Laboratory Medicine ›› 2016, Vol. 31 ›› Issue (4): 309-313.DOI: 10.3969/j.issn.1673-8640.2016.04.014

• Orginal Article • Previous Articles     Next Articles

Analysis of AmpC beta-lactamase and outer membrane porin OprD2 gene deletion in Pseudomonas aeruginosa

XU Weihong1, XU Bin1, YAO Yiting1, HUANG Mingmin1, ZHANG Jun2, ZHAO Hu3   

  1. 1.Shanghai Tongren Hospital,Shanghai 200050,China
    2. Huashan Hospital,Fudan University,Shanghai 200041,China
    3. Huadong Hospital,Fudan University,Shanghai 200040,China
  • Received:2015-04-02 Online:2016-04-30 Published:2016-05-12

Abstract:

Objective To understand AmpC beta-lactamase(AmpC) and outer membrane porin OprD2 gene deletion in Pseudomonas aeruginosa. Methods The three-dimensional test was used to determine AmpC . Polymerase chain reaction(PCR) was used to determine outer membrane porin OprD2 gene and ampC gene. The data were analyzed statistically. Results The 63 isolates of Pseudomonas aeruginosa were collected,of which 14 isolates(22.22%) produced AmpC,OprD2 gene was positive in 22 isolates(OprD2 gene deletion rate 65.08%) ,and ampC gene was positive in 62 isolates(93.94%). The resistance rates to ampicillin,ampicillin / sulbactam,cefotetan and ceftriaxone and cefazolin were 100.00%. The resistance rates of AmpC-producing isolates to imipenem, gentamicin and cefepime were 42.85%,64.29% and 57.14%,respectively. The resistance rates of non-AmpC-producing isolates were 30.61%,6.12% and 14.29%,respectively. The resistance rates of Pseudomonas aeruginosa to gentamicin and cefepime had statistical significance between AmpC-producing and non-AmpC-producing isolates(P<0.01),but there was no statistical significance for imipenem(P>0.05). A total of 6 isolates of Pseudomonas aeruginosa had OprD2 gene deletion,and the resistance rates to imipenem,ceftazidime and cefepime were 100.00%,66.67% and 55.56%. The resistance rates of 8 isolates of Pseudomonas aeruginosa with normal OprD2 gene expression and AmpC-producing isolates were 0.00%,25.00% and 37.50%. Conclusions Multi-drug resistant Pseudomonas aeruginosa might be caused by a variety of mechanisms. Enzyme production and molecular epidemiological studies for Pseudomonas aeruginosa should be strengthened.

Key words: Pseudomonas aeruginosa, AmpC beta-lactamase, ampC gene, OprD2 gene

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