Immunoblot fingerprinting of coagulase negative staphylococci.

Coagulase negative staphylococci have become prevalent nosocomial pathogens following the implantation of foreign bodies such as prosthetic valves, cerebrospinal fluid shunts, joint prostheses and central venous catheters. They are also the most common contaminants of blood cultures so that a means of differentiating contamination from a true bacteraemia is important.' Assessment of the clinical importance of an individual blood culture isolate is currently based on the clinical condition of the patient and the presence of similar isolates with identical antibiograms from subsequent blood cultures.2 Unrelated isolates from different patients, however, may have the same antibiogram,3 and retesting the same isolate does not always give reproducible results.4