OBJECTIVE To investigate the resistance of Acinetobacter baumannii(ABA),and the mechanism of imipenem resistance in A.baumannii.METHODS All specimens were identified by VITEK-60 and the drug resistance was detected by Kirby-Bauer test.Three dimensional test was used to detect ESBLs and AmpC.PCR and DNA sequencing were performed to determine VIM,IMP,OXA-23 and OXA-24 ?-lactamases.Outer membrane protein was analyzed by SDS-PAGE,Reserpine synergistic inhibition test was used to study the active efflux mechanism.RESULTS Totally 120 strains were isolated from sputum(76.9%),and 16 strains from secretion(10.3%).ICU was the main infected department(51 strains,32.7%).The resistance to sulperazone was the lowest(20.5%),and to imipenem accounted for 38.5%,Of the 20 imipenem resistant strains,10 strains were ESBLs positive(50%),and 20 strains were AmpC positive(100%).VIM,IMP and OXA-24 ?-lactamases were not detected out,19 strains(95%) produced OXA-23.Compared to the imipenem-sensitive strains,the resistant strains lacked the outer membrane protein of 22?103,29?103 and 33?103.The MICs of A.baumannii to imipenem were not decreased by reserpine which demonstrated that excretive mechanism was negative.CONCLUSIONS ICU is the main infected department for ABA.The resistance rate is increasing for longer-term usage of carbopenem;OXA-23 production is the important resistance mechanism in ABA,AmpC production and outer membrane protein lacking show close relation to the drug-resistance in A.baumannii.

OBJECTIVE To investigate the distribution and drug resistance of pathogenic bacteria in septicemia in order to provide the reference for clinical antimicrobial agents usage.METHODS The blood samples of inpatients were cultured with blood culture apparatus,VITEK-AMS was used to identify the bacteria and conduct drug resistance test and ESBLs produced by Escherichia coli,and Klebsiella were detected by disc diffusion confirmatory test.RESULTS The 221 strains of pathogens that caused septicemia were mainly distributed in ICU,blood department and infection department.The 61 strains of E.coli were isolated,among which ESBLs were detected and accounted for 39.3%(24),26 strains of Klebsiella were isolated,among which ESBLs were detected and accounted for 26.9%(7),ESBLs strains were more resistant than ESBLs negative strains.Thirty two strains of Staphylococcus were isolated,among which MRS were detected and accounted for 62.5%(20).The pathogens showed highly multiple drug-resistance.Vancomycin and imipenem were the highest susceptible for Gram-positive and Gram-negative bacteria,respectively.CONCLUSIONS The pathogens that caused septicemia are mainly distributed in ICU,blood department and infection department.The situation of antibiotic resistance of pathogens is very serious now.Therefore,it is important to prevent the septicemia and to detect enzyme producing strains regularly for reference of reasonable antibiotic use.

OBJECTIVE To study the change and significance of TNF-? and IL-18 in the Acinetobacter baumannii sepsis. METHODS Sixty male SD rats were divided into 6 groups. The first group was normal control group. The second to sixth groups were sepsis groups which were killed at 4h,16h,24h,48h,72h after injecting A. baumannii through intraperitoneal injection to make sepsis model. The level of TNF-? and IL-18 in the serum of rats was measured by enzyme linked immunosorbent assay (ELISA). RESULTS The level of TNF-? in the serum increased markedly in the sepsis groups (P