摘要
目的探讨亚抑菌浓度环丙沙星对大肠埃希菌喹诺酮类耐药质粒接合转移的影响。方法采用PCR法筛选含有质粒介导的喹诺酮类耐药基因[包括qnr A、qnr B、qnr C、aac(6')-Ib-c基因]的大肠埃希菌作为供体菌;质粒接合试验分析喹诺酮类耐药质粒的接合转移能力;不同亚抑菌浓度的环丙沙星处理供体菌后,观察喹诺酮类耐药质粒接合效率的改变。结果 16株供体菌携带质粒介导的喹诺酮类耐药基因,其中6株供体菌携带的喹诺酮类耐药质粒可以接合转移,接合效率为2.6×10-2~1.2×10-1;接合效率最高的1株供体菌经不同亚抑菌浓度的环丙沙星处理后,其接合效率最高可较无环丙沙星处理组增加1.5倍。结论亚抑菌浓度的环丙沙星可以促进大肠埃希菌喹诺酮类耐药质粒的接合转移。
Objective To investigate the effect of sub-minimum inhibitory concentration of ciprofloxacin on the conjugative transfer of quinolone-resistant plasmid of Escherichia coli. Methods Qnr A,qnr B,qnr C,aac( 6')-Ib-c genes were confirmed by PCR and DNA sequencing. The transferability of the plasmids harboring PMQR genes was investigated by conjugation test,so as to screen transferable Escherichia coli as donor. The effect of ciprofloxacin on conjugative transfer of drug resistant plasmids was observed after treatment with Escherichia coli with sub-MIC of ciprofloxacin. Results There were 16 strains of Escherichia coli which were detected the target genes. Among 16 strains of positive bacteria,the PMQR gene of the 6 strains was able to conjugative transfer,and the conjugative efficiency was between 2. 6 × 10-2 and 1. 2 ×10-1. The conjugative efficiency of the 1 strain with the highest transfer efficiency could be up to 1. 5 times when treated with different concentrations of ciprofloxacin. Conclusion The sub-minimum inhibitory concentration of ciprofloxacin can promote the conjugative transfer of quinolone-resistant plasmids.
引文
[1]van Duin D,Kaye KS,Neuner EA,et al.Carbapenem-resistant Enterobacteriaceae:a review of treatment and outcomes[J].Diagn Microbiol Infect Dis,2013,75(2):115-120.
[2]Diene SM,Rolain JM.Investigation of antibiotic resistance in the genomic era of multidrug-resistant Gram-negative bacilli,especially Enterobacteriaceae,Pseudomonas and Acinetobacter[J].Expert Rev Anti Infect Ther,2013,11(3):277-296.
[3]李涛,熊自忠,沈继录,等.大肠埃希菌与克雷伯菌属细菌qnr基因的检测[J].中华检验医学杂志,2005,20(2):112-114.
[4]Aldred KJ,Kerns RJ,Osheroff N.Mechanism of quinolone action and resistance[J].Biochemistry,2014,53(10):1565-1574.
[5]Soares S,Kristinsson KG,Musser JM,et al.Evidence for the introduction of a multiresistant clone of serotype 6B streptococcus pneumoniae from Spain to Iceland in the late 1980[J].J Infect Dis,1993,168(1):158-163.
[6]Gray TA,Krywy JA,Harold J,et al.Distributive conjugal transfer in mycobacteria generates progeny with meiotic-like genome-wide mosaicism,allowing mapping of a mating identity locus[J].PLo S Biol,2013,11(7):e1001602.
[7]Derbyshire KM,Gray TA.Distributive conjugal transfer:new insights into horizontal gene transfer and genetic exchange in mycobacteria[J].Microbiol Spectr,2014,2(1):4.
[8]Gualco L,Roveta S,Marchese A,et al.Pleiotropic effect of sodium arsenite on Escherichia coli[J].Res Microbiol,2004,155(4):275-282.
[9]Baharoglu Z,Bikard D,Mazel D.Conjugative DNA transfer induces the bacterial SOS response and promotes antibiotic resistance development through integron activation[J].PLo S Genet,2010,6(10):e1001165.
[10]Lopez E,Elez M,Matic I,et al.Antibiotic-mediated recombination:ciprofloxacin stimulates SOS-independent recombination of divergent sequences in Escherichia coli[J].Mol Microbiol,2007,64(1):83-93.
[11]Cattoir V,Poirel L,Rotimi V,et al.Multiplex PCR for detection of plasmid-mediated quinolone resistance qnr genes in ESBL-producing enterobacterial isolates[J].J Antimicrob Chemother,2007,60(2):394-397.
[12]Matsuo J,Oguri S,Nakamura S,et al.Ciliates rapidly enhance the frequency of conjugation between Escherichia coli strains through bacterial accumulation in vesicles[J].Res Microbiol,2010,161(8):711-719.
[13]Guan X,Xue X,Liu Y,et.al.Plasmid-mediated quinolone resistance-current knowledge and future perspectives[J].J Int Med Res,2013,41(1):20-30.
[14]Yang X,Xing B,Liang C,et al.Prevalence and fluoroquinolone resistance of pseudomonas aeruginosa in a hospital of South China[J].Int J Clin Exp Med,2015,8(1):1386-1390.
[15]Gupta P,Chhibber S,Harjai K.Subinhibitory concentration of ciprofloxacin targets quorum sensing system of Pseudomonas aeruginosa causing inhibition of biofilm formation&reduction of virulence[J].Indian J Med Res,2016,143(5):643-651.
[16]Ohlsen K,Ternes T,Werner G,et al.Impact of antibiotics on conjugational resistance gene transfer in staphylococcus aureus in sewage[J].Environ Microbiol,2003,5(8):711-716.