Sensitivity of Methicillin-Resistance and Methicillin-Susceptible Staphylococcus aureus Strains to Some Different Disinfectants

This investigation was planned to evaluate the sensitivity of methicillin-resistance Staphylococcus aureus(MRSA) and methicillin-susceptible Staphylococcus aureus(MSSA) strains to some different disinfectants. The isolated strains were obtained from milk and its surrounding animal milking environment of 60 dairy cattle houses including 30 houses for cows and 30 houses for buffalos. These isolates were identified by genotyping using PCR. Eight common disinfectants were applied in the following concentrations (as povidone-iodine 7.5%, Dettol 1%, quaternary ammonium compound 0.5%, MetriCide 28 (2.6%), AntisepticaCombi Surface 1%, formalin 0.5%, hydrogen peroxide 3% (10 v/v) and ethanol 70%). The Minimal inhibitory concentrations (MICs) for the disinfectants against each microbe were determined. The obtained results of MICs of the eight applied disinfectants against MRSA were (18750 mg/l, 6000 mg/l, 1250 mg/l, 3250 mg/l, 2500 mg/l, 625 mg/l, no sensitivity to hydrogen peroxide, 87500 mg/l), respectively. On the other hand, the results of MICs against MSSA were (9375 mg/l, 375 mg/l, 156 mg/l, 101.5 mg/l, 625 mg/l, 156 mg/l, 937 mg/l and 10937 mg/l), respectively. It can be concluded that, all tested MRSA and MSSA strains were sensitive to the used disinfectants applied except MRSA was not sensitive to hydrogen peroxide 3% (10 v/v). Moreover, it was found that the tested MSSA was sensitive than MRSA to all the applied disinfectants.