Research Publications (Food Safety)

Shiga toxin-producing Shigella species and Escherichia coli (STEC) are pathogenic bacteria that cause the bloody diarrheal diseases bacillary dysentery (Shigella spp.) and hemorrhagic colitis (STEC). Unfortunately, patients with these diarrheal diseases are at risk for developing potentially lethal extraintestinal complications such as hemolytic uremic syndrome (HUS), resulting in acute renal failure, and neurological sequelae such as seizures, cortical blindness, and coma. Shigella spp.

The frequent outbreaks of foodborne pathogens have stimulated the demand of biosensors capable of rapid and multiplex detection of contaminated food. In this study, surface plasmon resonance imaging (SPRi) was used in simultaneous label-free detection of multiple foodborne pathogens, mainly Salmonella spp. and Shiga-toxin producing Escherichia coli (STEC), in commercial chicken carcass rinse. The antibodies were immobilized on the same SPRi sensor chip as a label-free immunoassay.

Shiga toxin-producing Escherichia coli (STEC) is one of the most commonly heard sources of foodborne outbreaks but presently lacks studies of in the Kathmandu Valley. This study explored the presence of STEC in river water (n = 17), groundwater (n = 83), feces (n = 50), and manure (n = 20) in the Kathmandu Valley, Nepal. Samples that were confirmed to be E.

by Victoria Brusa, Magdalena Costa, Nora L. Padola, Analía Etcheverría, Fernando Sampedro, Pablo S. Fernandez, Gerardo A. Leotta, Marcelo L. Signorini

Shiga toxin–producing E. coli (STEC) and enterotoxigenic E. coli (ETEC) are the main agents of swine colibacillosis, an infectious disease which implies important economic losses. We characterized here 186 diarrheagenic E. coli from Spanish industrial pig farms (2005-2017) to know which clones were involved in this syndrome, and the rates of antibiotic resistance.

Following two O121 STEC outbreaks linked to wheat flour, this study was conducted to gain baseline information on the occurrence of bacterial pathogens and levels of indicator organisms in wheat flour in Canada. A total of 347 pre-packaged wheat flour samples were analyzed for Salmonella spp., Shiga Toxin-Producing Escherichia coli (STEC), Listeria monocytogenes ( L. monocytogenes ) , aerobic colony count (ACC), total coliforms, and generic Escherichia coli ( E. coli ) .

Background Produce-associated outbreaks of Shiga toxin–producing Escherichia coli (STEC) were first identified in 1991. In April 2018, New Jersey and Pennsylvania officials reported a cluster of STEC O157 infections associated with multiple locations of a restaurant chain. The Centers for Disease Control and Prevention (CDC) queried PulseNet, the national laboratory network for foodborne disease surveillance, for additional cases and began a national investigation.

Shiga toxin-producing Escherichia coli (STEC) serotype O103 is one of the primary pathogenic contaminants of beef products, contributing to several foodborne outbreaks in recent years. Here, we report the whole-genome sequence of a STEC O103:H2 strain isolated from cattle feces that contains a locus of enterocyte effacement (LEE) pathogenicity island.

Author(s): Pengwei Hu, Chuyun Liu, Jiawen Ruan, Meng Yuan, Changyan Ju, Yanping Ma, Yueming Yuan, Hui Chen, Muhua Yu, Yongxiang Duan

Aims The purpose of this study was to investigate the occurrence of E. coli O157 and O26 on Belgian dairy cattle farms, the presence of virulence genes in the confirmed isolates, and the association of E. coli O26 presence with calf diarrhea. Methods and Results In total, 233 recto‐anal mucosal swabs (RAMS) were obtained from healthy and diarrheic dairy calves on three farms, each alternately visited three consecutive times. RAMS were analyzed for presence of E.

Ingestion of Shiga toxin-producing Escherichia coli (STEC) can result in a range of illness severity from asymptomatic to hemorrhagic colitis and death; thus risk assessment of STEC strains for human pathogenicity is important in the area of food safety. Illness severity depends in part on the combination of virulence genes carried in the genome, which can vary between strains even of identical serotype.

We compared genomes from multiple isolations of Shiga toxin-producing Escherichia coli (STEC) O157:H7 from the same patient, in cases notified to Public Health England (PHE) between 2015 and 2019. There were 261 cases where multiple isolates were sequenced from the same patient comprising 589 isolates.

In December 2015, six cases of Shiga toxin (Stx)-producing Escherichia coli (STEC) O157:H7 stx2a/stx2c phage type (PT) 24 were identified by the national gastrointestinal disease surveillance system at Public Health England (PHE). Frozen grated coconut imported from India was implicated as the vehicle of infection. Short and long read sequencing data were interrogated for genomic markers to provide evidence that the outbreak strain was from an imported source.

The research showed that ruminant animal is the primary factor contributing to the prevalence of the STEC‐infecting phages on the organic farm in this study. Among environmental factors, high rain precipitation is likely to facilitate phage distribution in the surrounding environment of the farm. Most importantly, the presence of these phages has a negative correlation with their STEC hosts.

Porcine circovirus type 2 (PCV2) and Streptococcus suis serotype 2 (SS2) clinical coinfection cases have been frequently detected. The respiratory epithelium plays a crucial role in host defense against a variety of inhaled pathogens. Reactive oxygen species (ROS) are involved in killing of bacteria and host immune response.

Author(s): Neda Fallah, Mehran Ghaemi, Kiarash Ghazvini, Mehrnaz Rad, Abdollah Jamshidi

Author(s): Lanlin Yu, Su Zhang, Yuanyuan Xu, Xiaoyu Mi, Tong Xing, Jiaolong Li, Lin Zhang, Feng Gao, Yun Jiang

Stx bacteriophages are members of the lambdoid group of phages and are responsible for Shiga toxin (Stx) production and the dissemination of Shiga toxin genes (stx) across shigatoxigenic Escherichia coli (STEC). These toxigenic bacteriophage hosts can cause life-threatening illnesses, and Stx is the virulence determinant responsible for the severe nature of infection with enterohemorrhagic E. coli, a subset of pathogenic STEC.

Shiga toxin-producing Escherichia coli (STEC) is a leading cause of foodborne infections. Cattle are an important STEC reservoir, although little is known about specific pathogen traits that impact persistence in the farm environment. Hence, we sought to evaluate STEC isolates recovered from beef cattle in a single herd in Michigan. To do this, we collected fecal grabs from 26 cattle and resampled 13 of these animals at 3 additional visits over a 3-month period.

Shiga toxin-producing Escherichia coli (STEC) are major foodborne human pathogens that cause mild to hemorrhagic colitis, which could lead to complications of hemolytic uremic syndrome.  Seven serogroups, O26, O45, O103, O111, O121, O145 and O157, account for the majority of the STEC illnesses in the US.

Water use for antimicrobial intervention application for beef harvest has come under increased scrutiny in recent years in an effort to enhance water conservation during beef harvest and fabrication. This study was conducted to determine the efficacy of beef safety interventions for reducing surrogates of the Shiga toxin-producing Escherichia coli (STEC) on beef cuts while lowering intervention-purposed water use for a Small or Very Small beef establishment.

A total of 482 veal cutlet, 555 ground veal, and 540 ground beef samples were purchased from retail establishments in the Mid-Atlantic region of the U.S. over a non-contiguous, two-year period between 2014 and 2017. Samples (325 g each) were individually enriched and screened via real-time PCR for all seven regulated serogroups of Shiga toxin-producing Escherichia coli (STEC).

The use of molecular diagnostics for pathogen detection in epidemiological studies have allowed us to get a wider view of the pathogens associated with diarrhea, but the presence of enteropathogens in asymptomatic individuals has raised several challenges in understanding the etiology of diarrhea, and the use of these platforms in clinical diagnosis as well.

Many cattle are persistently colonized with Shiga toxin-producing Escherichia coli (STEC) and represent a major source of human infections with human-pathogenic STEC strains (syn. enterohemorrhagic E. coli (EHEC)). Intervention strategies most effectively protecting humans best aim at the limitation of bovine STEC shedding. Mechanisms enabling STEC to persist in cattle are only partialy understood.

Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen transmitted from animals to humans through contaminated food. Cattle are the main reservoir of STEC, but their genetic diversity is still poorly characterized, especially regarding strains isolated in Portugal. We therefore present the draft genomic sequences of 12 STEC strains isolated from cattle in the north of Portugal.