The potency of commonly used disinfectants on bacteria isolated from in-animate surfaces in the microbiology laboratory, Umaru Musa Yardua university Katsina

Abstract

Disinfection is the process of removing microorganisms including potentially pathogenic ones from the surface of in-animate objects. The ubiquity of microorganisms has implicated door knobs, human hands, desks surfaces etc. to be reservoirs of microorganisms. This study analyses three (3) samples from five (5) inanimate surfaces of the Microbiology laboratory, three different organisms were isolated and identified using series of biochemical tests, phenol coefficient and surface disinfection test were also carried out. The phenol coefficient test involve exposure of the isolates to different dilution of test disinfectants to determine the highest dilution factor that inhibit microbial growth while surface disinfection test involved the use of soiled slides to test the potency of the test disinfectants on the isolates. The organisms isolated were Staphylococcus aureus, Klebsiella sp. and E. coli. Klebsiella sp. showed the highest resistance to the test disinfectants than E. coli and S. aureus. The result of this study confirms the contamination of inanimate surfaces with variety of pathogenic bacteria (S. aureus 25%, E. coli 23% and Klebsiella sp. 52%). Disinfectant A had the highest phenol coefficient of 6.0, C had 4.0 and disinfectant B had the lowest phenol coefficient of 3.0. Microorganisms live as transient contaminants in fomites where they constitute a major health hazards as sources of community acquired infections. Therefore, constant and regular disinfection should always be conducted at different concentrations so as to determine the potent concentration against the adhered microorganisms on various surfaces of the laboratory.

Keywords: Disinfection, Phenol coefficient, Surface disinfection, Contamination, Inanimate surfaces.