Exploring Antibiotic Resistance Diversity in <em>Leuconostoc</em> spp. by a Genome-Based Approach: Focus on the <em>lsa</em>A Gene

• Main Authors: Elisa Salvetti, Ilenia Campedelli, Ilaria Larini, Giada Conedera, Sandra Torriani
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Microorganisms
• Subjects: <i>Leuconostoc</i>; food chain; genomes; antibiotic resistance; <i>lsa</i>A gene; clindamycin
• Online Access: https://www.mdpi.com/2076-2607/9/3/491

<i>Leuconostoc </i>spp. are environmental microorganisms commonly associated with fermented foods. Absence of antibiotic resistance (AR) in bacteria is a critical issue for global food safety. Herein, we updated the occurrence of AR genes in the <i>Leuconostoc</i> genus through in silico analyses of the genomes of 17 type strains. A total of 131 putative AR traits associated with the main clinically relevant antibiotics were detected. We found, for the first time, the <i>lsa</i>A gene in <i>L. fallax</i> ATCC 700006^T and <i>L. pseudomesenteroides</i> NCDO 768^T. Their amino acid sequences displayed high similarities (59.07% and 52.21%) with LsaA of <i>Enterococcus</i><i>faecalis</i> V583, involved in clindamycin (CLI) and quinupristin-dalfopristin (QUD) resistance. This trait has different distribution patterns in <i>Leuconostoc</i> nontype strains—i.e., <i>L. pseudomesenteroides</i>, <i>L. lactis</i> and <i>L. falkenbergense</i> isolates from fermented vegetables, cheeses, and starters. To better explore the role of <i>lsa</i>A, MIC for CLI and QUD were assessed in ATCC 700006^T and NCDO 768^T; both strains were resistant towards CLI, potentially linking <i>lsa</i>A to their resistant phenotype. Contrarily, NCDO 768^T was sensitive towards QUD; however, expression of <i>lsa</i>A increased in presence of this antibiotic, indicating an active involvement of this trait and thus suggesting a revision of the QUD thresholds for this species.