已发表论文

Second-line anti-tuberculosis drug resistance testing in Ghana identifies the first extensively drug-resistant tuberculosis case

 

Authors Osei-Wusu S, Amo Omari M, Asante-Poku A, Darko Otchere I, Asare P, Forson A, Otu J, Antonio M, Yeboah-Manu D

Received 27 September 2017

Accepted for publication 30 November 2017

Published 22 February 2018 Volume 2018:11 Pages 239—246

DOI https://doi.org/10.2147/IDR.S152720

Checked for plagiarism Yes

Review by Single-blind

Peer reviewers approved by Dr Akshita Wason

Peer reviewer comments 2

Editor who approved publication: Dr Sahil Khanna

Background: Drug resistance surveillance is crucial for tuberculosis (TB) control. Therefore, our goal was to determine the prevalence of second-line anti-TB drug resistance among diverse primary drug-resistant Mycobacterium tuberculosis  complex (MTBC) isolates in Ghana. 
Materials and methods:
 One hundred and seventeen MTBC isolates with varying first-line drug resistance were analyzed. Additional resistance to second-line anti-TB drugs (streptomycin [STR], amikacin [AMK] and moxifloxacin [MOX]) was profiled using the Etest and GenoType MTBDRsl version 2.0. Genes associated with resistance to AMK and MOX (gyrA gyrB eis rrs tap whiB7  and tlyA ) were then analyzed for mutation.

Results: Thirty-seven (31.9%) isolates had minimum inhibitory concentration (MIC) values ≥2 µg/mL against STR while 12 (10.3%) isolates had MIC values ≥1 µg/mL for AMK. Only one multidrug-resistant (MDR) isolate (Isolate ID: TB/Nm 919) had an MIC value of ≥0.125 µg/mL for MOX (MIC = 3 µg/mL). This isolate also had the highest MIC value for AMK (MIC = 16 µg/mL) and was confirmed as resistant to AMK and MOX by the line probe assay GenoType MTBDRsl version 2.0. Mutations associated with the resistance were: gyrA  (G88C) and rrs  (A514C and A1401G).
Conclusion: Our findings suggest the need to include routine second-line anti-TB drug susceptibility testing of MDR/rifampicin-resistant isolates in our diagnostic algorithm.
Keywords: tuberculosis, drug resistance, diagnosis, Ghana, XDR