SESSION TYPE: Pneumonia Treatment and Antibiotic Resistance
PRESENTED ON: Monday, October 22, 2012 at 04:00 PM - 05:30 PM
PURPOSE: To investigate antibiotic resistance and molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) from lower respiratory tracts.
METHODS: 107 strains of MRSA were isolated from lower respiratory tracts from 9 wards in Shanghai Pulmonary Hospital. Antibiotic-resistance was tested via Kirby-Bauer paper dispersion method. Panton-Valentine Leukocidin (PVL) gene and staphyloccoccal cassette chromosome mec (SCCmec) type was tested via PCR. Homology Analysis of 32 strains was performed using Pulsed field gel electrophoresis (PFEG).
RESULTS: All strains were susceptible to vancomycin, teicoplanin and linezolid but highly resistant or completely resistant to tetracycline, gentamicin, clindamycin, levofloxacin, azithromycin, erythromycin, trimethoprim/sulphamethoxazole and ciprofloxacin. Results of PVL genotype showed that 107 strains were negative. Results of SCCmec genotype showed that most of them (81.3%) were SCCmecIII type, SCCmecII type (15.9%) and SCCmecIV type (2.8%) were less, but no SCCmec I type or SCCmec V type was detected. PFGE results showed that 32 strains of MRSA could be divided into 4 groups: type A (25 strains), type B (5 strains), type C (1 strain) and type D (1 strain). Type A included 3 subtypes of A1 (17 strains), A2 (1 strain) and A3 (7 strains). Moreover, most of the strains were isolated from the some wards or units, e.g. intensive care unit (ICU) and tubercular ward, in a short time that showed outbreak states.
CONCLUSIONS: MRSA from low respiratory tracts were multiple-resistances. SCCmec III was the main SCCmec genotype. It could burst and prevalence in ICU ward or tuberculosis uint.
CLINICAL IMPLICATIONS: It will be helpful for the clinicians to choose a proper antibiotics in the clinical practice.
DISCLOSURE: The following authors have nothing to disclose: Haiqing Chu, Lan Zhao, Zhenming Zhang, Tao Gui, Lizhong Han, Yuxing Ni
No Product/Research Disclosure InformationShanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China