Hirschi, Blake; Pickett, Brad; Thompson, Jared; Telford, Mady; Berges, Bradford (Brigham Young University)
Faculty Advisor: Berges, Brad (Life Sciences, Microbiology and Molecular Biology)
Staphylococcus aureus (S. aureus) is a commensal bacterium commonly found amongst livestock and near 30% of humans' nostrils. However, through acquisition of certain genes S. aureus may develop antibiotic resistance such as in methicillin-resistant Staphylococcus aureus (MRSA). One hypothesized component lending to acquisition of genetic resistance in S. aureus is the synthesis of colony biofilms. Biofilms are comprised of a variety of substances including secreted polysaccharides, protein and even extracellular DNA. Our work postulates that extracellular DNA-based biofilms will transfer genes for antibiotic resistance at a higher rate than in polysaccharide/protein biofilms. Through employment of polymerase chain reaction (PCR), we aim to characterize a wide sample of methicillin-susceptible S. aureus (MSSA) human associated strains and MRSA livestock associated strains for multiple antibiotic resistances. Co-inoculating pairs of human associated and livestock associated strains, each lacking the other's resistance genes, will provide an environment wherein biofilm-mediated gene transfer may occur. Further pairing based on biofilm composition (DNA or polysaccharide/protein) will yield data concerning which biofilm facilitates gene transfer more efficiently. Subsequent genotyping will confirm whether resulting isolates acquired new antibiotic resistance through biofilm-mediated transfer, thus increasing pathogenicity.