Development of predictive models of biofilm formation by C. sakazakii, E. cloacae on surfaces used in the food industry and medicine.

Cronobacter sakazakii and Enterobacter cloacae exhibit the ability to form biofilms, making them resistant to drying, antibiotics, and changes in pH. These biofilms can adhere to different surfaces, including tissues, catheters, enteral feeding tubes, and work surfaces, potentially leading to cross-infection risks in both the food and medical sectors. The objective of this study was to develop a predictive model of biofilm formation over time by C. sakazakii and E. cloacae on medical polyvinyl chloride (PVC) at 37 °C and stainless steel (SS), polypropylene (PP) surfaces at 4 °C and different microbial inoculum concentration. A staining method and spectrophotometric measurement were used to assess biofilm formation. SyStat Software Inc. for Windows Table curve 3D v.4.0.05 and non-linear functions were used to develop predictive models. Analysis of biofilm formation on SS and PP surfaces at 4 °C by all analyzed bacteria suggests that hygiene procedures in refrigeration equipment should be performed daily, the maximum safe storage time for bottled milk is 24 h. At 37 °C E. cloacae posed the highest risk of biofilm formation on the surface of PVC tubing at 6-36 h. The six best response surface models of biofilm formation were selected for presentation. The majority of these models demonstrated good accuracy, as evidenced low mean standard errors (MSE), high coefficient R2 and Adjusted R(Aung and Chang, 20142). These models can be utilized to evaluate the microbiological risks in settings such as human milk banks, neonatal intensive care units and food industry plants.