Bacteriostatic efficacy of commonly used detergents against carbapenemase-producing Escherichia coli from food contact surfaces ISSN Nasarawa State, Nigeria

Carbapenemase-producing (CPEC) has been an issue of public health concern due to high resistance to major antibiotics. This pathogen can be acquired through the consumption of contaminated foods. The use of detergents for the control of pathogens in food contact surfaces is commonly practiced by most food vendors. This study is aimed at assessing the efficacy of some commonly used detergents against CPEC from food contact surfaces in Nasarawa State, Nigeria. A total of 924 swab samples from food contact surfaces (246 each from plates, cups and spoons and 186 from tabletops) in various food vending outlets were screened for phenotypic identification of CPEC using Imipenem (30µg) and Meropenem (10µg) antibiotics susceptibility disk diffusion method. Tubes of varying concentrations of test detergents (1:140, 1:160, 1:180, 1:200 and 1:220) were seeded against phenol as standard with varying concentrations of 1:50, 1:60, 1:70 1:80 and 1:90. Hawkers outlets had highest CPEC isolation frequencies among swab samples and isolates with values of 3.33% and 7.70% respectively while cups and spoons surfaces had highest samples (1.63%) and isolates (7.69%) frequencies respectively. Overall CPEC isolation frequencies were 1.30% and 6.00% among the screened samples and isolates respectively. Though there was significant difference (p<0.05) in the frequency values among the vending outlets, the contact surfaces had no significant difference at p>0.05. Highest phenol coefficient value of 2.6 was obtained for MFD while SLD and LPD had 2.3 and 1.7 respectively. The difference in the phenol coefficient values among the detergents were statistically insignificant (p>0.05). All detergents used in this study were effective against CPEC isolated from the food contact surfaces. Using locally produced detergents in appropriate concentrations especially for low-income earners is quite promising and is a good alternative to other branded detergents.