibelli Vaz, Rodrigo Tavanelli Hernandes, Inara Siqueira de Carvalho Teixeira, Sonia Izaura de Lima e Silva, Rejane Alexandre Silva Graciano, Sandra Regina Pinheiro, Luis Fernando dos Santos

Online Ahead of Print.

Shiga toxin (Stx)–producing Escherichia coli (STEC) strains are food- and waterborne pathogens that are often transmitted via beef products or fresh produce. STEC strains cause both sporadic infections and outbreaks, which may result in hemorrhagic colitis and hemolytic uremic syndrome. STEC strains may elaborate Stx1, Stx2, and/or subtypes of those toxins.

The purpose of this study was to evaluate (i) the behavior of several strains of non-O157 Shiga toxin–producing Escherichia coli (STEC) serogroups (O26, O103, O111, and O145) exposed to different stress conditions and (ii) the growth dynamics of stressed and nonstressed non-O157 STEC cells in five enrichment media. STEC strains were exposed to acid, cold, and freeze stresses. Lethal and sublethal injuries were determined by plating in parallel on selective and nonselective agar media.

Brittany N. Ross, Maricarmen Rojas-Lopez, Roberto J. Cieza, Brian D. McWilliams, Alfredo G. Torres

Culture-independent diagnostics reduce the reliance on traditional (and slower) culture-based methodologies. Here we capitalize on advances in next-generation sequencing (NGS) to apply this approach to food pathogen detection utilizing NGS as an analytical tool.

The ability of Escherichia coli O157:H7 to induce cellular damage leading to disease in humans is related to numerous virulence factors, most notably the stx gene, encoding Shiga toxin (Stx) and carried by a bacteriophage. Loss of the Stx-encoding bacteriophage may occur during infection or culturing of the strain. Here, we collected stx-positive and stx-negative variants of E. coli O157:H7/NM (nonmotile) isolates from patients with gastrointestinal complaints.

Although new serotypes of enterohemorrhagic Escherichia coli (EHEC) emerge constantly, the mechanisms by which these new pathogens arise and the reasons emerging serotypes tend to carry more virulence genes than other E. coli are not understood. An insertion sequence (IS) excision enhancer (IEE) was discovered in EHEC O157:H7 that promoted the excision of IS3 family members and generating various genomic deletions.

Taseen S. Desin, Hugh G. Townsend, Andrew A. Potter

Publication date: December 2015
, Volume 119

Author(s): Victoria Brusa, Lucía Galli, Luciano H. Linares, Emanuel E. Ortega, Juan P. Lirón, Gerardo A. Leotta

Abstract

Shiga toxins (Stx1 and Stx2, also called verocytotoxins) are commonly associated with Shiga toxin-producing Escherichia coli (STEC) and Shigella dysenteriae type 1 (Tesh and O’Brien 1991). Recent studies have documented cases of stx carriage in other Shigella species, including S. sonnei linked to travel to Morocco (Nyholm et al. 2015) and S. flexneri with travel history to Caribbean (Gray et al. 2014, 2015).

Harada, Tetsuya et al. Shiga toxin family members have recently been classified using a new nomenclature into three Stx1 subtypes (Stx1a, Stx1c, and Stx1d) and seven Stx2 subtypes (Stx2a, Stx2b, Stx2c, Stx2d, Stx2e, Stx2f, and Stx2g). To develop screening methods for Stx genes, including all of these subtype genes, and Escherichia coli O26-, O111-, and O157-specific genes in laboratory investigations of Shiga toxin–producing E.

Publication date: Available online 16 September 2015

Author(s): Gabriel Cabrera, Romina J. Fernández-Brando, María Pilar Mejías, María Victoria Ramos, María Jimena Abrey-Recalde, Silvia Vanzulli, Mónica Vermeulen, Marina S. Palermo

The objective of this study was to compare the acid resistanceAR) of non-O157 Shiga toxin-producing Escherichia coli (STEC) strains belonging to serogroups O26, O45, O103, O104, O111, O121, and O145 with O157:H7 STEC isolated from various sources in 400 mM acetic acid solutions (AAS) at pH 3.2 and 30 °C for 25 min with or without glutamic acid.

Publication date: February 2016
, Volume 53, Part B
Author(s): Cécile Callon, Céline Arliguie, Marie-Christine Montel

Publication date: 23 December 2015
, Volume 215
Author(s): Prashant Singh, Azlin Mustapha

Publication date: 23 December 2015
, Volume 215
Author(s): Gui-Ying Mei, Joshua Tang, Christine Carey, Susan Bach, Magdalena Kostrzynska

Publication date: Available online 21 August 2015

Author(s): Angelika Fruth, Rita Prager, Erhard Tietze, Wolfgang Rabsch, Antje Flieger

Publication date: 2 December 2015
, Volume 214
Author(s): H. Margot, M.H. Zwietering, H. Joosten, Emer O'Mahony, R. Stephan

Publication date: February 2016
, Volume 60
Author(s): Rui Li, Xiao Tan, Jie Xiao, Hongxun Wang, Zhiguo Liu, Min Zhou, Wanglai Bi, Takahisa Miyamoto

Publication date: December 2015
, Volume 110
Author(s): Byron D. Chaves, Alejandro Echeverry, Lyda G. García, M. Todd Brashears, Markus F. Miller, Mindy M. Brashears

Monu, Emefa Angelica et al. Produce has been associated with a rising number of foodborne illness outbreaks. While much produce is consumed raw, some is treated with mild heat, such as blanching or cooking.

Lee, Chi-Ching et al. This study investigated the role of extracellular cellulose production by Shiga toxin–producing Escherichia coli (STEC) on attachment to lettuce and spinach in different water hardness environments. Two cellulose-producing wild-type STEC strains, 19 (O5:H−) and 49 (O103:H2), and their cellulose-deficient derivatives were used. Strain 49 also produced colanic acid as a constituent of its extracellular polymeric substances.

Publication date: December 2015
, Volume 110
Author(s): B. Corliss, J.C. Brooks, J.N. Martin, A. Echeverry, A.R. Parks, S. Pokharel, M.M. Brashears