Sequence analysis for detection of drug resistance in Mycobacterium tuberculosis complex isolates from the Central Region of Cameroon

BMC Microbiology

Research Article

Francine Ntoumi¹  Matthias Frank²  Anne-Laure Tchokote Wetewale³  Jean-Paul Assam Assam³  Serges Tchatchouang³  Gaëlle Guiewi Makafe³  Véronique N Penlap Beng³  Jean-Claude Tedom³  Larissa Kamgue Sidze⁴  Emmanuel Mouafo Tekwu⁴  Sara Eyangoh⁵  Christopher Kuaban⁶ 

[1] Fondation Congolaise pour la Recherche Médicale, Université Marien Gouabi, Brazzaville, Congo;Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany;Central African Network for Tuberculosis, AIDS/HIV and Malaria (CANTAM), Brazzaville, Congo;Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany;Central African Network for Tuberculosis, AIDS/HIV and Malaria (CANTAM), Brazzaville, Congo;Deutsches Zentrum für Infektionsforschung (DZIF), Tübingen, Germany;Laboratory for Tuberculosis Research (LTR), Biotechnology Centre (BTC)-Nkolbison, University of Yaoundé I, Yaoundé, Cameroon;Central African Network for Tuberculosis, AIDS/HIV and Malaria (CANTAM), Brazzaville, Congo;Laboratory for Tuberculosis Research (LTR), Biotechnology Centre (BTC)-Nkolbison, University of Yaoundé I, Yaoundé, Cameroon;Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany;Central African Network for Tuberculosis, AIDS/HIV and Malaria (CANTAM), Brazzaville, Congo;Mycobacteriology Service, Reference laboratory of NTP, Centre Pasteur of Cameroon-Pasteur Institute International Network, Yaoundé, Cameroon;Pneumology unit, Jamot Hospital, Yaoundé, Cameroon;

关键词: Phenotype;    Mutation;    Drug resistance;    Mycobacterium tuberculosis;    Cameroon;   

DOI  :  10.1186/1471-2180-14-113

 received in 2014-01-13, accepted in 2014-04-29,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundThe potential of genetic testing to rapidly diagnose drug resistance has lead to the development of new diagnostic assays. However, prior to implementation in a given setting, the association of specific mutations with specific drug resistance phenotypes should be evaluated. The purpose of this study was to evaluate molecular markers in predicting drug resistance in the Central Region of Cameroon.ResultsFrom April 2010 and March 2011, 725 smear positive pulmonary tuberculosis patients were enrolled and all positive cultures were tested for drug susceptibility. A total of 63 drug resistant and 100 drug sensitive Mycobacterium tuberculosis complex clinical isolates were screened for genetic mutations in katG, inhA, ahpC, rpoB, rpsL, rrs, gidB and embCAB loci using DNA sequencing. Of the 44 isoniazid resistant (INHR) isolates (24 high level, 1 μg/ml and 20 low level, 0.2 μg/ml), 73% (32/44) carried the katG315 and/or the -15 inhA promoter mutations. Of the 24 high level INHR, 17 (70.8%) harbored katG315 mutation, 1 a point mutation (-15C → T) in the inhA promoter and 6 were (25.0%) wild types. Thus, for INHR high level detection, katG315 mutation had a specificity and a sensitivity of 100% and 70.8% respectively. Of the 20 low level INHR, 10 (50.0%) had a -15C → T mutation in the inhA promoter region, and 1 (2.2%) a -32G → A mutation in the ahpC promoter region. All of the 7 rifampicin resistant (RIFR) isolates carried mutations in the rpoB gene (at codons Ser531Leu (71.4%), His526Asp (14.3%), and Asp516Val (14.3%)). Of the 27 streptomycin resistant (SMR) isolates, 7 carried mutations at the rpsL and the gidB genes. 1 of the 2 ethambutol resistant (EMBR) isolates displayed a mutation in embB gene.ConclusionThis study provided the first molecular investigation assessing the correlation of phenotypic to genotypic characteristics on MTB isolates from the Central Region of Cameroon using DNA sequencing. Mutations on rpoB, katG315 and -15 point mutations in inhA promoter loci could be used as markers for RIF and INH -resistance detection respectively.

【 授权许可】

Unknown   
© Tekwu et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.