Acquired vancomycin resistance appears to be a serious and growing therapeutic challenge among various Gram-positive pathogens worldwide. In Enterococcus, different types of gene clusters encoding vancomycin (and teicoplanin) resistance have been identified; the vanA and, to a lesser extent, the vanB types are the most prevalent. Occasionally, the vanA cluster spread to S. aureus, constituting the first seven cases of VRSA (vancomycin-resistant S. aureus) that all emerged independently. Vancomycin treatment failure can be associated with van-independent mechanisms of (intermediate) resistance to vancomycin and seems to be an increasing problem in S. aureus and the CNS (coagulase-negative staphylococci).
(Future Microbiol. 2008;3(5):547-562)