Abstract
BackgroundThe aim of this study was to characterize the genomes of 30 Listeria monocytogenes isolates collected at a pig slaughterhouse to determine the molecular basis for their persistence.ResultsComparison of the 30 L. monocytogenes genomes showed that successive isolates (i.e., persistent types) recovered from thew sampling site could be linked on the basis of single nucleotide variants confined to prophage regions. In addition, our study revealed the presence among these strains of the bcrABC cassette which is known to produce efflux pump-mediated benzalkonium chloride resistance, and which may account for the persistence of these isolates in the slaughterhouse environment. The presence of the bcrABC cassette was confirmed by WGS and PCR and the resistance phenotype was determined by measuring minimum inhibitory concentrations. Furthermore, the BC-resistant strains were found to produce lower amounts of biofilm in the presence of sublethal concentrations of BC.ConclusionsHigh resolution SNP-based typing and determination of the bcrABC cassette may provide a means of distinguishing between resident and sporadic L. monocytogenes isolates, and this in turn will support better management of this pathogen in the food industry.
Highlights
The aim of this study was to characterize the genomes of 30 Listeria monocytogenes isolates collected at a pig slaughterhouse to determine the molecular basis for their persistence
Genetic factors associated with the quaternary ammonium compounds (QAC)-resistance phenotype and resistance to benzalkonium chloride (BC), a QAC largely used in the food industry, were identified [17, 20,21,22,23]
The qacH gene which codes for a small multidrug resistance protein family (SMR) transporter associated with the export of benzalkonium chloride and acquired by the Tn6188 transposon [19, 20, 24], and other QAC determinants originally observed in Staphylococci [25]
Summary
The aim of this study was to characterize the genomes of 30 Listeria monocytogenes isolates collected at a pig slaughterhouse to determine the molecular basis for their persistence. Listeria monocytogenes is a bacterial pathogen that causes listeriosis, the foodborne illness with the highest fatality rate [1, 2]. The ability of this organism to colonize and persist in food processing plants increases the risk of food contamination [3]. Genetic factors associated with the QAC-resistance phenotype and resistance to benzalkonium chloride (BC), a QAC largely used in the food industry, were identified [17, 20,21,22,23]. The qacH gene which codes for a SMR transporter associated with the export of benzalkonium chloride and acquired by the Tn6188 transposon [19, 20, 24], and other QAC determinants originally observed in Staphylococci [25]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
