Table 1. Results of PZA susceptibility of M. tuberculosis clinical samples tested by pncA sequencing, in-vitro synthesized PZase assay and BACTEC MGIT 960 System.
| No. of Strains | pncA sequencing results and mutations | PZase mutations | PZA susceptibility by sequencing | PZA susceptibility by the in-vitro PZase assay | PZA susceptibility by BACTEC 960 |
| 1,2,3,4,5,6,7,8,11, 14,16,19,20,22,2527,28,29,30,3132, 36, 40,42,43,46,Sputum sampled | WTa | WTa | S | S | S |
| 10,12,18,34,38,50 | WTa | WTa | S | S | R |
| 9 | T(202)→C | Trp (86)→Arg | R ref. [20] | R | R |
| 13 | G (362)→C | Arg(121)→Pro | R ref. [21] | R | R |
| 15 | C (169)→T | His(57)→Tyr | R ref. [2] | R | R |
| 17 | C (234)→T | WTb | S | S | S |
| 21 | A (29)→C | Gln(10)→Pro | R ref. [18] | R | R |
| 23 | A insertion between nt 192 and 193 | Frame shift | R | R | R |
| 24 | C(512)→A | Ala(171)→Glu | NA | S | R |
| 26 | ——c | ——c | NA | R | R |
| 33 | T(416)→G | Val(139)→Gly | R ref. [20] | R | R |
| 35 | G(145)→T | Asp(49)→Tyr | R | R | R |
| 37 | A(188)→C | Asp(63)→Ala | R ref. [28] | R | S |
| 39 | T(416)→G | Val(139)→Gly | R ref. [20] | R | R |
| 41 | T(199)→C | Ser(67)→Pro | R ref. [20] | R | R |
| 44 | ——c | ——c | NA | R | R |
| 45 | C(169)→T | His(57)→Tyr | R ref. [2] | R | R |
| 47 | T insertion between nt 396 and 397 | Frame shift | R | R | R |
| 48 | T(515)→C | Leu(172)→Pro | R ref. [2] | R | R |
| 49 | C(458)→T, C(474)→A | Thr(153)→Ile,Asp(159)→Glu | NA | S | R |
| 51 | 57–59, 62–65, 70–74 deleted | Frame shift | R | R | R |
a
, wild type sequence.
b
, silent mutation, the amino acid sequence was not changed.
c
, sequencing result is disordered.
d
, sputum sample was not tested by the BACTEC MGIT 960 system.
S, PZA susceptible.
R, PZA resistant.
NA, not available.
ref. , reference that reported the mutation sites leading to PZA resistance.