We analyzed highly vancomycin-resistant Gram-positive bacteria isolated from the saliva of migratory songbirds captured, sampled, and released from a birdbanding station in western Kansas. Individual bacterial isolates were identified by partial 16S rRNA sequencing. Most of the bacteria in this study were shown to be Staphylococcus succinus with the majority being isolated from the American Robin. Some of these bacteria were shown to carry vanA, vanB, and vanC vancomycin-resistance genes and have the ability to form biofilms. One of the van gene-carrying isolates is also coagulase positive, which is normally considered a virulence factor. Other organisms isolated included Staphylococcus saprophyticus as well as Enterococcus gallinarum. Given the wide range of the American Robin and ease of horizontal gene transfer between Gram-positive cocci, we postulate that these organisms could serve as a reservoir of vancomycin-resistance genes capable of transferring to human pathogens.

Non-therapeutic use of antibiotics in the agriculture industry has contributed to the development of antibiotic-resistant bacteria, which subsequently have been detected in air, soil, and surface and ground water by other researchers. From these sources resistant bacteria can be spread throughout ecosystems and potentially enter human populations. Saliva samples were taken from 114 migratory birds at the Fort Hays State University banding site during fall 2006. Each sample was plated on brain heart infusion agar and incubated in order to allow for bacterial growth. Isolated bacterial colonies were then Gram stained and tested for resistance to vancomycin. Differential and selective media were used for preliminary colony screening. Twenty vancomycin-resistant Gram-positive bacterial isolates were putatively identified using partial sequencing of the 16S rRNA gene. Four different bacterial species (Staphylococcus Succinus AF004219, Staphylococcus saprophyticus, Enterococcus gallinarum, and Staphylococcus sp. EU196332) were identified from the twenty vancomycin-resistant isolates collected from nine bird species.