OBJECTIVE With surveillance of the distribution and antibiotic resistance of Escherichia coli during the last six years in our hospital,the basis for the reasonable clinical use of antibiotic is provided to doctor.METHODS A total of 1 907 strains of E.coli isolated during the last six years were analyzed by Kirby-Bauer disk or VITEK-2 system.RESULTS Among 1 907 strains of E.coli,1 114 strains were isolated from urine,accounted for 58.4%;215 from pus or secret,accounted for 11.3%;165 from sputum,accounted for 8.7%;and 159 from blood,accounted for 8.3%.ESBLs production rate of E.coli increased steadily from 5.11%,10.34%,14.56%,15.14%,33.79% to 29.96%,separately during the six years.The resistance of E.coli with ESBLs to most antibiotics was much higher than those without ESBLs.And E.coli demonstrated much higher resistant rate to ciprofloxacin,penicillins,and first or second generation cephalosporins,and much lower to amikacin and cefoperazone/sulbactam.No strains were found to be resistant to imipenem.CONCLUSIONS E.coli is the major pathogen,causing nosocomial infection with multi-resistant mechanism, since ESBLs-producing strain is increasing as years gone,reasonable choice of antibiotic should be in term of result of antibiotic resistant test and patient symptom to cure the E.coli infection induced.

OBJECTIVE To compare the changing trends of antibiograms of Salmonella typhi and S.paratyphi A isolates.METHODS A total of 42 isolates of Salmonella obtained from blood cultures patients in the First Affiliated Hospital of Chinese Medical University between 2001-2004 were included in the study.K-B test was used for the antimicrobial susceptivity test and the results were read based on National Committee for Clinical Laboratory Standards(NCCLS) of USA.RESULTS Twenty two isolates were identified as S.typhi and 20 were identified as S.paratyphi A.Sensitivity of S.typhi isolates to cephalosporins and chloramphenicol was found to have increased from 2001 to 2004 while that of S.paratyphi A showed a decline,meanwhile there was obviously increasing in resistance to ciprofloxacin.CONCLUSIONS Perhaps the schedule of empirical treatment of typhoid fever needs to be adjusted.

OBJECTIVE To study clinical distribution of Serratia and learn the antimicrobial susceptibility to S.marcescens in vitro in order to offer the reference to optimally selecting antibiotic.METHODS It was analyzed that the 222 Serratia strains were distributed in and the was deteted 164 S.marcescens strains were isolated from our hospital from 2001 to 2006.Their VITEK-2 of French Bio-M?rieux Company was adopted to proceed the identification of bacteria and antimicrobial susceptibility test.Data were analyzed by WHONET 5.4.RESULTS Serratia were mainly isolated from sputum,urine,blood,secretion,bile,cerebrospinal fluid,abdominal fluid,et al.Infection of both in-and out-patients could be caused by Serratia and most were in surgery ward.S.marcescens had higher drug resistance rates to piperacillin,cefazolin,cefuroxime,gentamicin and tobramycin which were all above 60%.They were all susceptible to imipenem(minimum inhibitory concentration only 1 ?g/ml) and their susceptible rates to piperacillin/tazobactam,ceftazidime,cefepime,and levofloxacin were all higher than 80%.CONCLUSIONS Serratia are less isolated from clinics,but have much higher antimicrobial resistance to the 1st and 2nd generation cephalosporin and show diversely drug resistance to 3rd cephalosporin,so physicians should pay attention to the infection caused by them.

Objective To investigate the alternations in gene/amino acid sequence of penicillin-binding protein (PBP)2x from clinical isolates of Streptococcus pneumoniae, and to find the reasons for the rapid surge of penicillin and cefotaxime nonsusceptibility among pneumococcal isolates from Shenyang. Methods Thirty-four strains of Streptococcus pneumoniae were collected from January 2006 to February 2007. The antibiotics susceptibility of these strains was detected. PCR amplification and direct sequencing of pbp2x genes were performed. The sequence variations of PBP genes of the penicillin nonsusceptible Streptococcus pneumoniae(PNSP) in this region were studied by BLAST analysis. Results Two prominent substitutions were common to 12 PNSP isolates for which the MIC of penicillin resistance and cefotaxime were at least 0.5 mg/L, which included the replacement of Thr338→Ala in the first conservative motif STMK and Leu546→Val adjacent to third conservative motif KSG. The importance of the exchange of His394→Leu was identified in one PNSP isolate 15. The remarkable finding in this study was Met342→Ile following the first conservative motif STMK. pbp2x sequences of eight PRSP isolates shared Lys501-Glu505-Thr507 substitutions which might be served as a unique marker for PRSP in this region. Novel gene and amino acid sequence variants in 17 isolate were identified in this study, and these sequences have been deposited in the GenBank database and assigned accession No. EU044831, EU089706-EU089709, EU106881-EU106884 and EU124672. Conclusion It is likely that the emergence of penicillin and cefotaxime nonsusceptible Streptococcus pneumoniae in Shenyang might be associated with novel gene sequence variants.

OBJECTIVE To study the changing trends of drug-resistance of Acinetobacter baumannii isolates.METHODS All 668 isolates of A.baumannii were obtained from clinical patients in the First Affiliated Hospital of China University of Sciences Medical between 2001-2006.K-B test was used to determine the susceptibility and the results were read based on National Committee for Clinical Laboratory Standards(NCCLS)of the USA.RESULTS The number of A.baumannii isolates was increasing from 61 in the year of 2001 to 247 in the year of 2006.And during the six years,the resistant rate to ciprofloxacin,gentamicin and imipenem was increasing from 28.8%,25.4%,5.4% to 64.9%,72.7% and 48.5%,respectively.The resistant rate of the 50 multidrug-resistant A.baumannii isolates to polymyxin B was 18.6%.CONCLUSIONS During the six years,the isolating rate is increasing,the result showed that there is not a large scale outbreak.The resistant rate is so high that we must strengthen the monitoring and indentify the drug-resistance mechanisms.

OBJECTIVE To study the information of drug resistance of 1292 coagulase-negative staphylococci(CNS) isolates. METHODS There were 1292 isolates of CNS obtained from clinical patients in between 2001-2006.K-B test was used to determine the susceptibility and the results were read based on Clinical and Laboratory Standards Institute(CLSI) of the USA. RESULTS The isolating rate of CNS isolates was decreasing from 11.0% in the year of 2001 to 6.4% in the year of 2006.During the six years,the resistant rate to erythromycin,oxacillin and benzylpenicillin was high(90.0%,78.9% and 95.0%,respectively) and the resistant rate to cefepime,ciprofloxacin and levofloxacin increased from 17.3%,42.4%,and 28.7% in the year of 2001 to 39.1%,56.0% and 42.6% in the year of 2006.But the resistant rate to tetracycline,trimethoprim/sulfamethoxazole decreased from 71.2% and 72.0% in the year of 2001 to 52.7% and 33.3% in the year of 2006.The resistant rate to quinupristin /dalfopristin was 5.6%. CONCLUSIONS The steady resiatence rate of CNS over the past six years provides powerful evidence for the choice of clinical medication and practice of infection control.

OBJECTIVE To offer the clinical physician the basis of optimal application of antibiotic,we have investigated the variation of antibiotic resistance and the bacterial spectra in the blood culture.METHODS Blood was cultured in BACTEC9120 of BD.The clinical isolates were identified by API and VITEK-2 of Bio-Merieux of France.Antibiotic susceptive test was done by Kirby-Bauer method and the result which was analyzed by WHONET5.3 and SPSS11.5 software was determined by the NCCLS standard of 2005′s edition.RESULTS Organisms were isolated from the blood specimen of 1468 patients,and there were 743 strains of Gram-positive cocci accounted for 50.7%,565 strains of Gram-negative bacilli accounted for 38.5%.Ninety three strains of fungi accounted for 6.3%.We analyzed the drug-susceptive result of Staphylococcus,Escherichia coli,and Klebsiella pneumoniae during five years,and found that all the antibacterial drug lost efficacy in some degree,except that the sensitivity of the staphylococci to vancomycin was 100%.CONCLUSIONS Gram-positive cocci are the main bacteria in blood culture,the species from which are diversified,and the rate of the drug resistance of some bacteria is high.It indicated that doctors should take more blood culture and monitor the bacteria drug resistant for the data of etiology,so that they can utilize antibiotic more reasonably.

OBJECTIVE To learn the profile of Gram-negative bacilli in ICU ward during the eight years and analyze the drug resistant rates in order to provide the basis for empirical treatment of infection.METHODS The bacteria were identified by VITEK-2 and API system.Antibiotic sensitivity test adopted Kirby-Bauer method.Data were analyzed by WHONET5.4 software.RESULTS Totally 1492 strains of Gram-negative bacilli were isolated from ICU ward,which included 1146 strains of non-fermentaters,accounted for 76.8% and 346 strains of Enterobacteriaceae,accounted for 23.2%.The first five bacteria were Pseudomonas aeruginosa,Burkholderia cepacia,Acinetobacter baumannii,Stenotrophomonas maltophilia,and Escherichia coli by turns.The drug resistant rates were higher and had the tendency of increase by years.CONCLUSIONS Non-fermentaters are the main organisms in ICU ward.The species of bacteria are diversified and the drug resistant rates of them are serious,which should be monitored not only because helping clinical therapy but also discovering the prevalence of drug resistant strains.

OBJECTIVE To learn the epidemiology of respiratory infection in ICU and non-ICU wards,and analyze the difference of drug resistance of Gram-negative bacilli between those two wards in order to provide the basis of empirical therapy for the respiratory infection from the different wards.METHODS The bacteria were identified by VITEK-2 and API system.Antibiotic sensitivity test adopted by K-B method.Data were analyzed by WHONET 5.3 software.RESULTS Totally 2184 strains of Gram-negative bacilli were isolated all from the respiratory tract,among which 655 strains were isolated from ICU ward and 1529 strains were from non-ICU ward.In ICU ward,the first five bacteria were Pseudomonas aeruginosa,Burkholderia cepacia,Acinetobacter baumannii,Chryseobacterium meningosepticum,and Stenotrophomonas maltophilia.It showed that non-fermentatives were the main pathogenic bacteria in ICU.In non-ICU ward,the first five bacteria were P.aeruginosa,Klebsiella pneumoniae,A.baumannii,B.cepacia,and S.maltophilia.Drug resistant rate of strain from ICU ward was generally higher than that from non-ICU ward,while levofloxacin in ICU ward showed the better activity than in non-ICU ward.CONCLUSIONS The respiratory infection is one of the hazards in nosocomial infection,drug resistant rate of Gram-negative bacilli from respiratory specimen in ICU is generally higher than that in non-ICU,and the main strains are the mlti-resistant non-fermentatives,which should attract the clinician′s more attention.