Genotyping of Staphylococcus aureus strains isolated from Beijing.

Objective To analyze the genotype of Staphylococcus aureus strains isolated from the Beijing population during the years from 2000 to 2005 and to obtain a primary knowledge of the use of different genotyping methods. Methods Forty-eight methicillin-resistant S.aureus(MRSA) strains and three methicillin-sensitive S.aureus(MSSA) strains were analyzed on the basis of spa polymorphisms and by pulsed field gel electrophoresis(PFGE),and they were compared with the results of multi locus sequence typing(MLST).Results t030 and t037 were the most prevalent strain types,accounting for 47.92%(23/48) and 37.50%(18/48) of all MRSA strains,respectively,while t002 was only isolated 2005 and accounted for 14.58%(7/48).t377 and t304 were the spa types of the three MSSA strains.The PFGE patterns of the 51 strains belonged to five groups and eleven types.Conclusion t030 and t037 are the most prevalent spa types among clinical MRSA strains and are different types from those of MSSA strains.Group A and D are the most prevalent PFGE types.Rational combination of spa typing,MLST and PFGE will be of great significance in MRSA control and prevention.