Epidemiological typing of clinically significant strains of coagulase-negative staphylococci.

This study was undertaken to determine the characteristics of 202 isolates of coagulase-negative staphylococci (CNS) isolated from 78 patients (two-seven per patient) using biochemical identification, bacteriophage susceptibility patterns, reverse-typing, plasmid profiles, antimicrobial susceptibility testing and slime production. All the strains could be typed by using the six markers consecutively. In addition, we have been able to deduce the similarity of 58 strains from 24 patients by means of one marker or another (these are similar or different strains within one patient but not between one patient and another). The use of a combination of markers is the ideal method for typing the strains; thus making it possible to confirm if two or more isolates from the same patient are similar or not and if they produce infection or are simple contaminants.