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OBJECTIVE To investigate the drug resistance and the status of producing ESBLs and AmpC beta-lactamases of Klebsiella pneumoniae isolates from 2006 to 2007 in local district.METHODS From 2006 to 2007,110 strains of K.pneumoniae insensitive to cefoxitin were collected.The sensitiveness to 16 antibiotics were tested by K-B method and microdilution method.Genes of TEM,SHV,GES,PER,CTX-M-1,CTX-M-2,CTX-M-3,DHA and MIR-1/ACT-1 were tested by PCR.The gene transfer was detected by conjugation test.RESULTS The resistance rate of 110 K.pneumoniae strains to meropenem,imipenem,piperacillin/tazobactam,cefoperazone/sulbactam,ceftazidime and cefepime was 0-49.9%.The resistance rate to other antibiotics was 80-100%.And ESBLs production was the main result.Genes of ESBLs were CTX-M and SHV.Genes of AmpC beta-lactamases were ACT and DHA.They all could transfer the drug-resistance from plasmid to receptor bacteria.CONCLUSIONS Co-existing of ESBLs and AmpC beta-lactamases is the main reason of multi-drug resistance that K.pneumoniae.Transferring of drug-resistance gene leads to the spreading of drug-resistance.The drug-resistance rate of K.pneumoniae decreased during the last two years.
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OBJECTIVE To sudy drug resistance related gene of carbopenem resistant Pseudomonas aeruginosa and type 1 integrating enzyme gene.METHODS With PCR method to detect and analyze carbopenem resistant P.aeruginosa pertinent metal ?-lactamase IMP,VIM,SPM,GIM genes and cell membrane protein oprD2 gene and six main drug resistance genes of type Ⅰ integrating enzyme gene and five others.RESULTS Fifty one strains of imipenem and meropenem resistant P.aeruginosa SPM,GIM metal enzyme genes were detected to be negative,16 strains of IMP and 5 strains of VIM type metal enzyme were all positive,14 strains of carbopenem resistant P.aeruginosa oprD2 gene were positive,other 37 strains of P.aeruginosa oprD2 gene were negative,7 strains produced metal enzyme and cell membrane protein oprD2 gene were deleted at the same time,49 strains with type Ⅰ integrating enzyme gene intⅠ1 were positive.CONCLUSIONS It is indicated the gene deletion of P.aeruginosa outer membrane protein OprD2 is important mechanism of carbopenem resistant P.aeruginosa,the second is metal enzyme,type Ⅰ integrating enzyme exists largely in P.aeruginosa.This hints the monitoring that drug resistance gene spreads and propagates in bacterium strain must be reinforced.
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OBJECTIVE To investigate the resistance of Staphylococcus to erythromycin and clindamycin and detect the percentage and gene for inducible resistance in Tai'an.METHODS The susceptibilities of Staphylococcus to erythromycin and clindamycin were examined by Kirby-Bauer disc agar diffusion test and the inducible erythromycin resistance to clindamycin was checked by D-test according to the standards of NCCLS,and the resistance genes msrA,Vgb,sat4,ermA,ermB and ermC were detected by using PCR technology.RESULTS Among the 326 strains,162(44.12%)were all resistant to erythromycin and clindamycin;68(20.86%)were resistant to erythromycin and sensitive to clindamycin but they were positive in D-test;42(12.88%)were resistant to erythromycin and sensitive to clindamycin but they were negative in D-test.The rates of inducible resistance of MRSA,MSSA,MRCNS and MSCNS to clindamycin were 40.00%,56.25%,63.38% and 66.67%,respectively among the Staphylococcus which were resistant to erythromycin and sensitive to clindamycin.The gene ermC was the main one for inducible erythromycin resistance to clindamycin.The percentage of gene ermC was 85.29% and that of ermC and sat4 either was 7.35%;all the others were negative.CONCLUSIONS The rate of inducible erythromycin resistance to clindamycin in our area is relatively high,and D-test in clinical microbiology laboratory should be done so that the physicians can select the reasonable MLSB antimicrobial agents.