Unraveling Enterococcus susceptibility to quaternary ammonium compounds: genes, phenotypes, and the impact of environmentalc onditions

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Pereira, AP (Author) Other; Antunes, Patrícia (Author) FCNAUP; Bierge, P (Author) Other; Willems, RJL (Author) Other; Corander, J (Author) Other; Coque, TM (Author) Other; Pich, OQ (Author) Other; Peixe, L. (Author) FFUP; Freitas, AR (Author) Other; Novais, Carla (Author) FFUP

Journal

Title: Microbiology spectrum

Vol. 11

ISSN: 2165-0497

Publisher: American Society for Microbiology

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 3 Citations

Scientific classification

CORDIS: Health sciences

FOS: Medical and Health sciences

Associated Projects

AGRIFOOD-XXI - AGRIFOOD-XXI

Other information

Authenticus ID: P-00Z-756

DOI: 10.1128/spectrum.02324-23

Abstract (EN): Quaternary ammonium compounds (QACs) have been extensively used in the community, healthcare facilities, and food chain, in concentrations between 20 and 30,000 mg/L. Enterococcus faecalis and Enterococcus faecium are ubiquitous in these settings and are recognized as nosocomial pathogens worldwide, but QACs' activity against strains from diverse epidemiological and genomic backgrounds remained largely unexplored. We evaluated the role of Enterococcus isolates from different sources, years, and clonal lineages as hosts of QACs tolerance genes and their susceptibility to QACs in optimal, single-stress and cross-stress growth conditions. Only 1% of the Enterococcus isolates included in this study and 0.5% of publicly available Enterococcus genomes carried qacA/B, qacC, qacG, qacJ, qacZ, qrg, bcrABC or oqxAB genes, shared with >60 species of Bacillota,Pseudomonadota,Actinomycetota,or Spirochaetota. with >60 species of Bacillota, Pseudomonadota, Actinomycetota, or Spirochaetota. These genes were generally found within close proximity of antibiotics and/or metals resistance genes. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of benzalkonium chloride (BC) and didecyldimethylammonium chloride ranged between 0.5 and 4 mg/L(microdilution:37 degrees C/20h/pH = 7/aerobiosis)chloride ranged between 0.5 and 4 mg/L (microdilution: 37 degrees C/20 h/pH = 7/aerobiosis) for 210 E. faecalis and E. faecium isolates (two isolates carrying qacZ). Modified growth conditions (e.g., 22 degrees C/pH = 5) increased MICBC/MBCBC (maximum of eightfold and MBCBC =16mg/L)and changed bacterial growth kinetics under BC toward later stationary = 16 mg/L) and changed bacterial growth kinetics under BC toward later stationary phases in both species, including in isolates without QACs tolerance genes. In conclusion, Enterococcus are susceptible to in-use QACs concentrations and rarely carry QACs tolerance genes. However, their potential gene exchange with different microbiota, the decreased susceptibility to QACs under specific environmental conditions, and the presence of subinhibitory QACs concentrations in various settings may contribute to the selection of particular strains and, thus, require a One Health strategy to maintain QACs effectiveness.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 18