Reservoir of Bacterial Exotoxin Genes in the Environment

This is the first report of an environmental reservoir of a bacterial exotoxin gene harbored in an atypical host in the environment. Screening bacterial isolates from the environment via sea-specific PCR identified an isolate with a DNA sequence >95% identical to the Staphylococcus aureus enterotoxin A gene (sea). 16S DNA sequence comparisons identified the environmental isolate as a Pseusodomonad. Laboratory studies confirmed that this Pseudomonad is psychrophilic. The results indicate that the sea gene is present in an alternative bacterial host, providing the first evidence for an environmental reservoir of exotoxin genes in bacteria. Transfer of these genes between phage and alternative bacterial hosts may promote the evolution of novel human diseases.