Expression of ATP-binding cassette efflux pump gene Rv1217c-Rv1218c and its association with drug resistance of Mycobacterium tuberculosis / 中华传染病杂志

ABSTRACT

Objective To explore the association of ATP-binding cassette (ABC) efflux pump gene Rv1217c-Rv1218c and the drug resistance of Mycobacterium tuberculosis.Methods A total of 34 Mycobacterium tuberculosis clinical isolates including 24 drug-resistance isolates which were resistant to riffampicin,isoniazid,streptomycin or ethambutol and resistant to at least one second-line antituberculosis drug,and 10 drug-sensitive isolates were involved in this study.The RNA of isolated strains was extracted and then reverse transcribed. Gene expression was performed by real-time polymerase chain reaction (PCR) and data was analyzed by t test and Logistic regression analysis.Results The expressions of Rv1217c in rifampicin-resistant group (2.13 ± 1.89,t =3.44,P＜0.01),isoniazid-resistant group ( 1.84 ± 1.86,t =3.16,P＜ 0.05),streptomycin-resistant group ( 1.86 ±1.96,t=2.78,P＜0.05) and ethambutol-resistant groups (3.36±2.35,t=3.04,P＜0.05) were all higher than sensitive isolates (0.42 ± 0.31).The expressions of Rv1218c in rifampicin-resistant group (2.54±1.84,t=3.82,P＜0.01),isoniazid-resistant group (2.34± 1.84,t=3.72,P＜0.01),streptomycin-resistant group (2.15±1.86,t=3.01,P＜0.01) and ethambutol-resistant groups (3.78± 1.78,t=4.22,P＜0.01 ) were all higher than sensitive isolates (0.65 ± 0.42).The expressions of Rv1217c and Rv1218c in multidrug resistant group were 2.74±2.07 and 3.33± 1.77,respectively,which were both higher than polydrug resistant group (0.79 ± 0.47 and 1.03 ± 0.79,respectively; t =2.91,P＜0.05 ; t =3.84,P＜0.01,respectively).Logistic regression analysis found that high Rv1217c expression was positively correlated with rifampicin resistance and negatively correlated with isoniazid resistance (both P＜ 0.01 ),while high Rv1218c expression was negatively correlated with rifampicin resistance and positively correlated with isoniazid resistance (both P＜0.01 ).High expressions of two genes were both positively correlated with ethambutol resistance and multidrug resistance (both P＜0.01 ) and not statistically correlated with streptomycin resistance (P＞0.05).Conclusions The expressions of ABC efflux pump gene,Rv1217c-Rv1218c,are correlated with multiple drug resistance.The overexpression may contribute to the multidrug resistance of Mycobacterium tuberculosis.