Biology Project Abstract
ANTIMICROBIAL SYNERGY STUDIES OF METHACILLIN RESISTANT STAPHYLOCOCCUS AUREUS USING VANCOMYCIN AND RIFAMPIN COMBINATIONS WITH OR WITHOUT SUB-INHIBITORY GENTAMICIN
Presenters:
Laura Hawkes, Illinois Mathematics and Science Academy, 1500 West Sullivan Road, Aurora, IL, 60506; hawkgal4@imsa.edu
Azmina Lakhani, Illinois Mathematics and Science Academy, 1500 West Sullivan Road, Aurora, IL, 60506; alakhani@imsa.edu
Mentor:
Mr. Bill Kabat, Childrens Memorial Hospital, Department of Pediatric AIDS, 2300 Childrens Plaza, Chicago, IL, 60614; 773-880-4907; 773-880-3208; bkabat@Childrens memorial.org
Abstract:
The objective of this project was to examine the disconnect between combined vancomycin/rifampin minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values observed in clinical in vitro testing against Staphylococcus aureus. Micro dilution methods that have been universally agreed upon were used to identify the MICs and MBCs of these antibiotics alone and in various arrangements according to concentration. Drug combinations were then determined to be indifferent (showing negligible/no MIC/MBC change), additive (demonstrating minor advantageous change), synergistic (showing significantly beneficial change), or antagonistic (demonstrating disadvantageous change) for each study. Gentamicin was added at sub-inhibitory concentrations to the drug array to see whether it would help to lower the synergy MBCs, and thus lessen the MIC/MBC disconnect. It was found that although the addition of gentamicin at sub-inhibitory concentrations did not significantly impact the MICs of rifampin and vancomycin, the gap between the MICs and MBCs was dramatically narrowed as the concentrations of gentamicin were increased. Based on these preliminary synergy studies, it can be concluded that small amounts of gentamicin may assist rifampin and vancomycin in treating acute staphylococcal infections.