Determining the Efficacy of Some Hospital Disinfectants Against Methicillin-Resistant Staphylococci Isolated From Different Wards of an Educational Hospital

Introduction Disinfectants are widely used in health centers to control the growth of bacterial pathogens in inanimate objects (1). These compounds are used daily for sterilization or disinfection of medical devices and different wards of the hospitals. On the other hand, the inappropriate usage of many of these materials, poor efficacy of disinfectants, failure to provide effective concentrations of disinfectants, inappropriate physics of hospitals, and different responses of various pathogens have decreased the efficiency of disinfectants against hospital microorganisms (2). Hospital infections are common problems in hospitals and health centers, and one of the major factors regarding the spread of nosocomial infections is the inappropriate usage of disinfectants (3). The prevalence of nosocomial infections in Iran is 4.5%, and bloodstream infections, surgical site infections, and pneumonia are among the most common infections (4). The most common bacteria causing nosocomial infections include Acinetobacter baumannii, Clostridium difficile, Escherichia coli, Klebsiella pneumonia, methicillinresistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Vancomycin-resistant Enterococci (VRE) and Burkholderia cepacian (5). Staphylococci play a major role in nosocomial infections, which contribute to various infections in patients admitted to different wards of the hospitals (6-8). S. aureus is one of the most important bacteria that cause infectious diseases including food poisoning, scalded skin syndrome, furuncles, impetigo, folliculitis, and abscesses by producing enterotoxins and exfoliative toxins (9,10). On the other hand, coagulasenegative staphylococci have been one of the important causes of bacteremia, endocarditis, wound infection, urinary tract infections, pneumonia, skin infection, and soft tissue infection during the last decade (11,12). At first, methicillin-resistant staphylococci were identified at hospitals, while nowadays they are found both in the community and hospitals. These bacteria are among Abstract Objectives: Methicillin-resistant staphylococci are important causes of nosocomial infections. Due to the presence of these bacteria in hospitals as a significant challenge in hospital infection control, the identification of effective disinfectants against methicillinresistant staphylococci is necessary. This study was designed to evaluate the effectiveness of common hospital disinfectants against methicillin-resistant staphylococci. Materials and Methods: In this cross-sectional study, the effectiveness of 4 surface disinfectant cleaners (Deconex 50 AF, Microzed GP-H, Peranacid M1 and Surfocept quick) against methicillin-resistant staphylococci (10 Staphylococcus aureus, 10 Staphylococcus saprophyticus, and 55 Staphylococcus epidermidis) was evaluated using broth dilution method, disc diffusion assay, and cell viability assay. Results: The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of Peranacid and Surfocept against the isolates were higher than those of Deconex and Microzed. The results of disk diffusion assay showed that staphylococcus strains exhibited greater inhibition zone diameter than other disinfectants at different concentrations of Deconex and Microzed. According to the results of cell viability assay, S. aureus, S. epidermidis, and S. saprophyticus isolates did not grow at three concentrations (0.5%, 1% and 2%) of Deconex, Microzed, and Peranacid, respectively. Conclusions: Deconex and Microzed had more antimicrobial properties than the 2 other agents and methicillin-resistant staphylococcus isolates had a higher resistance to both Peranacid and Surfosept.