Antibiotic resistance among Gram-positive bacteria is a serious global health threat. Vancomycin-resistant enterococci (VRE) are especially concerning since they are susceptible to few if any antibiotics, and can serve as a reservoir for mobile genetic elements containing diverse resistance genes that could potentially be transmitted to other Gram-positive bacteria. The plasmids that confer resistance in Gram-positive bacteria, however, are poorly understood. In this project, a set of eight VRE strain was isolated from the influent of a wastewater treatment plant in San Diego County. Antibiotic susceptibilities were determined by disc diffusion
methods, revealing resistance most commonly to vancomycin, penicillin, linezolid, and erythromycin. Two novel plasmids were isolated from the strains, and the complete nucleotide sequences were determined by MinION sequencing technology. The plasmids contained a non-standard vanA operon and a novel macrolide-lincosamide-streptogramin B composite transposon.
Arete: The PLNU Honors Journal