Listeria monocytogenes: a causative agent of gastroenteritis?

The intestinal tract is the major portal of entry for Listeria monocytogenes, which becomes ingested via contaminated food. The pathogenic strains penetrate the mucosal tissue either directly, via engulfment by enterocytes, or indirectly, via active penetration of the Peyer's patches. There are now several reports clearly demonstrating that, in some cases, acute enteritis may be the only symptom of Listeria infection or may precede the typical symptoms of listeriosis such as sepsis and meningitis or encephalitis. Therefore, Listeria monocytogenes should be included in the list of foodborne gastrointestinal pathogens. Furthermore, a history of enteritis should prompt the physician to include listeriosis, which is often difficult to diagnose, in the differential diagnosis. Although Listeria monocytogenes is undoubtedly a potential enteric pathogen, it is still debatable whether its detection in a routine bacteriological examination of a stool specimen is of clinical significance.