W Liu1, J Chen2, Y Shen3, J Jin3, J Wu3, F Sun3, Y Wu4, L Xie4, Y Zhang5, W Zhang6. 1. Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China; Hangzhou Center for Disease Control and Prevention, Zhejiang, China. 2. Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China. Electronic address: jiazhen_chen@163.com. 3. Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China. 4. Hangzhou Center for Disease Control and Prevention, Zhejiang, China. 5. Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China; Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA. 6. Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China. Electronic address: zhangwenhong@fudan.edu.cn.
Abstract
OBJECTIVES: Pyrazinamide (PZA) is a crucial first-line tuberculosis (TB) drug recommended for both drug-susceptible and multidrug-resistant Mycobacterium tuberculosis. This study aimed to evaluate the performance of the sequencing method of pncA, rpsA and panD mutations in detecting PZA resistance in multidrug-resistant (MDR) TB isolates. METHODS: We sequenced the pncA, rpsA and panD genes and performed PZA susceptibility tests across 291 MDR-TB isolates to evaluate the performance of the sequencing method of these genes in detecting PZA resistance. RESULTS: Results showed that 145 (90.0%) of 161 PZA phenotypic resistant isolates had mutations in pncA. Among the 16 isolates (10.0%) which did not have mutations in pncA, ten and three isolates had mutations in rpsA and panD, respectively. The sequencing method for detecting mutations in pncA alone had 90.1% (95% confidence interval (CI), 84.4-94.2) sensitivity and 92.3% (95% CI, 86.3-96.3) specificity. The combination of all three genes increased the sensitivity from 90.1% (95% CI, 84.4-94.2) to 98.1% (95% CI, 94.7-99.6) (p < 0.001) while the specificity remained unchanged. In 120 PZA-susceptible and 16 PZA-resistant isolates without pncA mutations, rpsA/panD mutations were correlated with PZA resistance. CONCLUSIONS: PZA resistance was largely associated with mutations in pncA. Mutations in rpsA and panD were also associated with PZA resistance in MDR isolates expressing wild-type pncA. The detection of mutations in pncA, rpsA and panD can be useful for the determination of PZA resistance.
OBJECTIVES:Pyrazinamide (PZA) is a crucial first-line tuberculosis (TB) drug recommended for both drug-susceptible and multidrug-resistant Mycobacterium tuberculosis. This study aimed to evaluate the performance of the sequencing method of pncA, rpsA and panD mutations in detecting PZA resistance in multidrug-resistant (MDR) TB isolates. METHODS: We sequenced the pncA, rpsA and panD genes and performed PZA susceptibility tests across 291 MDR-TB isolates to evaluate the performance of the sequencing method of these genes in detecting PZA resistance. RESULTS: Results showed that 145 (90.0%) of 161 PZA phenotypic resistant isolates had mutations in pncA. Among the 16 isolates (10.0%) which did not have mutations in pncA, ten and three isolates had mutations in rpsA and panD, respectively. The sequencing method for detecting mutations in pncA alone had 90.1% (95% confidence interval (CI), 84.4-94.2) sensitivity and 92.3% (95% CI, 86.3-96.3) specificity. The combination of all three genes increased the sensitivity from 90.1% (95% CI, 84.4-94.2) to 98.1% (95% CI, 94.7-99.6) (p < 0.001) while the specificity remained unchanged. In 120 PZA-susceptible and 16 PZA-resistant isolates without pncA mutations, rpsA/panD mutations were correlated with PZA resistance. CONCLUSIONS:PZA resistance was largely associated with mutations in pncA. Mutations in rpsA and panD were also associated with PZA resistance in MDR isolates expressing wild-type pncA. The detection of mutations in pncA, rpsA and panD can be useful for the determination of PZA resistance.
Authors: Annelies Van Rie; John Z Metcalfe; Michael G Whitfield; David M Engelthaler; Christopher Allender; Megan Folkerts; Tim H Heupink; Jason Limberis; Robin M Warren Journal: J Clin Microbiol Date: 2021-11-10 Impact factor: 5.948