Listeria: Another Reason Why You Should Not Drink Hot Dog Juice

The bacteria Listeria has a special place in my heart--not to imply that I don't love all bacteria in their own special way. Listeria is in the headlines again with the national recall of Blue Bell products being announced after 10 cases of listeriosis were reported in 4 states, 3 of which were fatal.

Though listeria has only a small slice (~1%) of the total food-borne illness burden, it does claim a substantial proportion (~20%) of food borne deaths granting it a special status. This is really a ubiquitous bacteria that is present in herd animals and the soil. It can contaminate soft cheeses, hot dogs, deli meats, cantaloupes and other products. The immunocompromised, pregnant, and newly born are at particular risk for severe infection.

What makes it so deadly is its ability to move from the GI tract to the blood and then to other organs. One place where it is particularly damaging is in the central nervous system. Listeria meningitis and encephalitis have particularly high mortality rates.

The best means to prevent listeria are safe food handling procedures (i.e. avoid hot dog "juice" exposure) and for those at particularly high risk to avoid eating foods that may be contaminated with listeria. There is also an innovative product (ListShield) containing viruses that attack listeria (bacteriophages) that can be sprayed directly onto food to kill the bacteria.

So why does listeria have a special place in my heart? It's not its actin "jets" (so cool) or tumbling motility (really endearing to watch). It is because as a operating room volunteer in the mid-1990s applying to medical school, I knew I wanted to be an infectious disease physician. When I was done volunteering, I would roam over to the infectious disease division and poke around looking for real life infectious disease physicians and researchers. One day, I stumbled upon a researcher (who has long since left my institution) who worked on listeria and he explained its microbiology and disease-causing attributes to me with such passion, I'll never forget the incident and the time he took to indulge my interest in infectious disease.