Molecular epidemiological characteristics of Staphylococcus aureus isolated in intensive care units

Abstract:

ObjectiveTo investigate the molecular epidemiological characteristics and homology of Staphylococcus aureus (S. aureus) isolated from patients in intensive care units (ICUs) of a hospital,  so as to provide laboratory basis for the effective control of healthcareassociated infection(HAI). Methods62 S. aureus strains isolated from various specimens from ICU patients with infection in MarchAugust 2013 were collected, 7 housekeeping genes were amplified with polymerase chain reaction (PCR), the amplified products were sequenced, ST typing of strains was performed by multilocus sequence typing (MLST)， phylogenetic analysis of ST typing was conducted. Results62 S. aureus strains were amplified specific product of 7 housekeeping genes; there were 10 ST genotypes, in which 2 ST genotypes（STn1and STn2） were first discovered，1 ST genotype（ST675） was first discovered domestically. ST239 was the main ST type of S. aureus from ICU patients in this hospital, accounting for 74.20%，which distributed in 6 ICUs， ST5 distributed in 3 ICUs. 62 strains formed 7 main branches in the phylogenetic tree, 55 (88.71%) MRSA strains were detected. ConclusionS. aureus isolated from hospital ICUs has some homology, and the small number of types showed the trend of concentrated distribution.