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Objective To compare the sensitivity of four kinds of drug susceptibility test method in detecting sensitivity of tigecycline against Acinetobacter baumannii.Methods The susceptibility of 72 clinically isolated strains of carbapenemase-resistant Acinetobacter baumannii(CRAB) to tigecycline in vitro was detected with disk diffusion method,VITEK 2 Compact system,E-test and MIC test strip(MTS) test strip respectively,according to FDA standards,and the differences of four kinds of drug susceptibility test methods were compared.Results The susceptibility rates of 72 strains of CRAB to tigecycline by disk diffusion method,VITEK 2 Compact system,E-test and MIC test strip were 50.00%,69.44%,36.11% and 98.61% respectively,the intermediate rates were 48.61%,29.17%,26.39% and 1.39% respectively,the resistant rates were 1.39%,1.39%,37.50% and 0.00% respectively.Compared with MTS,the classification consistency rates of E-test,disk diffusion method and VITEK 2 Compact system were 36.11%,51.39% and 70.83% respectively.Conclusion There is difference among four kinds of method for conducting the drug susceptibility testing of tigecycline against CRAB,the consistency of disk diffusion method,VITEK 2 Compact system and E-test is lower.Detecting mediation or drug resistant strains of CRAB by disk diffusion method,VITEK 2 Compact system and E-test needs to be verified by MTS or Broth dilution method.
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Objective To investigate antimicrobial resistance and pathogen in hebei antibacterial resistance investigation net in 2012.Methods Antimicrobial susceptibility test was detected by Kirby-Bauer method or broth dilution test.Results were analyzed according to CLSI 2010 breakpoints.WHONET 5.5 software was used to analyze the data.Results A total of 10 504 clinical isolates were collected in 2012,of which gram negative bacilli and gram positive cocci accounted for 76.2%, 23.8%,respectively.The most common pathogen in gram-negative rod was E.coli,K.pneumoniae,P.aeruginosa, A.baumanii and E.cloacae respectively.The most common pathogen in gram-positive cocci was S.aureus,E.facium,E-.faecalis,S.pneumoniae and S.epidermidis.ESBL rate of E.coli and K.pneumoniae was 66.5 and 46.7%.The resistant rate of E.coli,K.pneumoniae,E.cloacae to imipenem was 0.1%,0.5%,8.9% and to meropenem was 0.1%,0.6%,4.2%, respectively.P.aeruginosa was resistant to imipenem and meropenem were 38.9% and 32.3%.A.baumanii was resistant to imipenem and meropenem were 5 6.5% and 5 9.7%.Methicillin-resistant strains accounted for an average of 5 7.5% in S.aureus and 87.3% in coagulase negative staphylococcus.Staphylococcus was still susceptible to minocycline and chloram-phenicol.No staphylococcal strains were found resistant to vancomycin,linezolid.But a few coagulase negative staphylococcal strains were resistant to teicoplanin.Conclusion Surveillance of antimicrobial agents played an important role in controlling hospital infection.
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Objective To analyze the characteristics of antibiotic resistance on group A streptococcus isolated from pediatrics in Beijing in 2011,to provide reference for clinical drug administration.Methods Strains of group A streptococcus were collected from the Departments of Pediatrics in 36 hospitals at different Districts of Beijing,from May to July 2011.Minimal inhibitory concentrations (MIC) with ten antibiotics of these isolates were tested by VITEK 2 Compact method.All the Susceptibility rate (S％),Intermediate rate (I％) and Resistance rate (R％) were calculated according to their MIC values.The macrolides resistant phenotype of group A streptococcus was detected by D-test.Results A total of 633 (19.1％) group A streptococcus strains were cultured from 3315 throat swabs.All the isolates were susceptible to penicillin,ampicillin,streptogramin,linezolid,tigecycline,vancomycin,while 96.5％ (611/633) of the isolates were susceptible to levofloxacin.A total of the 96.1％ (608/633) isolates exhibited resistance to erythromycin.The resistance rates to clindamycin and tetracycline were 79.3％ (502/633)and 93.7％ (593/633),respectively.A total of 9 different resistant patterns were observed,with the dominant patterns as:concomitant resistance to erythromycin,clindamycin and tetracycline (72.7％,460/633),followed by combined resistance to erythromycin and tetracycline (18.0％,114/633).The most commonly seen macrolide resistant phenotype was cMLS type (83.2％).In total,97 strains belonged to iMLS type and 5 strains to M type.Data through multivariate logistic regression analysis showed that factors as occupation and samples being collected from the sub-unban areas etc.were significantly associated with the resistance rates to tetracycline and the odds ratio (95％CI) as 2.43 (1.16-5.09) and 2.35 (1.47-3.73).Isolates collected from the sub-unban areas were significantly associated with resistance rates to clindamycin,with the odds ratio (95％CI) being 0.48(0.25-0.92).Conclusion All the isolates acquired from the Pediatrics Departments in Beijing were susceptible to penicillin and ampicillin.The high resistance rates of erythromycin,clindamycin and tetracycline resistance to group A streptococcus were observed,with the major resistant phenotype as cMLS.Factors as occupation and the collection site of samples were significantly associated with the resistance rates to tetracycline while the sites of sample collection were significantly associated with the resistance rates to clindamycin.
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Objective To investigate antimicrobial resistance of clinical isolates from 15 hospitals submitted to Guangzhou Surveillance of Antimicrobial Resistance (GSAR) in 2007,and to learn the feature of bacterial resistance in Guangzhou.Methods Disc diffusion test (K-B methods) was employed to study the antimicrobial resistance.Results Of 18 500 clinical isolates,Gram negative bacilli and Gram positive cocci accounted for 68.4% and 31.6%,respectively,and 45.7% isolates in Gram negative bacilli belonged to non-fermentative bacilli.The detection rotes of methiciHin-resistant strains was 55.9% in Staphylococcus aureus and 75.9% in coagulase negative Staphylococcus.All of the Staphylococcus pneumoniae isolates were penicillin-susceptible (PSSP) according to 2008 CLSI criterion.One strains of Enterobacter faecium were identified as vancomycin-resistance (VRE).The resistant rates of Enterobacter to imipenem and merpenem were the lowest.The prevalence of ESBLs-producing strains in Enterobacter coli and Klebsiella spp.isolates was 43.8% and 39.8%,respectively.Against all the ESBLs strains in Enterobacter coli and Klebsiella spp,meropenem,imipenem,cefoperazone/sulbactam,and piperacillin/tazobactam showed the lowest resistant rates,ranging from 0 to 14.1%,20.4%,24.4% and 25.4% isolates of Pseudomonas aernginosa were resistant to efoperazone/sulbactam,piperacillin/tazobactam and meropenem,while 75.6%,72.4% and 63.2% isolates of Pseudomonas aeruginosa were susceptible to piperacillin/tazobactam,meropenem and cefoperazone/sulbactam,respectively.The resistance rates of Acinetobacter spp.to cefoperazone/sulbactam and meropenem were 2.6% and 5.1%,respectively.Some panresistant isolates of Pseudomonas aeruginosa (5.5%) and Ac/naobacter baumannii (1.5%) emerged.The resistance of Pseudomonas aeruginosa and Aeinetobacter baumannii isolated from sputum sample was higher than those from blood sample.Conclusions The increase of isolated rates of non-fermentative Gram-negative bacilli and the emerging bacterial resistance and oandrug resistance in Pseudomonas aeruginosa and Acinetobacter baumannii warrants further enbancing the local surveillance of bacterial resistance and characterization of panresistance mechanism to inform the rational use of anfimicrobial agents and containment of bacterial resistance.
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Objective To investigate the resistance of clinical isolates from Shanghai Huashan Hospital in 2005.Methods Antimicrobial susceptibility test was carried out by Kirby-Bauer method.Results were analyzed according to CLSI 2005.Results Of the 3 896 clinical isolates,gram negative bacilli and gram positive cocci accounted for 68.1% and 31.9% respectively.About 93.2%(465/499)of S.aureus isolates were identified as methicillin-resistant Staphylococcus,94.9%(260/274)of coagulase negative Staphylococcus(CNS)isolates were methicillin-resistant.No vancomycin-resistant strain was found.The resistance rates of E.faecalis and E.faecium to high level gentamicin(120 ?g)were 67.4% and 82.8% respectively.Two strains of VRE were isolated.Both were VanA type.ESBLs-producing strains accounted for 47.6%(206/433)in E.coli and 69.6%(391/562)in Klebsiella spp(K.pneumoniae and K.oxytoca).Isolates of Enterobacteriaceae were still highly sensitive to imipenem and meropenem,resistance rates being 0-4% except Citrobacter isolates,9.1% of which were resistant.However,39.3% and 59.6% of P.aeruginosa strains were resistant to the above carbapenems,respectively.Conclusions The prevalence of MRSA and MRCNS is very high.ESBLs are prevalent in E.coli and Klebsiella spp.Two glycopeptide-resistant E.faecium isolates are identified firstly in Huashan Hospital.Our data will be useful for rational use of antimicrobial agents in the treatment of bacterial infections.
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Objective To explore the drug resistance of Staphylococcus isolates and offer scientific basis for reasonable usage of antibiotics.Methods MIC test was taken by broth microdilution method in 216 strains of Staphylococcus.Methicillin resistant Staphylococcus(MRS)strains were identified by Cefoxitin Kirby-Bauer disk diffusion method.Results The prevalence of methicillin-resistant Staphylococcus aureus(MRSA)and methicillin-resistant coagulase-negative Staphylococci(MRCNS)was 53.7% and 91.9%,respectively.Resistant rates of MRSA and MRCNS were higher than those of methicillin-susceptible Staphylococcus aureus(MSSA) and methicillin-susceptible coagulase-negative Staphylococci(MSCNS) to antimicrobial agents commonly used in clinic.Most of isolates of Staphylococcus were susceptible to synercid.All isolates were susceptible to both vancomycin and linezolid.Conclusion The increase of isolated rates of MRSA and MRCNS and the emerging bacterial resistance warrants further enhancing the detection of MRS and the surveillance of bacterial resistance to inform the rational use of antimicrobial agents and containment of bacterial resistance.