Comparison of pulsed-field gel electrophoresis and coagulase gene restriction profile analysis techniques in the molecular typing of Staphylococcus aureus

Abstract

Pulsed-field gel electrophoresis (PFGE) and coagulase gene restriction profile (CRP) analysis techniques were used to analyze 71 Staphylococcus aureus isolates recovered from nine food-borne disease outbreaks. Twenty-two PFGE profiles and 11 CRPs were identified, with discrimination indices of 0.86 and 0.72, respectively. In addition, the variable regions of the coagulase genes of 39 isolates were sequenced and showed extensive identity, indicating that this is not an efficient alternative for the molecular typing of S. aureus.

FIG. 1

PFGE profiles of S. aureus isolates. Chromosomal DNA was digested with SmaI, and the fragments were fractionated on a 0.9% agarose gel. The numbers above the lanes represent the assigned PFGE types and subtypes (1 to 17). Lanes M, bacteriophage lambda molecular weight markers.

FIG. 2

CRPs of S. aureus isolates. PCR amplicons of the 3′ region of the coagulase gene were digested with AluI and were then fractionated on a 2.5% agarose gel. The numbers above the lanes represent different CRPs (1 to 11). Lane M, molecular weight marker.