Detection of Novel Gene Mutations Associated with Pyrazinamide Resistance in Multidrug-Resistant
| Autor: | Hm Adnan, Hameed, Yaoju, Tan, Md Mahmudul, Islam, Zhili, Lu, Chiranjibi, Chhotaray, Shuai, Wang, Zhiyong, Liu, Cuiting, Fang, Shouyong, Tan, Wing Wai, Yew, Nanshan, Zhong, Jianxiong, Liu, Tianyu, Zhang |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Infection and Drug Resistance |
| ISSN: | 1178-6973 |
| Popis: | Objective Pyrazinamide (PZA) is a cornerstone of modern tuberculosis regimens. This study aimed to investigate the performance of genotypic testing of pncA+ upstream region, rpsA, panD, Rv2783c, and clpC1 genes to add insights for more accurate molecular diagnosis of PZA-resistant (R) Mycobacterium tuberculosis. Methods Drug susceptibility testing, sequencing analysis of PZA-related genes including the entire operon of pncA (Rv2044c-pncA-Rv2042c) and PZase assay were performed for 448 M. tuberculosis clinical isolates. Results Our data showed that among 448 M. tuberculosis clinical isolates, 113 were MDR, 195 pre-XDR and 70 XDR TB, while the remaining 70 strains had other combinations of drug-resistance. A total of 60.04% (269/448) M. tuberculosis clinical isolates were resistant to PZA, of which 78/113 were MDR, 119/195 pre-XDR and 29/70 XDR TB strains. PZAR isolates have predominance (83.3%) of Beijing genotype. Genotypic characterization of Rv2044c-pncA-Rv2042c revealed novel nonsynonymous mutations in Rv2044c with negative PZase activity which led to confer PZAR. Compared with phenotypic data, 84.38% (227/269) PZAR strains with mutations in pncA+ upstream region exhibited 83.64% sensitivity but the combined evaluation of the mutations in rpsA 2.60% (7/269), panD 1.48% (4/269), Rv2783c 1.11% (3/269) and Rv2044c 0.74% (2/269) increased the sensitivity to 89.59%. Fifty-seven novel mutations were identified in this study. Interestingly, a frameshift deletion (C−114del) in upstream of pncAwt nullified the effect of A−11G mutation and induced positive PZase activity, divergent from five PZase negative A−11G PZAR mutants. Twenty-six PZAR strains having wild-type-sequenced genes with positive or negative PZase suggest the existence of unknown resistance mechanisms. Conclusion Our study revealed that PZAR rate in MDR and pre-XDR TB was markedly higher in southern China. The concomitant evaluation of pncA+ UFR, rpsA, panD, Rv2783c, and Rv2044c provides more dependable genotypic results of PZA resistance. Fifty-seven novel mutations/indels in this study may play a vital role as diagnostic markers. The upstream region of pncA and PZase regulation are valuable to explore the unknown mechanism of PZA-resistance. Video abstract Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use: https://youtu.be/zW3IJ-ZxTmk |
| Databáze: | OpenAIRE |
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