Phenotype and genetic determination of resistance to common disinfectants among bioflm-producing and non-producing Pseudomonas aeruginosa strains from clinical specimens in Iran

Abstract

Background: Pseudomonas aeruginosa is a common pathogen in Hospitalized patients, and its various resistance mechanisms contribute to patient morbidity and mortality. The main aims of the present study were to assess the susceptibility of bioflm-producing and non-producing P. aeruginosa isolates to the fve commonly used Hospital disinfectants, to evaluate the synergistic efect of selected disinfectants and Ethylene-diamine-tetra acetic acid (EDTA), and the efect of exposure to sub-inhibitory concentrations of Sodium hypochlorite on antimicrobial susceptibility test. Results: The results showed that sodium hypochlorite 5% and Ethanol 70% were the most and least efective disinfectants against P. aeruginosa, respectively. The addition of EDTA signifcantly increased the efectiveness of the selected disinfectants. The changes in the antibiotic-resistance profles after exposure to sub-inhibitory concentrations of disinfectants were observed for diferent classes of antibiotics (Carbapenems, Aminoglycosides, Cephalosporins, Fluoroquinolones). As well as near the all isolates harbored efux pump genes and 117 (97.5%) of isolates produced bioflm. Conclusion: In the current study, the mixture of disinfectant and EDTA were the most suitable selection to disinfect Hospital surfaces and instruments. Also, it was clear that exposure to sub-inhibitory concentrations of Sodium hypochlorite results in resistance to some antibiotics in P. aeruginosa species. Strong and intermediate bioflm formers belonged to MDR/XDR strains. Future studies should include more complex microbial communities residing in the Hospitals, and more disinfectants use in Hospitals. Keywords: Nosocomial infection, Disinfectant-resistance, Bioflm, Hospital disinfectants, Pseudomonas aeruginosa, Clinical isolate