Assessment of the Inhibitory Efficacy of Two Commonly Used Disinfectants (Ethanol and Phenol)

Abstract: Different kinds of disinfectants have been widely used in different research laboratories. In Nigeria, common laboratory disinfectants include alcohols like ethanol and also phenolic compounds. The antibacterial efficacy of two disinfectants (ethanol, phenol) was assessed in this study against isolates obtained from laboratory sites. Antibacterial activity test was carried out using agar plate diffusion method. Different concentrations of the disinfectants (1-5% for phenol, 50-70%, 85% and 99.7% for ethanol) were tested against the isolates. Isolates from laboratory sites used include Escherichia hermanii, Stenotrophomonas maltophilia, Providencia stuartii, Leclercia adecarboxylata and Enterobacter cloacae. Isolates were identified using standard microbiological techniques and Matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. The outcome of the study showed phenol at a concentration of between 3-5% to have better inhibitory effects against the isolates compared to ethanol. The antimicrobial efficacy of disinfectants routinely supplied to the laboratory should be periodically assessed to ensure use at appropriate inhibitory concentration and proper control of infections.