Mechanisms of Vancomycin Resistance in Mixed Species Biofilms

Mechanisms of Vancomycin Resistance in Mixed Species Biofilms

The studies conducted are aimed at determining the interactions between Candida albicans and Staphylococcus aureus in a mixed biofilm. Microbes generally prefer to grow as part of a biofilm, as opposed to individual planktonic cells, in order to communicate, share nutrients, and gain protection from environmental stresses. The bacterium Staphylococcus aureus and the fungus Candida albicans are the most common microbes found to grow within biofilms in humans and are among the leading causes of infectious disease. Previous research in our lab has indicated that S. aureus is less susceptible to the antibiotic vancomycin when grown in a mixed biofilm. To determine if the reason for the increased resistance was a change in gene expression of antibiotic resistant genes, the total RNA of mixed biofilms and pure biofilms was isolated for comparison. Electrophoresis was used to determine the presence and total quantity of RNA. The RNA was converted to complimentary cDNA, and PCR was used to isolate the genes involved in increasing antibiotic resistance. The bands seen during gel electrophoresis indicated a change in the expression of one drug pump in the mixed species biofilm in comparison to the pure biofilm. However, this project is still underway and further tests are needed to show precision reproducibility of those initial results.