TABLE 1.
Xpert Ultra raw resultsa
| Mutation(s)b | No. of strains tested | Nucleotide change(s) | Xpert Ultra probe(s) | Wild-typeTm range(s) (mean[s]) | Mutant Tm range(s) | ∣ΔTm∣ mean(s) or range(s) |
|---|---|---|---|---|---|---|
| Val170Phe | 3 | GTC→TTC | ND | ND | ND | ND |
| Glu250Gly# | 2 | GAG→GGG | ND | ND | ND | ND |
| Arg299Cys# | 1 | CGC→TGC | ND | ND | ND | ND |
| *Leu430Pro | 8 | CTG→CCG | rpoB1 | 69.1–69.5 (69.3) | 63.0–63.4 | 5.9–6.3 |
| Leu430Pro + *Met434Ile | 1 | CTG→CCG; ATG→ATA | rpoB1; rpoB2 | 69.1–69.5 (69.3); 72.8–73.2 (73) | 63.2; 69.8 | 6.1; 3.2 |
| Leu430Pro + Met434Val | 1 | CTG→CCG; ATG→GTG | rpoB1 | 69.1–69.5 (69.3) | 63.0 | 6.3 |
| Leu430Pro + His445Gln | 1 | CTG→CCG; CAC→CAG | rpoB1; rpoB3 | 69.1–69.5 (69.3); 75.5–76.0 (75.75) | 63.5; 72.2 | 5.8; 3.6 |
| Leu430Pro + His445Gln | 1 | CTG→CCG; CAC→CAA | rpoB1; rpoB3 | 69.1–69.5 (69.3); 75.5–76.0 (75.75) | 63.1; 71.7 | 6.2; 4.1 |
| Asp435Gly + Met434Thr | 1 | GAC→GGC; ATG→ACG | rpoB2 | 72.8–73.2 (73) | 69.7 | 3.3 |
| *Asp435Phe | 1 | GAC→TTC | rpoB2 | 72.8–73.2 (73) | 67.7 | 5.3 |
| *Asp435Tyr | 11 | GAC→TAC | rpoB2 | 72.8–73.2 (73) | 68.6–69.0 | 4.0–4.4 |
| Asp435Tyr + Asn437Asp | 1 | GAC→TAC; AAC→GAC | rpoB2 | 72.8–73.2 (73) | 66.6 | 6.4 |
| Asp435Tyr + Met434Ile | 1 | GAC→TAC; ATG→ATT | rpoB2 | 72.8–73.2 (73) | 68.5 | 4.5 |
| *Asp435Val | 5 | GAC→GTC | rpoB2 | 72.8–73.2 (73) | 69.3–69.5 | 3.5–3.7 |
| Asp435Val + Gln432Glu | 1 | GAC→GTC; CAA→GAA | rpoB2; rpoB1 | 72.8–73.2 (73); 69.1–69.5 (69.3) | 70.5; 65.9 | 2.5; 3.4 |
| *Ser441Gln | 1 | TCG→CAG | rpoB2; rpoB3 | 72.8–73.2 (73); 75.5–76.0 (75.75) | 68.3; 73.5 | 4.7; 2.3 |
| *Ser441Leu | 1 | TCG→TTG | rpoB2; rpoB3 | 72.8–73.2 (73); 75.5–76.0 (75.75) | 70.0; 73.5 | 3.0; 2.3 |
| His445Gly | 1 | CAC→GGC | rpoB3 | 75.5–76.0 (75.75) | 70.9 | 4.9 |
| His445Thr | 1 | CAC→ACC | rpoB3 | 75.5–76.0 (75.75) | 70.9 | 4.9 |
| His445Ser | 1 | CAC→AGC | rpoB3 | 75.5–76.0 (75.75) | 71.1 | 4.7 |
| His445Ser + *Lys446Gln + Thr444Thr | 1 | CAC→TCC; AAG→CAG; ACC→ACG | rpoB4B | 67.0–67.6 (67.3) | 62.3 | 5.0 |
| His445Asp | 3 | CAC→GAC | rpoB3 | 75.5–76.0 (75.75) | 71.9–72.1 | 3.7–3.9 |
| His445Leu | 2 | CAC→CTC | rpoB3 | 75.5–76.0 (75.75) | 72.2–72.3 | 3.5–3.6 |
| His445Asn | 2 | CAC→AAC | rpoB3 | 75.5–76.0 (75.75) | 72.3–72.4 | 3.4–3.5 |
| His445Asn + *Asp435Glu | 1 | CAC→AAC; GAC→GAA | rpoB3; rpoB2 | 75.5–76.0 (75.75); 72.8–73.2 (73) | 72.4; 70.2 | 3.4; 2.8 |
| His445Tyr | 4 | CAC→TAC | rpoB3 | 75.5–76.0 (75.75) | 72.5–72.6 | 3.2–3.3 |
| *His445Arg | 4 | CAC→CGC | rpoB3 | 75.5–76.0 (75.75) | 73.9 | 1.9 |
| His445Arg + Ser428Arg | 1 | CAC→CGC; AGC→AGG | rpoB1 | 69.1–69.5 (69.3) | 65.8 | 3.5 |
| Ser450Phe | 1 | TCG→TTC | rpoB3 | 75.5–76.0 (75.75) | 71.8 | 4.0 |
| *Ser450Leu | 14 | TCG→TTG | rpoB3; rpoB4A | 75.5–76.0 (75.75); 67.0–67.6 (67.3) | 72.9–73.3; 73.3–73.8 | 2.5–2.9; 6.0–6.5 |
| Ser450Leu + Thr482Asn | 2 | TCG→TTG; ACC→AAC | rpoB2; rpoB3; rpoB4A | 72.8–73.2 (73); 75.5–76.0 (75.75); 67.0–67.6 (67.3) | 69.2–69.5; 73.1–73.3; 73.6–73.7 | 3.5–3.8; 2.5–2.7; 6.3–6.4 |
| Ser450Leu + Ile491Val | 2 | TCG→TTG; ATC→GTC | rpoB2; rpoB3; rpoB4A | 72.8–73.2 (73); 75.5–76.0 (75.75); 67.0–67.6 (67.3) | 70.0; 73.2–73.3; 73.6–73.7 | 3.0; 2.5–2.6; 6.3–6.4 |
| *Ser450Trp | 3 | TCG→TGG | rpoB3; rpoB4A | 75.5–76.0 (75.75); 67.0–67.6 (67.3) | 73.1–73.5; 70.6–71.0 | 2.3–2.7; 3.3–3.7 |
| Ser450Trp + *Ser431Gly | 1 | TCG→TGG; AGC→GGC | rpoB3; rpoB4A; rpoB1 | 75.5–76.0 (75.75); 67.0–67.6 (67.3); 69.1–69.5 (69.3) | 73.2; 70.7; 66.4 | 2.6; 3.4; 2.9 |
| *Leu452Pro | 12 | CTG→CCG | rpoB4B | 67.0–67.6 (67.3) | 61.2–61.6 | 5.7–6.1 |
| Ile491Phe | 10 | ATC→TTC | ND | ND | ND | ND |
a
Capturing probes, wild-type melt peak temperature (Tm) ranges and means, mutant Tm ranges, and absolute values of melting temperature shift (ΔTm) ranges associated with specific rpoB mutations in the strains tested and the corresponding nucleotide changes. ND, strains that harbored corresponding mutations outside the RRDR yielded a “RIF Resistance Not Detected” result. *, rifampin resistance-determining region (RRDR) mutation unambiguously identified by unique combinations of Ultra probes and ΔTms, including disputed ones (in italics). #, rifampin susceptible according to phenotypic testing.