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OBJECTIVE To investigate the prevalence of meticillin-resistant Staphylococcus haemolyticus(MRSH)and resistance in S.haemolyticus isolates. METHODS MRSH was detected by cefoxitin disc test and susceptibilities were tested by agar dilution method. RESULTS There were 86.4% of MRSH isolates.MRSH was highly resistant to penicillin,cefazolin,cefuroxime,ceftriaxone,tetracycline,ciprofloxacin,and clindamycin.The resistance rate to amikacin,rifampicine and chloramphenicol was 16.9%,11.2% and 28.1%,respectively.All isolates were susceptible to vancomycin and teicoplanin.Except for tetracycline,amikacin,rifampicin,and chloramphenicol,the resistant rate to other antimicrobial agents was significantly higher in MRSH than in MSSH. CONCLUSIONS MRSH is mostly occupied in S.haemolyticus isolates and resistant to most of antimicrobial agents.More attention should be paid to survey and detect these strains.
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OBJECTIVE To investigate the prevalence of meticillin-resistant Staphylococcus (MRS) isolates in Staphylococcus auricularis and S. hominis and detect their drug resistance. METHODS MRS isolates were detected by cefoxitin disc test and susceptibilities were tested by agar dilution method. RESULTS 94.7% and 91.7% MRS isolates were in S. auricularis and S. hominis. MRS strains were resistant to most of antimicrobial agents. There were no isolates resistant to vancomycin and teicoplanin. CONCLUSIONS MRS isolates are highly prevalent in S. auricularis and S. hominis with resistance to most of antimicrobial agents.
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Objective To investigate the resistance to fluoroquinolones and amikacin in escherichia coti isolates. Methods ESBLs-producers were detected by CLSI phenotypic confirmatory test and susceptibilities were tested by agar dilution method. Results 33. 8% of 361 isolates were ESBLs-producers. The resistant rate of ciprofloxacin,levofloxacin, amikaxin was 93.4%, 90.9%, 13.1% in ESBLs-produeers, and that was 69.5%,68.6 %, 19.7 % in non-ESBLs-producers, respectively. Conclusion Amikaxin is active against most escherichia coli isolates; those isolates are highly resistant to fluoroquinolones, especially, in ESBLs-producers.
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objective To detect MRSE and resistance in staphylococcus epidermidis isolates. Methods MRSE isolates were detected by cefoxitin disk test and susceptibilities were tested by agar dilution method. Results 79.7% of 128 isolates were MRSE strains with resistance to most antimicrobial agents, but those isolates were still susceptible to vancomycin and teicoplanin. Resistant rate in MRSE was higher than that in MSSE to most antimicrobial agents except penicillins, glycopeptides and macrolides. Conclusion MRSE with multi-resistance ale highly prevalent in staphylococcus epidermidis isolates and no isolate is resistant to glycopeptides.
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OBJECTIVE To investigate the resistance of Pseudomonas aeruginosa strains to 5 ?-lactams.METHODS Susceptibility of 218 P.aeruginosa strains isolated from Anhui Province in 2005 to ceftriaxone,cefotaxime,ceftazidime,aztreonam,and piperacillin were tested by agar dilution method.RESULTS The resistance rate to ceftriaxone,cefotaxime,aztreonam,piperacillin,and ceftazidime were 59.2%,57.3%, 56.0%,51.8%,and 39.0%,respectively.There was statistically significant difference between ceftazidime and other 4 ?-lactams(P0.05).CONCLUSIONS Ceftazidime is the most susceptible antibiotic to P.aeruginosa strains among 5 ?-lactams tested.
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OBJECTIVE To investigate pathogens and their resistance in infective endocarditis patients.METHODS Pathogens and their resistance were detected by MicroScan WalkAway-40 system.RESULTS Most of pathogens were Streptococcus pyogenes and Staphylococcus.The resistant rate of S.pyogenes to tetracycline,erythromycin,ampicillin,penicillin,gentamicin and chloramphenicol was 78.6%,42.9%,14.3%,0,0 and 0,respectively.Four were MRS in 10 Staphylococcus isolates and they were resistant to most antimicrobial agents except vancomycin and higher than MSS.CONCLUSIONS Most of pathogens are S.pyogenes and Staphylococcus in infective endocarditis patients;most S.pyogenes isolates are resistant to tetracycline,erythromycin,but susceptible to penicillins;MRS are resistant to most of antimicrobial agents except vancomycin.
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OBJECTIVE To investigate the prevalence of extended-spectrum ?-lactamases(ESBLs) and the resistance in Escherichia coli isolates from biliary tract and abdominal cavity.METHODS ESBLs-producers were detected by CLSI Phenotypic Confirmatory Test and susceptibilities were tested by agar dilution method.RESULTS 50.1% Of isolates were ESBLs producers in those isolates.ESBLs producers were highly resistant to ampicillin,cefazolin,cefuroxime,fluoroquinolones,and cefotaxime.The resistant rate to ceftazidime,cefepime,cefoperazone-sulbactam,amikacin,and cefmetazole was less than 40%.None was resistant to meropenem in ESBLs producers.In non-ESBLs producers the resistant rate to ampicillin,cefazolin,cefuroxime,fluoroquinolones was more than 40% and most were susceptible to other antimicrobial agents.The resistant rate to ampicillin,cefazolin,cefuroxime,and ciprofloxacin was significantly higher in ESBLs producers than non-ESBLs producers.CONCLUSIONS With resistance to most of antimicrobial agents,ESBLs-producers were highly prevalent in E.coli isolates from biliary tract and abdominal cavity,so more attention should be paid to survey and detect those strains.
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OBJECTIVE To investigate the sensitivity to vancomycin of Enterococcus in clinic and the genotype and homology of glycopeptides-resistant strains.METHODS The sensitivity to vancomycin in 72 enterococci strains was detected with agar dilution;the existence of vanA,vanB,vanC1 and vanC2 in enterococci was detected by PCR and ERIC-PCR.RESULTS More than 50% of enterococci intermediated to vancomycin were resistant to other antimicrobial agents commonly used in clinic,except for teicoplanin and linezolid.Gene of vanC2 was present in two strains,but none with vanA and vanB.The ten strains of enterococci intermediated to vancomycin were divided into eight types,in which type A(3 strains) was isolated from the same hospital.CONCLUSIONS Multidrug resistance is observed in enterococci resistant to vancomycin,which are sensitive to teicoplanin and linezolid.Gene of vanC2 is found in some of them,suggesting clone transmission happen among strains.
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OBJECTIVE To analyze the drug resistance of 141 clinical strains of Acinetobacter baumannii to 15 kinds of antimicrobial agents for the rational application of antimicrobial agents.METHODS All 141 strains of A.baumannii isolates were tested for minimal inhibitory concentration(MIC) to 15 kinds of antimicrobial agents included meropenem,imipenem,piperacillin,and so on using agar dilution method.RESULTS The lowest resistance rate of A.baumannii to the antimicrobial agents was to imipenem(22.7%),then was to meropenem and cefoperazone/sulbactam.The highest resistance rate was tetracycline(81.5%).The resistance rate to other antimicrobial agents was to about or more than 50%.CONCLUSIONS Most of A.baumannii isolates are susceptible to meropenem,imipenem,and cefoperazone/sulbactam and resistant to other antimicrobial agents,therefore,we should enhance to this kind of isolates detection.
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Objective To study the biologic characteristics of the new qnr gene subtype and multi-drug resistant mechanism in a clinical isolate of Klebsiella oxytoca.Methods We cloned and expressed the qnr gene,?-lactamase and integrase genes were detected by PCR.Results Susceptibility of transformant containing qnr gene against common fluoroquinolones was 3~25 times lower than recipient stain,but drug-resistance was 4~256 times lower than the clinical isolate.KLUC-1,TEM-1 and OXA-30 genes were also found in the isolate.Conclusions qnr gene can raise the drug-resistance to fluoroquinolones slightly. There are multiple drug-resistant genes in the strain containing the qnr gene.
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Objective To investigate the ESBL gene in a Klebsiella pneumoniae strain isolated from a patient in Huashan Hospital, Shanghai. Methods ESBL gene in the transconjugant from Klebsiella pneumoniae isolate was amplified by PCR. The PCR products were cloned into pHSG398 vector. The antibiotic susceptiblity and ?-lactamases activity of the clone strain were tested; The PCR product was sequenced and analyzed. Results The ESBL gene was identified as CTX-M-12 gene and CTX-M-12 is much more active against cefotaxime than against ceftazidine.Conclusions A clinical isolate of Klebsiella pneumoniae k99-442 isolated from a patient in Huashan Hospital, Shanghai produced ESBL type CTX-M-12 which caused this isolate resistant to most ?-lactams.
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OBJECTIVE To investigate the genotypes of meticillin-resistant Staphylococcus aureus(MRSA)and its resistance.METHODS A total of 73 MRSA clinical isolates were collected in Anhui Province,MIC of sixteen different antibacterial agents against the isolates were determined by agar dilution method.PCR amplified the mec associated hypervariable region(HVR)of MRSA,and the genotypes were classified based on the fragments of amplified products.The correlation of genotypes and antimicrobial resistance was analyzed.RESULTS Seventy three strains of MRSA from Anhui Province were grouped into A,B and C genotypes based on HVR polymorphism,and respectively 17.8%,23.3%,and 58.8%.All strains were sensitive to vancomycin.CONCLUSIONS MRSA is multi-drug resistant and can be divided into 3 genotypes based on the HVR PCR amplified products.HVR PCR method is a rapid and convenient method for molecular epidemiology study of MRSA infections.
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OBJECTIVE To investigate the prevalence of extended-spectrum ?-lactamases (ESBLs) and antibiotic resistance in Klebsiella pneumoniae isolates.METHODS ESBLs-producers were detected by CLSI phenotypic confirmatory test and susceptibilities were tested by agar dilution method.RESULTS 41.1% Of isolates were ESBLs producers in those isolates. ESBLs producers were highly resistant to piperacillin,cefazolin,cefuroxime,fluoroquinolones,chloramphenicol,SMZ-TMP and amikacin. The resistant rate to piperacillin-tazobactam,and ceftazidime was 26.3% and 34.2%. None was resistant to imipenem and meropenem in ESBLs producers. Except for carbapenems,the resistant rate to other antimicrobial agents was significantly higher in ESBLs producers than non ESBLs producers.CONCLUSIONS With resistance to most of antimicrobial agents,ESBLs-producers are highly prevalent in K. pneumoniae isolates,more attention should be paid to monitor these strains.
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OBJECTIVE To investigate the resistance in clinical isolates of Stenotrophomonas maltophilia to antimicrobial agents. METHODS Susceptibility of 48 S. maltophilia isolates were tested by agar dilution or K-B method. RESULTS The lowest resistance rate of isolates to the antimicrobial agents was to ticarcillin/clavulanic acid (12.5%),then to minocycline (25.0%) and trimethoprim/sulfamethoxazole (31.3%). The resistance rate to ceftazidime,ceftazidime/sulbactam,levofloxacin,and chloramphenicol was 62.5%,52.1%,52.1%,and 50.0%,respectively. CONCLUSIONS Most of S. maltophilia isolates are susceptible to ticarcillin/clavulanic acid,minocycline,trimethoprim/sulfamethoxazole and resistant to other antimicrobial agents. More mornitoring should be enhanced.
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OBJECTIVE To investigate the resistance and molecular epidemiology of Pseudomonas aeruginosa isolated from ICU. METHODS Susceptibility of P. aeruginosa isolates to 14 antimicrobial agents were tested by microScan WalkAway-40 system,and Molecular typing was analyzed by enterobacterial repetitive intergenic consensus(ERIC-PCR). RESULTS The lowest resistance rate of P. aeruginosa to the antimicrobial agents was to ceftazidime (27.3%),then to cefepime (45.5%). The highest resistance rate was to cefotaxime (100.0%) and the resistance rate to other antimicrobial agents was more than 60.0%. Patterns of ERIC-PCR were same in 5 strains of P. aeruginosa. CONCLUSIONS P. aeruginosa isolated from ICU is resistant to most of antimicrobial agents and clone spread is found in them. We should enhance detection and surveying of these isolates.
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OBJECTIVE To investigate the resistance to ?-lactam antibiotics and meropenem of non-ESBLs-producing Escherichia coli isolates.METHODS Non-ESBLs producers of E.coli isolates were detected by CLSI phenotypic confirmatory test,and susceptibility of these isolates to ?-lactam antibiotics and meropenem was tested by agar dilution method.RESULTS The resistance rate of these isolates to ampicillin,cefazolin and cefoxime was more than 60% and that to cefoperazone-sulbactam,cefmetazole and cefepime was 19.2%,23.8% and 31.8%,respectively,but most were susceptible to cefotaxime,ceftazidime,and meropenem.CONCLUSIONS The most isolates of non-ESBLs-producing E.coli are resistant to ampicillin and to the first and second generation cephalosporins,but they are susceptible to meropenem and the third generation cephalosporins.
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Aim To identify the extended-spectrum ?-lactamases(ESBLs) gene in Klebsiellae pneumoniae isolates with qnr gene.Methods Antimicrobial agents susceptibilities were determined with standard agar dilution procedure on Mueller-Hintonagar and 3 isolates with qnr gene were confirmed as ESBLs producing strains by NCCLS Confirmatory Test.The partial blagene of ESBLs producing isolates were detected by PCR using universal primers for TEM,SHV,CTX-M-1group,CTX-M-2 group,CTX-M-13group,OXA-1group,OXA-2 group,OXA-10 group,PER-1 and VEB-1,respectively.At the same time,Class 1 integrase gene was also detected by PCR.The entire blaCTX-M-13group,blaTEM,blaOXA-1group were amplified by PCR using the primers outside the Open Reading Frame(ORF) of these ?-lactamases.The PCR products were also directly sequenced and analyzed;the clinical isolates of ESBLs producers were detected by PFGE. Results 3 Klebsiellae pneumoniae isolates with qnr gene were ESBLs producers and they produced CTX-M-14 ESBLs and TEM-1 ?-lactamases.1 isolate simultaneously produced OXA-1?-lactamases,and 3 isolates carried class 1 integron.Besides quinolones,ESBL producers were also resistant to most ?-lactams,and PFGE patterns of two isolates were same.Conclusion 3 Klebsiellae pneumoniae isolates with qnr gene produced CTX-M-14 ESBLs,which caused their multi-resistance,and clone spread was found in them.More attention should be paid to detect those strains.