Evaluation of susceptibilities of some pathogenic Bacteria to Benzalkonium chloride

Objectives: Nowadays increasing resistance of pathogenic bacteria against antimicrobials is a worldwide challenge. Antiseptics are commonly used for the management of MDR (multiple drug resistance) pathogens in hospitals so knowledge of the present susceptibility levels of pathogenic bacteria to different antimicrobials is indicated. The aim of the present study was to evaluate the susceptibilities of some pathogenic bacteria to benzalkonium choloride (BKC) as a routine hospital and field disinfectant.Materials and Methods: Tube double serial dilution method was used to determine minimum inhibitory concentrations (MIC) of 40 hospital/field and standard isolates of four pathogenic bacteria namely: Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Escherichia coli (each 10 isolates).Results Conclusion: According to the obtained results, the mean MICs of BKC for Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Escherichia coli isolates were 10, 28, 26and 5(µg/ml) respectively. Ps. aeroginosa was more resistant to BKC than other three examined bacteria. All examined isolates showed some degree of resistance against BKC.