title: Listeria monocytogenes isolates from food and food environment harbouring tetM and ermB resistance genes.
abstract: Listeria monocytogenes is a foodborne pathogen that has become an important cause of human and animal diseases worldwide. The purpose of this study was to evaluate the serotypes, virulence potential, antimicrobial resistance profile, and genetic relationships of 50 L. monocytogenes isolates from food and food environment in southern Brazil. In this study, the majority of L. monocytogenes isolates belonged to the serotypes 1/2b (42%) and 4b (26%), which are the main serotypes associated with human listeriosis. In addition, all isolates harboured internalin genes (inlA, inlC, inlJ), indicating a virulence potential. The isolates were sensitive to most of the antimicrobial compounds analysed, and five isolates (10%) were multi-resistant. Two isolates harboured antimicrobial resistance genes (tetM and ermB) and in one of them, the gene was present in the plasmid. Moreover, according to the pulsed field gel electrophoresis assay, two multi-resistant isolates were a single clone isolated from food and the processing plant. The isolates were susceptible to the most frequently used antibiotics for listeriosis treatment. However, the presence of multidrug-resistant isolates and antimicrobial resistance genes including in the plasmid could even be transferred between bacterial species, suggesting a potential health risk to consumers and a potential risk of spreading multi-resistance genes to other bacteria.
  
  
  CONCLUSIONS
  Listeria monocytogenes is an important agent of foodborne diseases. The results of this study suggest a potential capacity of L. monocytogenes isolates from food and food environment to cause human infections. Antimicrobial multi-resistance profiles were detected in 10%, and two isolates harboured tetM and ermB resistance genes. Moreover, the present research can help to build up a better knowledge about antimicrobial resistance of L. monocytogenes. Additionally, we found one isolate carrying tetM resistance gene in a plasmid, that suggests a possible transmission between commensal and/or other pathogenic bacteria of food environment, thereby raising up concerns regarding bacterial resistance.
authors.affiliation: Departamento de Ciência e Tecnologia Agroindustrial, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil.|Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Haubert
authors.affiliation: Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Mendonça
authors.affiliation: Departamento de Medicina Veterinária Preventiva, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: G V
authors.initials: GV
authors.lastname: Lopes
authors.affiliation: Departamento de Medicina Veterinária Preventiva, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: M R
authors.initials: MR
authors.lastname: de Itapema Cardoso
authors.affiliation: Departamento de Ciência e Tecnologia Agroindustrial, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil.|Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil.
authors.forename: W P
authors.initials: WP
authors.lastname: da Silva
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D001938:Brazil; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D008088:Listeriosis / Q000382:microbiology; D008460:Meat / Q000382:microbiology; D008780:Methyltransferases / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D013753:Tetracycline Resistance / Q000235:genetics*; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C103178:inlC protein, Listeria monocytogenes; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase
keywords: Listeria; antimicrobial resistance; internalin genes; plasmid; pulsed field gel electrophoresis; virulence