PCR FINGERPRINTING FOR EPIDEMIOLOGIC STUDIES OF STAPHYLOCOCCUS-AUREUS

Staphylococcus aureus isolates (n = 126), collected during two differe nt periods from patients hospitalised in pediatric wards, were analyse d using polymerase chain reaction (PCR) mediated genotyping. These iso lates were compared with 29 isolates from individuals attending the ou t-patient clinic of the same hospital and 13 isolates from pediatric h ospital personnel. Within a group of 99 isolates gathered from 48 indi viduals during surveillance period I, 22 distinct genotypes were ident ified by application of two PCR assays. Among the 58 isolates collecte d in surveillance period II from pediatric and out-clinic patients, 25 genotypes were detected by a single PCR assay only. Based on these re sults it was demonstrated that patients can be colonised with multiple strains that may persist in a certain anatomical location for prolong ed periods of time. It is shown that persistence of a S. aureus strain in a pediatric ward can be deduced from the PCR genotyping studies. A s such PCR can be used for longitudinal monitoring of bacterial infect ions in hospital departments, analysis of patient-to-patient and perso nnel-to-patient transmission and for detection of genetic variation in general in S. aureus. Also, isolate-specific DNA probes can be genera ted for S. aureus by PCR genotyping. The probes can be used for the re cognition of re-emerging S. aureus epidemics.