Adaptation to Biocides Cetrimide and Chlorhexidine in Bacteria from Organic Foods: Association with Tolerance to Other Antimicrobials and Physical Stresses.
Chlorhexidine (CH) and quaternary ammonium compounds (QAC), such as cetrimide (CE), are widely used as disinfectants because of their broad antimicrobial spectrum. However, their frequent use for disinfection in different settings may promote bacterial drug resistance against both biocides and clinically relevant antibiotics. This study analyzes the effects of stepwise exposure to cetrimide (CE) and chlorhexidine (CH) of bacteria from organic foods and previously classified as biocide-sensitive. Gradual exposure of these strains to biocides resulted in mainly transient decreased antimicrobial susceptibility to other antibiotics and to biocides. Biocide-adapted bacteria also exhibit alterations in physiological characteristics, mainly decreased heat tolerance, or gastric acid tolerance in CE-adapted strains, while bile resistance does not seem to be influenced by biocide adaptation. Results from this study suggest that changes in membrane fluidity may be the main mechanism responsible for the acquisition of stable tolerance to biocides.
Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén , 23071-Jaén, Spain.
Rebeca
R
Gadea
Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén , 23071-Jaén, Spain.
Nicolás
N
Glibota
Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén , 23071-Jaén, Spain.
Rubén
R
Pérez Pulido
Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén , 23071-Jaén, Spain.
Antonio
http://orcid.org/0000-0002-5894-5029
A
Gálvez
Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén , 23071-Jaén, Spain.
Elena
E
Ortega
D000222:Adaptation, Physiological / Q000187:drug effects*; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D018407:Bacterial Physiological Phenomena / Q000187:drug effects; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D058870:Food, Organic / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D013312:Stress, Physiological / Q000187:drug effects
D002593:Cetrimonium Compounds; D004202:Disinfectants; D002710:Chlorhexidine; D000077286:Cetrimonium
adaptation; antibiotics; biocides; cetrimide; chlorhexidine; resistance genes