Not just cabbage and lettuce and cantaloupes: Listeria in produce

Foodborne transmission of Listeria monocytogenes was first demonstrated through the investigation of the 1981 Maritime Provinces outbreak involving coleslaw.

sheep.cabbageIn the following two decades, most listeriosis outbreaks involved foods of animal origin, e.g., deli meats, hot dogs, and soft cheeses. L. monocytogenes serotype 4b, especially epidemic clones I, II, and Ia, were frequently implicated in these outbreaks. However, since 2008 several outbreaks have been linked to diverse types of fresh produce: sprouts, celery, cantaloupe, stone fruit, and apples. The 2011 cantaloupe-associated outbreak was one of the deadliest foodborne outbreaks in recent U.S. history.

This review discusses produce-related outbreaks of listeriosis with a focus on special trends, unusual findings, and potential paradigm shifts. With the exception of sprouts, implicated produce types were novel, and outbreaks were one-time events. Several involved serotype 1/2a, and in the 2011 cantaloupe-associated outbreak, serotype 1/2b was for the first time conclusively linked to a common-source outbreak of invasive listeriosis. Also in this outbreak, for the first time multiple strains were implicated in a common-source outbreak.

In 2014, deployment of whole genome sequencing as part of outbreak investigation validated this technique as a pivotal tool for outbreak detection and speedy resolution. In spite of the unusual attributes of produce-related outbreaks, in all but one of the investigated cases (the possible exception being the coleslaw outbreak) contamination was traced to the same sources as those for outbreaks associated with other vehicles (e.g., deli meats), i.e., the processing environment and equipment. The public health impact of farm-level contamination remains uncharacterized.

This review highlights knowledge gaps regarding virulence and other potentially unique attributes of produce outbreak strains, the potential for novel fresh produce items to become unexpectedly implicated in outbreaks, and the key role of good control strategies in the processing environment.

Fresh produce–associated listeriosis outbreaks, sources of concern, teachable moments, and insights

Journal of Food Protection®, Number 2, February 2016, pp. 184-344, pp. 337-344(8)

Garner, Danisha; Kathariou, Sophia

Was it the cabbage? 15 sickened by E. coli O111 linked to Minnesota Applebee’s; know thy suppliers

Green, whole head cabbage was the likely source of E. coli O111 illnesses traced to eating at Applebee’s restaurants in Minnesota this summer, state health officials said Friday.

applebees.ricky_.bobby_Fifteen people were sickened by the produce, which was likely contaminated before it was distributed to restaurants, the department said. Health investigators interviewed 14 who were taken ill: 13 ate at nine Applebee’s restaurants in Minnesota; one ate at a Yard House restaurant.

Many of the cases involved people eating the oriental chicken salad at Applebee’s. This particular strain of E. coli O111 had not been seen in the United States previously, the department said.

Applebee’s pulled the item off its menus and returned it after tapping a different source for the ingredients.

Minnesota investigators traced the cabbage to a common supplier outside of Minnesota and continue to work with the U.S. Food and Drug Administration to investigate its source. “The FDA examination of the potentially involved farms is still ongoing. Single cases of illness that match the outbreak strain have occurred in three other states,” the department said.

Netherlands finds E. coli again in beet sprouts; Thailand finds E. coli in European cabbage

Seek and ye shall find.

But countries still won’t test their way to a safe food supply.

Testing is extremely useful for validating safety procedures and to have a sense of what’s out there.

There’s lots of various E. coli out there.

RNW reports for the second time this week the Dutch Food Quality Authority (nVWA) has found sprouts contaminated with the EHEC bacterium, although it is not the O104 variant. A spokesperson for the Authority said on Friday that the beet seed sprouts have been withdrawn from the market on the orders of Health Minister Edith Schippers.

Meanwhile, Thailand said on Saturday that it had detected E. coli in cabbage imported from Europe and was checking whether it was the lethal strain involved in a killer outbreak in northern Germany.

On Friday Thailand said that E. coli found in avocados a day earlier was not the deadly strain that has swept Europe in recent weeks.

Testing has a role — make it meaningful.