Influence of container design material, cleaning regime, water quality and personnel hygiene on biofilm formation in farm-level milk containers in Kajiado county, Kenya.

Abstract

Food safety and the reduction of food losses remain critical concerns, particularly due to the consumption of milk contaminated with microorganisms. Milk is highly susceptible to contamination from microbes that form biofilms on milk handling equipment. Biofilms are heterogeneous and complex, making them difficult to eradicate. Therefore, this research aimed to investigate the influence of container design material and cleaning regime on biofilm formation in farm-level milk handling containers. The study employed a completely randomized design focusing on mazzicans and jerry cans. Chi-square tests, Fisher’s Exact test, logistic regression and robust permutation tests were used to analyze the data using R Core Team software version 4.4.0 of 2024. Bacterial multispecies comprising of Staphylococcus aureus (71%), Bacillus cereus (60.5%) and Pseudomonas aeruginosa (27.6%) were reported to co-exist as biofilms. Chi square test of independence revealed that there is association between cleaning regime and biofilm formation (P < 0.001). Logistic regression tests further revealed that using liquid detergent significantly reduces the likelihood of biofilm formation compared to the bar soap regime with a odds ratio of 0.01 (P <0.001). Fisher’s Exact test also revealed that there is an association between water quality, personnel hands and biofilm formation with an odds ratio of 0.203 (P = 0.03792). The odds ratio of 0.203 also revealed that biofilm formation is less likely in water compared to personnel hands. Logistic regression test also revealed that there was no significant influence of container design material on biofilm formation with an odds ratio of 0.84 (P = 0.768). It was concluded that biofilm is a potential food safety concern and a source of spoilage of milk products in Kajiado County thus a contributor of food waste and loss leading to economic losses. It is recommended that cleaning regime needs to be standardized since it is a contributing factor to proliferation of biofilms. Stringent water quality and personnel hygiene practices are required also to avert biofilm formation. Future studies are recommended to determine changes in biofilm formation on different containers under varying conditions.