ABSTRACT
Objective To study the clinical distribution and detection of the efflux pump gene in multiple drug-re?sistant acinetobacter baumannii. Methods The clinical distribution of 96 strains of multiple drug-resistant acinetobacter baumannii was analyzed. K-B method was used to detect 96 strains of multi resistant bauman resisted to 15 kinds of antibiot?ics. PCR amplification was used to detect the efflux pump gene. Results Ninety-six strains of multiple drug-resistant aci?netobacter baumannii mainly distributed in intensive care unit (ICU, 54.2%) and respiratory department (18.8%). The drug resistance rates to quinolone, cephalosporins, amino glucoside, tetracycline were above 70%. The 52 strains of multiple drug-resistant acinetobacter baumannii detected in ICU included 18 strains of adeB (34.62%), 16 strains of adeR (30.77%), 18 strains of adeS (34.62%), 18 strains of adeJ (34.62%), 0 strain of adeE and18 strains of adeM (34.62%). The18 strains of multiple drug-resistant acinetobacter baumannii detected in respiratory department included 9 strains of adeB, 8 strains of adeR, 8 strains of adeS, 8 strains of adeJ, 0 strain of adeE and 8 strains of adeM. Conclusion Efflux pump genes are impor?tant factors for multiple drug-resistant acinetobacter baumannii distributed in ICU and respiratory department.
ABSTRACT
Objective To detect the mutations of the marOR gene and study the relations with the expressing level of the acrAB-tolC efflux pump in Shigella. Methods marOR genes were amplified by PCR for 100 clinical isolates and 5 reference strains of Shigella. The PCR products were digested by restriction endonuclease Taq Ⅰ , then analyzed by single strand conformation polymorphism(SSCP). The marOR genes of the mutated strains and sensitive strain were sequenced and the expressing leveLs of acrA, acrB and talC were determined by RT-PCR. Susceptibility tests of tetracycline (TE), chloramphenicol (C), ampicillin (Am) , gentamycin (GM), norfloxacin (NOR) and selectrin (SMZ-TMP) were performed in sequenced strains. Results marOR genes were found in all strains detected. SSCP analysis found the rate of mutations in marOR genes was 23%. Among 11 marOR gene-mutated strains which were sequenced, there were 9 strains having a four-base absence and three single-base mutations in different loci. The expressing levels of the acrAB-tolC efflux pump in the 11 strains were higher than those in sensitive strains and reference strain. Furthermore the 11 strains were multi-drug resistance. Conclusion The mutation rate of marOR gene in Shigella was high and the acrAB-tolC efflux pump genes were over-expressive in marOR gene-mutated strains which were multi-antibiotic resistance in the study.
ABSTRACT
Multidrug efflux pump is the main reason for bacterial multidrug resistance, and it’s a chal- lenge for the treatment of infectious diseases. Analysis of multidrug efflux pump offers us the mecha- nism and treatment ideas of bacterial multidrug resistance. New advances have been made in the study of Escherichia coli AcrAB-TolC efflux pump structure and its regulation, which provides data for the multidrug resistance research in pathogenic bacterium. Progress in this area is reviewed here.