Listeria monocytogenes : A Causative Agent of Gastroenteritis?

Abstract

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.

Listeriolysin O affects barrier function and induces chloride secretion in HT-29/B6 colon epithelial cells

“…In general, epidemiological data of food-borne outbreaks of gastroenteritis (2,17,30,39,45) support the idea of Listeria being a diarrheic agent, as do the few feeding studies on animals challenged with live Listeria (3,23), although high doses of ingested bacteria appear to be necessary. Some information, which, at first sight, seems to be counter-indicative of a diarrheic potential is available from a human challenge study by Angelakopoulos et al (1) using mutant Listeria strains of attenuated pathogenicity but not deficient in listeriolysin O.…”

“…There is accumulating evidence of Listeria monocytogenes causing diarrhea (45,39,30,2,17), which often precedes systemic infection. To understand the pathological processes, it is necessary to clarify how diarrheal effects are mediated and whether or not active intestinal ion and fluid secretion and/or an impaired epithelial barrier function may contribute.…”

“…Once infected, both humans and animals produce antibodies against the major Listeria virulence factor listeriolysin O (LLO) (5,14,37), even in cases of noninvasive mild illness with diarrhea (17). Although sporadic gastroenteritis due to L. monocytogenes may be uncommon (44), several outbreaks of food-borne gastroenteritis are known to have been caused by L. monocytogenes, with diarrhea as the most prevalent symptom (2,17,30,39,45). LLO is an extracellularly secreted 56-kDa protein and a member of the cholesterol-dependent cytolysin family.…”

The Proinflammatory Response Induced by Wild-TypeYersinia pseudotuberculosisInfection Inhibits Survival ofyopMutants in the Gastrointestinal Tract and Peyer's Patches

“…Since a number of organisms, including Salmonella, Listeria, and Candida spp., disseminate from the intestines to distal organs (16,24,53,59), this finding is important when considering host responses to disseminated infection and potential consequences for normal intestinal flora and tissues. It is interesting that the intestinal regions where yopE and yopH mutants were inhibited by systemic infection were the same tissues that these yop mutant strains colonized better in IFN-␥ Ϫ/Ϫ mice than in BALB/c mice in competition infections.…”

“…Many enteric bacterial pathogens, such as Listeria, Salmonella, and enteric Yersinia species, spread from initial sites of infection in the intestinal tract to systemic sites, while others, such as vibrios, clostridia, and enteropathogenic Escherichia coli, rarely leave the intestinal tract (24,39,53,59). Following infection with gram-negative enteric Yersinia pathogens, sites of inflammation include different regions of the intestines, as well as the associated lymphoid tissues of the Peyer's patches (PP) and mesenteric lymph nodes (MLN), and distal systemic sites, such as the spleen and liver (10,17).…”