12. Listeriosis

Lecture Summary
Listeria is a gram positive rod that can cause rare but devastating infections in humans. The young, old, pregnant, and immunocompromised are at highest risk for listeriosis, the disease caused by this ubiquitous environmental bacteria. This podcast will review the basic bacteriology, epidemiology, diagnosis, treatment, and prevention of listeriosis.

Key Points
-       Listeria is ubiquitous in nature and the gastrointestinal tracts of many animals including humans are often colonized. Most infections are from Listeria monocytogenes, but other listeria can also cause infection.

-       Invasive infections are rare but carry a high mortality. 

-       Most infections come from food.

-       Infections in pregnancy are often more mild but can cross the placenta causing fetal demise and neonatal sepsis.

-       Queso Fresco and other Latin soft cheeses account for the majority of soft cheese related infections and have occurred in both pasteurized and unpasteurized cheeses. Hispanic pregnant woman are disproportionately affected by listeria, likely for this reason.

-       Listeria should be cultured from sterile body sources like blood, CSF, or placental tissue to confirm infection.

-       Ampicillin or Penicillin are the first line treatments. Trimethoprim Sulfamethoxazole, meropenum, and even Vancomycin have also gotten the job done.

References

Listeriosis. WHO. Available at https://www.who.int/news-room/fact-sheets/detail/listeriosis

FoodNet 2015 Report. CDC. Available at https://www.cdc.gov/foodnet/pdfs/FoodNet-Annual-Report-2015-508c.pdf

Listeriosis – wikipidia.org

Listeria – uptodate.com

Jackson et al. Listeriosis outbreaks associated with soft cheeses, United States, 1998-2014. Emerg Inf Dis. 2018.

Drevets et al. Listeria monocytogenies: epidemiology, human disease, and mechanics of brain invasion. FEMs Immunology and Medical Microbiology. 2008.

JanakiramanV. Listeriosis in pregnancy: diagnosis, treatment, and prevention. Rev Obstet Gynecol. 2008.