Tarbiat Modares University Infection Epidemiology and Microbiology 2588-4107 12 2 2026 09 01 Evaluation of Disinfectant Efficacy and Antimicrobial Resistance in Nosocomial Pathogens with Emphasis on Pseudomonas aeruginosa 121 134 29047 10.52547/iem.12.2.121 EN Siham R. Agouri Department of Microbiology, Faculty of Sciences, Benghazi University, Beng hazi, Libya Asma Elramli Department of Medical Technology, College of Science and Technology - Qaminis, Benghazi, Libya. Alakeed Laboratory, Benghazi, Libya 0009-0006-6779-2008 Suad A. Ajaj Department of Medical Technology, College of Science and Technology - Qaminis, Benghazi, Libya Ahmed A Zaghdani Microbiology department, Libyan biotechnology research Centre, Tripoli, Libya Fawzya A. Al-Majbari Alakeed Laboratory, Benghazi, Libya Eljomhoriea Medical Hospital, Faculty of Public Health, University of Benghazi, Libya Salah Edin El Meshri Microbiology department, Libyan biotechnology research Centre, Tripoli, Libya Abdelmenem Abid Eljomhoriea Medical Hospital, Faculty of Public Health, University of Benghazi, Libya 0009-0005-7902-1334 Ghassan Tayh Department of Microbiology and Immunology, National School of Veterinary Medicine, University of Manouba, LR16AGR01, 2020 Sidi Thabet, Ariana, Tunisia. Khaled M Ibrahim Microbiology department, Libyan biotechnology research Centre, Tripoli, Libya 0000-0003-3348-1448 Journal Article 2025 10 10 <strong>Background:</strong> This study aimed to assess the efficacy of selected disinfectants in Benghazi Medical Center hospital in Libya. <br><strong>Materials & Methods:</strong> A total of 64 swabs were collected from healthcare workers’ hands, and 96 samples were collected from the hospital environment. Five bacterial species isolated from these samples were selected to investigate the bactericidal efficacy of <br>five disinfectants. 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 overnight at 37 °C. Bactericidal efficacy was assessed based on <br>colony growth. Phenotypic expression of ESBLs (extended spectrum beta lactamases) and MBLs (metallo beta-lactamases) was assessed in all bacterial isolates. Antimicrobial resistance genes were detected by PCR (polymerase chain reaction).<br><strong>Findings:</strong> Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Micrococcus spp., and Klebsiella pneumonia were isolated and identified by microbiological 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 methicillin-resistant S. aureus survived in iodine-containing medium. Notably, P. aerugino<br>sa isolates were detected as MDR strains in various hospital environments, including floors, wash basins, and even people’s hands and disinfectant bottles. <br><strong>Conclusion:</strong> 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 the effectiveness of disinfectants and antibiotics and to prevent the dissemination of resistant bacteria within hospital environments. https://iem.modares.ac.ir/article_29047_226ad861fc651e3635a98cc062b602f6.pdf