Staphylococcal chromosome mec genotyping and molecular epidemiology of hospi-tal-acquired methicillin-resistant Staphylococcus aureus / 中国感染与化疗杂志

ABSTRACT

Objective To investigate the staphylococcal chromosomal cassette mec (SCCmec)genotypes and molecular epidemi-ology of hospital-acquired MRSA.Methods A total of 26 non-duplicate MRSA isolates with the same resistant pattern were studied.SCCmec genotyping was analyzed by multiplex PCR.Repetitive element polymerase chain reaction (Rep-PCR)tech-nique was used to analyze the homology between these strains based on the DiversiLab system.Results The most common geno-type of these MRSA strains was SCCmec-III (84.6%).Two strains belonged to SCCmec-II and 1 SCCmec-IV.SCCmec-I strain was not identified.Based on the results of DiversiLab analysis,these MRSA strains were classified into 10 groups.The genetic similarity ranged from 40% to 100% among these SCCmec types.The two strains of SCCmec-II belonged to the same subtype.The similarity coefficient was higher than 90% for one strain of SCCmec-III subtype 1.The 4 strains of SCCmec-III subtype 3 were grouped into the same set with a similarity coefficient of > 95%.The MRSA strains of SCCmec-III subtype 2 was divided into 5 groups (similarity co-efficient > 90%).Conclusions SCCmec-III is the major genotype of MRSA isolates in our hospital.MRSA strains may spread in some wards.Clinicians and infection control department should pay close attention to this issue.