title: Antimicrobial resistance of Listeria monocytogenes isolated from various cabbage farms and packing sheds in Texas.
abstract: Twenty-one isolates of Listeria monocytogenes from cabbage, environmental, and water samples were evaluated for antimicrobial resistance by the disk diffusion method. Ninety-five percent (20 of 21) of the isolates tested were resistant to two or more antimicrobial agents. This finding is significant, since multiresistant strains of Listeria spp. are not commonly found in nature. Eighty-five percent (17 of 20) of the multiresistant strains were resistant to penicillin, and the remaining multiresistant isolates were somewhat sensitive to penicillin. A multiresistant strain showing intermediate sensitivity to penicillin was resistant to gentamicin. One isolate was susceptible to all antimicrobial agents except penicillin. Penicillin- and gentamicin-resistant L. monocytogenes have not previously been reported from human, food, or environmental samples. This study provides evidence of the emergence of multiresistant L. monocytogenes strains, pointing to an increase in the potential threat to human health posed by this pathogen.
authors.affiliation: Department of Animal Science, Texas A&M University, College Station 77843-2471, USA.
authors.forename: Marie Ann
authors.initials: MA
authors.lastname: Prazak
authors.forename: Elsa A
authors.initials: EA
authors.lastname: Murano
authors.forename: Imelda
authors.initials: I
authors.lastname: Mercado
authors.forename: Gary R
authors.initials: GR
authors.lastname: Acuff
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001937:Brassica / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005516:Food Microbiology; D005839:Gentamicins / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000472:pathogenicity; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins