The evolution of FDA's policy on Listeria monocytogenes in ready-to-eat foods in the United States

In the mid-1980s, Listeria monocytogenes (Lm) gained acceptance as a ubiquitous foodborne bacterial pathogen with a high mortality rate in persons with weakened immune systems, or in pre-term and newborn infants. Lm's ability to grow at temperatures approaching 0 degrees C make it a particularly vexing problem for many food industries. With the exception of a brief flirtation with establishing a tolerable limit of 100 cfu/g in foods in which it cannot grow, Lm has been regulated at the limit of detection (zero tolerance) of approved methods by the US Food and Drug Administration (FDA). Very recently FDA has accumulated evidence that points to continuation of a conservative approach (i.e. zero tolerance) to regulating Lm in foods for the foreseeable future barring the development of unique regulatory approaches.