Effect of Media and pH on Biofilm Formation in High and Low Biofilm-forming Isolates from Chronic Diabetic Foot Ulcers

Abstract Introduction: Biofilm formation among clinical isolates poses a significant challenge, especially in chronic wounds such as chronic diabetic foot ulcers (CDFUs). To understand the nature of bacteria and to formulate effective treatment strategies, it is crucial to detect the biofilm among clinical isolates. While there is a standard method for detecting biofilm formation, no universal protocol defines the optimal conditions for it. Hence this study is carried out to standardize stress condition required for biofilm formation. Methodology: The present study included two known biofilm-forming bacteria (high biofilm former and low biofilm former) isolated from CDFUs and using two different bacterial culture media formulating nine stress conditions based on varying pH and glucose concentrations, further subjecting for tissue culture plate-based biofilm detection assay to detect the biofilm formation in these isolates in order to optimize ideal stress condition. Results: Biofilm formation among both isolates was found to be enhanced by TSB with alkaline pH compared to standard BHI. TSB with alkaline pH was found to be promising in enhancing the biofilm production especially in high biofilm former. Conclusion: This study revealed nutrient-rich, high-glucose media, particularly under alkaline conditions, produces more pronounced biofilm in high biofilm-forming isolate and Trypticase soya broth with an alkaline pH found to be ideal media for biofilm detection of bacteria isolated from CDFUs.