Research Publications (Food Safety)

by Mariana Cap, Celeste Cingolani, Carla Lires, Marina Mozgovoj, Trinidad Soteras, Adriana Sucari, Jimena Gentiluomo, Adriana Descalzo, Gabriela Grigioni, Marcelo Signorini, Celina Horak, Sergio Vaudagna, Gerardo Leotta

This study examined the biofilm-forming ability of six non-O157 Shiga-toxin-producing Escherichia coli (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.

Shiga toxin-producing Escherichia coli (STEC) is a foodborne disease with worldwide outbreaks. STEC serotypes O157, O26, O45, O103, O111, O121, and O145 cause the most outbreaks. There is little published information regarding the other serotypes. We report the draft genome sequences for 11 uncommon STEC serotypes from Nebraska.

Escherichia coli serogroups O157, O26, O45, O103, O111, O121, and O145, when carrying major virulence genes, the Shiga toxin genes stx1 and stx2 and the intimin gene eae, are important foodborne pathogens. They are referred to as the "top 7" Shiga toxin-producing E. coli (STEC) serogroups and were declared by the USDA as adulterants to human health. Since top 7 serogroup-positive cattle feces and ground beef can also contain nonadulterant E.

Extended-spectrum β-lactamase (ESBL)-producing bacteria constitute an emerging global health issue with food products being vehicles of transmission and the aquatic environments serving as potential reservoirs. This study aimed to characterize ESBL-producing Escherichia coli in Nile perch and water from Lake Victoria in Tanzania. A total of 180 samples of Nile perch and 60 water samples were screened for ESBL-producing E.

Author(s): Marina C. Lamparter, Annica Seemann, Carolin Hobe, Elisabeth Schuh

Current California agricultural practices strive to comanage food safety and habitat conservation on farmland. However, the ecology of foodborne pathogens in wild bird populations, especially those avian species residing in proximity to fresh produce production fields, is not fully understood. In this repeated cross-sectional study, avifauna within agricultural lands in California were sampled over 1 year.

aEPEC are associated with persistent diarrhea, and diarrheal outbreaks in both humans and animals worldwide. They are differentiated from typical EPEC by the lack of bundle-forming pili, and from EHEC by the lack of phage-mediated stx toxins. However, phylogenetic analyses often associate aEPEC with EHEC, promoting the hypothesis that aEPEC are the progenitors of EHEC, which is supported by aEPEC conversion to EHEC by stx-carrying phages.

Author(s): Ayanna Glaize, Eduardo Gutierrez-Rodriguez, Irene Hanning, Sandra Díaz-Sánchez, Chris Gunter, Arnoud H.M. van Vliet, Wes Watson, Siddhartha Thakur

Shiga toxin‐producing Escherichia coli (STEC) can cause diarrhoea and severe diseases in humans, such as haemolytic uraemic syndrome. STEC virulence is considered to correlate with the amount of Shiga toxins (Stx) produced, especially Stx2, whose subtype Stx2a is most frequently associated with high virulence. Stx are encoded in prophages, which play an important role in STEC pathogenesis.

Author(s): Lin Chen, Xue Zhao, Ji'en Wu, Qin Liu, Xinyi Pang, Hongshun Yang

by Hiroaki Baba, Hajime Kanamori, Hayami Kudo, Yasutoshi Kuroki, Seiya Higashi, Kentaro Oka, Motomichi Takahashi, Makiko Yoshida, Kengo Oshima, Tetsuji Aoyagi, Koichi Tokuda, Mitsuo Kaku

Author(s): Alexander Gill, Tanis McMahon, Forest Dussault, Nicholas Petronella

Author(s): Minto Michael, Jennifer Acuff, Keyla Lopez, Daniel Vega, Randall Phebus, Harshavardhan Thippareddi, Lakshmikantha H. Channaiah

This study investigated the occurrence of shiga toxin‐producing Escherichia coli (STEC), thermotolerant Campylobacter spp. and Salmonella spp. in Swedish dairy milk. A total of 302 inline milk filters were analyzed. Salmonella was not isolated from any filters. Polymerase chain reaction screening detected thermotolerant Campylobacter in 30.5% of the milk filters analyzed and it was isolated from 12.6% of filters.

Author(s): E. Frank, R. Bonke, N. Drees, M. Heurich, E. Märtlbauer, M. Gareis

Shiga toxin‐producing Escherichia coli (STEC) is a zoonotic pathotype associated with human gastrointestinal disease that may progress to severe complications. Ruminants, especially cattle, are the main reservoirs of STEC from which they can contaminate the environment and foods of animal or vegetable origin. Besides Shiga toxin, other virulence factors are involved in STEC virulence. O157:H7 remains the most frequent serotype associated with disease.

Author(s): Anna Szczerba-Turek, Jan Siemionek, Piotr Socha, Agata Bancerz-Kisiel, Aleksandra Platt-Samoraj, Karolina Lipczynska-Ilczuk, Wojciech Szweda

We report high-quality closed reference genomes for 1 bovine strain and 10 human Shiga toxin (Stx)-producing Escherichia coli (STEC) strains from serogroups O26, O45, O91, O103, O104, O111, O113, O121, O145, and O157. We also report draft assemblies, with standardized metadata, for 360 STEC strains isolated from watersheds, animals, farms, food, and human infections.

We present the complete genome sequence of an enterohemorrhagic Escherichia coli O111:H8 strain. This strain was isolated from a hemolytic-uremic syndrome patient and was responsible for a large outbreak associated with the consumption of raw beef in 2011.

Certain foodborne Shiga toxin-producing Escherichia coli (STEC) strains carry genes encoding the subtilase cytotoxin (SubAB). Although the mode of action of SubAB is under intensive investigation, information about the regulation of subAB gene expression is currently not available. In this study, we investigated the regulation of the chromosomal subAB1 gene in laboratory E. coli strain DH5α and STEC O113:H21 strain TS18/08 using a luciferase reporter gene assay.

Shiga toxin-producing Escherichia coli (STEC) O145 is one of the most prevalent non-O157 serogroups associated with foodborne outbreaks. Lytic phages are a potential alternative to antibiotics in combatting bacterial pathogens. In this study, we characterized a Siphoviridae phage lytic against STEC O145 strains as a novel antimicrobial agent. Escherichia phage vB_EcoS-Ro145clw (Ro145clw) was isolated and purified prior to physiological and genomic characterization.

Author(s): Guerrino Macori, Siobhán C. McCarthy, Catherine M. Burgess, Séamus Fanning, Geraldine Duffy