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Transcriptomic response of Escherichia coli on meat

Posted by: Colleen MacMillan

July 27, 2017

Date

Tuesday 8 August 2017

Time

12:30-13:00 (AEST – Canberra Brisbane Armidale Werribee); 12:00 (ACST – Adelaide); 10:30 (AWST – Perth)

Venues

CSIRO: Black Mountain – Discovery Theatre; Adelaide Waite – B101-FG-SmallWICWest; Brisbane QBP – Level 3 South telepresence room (3.323); Armidale – B55-FG-R00-Small; Perth Floreat – B1b Boardroom; Werribee (Melbourne) – Peacock Room

Speaker

Dr Thea King (Research Scientist) CSIRO Agriculture and Food

Synopsis

Cattle are the main reservoir for E. coli O157 and the majority of food-borne illnesses associated with this organism are attributed to the consumption of foods of bovine origin. To date, little work has been undertaken to understand the physiological state of E. coli in complex food matrices such as meat. Published reports also suggest that there are regional variations in E. coli O157 genotypes and this may provide a basis for the different disease burdens observed globally. It is therefore reasonable to predict that the different genotypes possess genetic repertoires that respond uniquely to the environmental conditions experienced in the meat production environment. This study analysed the transcriptome of E. coli on beef during attachment at a low temperature relevant to conditions experienced during carcass chilling.  The aim of the study was to identify genes that may be associated with growth and survival on the beef carcass and, to compare the response of an E. coli isolate representative of the general genetic ‘type’ found in Australia to that of a pathogenic clinical isolate not typically found in Australia. The RNA-Seq study revealed a common gene expression response elicited by both strains, with the most highly up-regulated genes including those involved in the response to acid, osmotic, oxidative and cold stress. Both strains also up-regulated genes involved in multidrug resistance and encoding Shiga toxin subunits. The E. coli isolates also displayed unique gene expression profiles on meat, indicating that the genotypes may differ in their ability to persist in the meat production environment and therefore also in their ability to cause disease.

Biography

Thea is a Research Scientist in the Food Safety and Stability group at CSIRO. Thea has worked at CSIRO for over a decade and has research experience working on food borne bacterial pathogens. Most of this research has focused on Shiga toxigenic E. coli (STEC) and has included using different omics techniques to understand the physiological state of this pathogen when present on foods and in the food production environment. These studies have provided a fundamental insight into how STEC adapt and grow on specific food matrices and during exposure to their associated environmental conditions. This information can be utilized to tailor preservation processes used by the food industry and for rational development of new control strategies for foodborne pathogens. Thea has provided advice and worked on research projects with the red meat, poultry and dairy industries.


 

 

 

 

 

 

 

This is a public seminar.

No visitor pass is required for non-CSIRO attendees attending via Discovery Lecture Theatre