Evaluation of Disinfectant Efficacy and Antimicrobial Resistance in Nosocomial Pathogens with Emphasis on Pseudomonas aeruginosa

Aims: The aim of this study was to assess the efficacy of selected disinfectants at Benghazi medical center hospital.
Methods: A total of 64 hand swabs were collected from healthcare workers and 96 samples from the hospital environment. Five bacterial species were selected from the collection to test the bactericidal efficacy of five disinfectant products. Bacterial suspensions were prepared in 9 mL of broth medium and mixed with 1 mL of each disinfectant. All inoculated nutrient agar and MacConkey agar plates were incubated at 37 °C overnight. Bactericidal efficacy was assessed based on colony growth. In addition, the phenotypic expression of ESBL and MBL was assessed in all bacterial isolates. Antimicrobial resistance genes were detected by PCR.
Findings: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Micrococcus spp and Klebsiella pneumonia were isolated and identified by microbiological examinations and biochemical tests. All isolates were found to be multidrug-resistant (MDR). The tested disinfectants demonstrated high bactericidal efficacy against these isolates. However, P. aeruginosa was not affected by hydrogen peroxide and alcohol and the methicillin resistant S. aureus survived in iodine-containing medium. Notably, P. aeruginosa isolates, along with their resistance profiles, were detected as MDR strains in various hospital environments, including floors, wash basins, and even on people’s hands and disinfectant bottles.
Conclusion: The selection of appropriate disinfectants (or chemical sterilants) is crucial and should be based on their proven efficacy against microbial agents. Proper testing is essential to ensure effectiveness and to prevent the dissemination of disinfectant-resistant and antibiotic-resistant bacteria within hospital environments.