Clinical Microbiology: Open Access

Magnitude of gene mutations conferring drug resistant in Mycobacterium tuberculosis strains in southwest Ethiopia

6^th Clinical Microbiology Conference

October 20-22, 2016 Rome, Italy

Mulualem Tadesse, Dossegnaw Aragaw, Belayneh Dimah, Feyisa Efa, Kedir Abdella, Wakjira Kebede, Ketema Abdissa and Gemeda Abebe

Jimma University, Ethiopia

Posters & Accepted Abstracts: Clin Microbiol

Abstract:

Background: The nature and frequency of mutations in rifampicin (RIF) and isoniazid (INH) resistance M. tuberculosis isolates vary considerably according to the geographic locations. However, information regarding specific mutational patterns in Ethiopia remains limited. Methods: Mutations associated with RIF and INH resistance was studied by GenoType MTBDRplus line probe assay in 112 M. tuberculosis isolates. Culture (MGIT960) and identification tests were performed at Mycobacteriology Research Center of Jimma University, Ethiopia. Results: Mutations conferring resistance to INH, RIF and MDR were detected in 36.6% (41/112), 30.4% (34/112) and 27.7% (31/112) of M. tuberculosis isolates respectively. The retreatment category â??treatment failureâ?? is associated with a high rate of mutations associated with drug resistance (p-value <0.05). Among 34 rifampicin resistant isolates, 82.4% (28/34) had rpoB gene mutations at codon 531, 2.9% (1/34) at codon 526 and 5 had mutations only at wild type probes. The later isolates were depicted as unknown. Of 41 INH resistant strains, 87.8% (36/41) had mutations in the katG gene at Ser315Thr1 and 9.8% (4/41) of strains had mutation in the inhA gene at C15T. One INH resistant strain had mutation only at KatG wild type probe. Mutations in inhA promoter region were strongly associated with INH monoresistance. Monoresistance to INH (10 isolates) was frequently observed as compared to RIF monoresistance (3 isolates). Conclusions: High rate of drug resistance, including MDR, was commonly observed among failure cases. The most frequent gene mutations associated with the resistance to INH and RIF were observed in the codon 315 of the katG gene and codon 531 of the rpoB gene, respectively. Further studies on mutations in different geographic regions using DNA sequencing techniques are warranted to improve the kit by including more specific mutation probes in the kit.

Biography :

Email: mulualemt.tadesse@gmail.com