title: Comparison between Flow Cytometry and Traditional Culture Methods for Efficacy Assessment of Six Disinfectant Agents against Nosocomial Bacterial Species.
abstract: The present study was undertaken to compare the use of flow cytometry (FCM) and traditional culture methods for efficacy assessment of six disinfectants used in Quebec hospitals including: two quaternary ammonium-based, two activated hydrogen peroxide-based, one phenol-based, and one sodium hypochlorite-based. Four nosocomial bacterial species,Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Vancomycin-resistantEnterococci faecalis, were exposed to minimum lethal concentrations (MLCs) and sublethal concentrations (1/2 MLCs) of disinfectants under study. The results showed a strong correlation between the two techniques for the presence of dead and live cell populations, as well as, evidence of injured populations with the FCM. The only exception was observed with sodium hypochlorite at higher concentrations where fluorescence was diminished and underestimating dead cell population. The results also showed that FCM can replace traditional microbiological methods to study disinfectant efficacy on bacteria. Furthermore, FCM profiles forE. coliandE. faecaliscells exposed to sublethal concentrations exhibited distinct populations of injured cells, opening a new aspect for future research and investigation to elucidate the role of injured, cultural/noncuturable/resuscitable cell populations in infection control.
authors.affiliation: Centre Intégré de Santé et de Services Sociaux de Lanaudière Québec, QC, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Massicotte
authors.affiliation: Food Research and Development Centre, Agriculture and Agri-Food Canada St-Hyacinthe, QC, Canada.
authors.forename: Akier A
authors.initials: AA
authors.lastname: Mafu
authors.affiliation: Hôpital du Sacré-Coeur de Montréal Montréal, QC, Canada.
authors.forename: Darakhshan
authors.initials: D
authors.lastname: Ahmad
authors.affiliation: Department of Microbiology, Infectiology and Immunology, University of Montreal, Edouard-Montpetit Montreal, QC, Canada.
authors.forename: Francis
authors.initials: F
authors.lastname: Deshaies
authors.affiliation: Hôpital du Sacré-Coeur de Montréal Montréal, QC, Canada.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Pichette
authors.affiliation: Department of Microbiology, Infectiology and Immunology, University of Montreal, Edouard-Montpetit Montreal, QC, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Belhumeur
keywords: dead and live in between cell populations; disinfectant; flow cytometry; healthcare facilities; minimum lethal concentrations; nosocomial infections; viability status profiling