title: Antimicrobial resistance and co-selection phenomenon in Listeria spp. recovered from food and food production environments.
abstract: Antimicrobial resistance (AMR), co-selection phenomenon, and the relationship between reduced susceptibility (RSC) to ciprofloxacin (CIP) and resistance to other antimicrobials in Listeria spp. (n = 103) recovered from food processing environments (FPE) and food were investigated. Resistance of Listeria monocytogenes and other listeriae, respectively, to cefoxitin (FOX; 98% vs. 88%), CIP (7% vs. 4%), clindamycin (CLI; 33% vs. 59%) and tetracycline (6% vs. 8%) was observed, as was RSC to CIP (67% vs. 57%) and CLI (65% vs. 41%). L. monocytogenes also possessed RSC to linezolid (LZD; 6%), rifampicin (2%) and streptomycin (6%), with other listeriae displaying RSC to chloramphenicol (4%). L. monocytogenes serotype 1/2a (90%) isolates were more frequently resistant or possessed RSC to CIP compared to serotype 4b (55%) (p = 0.015). When eight strains were experimentally adapted to high concentrations of CIP, co-selection occurred as MICs to benzalkonium chloride (BAC) increased (n = 5), gentamicin MICs remained the same (n = 6) or increased 2-fold (n = 2), and led to RSC to LZD (n = 1) and resistance to CLI (n = 8). Overall, levels of resistance/RSC to CIP in food chain isolates, particularly 1/2a, are concerning. Further, reduced sensitivity to disparate antimicrobials following CIP exposure highlights the need for increased knowledge of co-selection phenomenon linked with antimicrobial agents.
authors.affiliation: Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, 218-2205 East Mall, Vancouver, BC V6T 1Z4, Canada.
authors.forename: Jovana
authors.initials: J
authors.lastname: Kovacevic
authors.forename: Jason
authors.initials: J
authors.lastname: Sagert
authors.forename: Anna
authors.initials: A
authors.lastname: Wozniak
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Gilmour
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Allen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D003611:Dairy Products / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D005399:Fishes; D005506:Food Contamination / Q000032:analysis; D005511:Food Handling; D008087:Listeria / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D017747:Seafood / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents