Rep-PCR-based typing as a tool for tracking of MRSA infection origin

Abstract

A performance of rep-PCR fingerprinting method with the (GTG)5 primer was explored in order to evaluate its practical application for confirmation the source of human staphylococci infection. A laboratory worker daily working with the MRSA and Staphylococcus aureus strains has been tested positively for MRSA nosocomial infection. The collection of nine MRSA strains held in the laboratory has been typed with the rep-PCR method. Analysis of the fingerprints with the unweighted pair-group method using arithmetic averages (UPGMA) clustering method revealed presence of six strain clusters with similarity lower than 85%. The fingerprint of MRSA strain infecting the human differed significantly from remaining fingerprints. This provided clear evidence that MRSA strain infecting the personal did not come from the laboratory strains collection. Our experimental results showed rep-PCR with the (GTG)5 primer as an effective tool applicable for differentiation of individual S. aureus strains. However, the reproducibility and discrimination power of the method depended on strict observance of the optimal PCR time and temperature profile and PCR composition as well.