
The In Vitro Efficacy Testing Of Skin Disinfectants Against Nosocomial Pathogens
231-235
Correspondence
Dr. Jayakumar S, MD
Associate Professor, Department of Microbiology,
Saveetha Medical College & Hospital, Saveetha University, Thandalam
Kancheepuram District – 602 105
Tamilnadu.
E mail: drjk_micro@rediffmail.com
Mobile Number: 94437 50196
Background
Nosocomial infections increase the morbidity among hospitalized patients and are a major cause of death. The national surveillance data and public health research have demonstrated that hospital- acquired infections (HAIs) take a major human toll on society. Disinfectants play a major role in reducing the hospital acquired infections (HAIs). There are many skin disinfectants which are commercially available and there has been a considerable recent interest in the bacterial adaptation and resistance to skin disinfectants.
Aim
To study the bactericidal activity of 0.5% chlorhexidine gluconate, 0.5% chlorhexidine gluconate in 80% ethanol, 5% povidone – iodine, 10% povidone – iodine and 10% 20%, 30%,40%, 60%, 80% and 99.5% ethanol against Methicillin resistant Staphylococcus aureus [MRSA], multi drug resistant [MDR] Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli - extended spectrum beta lactamase producers [ESBL] and Klebsiella pneumoniae [ESBL]. Each strain was evaluated in quadruplicate.
Methods
The testing was carried out by means of a suspension test. The pathogen was exposed to each of the disinfectants at various concentrations for 15, 30, 60,120 and 240 seconds at room temperature. After the exposure of the inocula to the disinfectants, the antimicrobial activity of the disinfectants in the suspensions was inactivated by neutralizers. Of the resulting suspensions, 100µl of each was transferred to nutrient agar plates in triplicates and these were incubated at 37˚C for 72 hrs. The number of colonies in each plate was counted and tabulated.
Results
Povidone-iodine (10%) and 60% ethyl alcohol were found to be effective against 20 bacterial strains than 0.5% chlorhexidine gluconate, 0.5% chlorhexidine gluconate in 80% ethyl alcohol and 5% povidone-iodine. Statistical analysis was done by a nonparametric test. The differences in the percentage change in the colony counts between the 4 disinfectants were significant at 15 and 30 seconds of exposure [P < 0.05].
Conclusion
The results suggest that 10% povidone-iodine and 60% ethyl alcohol were superior and more potent as well as rapid against the common nosocomial pathogens.