Genetic diversity and drug resistance of in Ecuador.

Background: The genetic diversity of in Quito, Ecuador is not well known.

Objective: To investigate mutations related to drug resistance and bacterial genotypes in strains in Ecuador.

Design: This was a retrospective study of isolates from 104 patients. Isolates were phenotypically resistant to rifampicin (RMP) and/or isoniazid (INH). The genotype was determined using 24-locus mycobacterial interspersed repetitive units-variable-number tandem repeats (MIRU-VNTR).

Results: Isolates showed mutations in the B and G genes, and the A promoter. In B, we found 13 genetic alterations at codons 511, 513, 514, 515, 516, 526 and 531. Forty-six (44.2%) RMP-resistant isolates belonged to codon 531. In G, there were nine genetic alterations at codons 296, 312, 314, 315, 322, 324 and 351. Fifty-three (51%) INH-resistant isolates belonged to codon 315. Five mutations not previously described were identified in G: Thr324Ser, Thr314Ala, Ala312Pro, Trp351Stop and deleted G at 296 codon. The Latin American Mediterranean (LAM) (33.7%) and Ghana (30.8%) lineages presented most of the main mutations observed.

Conclusion: This is the first report from Ecuador; it describes five new mutations in G and indicates that LAM is the most prevalent lineage.