Comparison of the Efficacy of Cleaning Agents for the Surface of Laboratory Benches in Microbiology Laboratory at Faculty of Medicine, Thammasat University

Abstract

This research aimed to compare the efficacy of cleaning agents for the surface of laboratory benches in Microbiology Laboratory at the Faculty of Medicine, Thammasat University. The experiment was set up to investigate the efficacy of cleaning agents, including the detergent group
(i.e., 0.5% washing powder) and antiseptic group. For antiseptic group it could be divided into 2
sub-groups, which were disinfection solution (i.e., 70% alcohol and 0.5% sodium hypochlorite) and ready-to-use disinfectant (i.e., 0.5&% commercially available solution). Tap water was used as a
control. Samples were collected from the surface of the laboratory table by a swab test method which was performed on an area of 25.81 square centimeters (4 square inches), a total of 4 areas per cleaning agent. The tests were conducted before and after the cleaning with tested agents on the days that had the microbiology laboratory lessons. The experiments were performed on 7
occasions with 10 tested tables and 20 samples per occasion. The different efficiencies among cleaning products in different periods were investigated using the colony count method, and
one-way ANOVA was used to evaluate statistically different. The results before cleaning the number of microorganisms found were no different disinfectant. After cleaning, the number of microorganisms found was significantly different (p<0.05). Data on the growth of microorganisms when using different cleaning agents before and after cleaning were recorded. It was found that the mean microbial count before cleaning was in the range of 9.39 - 18.18 CFU / cm² while the mean microbial count after cleaning was 0.39 – 2.14 CFU / cm². The results before and after the cleaning usage with Scheffe method, there was no different disinfectant property between before and after cleaning laboratory benches when using 0.5% washing powder, 70% alcohol, 0.5% sodium hypochlorite, and 0.5% readyto-use disinfectant. Further bacterial identification of all isolates showed Staphylococcus sp. and Bacillus sp. both before and after cleaning. When analyzing the average number of
microorganisms, it was found that 0.5% ready-to-use disinfectant and 70% alcohol were the best destruction of Staphylococcus sp. and Bacillus sp., respectively.