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Objective To investigate the drug resistance,source and molecular epidemiology of methicillin-resistant Staphyloccus aureus(MRSA)causing nosocomial infection. Methods Fifty-seven pathogenic MRSA strains were isolated from Beijing Tongren Hospital during 2007 and 2008.K-B method,MIC assay,multiple PCR,automatic repetitive element sequence-based PCR(REP-PCR)typing platform and DL MRSA Library were used to identify the resistant phenotypes,Panton-Valentine leukocidin gene (pvl)and REP-PCR types of the MRSA.Results All strains were classified as 6 antibiotic resistant phenotypes(a-f)based on the resistance to rifampin,clindamycin,levofloxacin and cotrimoxazole.The MRSAs with Staphylococcal cassette chromosome mec(SCCmec)Ⅲ and SCCmec Ⅱ accounted for 91.23% (52/57)and 5.26%(3/57)of all strains,respectively.Only one strain was pvl positive.All strains were typed as REP-A-F(6 types)and three single clones by automatic REP-PCR typing platform,in which REP-C was predominant(30/57,52.63%).Three out of 6 REP-D strains were from laryngology wards.The REP-C-SCCmec Ⅲ were genetically most close to the Brazilian clone-SCCmec Ⅲ in DL MRSA Library.Conclusion s REP-C-SCCmec Ⅲ-a type are the major epidemic hospital-associated MRSA and the REP-D-SCCmec Ⅲ-d is usually isolated from patients received laryngeal surgery. Automatic REP-PCR typingplatform combined with DL MRSA Library database is an effective approach to study the nosocomial infection.
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Objective To study the genotypic and biological characteristics of catheter-related MRSE isolates and to further provide information for the diagnosis and prevention of catheter-related bloodstream infection. Methods Thirty strains of catheter-related MRSE isolates were collected from venosus blood and whole blood of 30 inpatients including 20 males and 10 females from Beijing Tongren Hospital, Capital Medical University from January 2006 to December 2009. The genetic features of these strains were determined by MLST. PCR was used to detect the icoA gene (encoding the polysaccharide intercellular adhesion associated with pathogenicity), and the antimicrobial susceptibility test was detected by disc diffusion test. Results A total of 15 STs were obtained from 30 strains ST259, ST20, ST2 and ST235 were common clones obtained from 17 strains. Four novel STs were found and uploaded to the MLST database (http://www. mlst. net), including ST259 (6 strains), ST260 (1 strain), ST261 (1 strain) and ST262 (1 strain). The ST259 was the dominant clone of catheter-related MRSE isolates in this hospital, and 3 strains carrying icaA gene were detected in this study. Conclusion Some ST259 isolates express high pathogenesis among the four novel STs, which may make them as the pandemic strains in nosocomial infection, and this would increase the difficulty of the prevention and control of nosocomial infection.
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OBJECTIVE To approach to the point of clinical diagnosis and treatment in patients with Chryseobacterium meningosepticum(CM) infection,and test the high sensitivey antibiotic in order to provide evidence for clinical rational drug utilization.METHODS We had retrospectively analyzed the 36 clinical infections with CM during 2003.A microdilution broth method was used to detect the C.meningosepticum MIC and metallo-?-(lactamases-)production.RESULTS C.meningosepticum infections related to the critical underlying diseases,old age,stay in hospital,nosocomial infections and broad spectrum antibiotics use.Metallo-?-lactamases-producing accounted for 100% in all CM isolates.CM were susceptible or partly susceptible to VAN,CTX/CA,PIP/SU,CFP/SU,PIP,CIA,PIP which were 100%,100%,91.7%,88.9%,86.1%,72.2%,and 44.4%,respectively.The(susceptibility) to other 21 kinds of antimicrobials were in 8.3%.CONCLUSIONS CM is multi-drug resistant.The main risk factors of CM infection are old age,long-term in hospital,critical underlying disease,and decreased immunological function.VAN,CTX/CA,PIP/SU, CFP/SU,PIP,CIA,and PIP are the effective antibiotics(against) CM.