OBJECTIVE To study the isolation and resistance tendency of Acinetobacter calcoaceticus-baumannii to antimicrobial agents from 1998 to 2004 to provide valuable data for infection prevention and therapy. METHODS We reviewed the isolation rates,distribution in clinical specimens and wards,and the resistance rates of(A.calcoaceticus-baumannii)to 14 kinds of antimicrobial agents from 1998 to 2004. RESULTS There was an increasing tendency of isolation rates of A.calcoaceticus-baumannii every year,which was 0.18% in 1998 but 1.48% in 2004.In the seven years,there was the highest isolation rate of 70.58% in specimens from respiratory tract,the next was from the urine(9.42%),and blood(4.63%).Concerning the wards distribution,ICU had the highest rate of 47.28%.In 1998,A.calcoaceticus-baumannii had resistance rates more than 50% only to one kind of antimicrobial agents(aztreonam),but in 2004,it had increased to thirteen kinds(except cefoperazone/sulbactam).About the fourteen kinds of antimicrobial agents we inspected,that were increased in their resistance rate.The highest increasing of resistance rate was ceftazidime from 11.1% in 1998 to 88.9% in 2004,the imipenem was second for 0.0% to 64.8%,and the third was sulfamethoxazole/trimethoprim form 0.0% to 64.0%,while there still was an increasing resistance tendency to them. CONCLUSIONS The clinical isolation rate of A.calcoaceticus-baumannii is increasing,and it has higher resistance rates to many antimicrobial agents as well as an increasing resistance tendency to relatively susceptive antimicrobial agents every year.So physicians should prescribe on the basis of antimicrobial agents susceptibility tests in vitro.

0.05) and the two methods had good correlation(r=0.822).CONCLUSIONS The method of FCST established by as in this study is simple,repeatable,with high accuracy and easy to determine MIC and has good application prospects in clinical antifungal susceptibility testing.

Objective To investigate the resistant mechanism of quinolones on multi-drug resistant Klebsiella caused pneumonia(MDR-KPN).Methods From August 2008 to May 2010,47 strains of MDR-KPN were collected from 6 hospitals in Hangzhou and Huzhou in Zhejiang province in China.Drug target genes to quinolones (gyrA,parC) and quinolone-resistance genes mediated by mobile genetic elements [qnrA,qnrB,qnrS,aac (6')-Ⅰ b-cr,qepA] were analyzed by PCR and verified by DNA sequencing.Results Positive results were found in 47 strains of MDR-KPN,43 strains (91.5％) of gyrA mutation,40 strains(85.1％) ofparC mutation,3 strains (6.4％) of qnrB2,1 strain (2.1％) ofqnrB 4,8 strains (17.0％) ofqnrS 1,5 strains (10.6％) of qnrS 4,2 strains (4.3％)of aac (6')-Ⅰ b-cr respectively.Moreover,5 novel variants of gyrA (GenBank accession number:JN811952,JN811953,JN811954,JN811955,JN811956),5 novel variants of parC (GenBank accession number:JN817432,JN817433,JN817434,JN817435,JN817436)were also identified.In addition,qnrS4 (GenBank accession number:JN836269) appeared to be the novel variants of qnrS.Conclusion Quinolone-resistance-determining region played a key role on the resistance to quinolones in this group of MDR-KPN,and quinolone-resistance genes mediated by mobile genetic elements [qnrB2,qnrB4,qnrS1,qnrS4,aac (6')-Ⅰ b-cr] showed positive in some parts of the strains.This was the first report on emergence of qnrS4 in the world.

Objective To investigate the source of the first human case of avian influenza A (H5N1) infection in Beijing. Methods Interviewing the relatives of the case and other key persons, collecting and detecting samples of related biological, epidemiological and environmental data of the case were conducted. Later, the infection source was thoroughly investigated. Results The case ever contacted a slaughtered duck 5 days prior to the onset of illness, and the duck was bought from a stall of a wet market in Yanjiao area of Hebei province. Ten environmental samples were collected in this stall and the neighboring stall of the market. Another 6 samples were tested positive for H5N1 virus by PCR method, with 5 virus strains isolated. The whole-genome sequencing indicated that the amino acid homology between the H5N1 virus strains from the environment and the virus isolated from the case reached 99.8%-100%. Conclusion From both epidemiological and virological evidence, it was proved that the first human case of avian influenza A (H5N1) infection in Beijing was infected by a duck that carrying H5N1 virus the case contacted 5 days proceeding the onset of illness.