title: Virulence factors and resistance to antimicrobials in Listeria monocytogenes serotype 1/2c isolated from food.
abstract: OBJECTIVE
  The aim of this study was to assess the potential risk posed to the human population by the presence of Listeria monocytogenes serotype 1/2c in food based on the characterization of virulence factors of Listeria involved in the invasion of host cells and sensitivity to antimicrobial agents.
  
  
  RESULTS
  In addition to sequencing of the inlA and inlB genes, the presence of genes lapB, aut, fbpA, ami, vip and llsX was tested. A premature stop codon (PMSC) in the inlA gene was detected in all tested strains of serotype 1/2c and, concurrently, two novel PMSC mutation types were identified. However, neither PMSC in the inlB gene nor deletion of the lapB, aut, fbpA, ami and vip genes were found in any of the strains. The presence of the llsX gene was not confirmed. Even though all L. monocytogenes strains showed sensitivity to the tested antimicrobials on the basis of their phenotype, sequencing revealed the presence of IS1542 insertion in the inlA gene, indicating the possibility of sharing of mobile genetic elements associated with antimicrobial resistance among strains.
  
  
  CONCLUSIONS
  Other than the presence of PMSCs in the inlA gene, no PMSC in inlB or deletion of other factors linked to the invasiveness of listeria were detected. Tested strains showed sensitivity to antibiotics used in the therapy of listeriosis.
  
  
  CONCLUSIONS
  Strains of L. monocytogenes serotype 1/2c typically carry a PMSC in the inlA gene, but these strains still represent a potential threat to public health. The possibility of transfer of IS1542, associated with resistance to vancomycin, between enterococci and Listeria spp. was revealed.
authors.affiliation: Veterinary Research Institute, Brno, Czech Republic.
authors.forename: T
authors.initials: T
authors.lastname: Gelbíčová
authors.affiliation: Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.
authors.forename: R
authors.identifier: http://orcid.org/0000-0002-3950-675X
authors.initials: R
authors.lastname: Pantůček
authors.affiliation: Veterinary Research Institute, Brno, Czech Republic.
authors.forename: R
authors.initials: R
authors.lastname: Karpíšková
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018389:Codon, Nonsense; D024881:Drug Resistance, Bacterial; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D010641:Phenotype; D065288:Serogroup; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018389:Codon, Nonsense; D037521:Virulence Factors
keywords: antibiotics; internalin A; internalin B; premature stop codon; sequencing