Biofilm characterization of Staphylococcus epidermidis strains on varied surfaces as a tool for contamination control strategy in a pharmaceutical industry facility

Introduction: Biofilms are complex structures formed by microorganisms that organize themselves into aggregates, usually adhering to abiotic surfaces.Organisms such as Staphylococcus epidermidis, capable of forming biofilms, exhibit increased resistance to physical and chemical agents, contributing to the persistence in industrial environments.Objectives: This study aimed to evaluate the biofilm formation of S. epidermidis strains isolated in a pharmaceutical industry on surfaces made of stainless steel (SS), vinyl revetment (VR) and acrylic (AC). Methodology:The biofilm formation test was carried out using 50 strains in 24-well microplates containing the respective carriers.After microbial growth in brain heat infusion broth, the microplates were washed, and biofilm formation was revealed using CCK-8 reagent.The plates were incubated at 37C/2 h and the absorbance of the samples was measured at 450 nm to determine the viability of the cells in a biofilm state.Pseudomonas aeruginosa was used as positive control.The results, expressed as a percentage, were calculated according to the following formula: 100 x [(OD sample -OD negative control ) (OD positive control -OD negative control )].Results: After interpreting the results, it was observed that the OD percentages from surfaces varied between 1.3 and 57.6% in SS, 0.5% and 59.3% in VR and 1.2 and 94.5% in AC.The greatest amount of biofilm was found in the VR and AC, showing a significant increase compared to the SS (P0.002), but there was no difference between them. Conclusion:Biofilm formation varied according to the strain and surface analyzed, as it was not possible to establish a pattern.As these are porous surfaces, there was greater microbial growth on VR and AC.Future trials will be carried out to test the disinfectants used in surface cleaning to analyze their effectiveness.The plate test containing carriers seems to be an effective technique that can be applied to evaluate biofilms on different surfaces present in industries.This technique can be integrated into the contamination control strategy, contributing to the development of preventive and corrective measures aimed at eradicating microbial biofilms.