| Objective:1. To study the prevalence of the infection of Acinetobacter baumannii strains and analyze the tendency and reduce the drug resistance.2. To study the main genotype of carbapenemases in Acinetobacter baum- annii isolated in our hospital. In combination with other drug resistance mechanisms gor the development of new antimicrobial agents and its application to provide some help.Methods:From 2008 to 2009, we have collected 203 strains of Acinetobacter baumannii by Siemens walkaway96 in our hospital. All datas were analyzed by WHONET 5.3 software. Summarized the distribution of the different samples,separation rate from different sections and the resistance situation. Collected the strains of IPM resistance by other ways of K-B. The antibiotic susceptibility tests were performed by Disk diffusion method recommended by Clinical and Laboratory Standards Institute(CLSI) 2009. Detected the strains with carbapenemase by Hodge Test; The Metallo-beta-lacamase-Producing Isolates were detected by Double-Disk Synergy Test; PCR was performed to detect the strains with OXA-23.And then, sequenced and analyzed the PCR products by forward ways. Remove the first and last bases then make the sequence alignments and analyses with the BLAST program online .Result:1.The distribution in the different samples and different sections .From 2008 to 2009 , we have collected 203 strains of Acinetobacter baumannii in our hospital . The isolates was mostly from the sputum ,accounted for 72.9%. And the isolation rate of Neurosurgery in which the highest (96/203),accounting for 47.3%,followed by Respiratory (59/203), accounting for 29%.2. The Susceptibility of antimicrobial agents of Acinetobacter baumanniiIn our daily antimicrobial, the most sensitive is IPM ,followed is cefoperazone/sulbactam. But the resistance rate is 32% and 41.9% respec- tively ,which is far higher than 4.7% and 10.8% in 2003-2004. The resistance rate of ampicillin/sulbactam,cefepime,amikacin,ciprofloxacin and other daily drugs were all higher than 60%.3. Detected the carbapenemase from IPM-resistant acinetobacter baumanniiDetected the carbapenemase from IPM-resistant acinetobacter baumannii by Hodge Test ,the results were positive for all .4. The detection of Metallo-β-lactamaseDetected the Metallo-β-lactamase by Double-Disk Synergy Test , 26 strains of IPM-resistant acinetobacter baumannii were negative for all .5. Detect the strains with OXA-23 by PCRThere are 26 strains of IPM-resistant acinetobacter baumannii.Primer was designed according to OXA-23(ari-1) , PCR in specific conditions, 24/26 was positive , accounting for 92.3% .6. sequenced and analyzed the PCR productsThe detection of PCR was just OXA-23.Results:Acinetobacter baumannii is one of the most important opportunistic Pathogen in hospital , The man who have smoked for years , with a poor basic situation , be ill at hospital for a long time , use the antimicrobial in large doses for a long time , use immunosuppressive agents , and the use of a variety of implantable devices are susceptible. The resistance showed a rising trend . IPM is the most effective drug for severe infection of Acinetobacter baumannii . Carbapenemase-resistant acinetobacter baumannii have a variety of resistance mechanisms , the most important is Carbapenemase.And the OXA-23 is the most important Carbapenemase. It is plasmid-mediated and easily spreading in different isolates.So, we must do something to improve the current situation.For example :strengthen the protection , reduce the use of implantable devices , do the routine cleaning and disinfection work , doctors and nuraes should wash their hands frequently ,and be carefully use this kind of antibiotic to decrease the development of resistance.IPM-resistant acinetobacter baumannii is mostly produce class D Carbapenemase , especially , OXA-23. It can be seen that as soon as possible to find out an effective screening method of OXA , to cut off the dissemination, to invent the effective inhibitor of OXA,it is the currant focus . |
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