title: Incidence and susceptibility to antimicrobial agents of Listeria spp. and Listeria monocytogenes isolated from poultry carcasses in Porto, Portugal.
abstract: The occurrence of Listeria spp. and Listeria monocytogenes in 63 samples of Portuguese poultry carcasses obtained from two local butcher shops and one canteen in the city of Porto, Portugal, and the susceptibility of these bacteria to antimicrobial agents allowed for use in human or animal therapeutics were evaluated. All poultry samples were contaminated with Listeria spp., and L. monocytogenes was isolated from 41% (26 of 63) of the samples. Other Listeria species, including L. innocua, L. welshimeri, and L. seeligeri, were also isolated from poultry samples. A multiplex polymerase chain reaction method was used for the identification of all of the Listeria isolates; this method showed total conformity with the conventional method of biochemical identification and proved to be more reliable, faster, and less arduous. In addition, high percentages of Listeria spp. (84%) and L. monocytogenes (73%) isolates were found to be resistant to one or more antimicrobial agents of different groups, and 12 different resistance profiles were recorded. The frequency of the resistance of L. monocytogenes isolates to enrofloxacin and clindamycin is notable. The results of this study suggest a high incidence of L. monocytogenes on Portuguese poultry products available for consumers and indicate that poultry could be a potential vehicle of foodborne infections due to strains of L. monocytogenes that are resistant to antimicrobial agents.
authors.affiliation: Faculty of Nutrition and Food Sciences, University of Porto, Dr. Roberto Frias, 4200 Porto, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Antunes
authors.forename: Cristina
authors.initials: C
authors.lastname: Réu
authors.forename: João Carlos
authors.initials: JC
authors.lastname: Sousa
authors.forename: Nazaré
authors.initials: N
authors.lastname: Pestana
authors.forename: Luísa
authors.initials: L
authors.lastname: Peixe
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002645:Chickens / Q000382:microbiology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D005506:Food Contamination; D005516:Food Microbiology; D006801:Humans; D015994:Incidence; D008087:Listeria / Q000187:drug effects* / Q000302:isolation & purification*; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D011174:Portugal
chemical_list: D000900:Anti-Bacterial Agents