We are studying the lateral transfer of transmissible antibiotic resistance plasmids among stream bacteria impacted by fecal runoff from poultry and cattle. Such plasmids are typically large (ca. 40 – 100 kb) and occur in low copy numbers in the cell and have therefore typically been difficult to isolate and therefore to study. Traditional protocols, based upon variations of the standard alkaline-lysis method, are long (ca. 1 1/2 to 2 days) and difficult. Commercial kits designed for the isolation of Baterial Artificial Chromosomes (BACs) can be used and are an improvement; however, these are expensive and still require hours of sustained effort. We have adapted a method published by Rondon et al. (1999), originally designed for the isolation of... |