Molecular clasification of methicillin resistant Staphylococcus aureus strains isolated fromnose swabs of medical staff in neonatal department and clinic / 国际检验医学杂志

ABSTRACT

Objective To understand the biological characteristicsand drug resistance of methicillin-resistant staphylococcus aureus (MRSA) isolated from neonatal clinic and the nose swabs of medical staff in the neonatal department.Methods Twenty-six strains of MRSA clinically isolated from the neonatal department and the nose swabs of medical staff in this department were collected and performed the multilocus sequence typing (MLST),spa typing, staphylococcus cassette chromosome mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE) typing.The Panton-Valentine leukocidin (PVL) gene was simultaneously detected.The antimicrobial susceptibility test of 14 antibacterial dugs was performed.Results Among 26 strains of MRSA,53.8% was isolated from sputum,2 strains were detected from the nase swab of medical staff.The MLST type had 5 types,ST59 accounted for 76.9%.The spa type had 8 types,t437 acoounted for 65.4%.the SCCmec type had only 2 types,20 strains were SCCmecⅣ(76.9%,20/26) and 4 strains(15.4%) were SCCmecV.In the PLV gene detection,the PVL positive rate was 15.4%.One strain of MRSA from the nose swabs of medical staff in the neonatal department was100% homologous with 1 strain from the patient by PFGE analysis.The drug susceptibility test results showed that all MRSA strains were 100% sensitive to antibacterial drugs of nitrofurantoin,quinupristin/dalfopristin,vancomycin and quinolone,while had higher resistance rates to tetracycline,erythromycin and clindamycin,which were above 50%.Conclusion In MRSA strains isolated from the neonatal department in this study,the most common clones were MRSA-ST59-SCCmecⅣ-t437.Erythromycin and clindamycin should not be preferred in the empiric treatment of newborn MRSA.