DIVERSITY OF BACTERIAL CONTAMINATION ON IN-ANIMATE SURFACES OF A TERTIARY CARE HOSPITAL AND THEIR SENSITIVITY TO DISINFECTANTS

Abstract

Healthcare-associated infections are major causes of morbidity and mortality among
hospitalized patients. These infections are associated with frequent in-animate surface contamination in
hospitals. In the present study antibacterial activity of three commercially available disinfectants
including Benzalkonium chloride (BZK), Polyhexamethylene biguanide (PHMB) and Glutaral C11-C15 Pareth 9 against Escherichia coli, Pseudomonas spp., Serratia spp. and Vibrio spp. isolated from
inanimate surfaces of urology ward were evaluated. Efficacy of disinfectants was determined by
minimum inhibitory concentration (MIC) and agar well diffusion. Mean zones of inhibition (ZOI) of
BZK against the isolates ranged from 23.8 to 26mm followed by PHMB 23.3 to 27.4mm and Glutaral
C11-C19 Pareth 9 12 to 13mm. The MIC ranges were 2.5-20µL/mL for BZK; 1-16 µL/mL for PHMB
and 8-64 µL/mL for Glutaral C11-C19 Pareth 9. It was concluded that Glutaral C11-C19 Pareth 9 had
minimum efficacy against E. coli, Pseudomonas spp. and Serratia spp. while Vibrio spp. were least
susceptible to BZK. The mean MIC value of PHMB against E. coli, Pseudomonas spp. Vibrio spp. and
Serratia spp. was the lowest among the disinfectants.