TABLE 3.

INH resistance-associated mutations in M. tuberculosis

Gene or gene regionNo. of isolates with mutations at:% of isolates with mutation at single locusMIC rangeb (μg/ml)
Single locusaMultiple loci
furA 010
katG 151439.50.1->256
mabA 182.62
inhA 020
ahpC 020
Rv0340 010
iniB 010
iniA 030
iniC 010
srmR homolog010
fabD 000
kasA 030
accD6 000
fbpC 000
fadE24 010
efpA 000
Rv1592c 020
Rv1772 102.60.125
ndh 000
nhoA 000
    Total1744.7
  • a The 15 katG mutations were Trp90STOP (TGG→TAG), Asn138Ser (AAC→AGC), Ser315Ile (AGC→ATC), Trp397Tyr (TGG→TAC) and Asn529Asp (AAC→GAC) (same isolate), Trp438Arg (TGG→CGG), and deletion of katG (n = 1 each) and Ser315Thr (AGC→ACC; n = 9). One isolate had two mutations in mabA. They were at position −15 (C→T) and Thr21A1a (ACC→GCC). The mutation in Rv1772 was Thr4A1a (ACA→GCA; n = 1). Seventeen isolates had INH resistance-associated mutations in two or more genes.

  • b The MIC range shown is for the isolates with single-locus mutations. The MICs for isolates with multiple mutations are shown in Table 4.