Prevalence and antimicrobial resistance of Listeria species and subtyping and virulence factors of Listeria monocytogenes from retail meat

In this study, of 124 samples of ground beef and chicken meat, 101 (81.5%) were positive forListeria spp.Listeria innocua (35.5%) andListeria monocytogenes (26.6%) were the most frequently isolated species. All 33 (100%)L. monocytogenes isolates were positive for the virulence geneshlyA,actA,inlA, inlB, inlC, inlJ,prfA,plcA, andiap. Serotype 1/2a, which is one of the listeriosis ‐associated serotypes, was the most predominant serotype (57.6%), followed by 1/2c (39.4%) and 3c (3%). In polymerase chain reaction ‐restriction fragment length polymorphism (PCR‐RFLP) analysis ofinlA for subtyping of theL. monocytogenes strains, theAluI andMluCI enzymes generated two different profiles. Almost all chicken strains were grouped in similar PCR ‐RFLP profiles with both restriction enzymes. MostListeria isolates were resistant to ceftriaxone (79.7%), fusidic acid (63.3%), and clindamycin (47.7%). Resistance to penicillin and ampicillin occurred in 1.6 and 17.9% of the isolates, respectively. The percentage of resistance to three or more agents was 48.1%.Practical applicationThe presence ofListeria spp., especiallyL. monocytogenes, in foods is inevitable because of the ubiquitous nature ofListeria spp. Illnesses resulting from the consumption of contaminated food severely affect sensitive groups, especially pregnant women, unborn fetuses and newborns as a result of transmission across the placenta or during delivery. Immunosuppressed adults are also sensitive to infection.Listeria...
Source: Journal of Food Safety - Category: Food Science Authors: Tags: ORIGINAL ARTICLE Source Type: research