Efficiency of some commonly used disinfectants on bacterial isolates from critical areas of tertiary care hospital

Abstract

Aim of the study: Monitoring bacterial susceptibility to antimicrobials and disinfectants may help the management of nosocomial infection. Environmental surfaces are epidemiologically important reservoir of nosocomial bacterial species. The successful eradication of these pathogens with antibiotics has been complicated by the development of highly resistant strains as well as the appearance of new virulent pathogens. Materials and Methods: Mop water with added disinfectant was collected from critical areas of the hospital which were- surgical operation theatre, ophthalmology operation theatre, and intensive care unit of medicine. Isolates were tested by surface test method for efficacy of 6 commonly used disinfectants; Sodium hypochlorite, Phenyl black, Povidone iodine, Lysol (cresol) - benzalkonium chloride, Chloroxylenol & Chlorhexidine for recommended dilutions. Results: Majority of isolates were from M-ICU. Strains representative of GNB (gram negative bacilli) were most prevalent as compared to NFGNR. Recommended dilution of all the disinfectant was found satisfactory except phenyl black. Recommended dilution for phenyl black is 1:200 in water and as per our results of the study; MIC and MBC of organisms were found to be high. So it is recommended to use it in the critical areas of hospital with caution. Conclusion: The problem of hospital infection is a real one. Antibiotic resistant NFGNR, especially Pseudomonas spp. have played a predominant role. Antimicrobial activity of disinfectants may be influenced by their formation, level of organic load, synergy, temperature, dilution rate and tests methods. Disinfectant testing strategies should be part of any healthcare infection control policy. Keywords: Disinfectants, Bacteria, Surface test.