Role of VirAB in antimicrobial resistance and biofilm formation of Listeria monocytogene

Abstract:

[Background] Reduced susceptibility has been found in Listeria monocytogenes to antimicrobial agents such as several clinical commonly used antibiotics and nisin. However, mechanisms behind this are still unclear. [Objective] To study the role of VirAB transporter in resistance to antimicrobial agents and biofilm formation of L. monocytogenes. [Methods] Gene deletion mutants were constructed by homologous recombination, and resistance to antimicrobial agents was determined in the wild-type and mutant strains. The ability of biofilm formation was measured using the microplate method. Swimming motility of these strains was investigated by plate migration method. [Results] The mutant strain ΔvirAB showed increased sensitivity to cephalosporin, nisin and ethidium bromide compared to the wild-type strain; the mutant strain exhibited varying degrees of growth defects in the presence of sub-lethal concentrations of benzalkonium chloride, kanamycin and tetracyclines. Decreased ability of biofilm formation was observed in ΔvirAB. [Conclusion] VirAB plays an important role in resistance to antimicrobial agents and biofilm formation of L. monocytogenes.