Graduate Student’s Successful Defense
Congratulations to Austin Bates for successfully defending his MS thesis. His supervisory committee included Drs. Brenda Schroeder (chair), Tobin Peever and Linda Thomashow. Austin’s dissertation research dealt with multi-locus sequence analysis of environmental strains of Enterobacter cloacae. E. cloacae is a bacterial storage pathogen of onion causing Enterobacter bulb decay and is a pathogen of numerous other plant species. Interestingly, E. cloacae is also an opportunistic human pathogen causing nosocomial infections in immunocompromised individuals. The identification of isolates as E. cloacae requires a large number of physiological tests and the results are inconsistent across the strains. This is further complicated by the fact that E. cloacae is part of what is referred to as the Enterobacter cloacae complex (ECC) which is composed of six Enterobacter species closely related species with very similar biochemical profiles. Austin determined the placement of plant-associated environmental isolates within the ECC, a MLSA using four housekeeping genes including fusA, gyrB, leuS, rpoB to verify the placement of newly identified environmental isolates within the ECC and verified if that placement is different between environmental and medical strains of E. cloacae. He found that use of MSLA allows for a more consistent, reliable and easier placement of environmental strains of E. cloacae within the ECC compared to alternatives such as biochemical tests.