Research round-up: Horse meat as beef, Listeria and SalmoNet

By Joseph James Whitworth

- Last updated on GMT

©iStock. Let us know about your work for a chance to feature in our round-up: joe.whitworth@wrbm.com
©iStock. Let us know about your work for a chance to feature in our round-up: joe.whitworth@wrbm.com

Related tags Foodborne illness Food safety Salmonella

From refrigerators and freezers to freeze dryers a lab can be a cold place. Especially in winter. While you wait for your samples to warm up read our research round-up.

Firstly, horse meat has been found in nearly 10% of meat products sold as beef or not clearly labelled in Mexico, according to researchers at the Universidad Nacional Autonoma de Mexico​.

The study, commissioned by Humane Society International, looked at 433 samples of cooked and uncooked meat from vendors in six cities.

Samples positive for horse meat were from informal selling points such as street stalls and markets.

Anton Aguilar, HSI/Mexico director, said: “The results of this study show that it is important for consumers to realize that meat mislabeling may occur and can be hazardous for their health, especially because the majority of vendors surveyed in the study were unaware that they were selling horsemeat as beef.”

New Zealand researchers have found Listeria monocytogenes​ in packaged ready-to-eat red meats at retail.

The failure of 19 lots (6.4%) was due to L. monocytogenes in product of eight of 33 producers tested.

Thirteen of 95 positive samples contained between 50 and 500 CFU/g L. monocytogenes but all were manufactured by the same operator.

Pulsed-field gel electrophoresis typing of the L. monocytogenes isolates from the survey identified 12 different pulsotypes. Different pulsotypes were found in samples from the same operator sampled on separate occasions.

“The detection of Listeria in samples may highlight the existence of problems in operator processing and/or packaging processes and suggests that improvements in good hygienic practice and implementation of more effective risk mitigation strategies are needed,”​ they said.

Scientists at Quadram Institute​ are helping to uncover what makes certain strains of bacteria more dangerous than others.

They have been looking at the genetic differences between invasive and less invasive Salmonella strains.

Dr Tamás Korcsmáros, a systems biologist from the Quadram Institute and the Earlham Institute, has led development of SalmoNet​ alongside a research group of Dr Rob Kingsley and with network modelling and food safety scientist, Professor Jozsef Baranyi.

SalmoNet uses network biology and bioinformatic techniques to collate molecular interactions within Salmonella, and to link information on how genes and metabolic pathways are regulated and how proteins interact with each other.

The core is data derived from ten of the best characterised Salmonella strains, five well-known as gastro-intestinal and five invasive extra-intestinal strains capable of causing systemic infections.

SalmoNet will be used as a source of novel predicted interactions for experimental validation, or provide interaction information to interpret the measurements from lab experiments.

A bat found in salad ​earlier this year most likely came from the field during harvesting and cutting and was transported to the processing facility, according to researchers.

In April, two Florida residents ate part of the same pre-packaged salad, produced by Fresh Express, before discovering the partial remains of a bat carcass.

Fresh Express recalled Organic Marketside Spring Mix sold in Walmart stores in the Southeastern region of the US.

No rabies virus was detected in the specimen and the salad was rinsed before packaging, thereby diluting any potential virus.

CDC and FLDOH determined the immediate concern was for potential rabies virus exposure because 6% of bats submitted to public health departments annually test positive for it.

Polymerase chain reaction and direct fluorescent antibody tests were inconclusive because of the deteriorated condition of the carcass.

Cutting and harvesting of greens for the salad was in fields in the west and southwest US before they were transported to a processing plant in Georgia. At the plant, they were washed with chlorinated water and packaged.

Paid-sick-leave laws may contribute to a decline in foodborne illness outbreaks, according to a study led by a Penn State​researcher.

More than 50% of foodborne illness outbreaks in the US originate at food establishments, of which 46% are connected to an infected worker.

Researchers found illness rates declined after implementation of paid-sick-leave laws in jurisdictions with regulations more supportive of employees taking leave and increased in jurisdictions with less supportive laws.

Paid-sick-leave laws more supportive of employees taking sick leave were associated with an adjusted 22% decrease in foodborne illness rates.

“What this study tells us is that paid-sick-leave laws that are more employee-friendly were associated with reduced foodborne illness rates,”​ said Charleen Hsuan, lead investigator and assistant professor of health policy and administration at Penn State.

“However, this decrease was primarily driven by a reduction in infections related to the Campylobacter bacterium, which are more likely to be associated with poor food safety practices, and less with sick food workers."

The Food and Drug Administration (FDA) has awarded $17m to the University of Maryland​ (UMD) to help improve national food safety programs and international standards.

The grant will allow the Joint Institute for Food Safety and Applied Nutrition (JIFSAN), a partnership between the FDA and UMD, to conduct multi-institutional, multidisciplinary research projects over the next five years.

“The work conducted by JIFSAN is important on a global scale, helping food safety professionals from across the world understand how to properly implement and advance a healthy food system,”​ said Craig Beyrouty, dean and director of UMD’s College of Agriculture and Natural Resources.

UT Southwestern Medical Center​ scientists have found the host’s inflammatory response helps make nutrients available to Salmonella.

Sebastian E. Winter, an assistant professor of Microbiology and senior author of the study, said Salmonella alters the nutrient environment in the gut.

Manipulation of the gut environment to benefit the bacteria begins when Salmonella induces a potent inflammatory response in the intestine, which manifests as diarrhea in the host.

Researchers found that when Salmonella senses byproducts of inflammation, the bacteria reprogram their own metabolism to use fermentation end products as primary nutrients.

A seven-year national research project led by Nebraska scientists​ was recognized for its efforts to reduce foodborne illness caused by Shiga toxin-producing E. coli (STEC).

The Coordinated Agricultural Project (CAP) on E. coli was selected for a Partnership Award from the National Institute of Food and Agriculture of the US Department of Agriculture.

It involves 51 collaborators from 18 institutions and will finish at the end of next year.

“It is clear that the Shiga toxin-producing E. coli coordinated agricultural project is having major, cross-functional impacts on beef safety research and education, with positive public health implications continuing for years to come​,” said Ronnie Green, University of Nebraska-Lincoln Chancellor.

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