• Raza, Syed Mohsin
• Mushtaq, Fizza
• Rakha, Allah
• Saleem, Sidrah
• Aslam, Hina
• Din, Sunia Karam
• Ahmad, Irfan

Abstract

<jats:title>Abstract</jats:title><jats:p>Background: To treat tuberculosis is very complicated and difficult procedure that involves the administration of a panel of five antimicrobial drugs for the period of 6 months. The purpose of this study was to determine antimicrobial drug resistant features of <jats:italic>Mycobacterium tuberculosis </jats:italic>associated with treatment failure and to determine efficacy of the second line drugs and the efflux pump inhibitor verapamil against <jats:italic>M. tuberculosis </jats:italic>associated with treatment failure.Methods: The identity of isolates was confirmed by ZN staining and multiplex PCR through detection of <jats:italic>Mycobacterium</jats:italic> species specific loci <jats:italic>rv0577</jats:italic>, <jats:italic>mtbk_20680</jats:italic>, <jats:italic>16S rRNA</jats:italic>, <jats:italic>RD9,</jats:italic> <jats:italic>IS 1311,</jats:italic> <jats:italic>mass_3210 </jats:italic>and <jats:italic>mkan_rs12360</jats:italic>. Drug susceptibly testing (DST) and efficacy of the efflux pump inhibitor verapamil were performed through MGIT 960. Mutations associated with drug resistance were determined through DNA sequencing of <jats:italic>ropB, katG, pncA, rrs and eis</jats:italic> loci. The transcription of efflux pump gene <jats:italic>rv1258 </jats:italic>was assessed by real time quantitative PCR.Results: Upon monitoring 1200 tuberculosis patients, 64 were found not-cured after six months of treatment course. From <jats:italic>M. tuberculosis</jats:italic> isolates recovered from sputum of these 64 patients, 3.1% isolates were detected resistant to four anti <jats:italic>M. tuberculosis</jats:italic> drugs (extreme drug resistant) 48.4% were resistant to three anti <jats:italic>M. tuberculosis drugs</jats:italic> (extensive drug resistant), 26.5% were resistant to two anti <jats:italic>M. tuberculosis </jats:italic>drugs<jats:italic> </jats:italic>(multi drug resistant).<jats:italic> </jats:italic>High frequency of resistance to the second line drug amikacin was detected in 26,5% isolates whereas moxifloxacin and linezolid resistance was detected in only 3.1% isolates. The Serine 315 in <jats:italic>katG </jats:italic>was the most frequent amino acid mutated in treatment failure group. Three novel mutations were detected at codons 99, 149 and 154 in <jats:italic>pncA </jats:italic>associated with pyrazinamide resistance. Rifampicin and isoniazid enhanced the transcription of the efflux pump gene r<jats:italic>v1258 </jats:italic>in drug susceptible isolates collected from the treatment failure patients whereas verapamil reduced minimum inhibitory concentrations of antimicrobial drugs in these isolates.Conclusion: The use of Amikacin as a second line drug is not appropriate as compare to moxifloxacin and linezolid. Verapamil enhanced anti-bacterial activity of rifampicin and isoniazid in drug susceptible <jats:italic>M. tuberculosis</jats:italic> isolates cured from treatment failure patients but not in drug resistant isolates.</jats:p>

Topics

• electrochemical-induced impedance spectroscopy