OBJECTIVE To investigate nosocomial infection and antibiotic resistance of Pseudomonas aeruginosa among geriatrics patients and to instruct clinical monitoring and control infection.METHODS P.aeruginosa isolates from geriatrics patients were identified and the resistance to antibiotics was determined by K-B method.RESULTS The risk factors of nosocomial infection were underlying diseases,low immunological function,long time hospitalization,invasive treatment,and prolonged antibiotic therapy.The resistant rates to trimethoprim/sulfamethoxazole and cefotaxime in PA were 74.8% and 60.2%,respectively.The resistance rate to imipenem was 3.9%.CONCLUSIONS It is suggested to carry out proper measurement to control the spread of multiresistant strains in order to improve the treatment of PAE infection in geriatrics patients.

OBJECTIVE To investigate the drug-resistance of AmpC enzyme derepressing Enterobacter cloacae isolated from patients of respiratory department.METHODS Totally 364 strains of E.cloacae(162 strains from respiration department) collected from Jan 2001 to Dec 2006 were investigated to know their ward distribution,infection site and susceptibility test results.Three-dimensional tests were adopted to test AmpC lactamase.RESULTS Among the total 162 strains from respiration department,AmpC producers were 76 strains,accounting for 46.91%. Among the 202 strains from the other departments,however,AmpC producers were 36 strains,accounting for 17.82%.And drug-resistance of E.cloacae from respiration department was distinctly higher than that from the other departments.CONCLUSIONS E.cloacae from respiratory department has the higher isolating rate and drug-resistance rate.We should take effective measurement to contain nosocomial infections with E.cloacae.

OBJECTIVE To investigate the resistance phenotype and clinical feature of super extended spectrum ?-lactamases(SSBLs) producing Escherichia coli in order to provide reference for the clinical application of drugs.METHODS Totally 945 strains of ESBLs producing E.coli collected from Jan 2003 to Jun 2007 were identified by API microbiological assay system.Susceptbility tests were performed by K-B methods.Improved three-dimensional tests were adopted to test ESBLs and AmpC lactamase.Test data were analyzed statistically by WHONET 5.3 software.RESULTS From them eighteren strains of SSBLs producers were detected.Between the positive for ESBLs strains and the negative strains,there were some significant differences in the antimicrobial resistance(P