GENE-TRANSFER, GENTAMICIN RESISTANCE AND ENTEROCOCCI

Enterococci are versatile pathogens by virtue of their ability to exhi bit low-level intrinsic resistance to clinically useful antibiotics an d their tolerance to adverse environmental conditions. In the last 20 years these pathogens have become progressively more difficult to trea t because of their aptitude for acquiring antibiotic-resistance genes. Of increasing concern is the rapid dissemination of the AAC6'-APH2 '' bi-functional aminoglycoside modifying enzyme. This enzyme confers hi gh-level resistance to gentamicin and all other related aminoglycoside s with the exception of streptomycin. The gene conferring this phenoty pe has been associated with both narrow and broad host range plasmids, and has recently been found on conjugative transposons. The nature of these conjugative elements raises the possibility of the resistance g ene spreading to other pathogenic bacteria.