On Tuesday, the U.S. Centers for Disease Control and Prevention (CDC) announced an outbreak of Escherichia coli (E. coli) linked to McDonald’s quarter pounders.
According to the Associated Press, 49 cases between Sept. 27 through Oct. 11 were reported in the states of Colorado, Iowa, Kansas, Missouri, Montana, Nebraska, Oregon, Utah, Wisconsin and Wyoming. Known widely as E. coli, the bacteria are found in places like the intestines of people and animals, but some can be harmful to the body.
Florida State University Health, Nutrition, and Food Sciences Associate Professor Prashant Singh is a food safety microbiologist by training, and his core area of research is the development of rapid methods for the detection of foodborne pathogens.
His laboratory focuses explicitly on developing methods for the specific detection of virulent strains of Shiga toxin-producing non-O157 E. coli and salmonella.
Singh’s areas of expertise include E. coli, food safety, food-borne outbreaks and pathogens and food microbiology. He was recently awarded a $150,000 grant to develop a method to detect salmonella contamination in beef samples.
Singh is available to speak with reporters on the latest E. coli outbreak.
Prashant Singh, Associate Professor of Health, Nutrition, and Food Sciences
Email: psingh2@fsu.edu
Quotes from Prashant Singh:
On the E. coli outbreak being traced to slivered onions:
“Onions, which are another ingredient for the McDonald’s quarter pounders, do not have a mandatory STEC testing requirement, and they do not undergo high heat treatment to ensure the elimination of contaminating STEC strains. In this outbreak, onions are also considered a suspect.”
On the testing of E. coli in beef:
“In the United States, E. coli O157:H7, along with six other E. coli serogroups (O26, O45, O111, O103, O121, and O145), are considered adulterants in beef, which means that all beef products must be tested before it is released in the commerce. Among them, E. coli O157:H7 strains are most frequently isolated from beef samples. The E. coli O157:H7 strain can cause life-threatening infections. The STEC strains have two crucial virulence genes (i.e., eae and stx ). The eae gene codes for intimin protein, which facilitates strong attachment of these pathogens to the host cells. Meanwhile, the stx gene encodes for Shiga toxin, which can bind to the GB3 receptors and are found on the surface of intestine and kidney cells. The toxin can also lyse the red blood cells. In extreme cases, STEC strains can lead to hemolytic uremic syndrome (HUS), which involves kidney failure and death. What makes these infections even worse is that antibiotics cannot be used against them, as the administration of antibiotics induces the Shiga toxin production by STEC cells, which will overwhelm the body.
“Due to these reasons, the beef samples are always tested for the presence of E. coli O157:H7. This testing is performed internally by large beef processors, whereas small and medium-sized operations ship the samples to an external testing lab, which has a longer turnaround time.”