Analysis On The Vancomycin Susceptibility And The Molecular Epidemiological Characteristics Of Staphylococcus Aureus

Objective:1.To study the prevalence of the infection of Staphylococcus aureus isolates and investigate the resistance of Staphylococcus aureus to commonly used antimicrobial agents, So as to guide the rational antimicrobial application in clinic.2. Isolated in our hospital Staphylococcus aureus to vancomycin minimal inhibitory concentration testing(MIC) and The genotypes of MRSA strains were characterized by using pulsed field gelelect rophoresis(PFGE).Methods:From 2008to 2010 we have collected 341 strains of Staphylococcus aureus isolates in our hospital. All datas were analyzed by WHONET 5.5 software. Summarized the distribution of the different samples,separation rate from different sections and the resistance situation. From January 2005 to August 2010 we randomly selected 189 strains of Staphylococcus aureus. Agar dilution method was used to determine the minimal inhibitory concentrations (MIC) of vancomycin, which method recommended by Clinical and Laboratory Standards Institute(CLSI) 2010.The genotypes of MRSA strains were characterized by using pulsed field gel electrophores (PFGE).Electrophoresis and PFGE patterns obtained were compared.Result:1,The distribution in the different samples and different sectionsFrom Jaunary,2008 to December,2010 , we have collected 341 strains of Staphylococcus aureus isolates in our hospital.The isolates was mostly from the sputum,accounted for55.1%.And the isolation rate of neurosurgery in which was the highest, accounting for 41%.followed by department of orthopaedics, accounting for 24.3%.2,antibiotic resistanceFrom Jaunary,2008 to December,2010 , we have collected 341 strains of Staphylococcus aureus isolates in our hospital,which MRSA 248, accounting for72.7%. Ministry of national resistance than the data network.MRSA and MSSA (methicillin-sensitive Staphylococcus aureus) was significantly different drug resistance. MRSA in addition to vancomycin, teicoplanin, but resistance to other antibiotics are more than 90%. MSSA was resistance to penicillin 100%. Resistant to erythromycin is 60% or more and Resistance to other antibiotics in 50%.3,the minimal inhibitory concentrations (MIC) of vancomycinBy Staphylococcus aureus to vancomycin minimal inhibitory concentration detected that MIC90 was 1ug/ml in 2004 and 2005, MIC501ug/ml and MIC90 was 2ug/ml from 2006 to August,2010.4,pulsed field gel electrophores(PFGE)PFGE analysis of the 25MRSA isolates revealed that the MRSA in our hospital there are four types A, B, C, D. A type of which there are three subtypes A1, A2, A3. A Type was mainly in the hospital.Results:Staphylococcus aureus is one of the most important opportunistic Pathogen in hospital. The isolates was mostly from the sputum And the isolation rate of neurosurgery in which was the highest. Staphylococcus aureus flow between patients and patients, patients and medical personnel by air. Nowadays,MRSA prevalence in hospitals rise and The incidence of MRSA was higher than the domestic average. The man who was ill at hospital for a long time ,have smoked for years , with a poor basic situation , use the antimicrobial in large doses for a long time, use immunosuppressive agents, and the use of a variety of implantable devices are susceptible.MRSA is a multidrug resistant and resistant to almost all antibiotics. The current treatment of MRSA infections to vancomycin has become the best choice. Foreign countries have reported vancomycin-resistant Staphylococcus aureus (VRSA). As can be seen from the MIC,Although vancomycin-sensitive Staphylococcus aureus is still 100%, but sensitivity decreased. There were A types MRSA clones in our hospital, and clone covered Between different departments in our hospital.Complexity of the mechanism of resistance to MRSA, transmission and strong, harmful strong, so we should pay attention to infection control, to take effective measures to prevent pathogenic bacteria spread between the various departments.