Listeria outbreaks have gotten quite common with time. A recent study has found disturbing evidence that the normally “harmless” pathogen is developing potentially harmful characteristics at an alarming pace. What’s more, the bacteria were collected from meat samples within the food processing facilities.
A strain of the microbe, Listeria monocytogenes, is usually present in the food processing industry and is harmful to humans. It not only causes severe illness, but additionally it is becoming increasingly immune to food safety measures taken around the globe.
Worryingly, two different harmless species of Listeria were found to own genetic changes that could be harmful to humans, SciTechDaily reported.
The Whole Genome Sequencing study in South Africa, led by a team of researchers on the University of Johannesburg, found among the changing characteristics of Listeria present in the country.
The study, published within the journal Microbiology Spectrum, showed that Listeria innocua strains are developing resistance to stresses similar to temperature, pH, and dehydration. Also, hypervirulence observed within the strained is genetically equivalent to that of Listeria monocytogenes.
“The Listeria innocua that we tested has among the genes which might be also present in pathogenic Listeria monocytogenes,” lead creator, Dr. Thendo Mafuna from the Department of Biochemistry on the University of Johannesburg said. These shared genes could cause disease in humans and induce stress tolerance to the disinfectant Benzalkonium chloride (BC or BAC).
Furthermore, some strains of L. innocua and L. welshimeri had all three genes immune to the widely-used disinfectant from the quaternary ammonium compound (QAC or QUAT) group of chemicals, the study found.
“Big industrial food processors will want to investigate how efficient BC or quat disinfectants are of their facilities. This will be done by taking swabs before cleansing and again after cleansing, culturing those, to see how well the disinfectant regimes are working,” Mafuna noted, based on the outlet.
The 2 non-pathogenic strains of Listeria were present in samples taken from raw, dried and processed meats at business food processing facilities within the country.
For the study, 258 strains from butcheries, abbatoirs, stores, cold stores, and processing facilities from across the country were analyzed. Of the samples, 38 of them were found to be nonpathogenic L. Innocua and three were nonpathogenic L. welshimeri.
“We want to take a look at our own facilities in South Africa to actually see what is going on. Our analyses of those bacteria may help us predict which sequence types to be looking out for,” Mafuna commented.
Last 12 months, a listeria outbreak affected 10 states within the U.S. The Centers for Disease Control and Prevention (CDC) issued a proper food safety alert on Big Olaf Creamery ice cream products. Based on the map the CDC posted online, the Listeria cases were reported in the next states: Florida, Georgia, Illinois, Kansas, Colorado, Minnesota, Pennsylvania, Recent York, Massachusetts, and Recent Jersey.