Detection and analysis of the multi-drug resistant regulator A in the clinical isolates

doi:10.3969/j.issn.1673-8640.2013.04.001

›› 2013, Vol. 28 ›› Issue (4): 259-262.DOI: 10.3969/j.issn.1673-8640.2013.04.001

1. Department of Clinical Laboratory，Yueyang Hospital of Integrated Traditional Chinese and Western Medicine,Shanghai University of Traditional Chinese Medicine，Shanghai 200437，China; 2. Department of Clinical Laboratory，Shanghai Sixth People′s Hospital，Shanghai Jiaotong University, Shanghai 200233,China

Received:2012-04-02 Revised:2012-06-18 Online:2013-04-30 Published:2013-04-05

Abstract

Abstract: Objective　To detect the expression of multi-drug resistant regulator A (MarA) in Escherichia coli，and to analyze the relationship of MarA with the resistance to 3rd and 4th generation cephalosporin. Methods　A total of 49 isolates of Escherichia coli between 2003 and 2009 were collected randomly. Real-time quantitation reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression levels of anti-putative outer membrane porin F protein (OmpF) antisense RNA-F (MicF)，efflux pump AB (AcrAB) and MarA. The antibiotic sensitivity was also analyzed by disk diffusion method. Results　Among the 49 isolates of Escherichia coli，7 of 49 isolates (14.29%) had high AcrAB transcription level，13 of 49 isolates (26.53%) had MicF transcription level，11 of 49 isolates (22.45%) had high MarA transcription level，and 2 isolates had the 3 resistant factors simultaneously with increasing level. The resistance rates to cefotaxime，ceftazidime and cefepime were 79.59%, 75.51% and 51.02%. The increasing expression level of AcrAB group showed that the resistance rates to these 3 antibiotics were 100.00%，100.00% and 57.14%，respectively. The increasing expression level of MarA group showed that the resistance rates to these 3 antibiotics were 75.00%，100.00% and 58.33%，respectively. The resistance rate increased to 100.00%，when all the 3 resistant factors existed simultaneously. Conclusions　MarA plays an important role in regulating the expressions of AcrAB and MicF. The increasing expression levels of AcrAB and MicF regulated by MarA will lead to high resistance rate to antibiotics.

Key words: Multi-drugresistantregulatorA, AntisenseRNA-F, Effluxpump, Escherichiacoli

LI Li 1，JIANG Yanqun 2, SHEN Jianxiong 1，XUE Zhizhong 1. Detection and analysis of the multi-drug resistant regulator A in the clinical isolates[J]. , 2013, 28(4): 259-262.

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