Characterization of pncA mutations in pyrazinamide-resistant Mycobacterium tuberculosis isolates from Korea and analysis of the correlation between the mutations and pyrazinamidase activity

Yoon, Jang Ho; Nam, Ji Sun; Kim, Kyungjin; Ro, Young-Tae

doi:10.1007/s11274-014-1706-0

Cited by 28 publications

(22 citation statements)

References 36 publications

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“…Thus, loss-of-function mutations in pncA represent the primary mechanism of PZA resistance in clinical isolates. Diverse pncA mutations, including single and multi-nucleotide polymorphisms and indels, have been reported in PZA resistant clinical isolates along the entire 561 base pair gene length [26,27] . Recently, Yadon et al [28] created a comprehensive library of PncA polymorphisms through saturating mutagenesis and identified over 300 substitutions, some of which were previously reported in clinical isolates, that conferred PZA resistance in vitro and in vivo.…”

Section: Proposed Molecular Targets For Pzamentioning

confidence: 99%

Impact of the host environment on the antitubercular action of pyrazinamide

Lamont

Baughn

2019

eBioMedicine

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a b s t r a c tPyrazinamide remains the only drug in the tuberculosis pharmacopeia to drastically shorten first-line therapy from nine to six months. Due to its unparalleled ability to sterilize non-replicating bacilli and reduce relapse rates, PZA is expected to be irreplaceable in future therapies against tuberculosis. While the molecular target of PZA is unclear, recent pharmacokinetic studies using small animal models and patient samples have highlighted the importance of host metabolism and immune responses in PZA efficacy. Delineating which host factors are important for PZA action will be integral to the design of next-generation therapies to shorten current TB drug regimens as well as to overcome treatment limitations in some patients. In this review, we discuss evidence for influence of the host environment on PZA activity, targets for PZA mechanism of action, recent studies in PZA pharmacokinetics, PZA antagonism and synergy with other first-line anti-TB drugs, and implications for future research.

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Section: Proposed Molecular Targets For Pzamentioning

confidence: 99%

Impact of the host environment on the antitubercular action of pyrazinamide

Lamont

Baughn

2019

eBioMedicine

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“…10,[15][16][17] However, Yoon et al 18 reported that mutations at another site may affect the activity of the protein by altering the expression level or the folding effect. 18 In the current study, we performed PZA drug susceptibility testing followed by the sequencing of the pncA gene, which showed some novel mutations that were found to be associated with resistance (under review in BMC (BioMed central) infectious disease). The sequences were submitted in the GeneBank (Accession No MH461111-17).…”

Section: Introductionmentioning

confidence: 99%

Pyrazinamide resistance and mutations L19R, R140H, and E144K in Pyrazinamidase of Mycobacterium tuberculosis

Khan

Junaid

Mao

et al. 2018

J of Cellular Biochemistry

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Pyrazinamide (PZA) is an important component of first‐line antituberculosis drugs activated by Mycobacterium tuberculosis pyrazinamidase (PZase) into its active form pyrazinoic acid. Mutations in the pncA gene have been recognized as the major cause of PZA resistance. We detected some novel mutations, Leucine19Arginine (L19R), Arginine140Histidine (R140H), and Glutamic acid144 Lysine (E144K), in the pncA gene of PZA‐resistant isolates in our wet lab PZA drug susceptibility testing and sequencing. As the molecular mechanism of resistance of these variants has not been reported earlier, we have performed multiple analyses to unveil different mechanisms of resistance because of PZase mutations L19R, R140H, and E144K. The mutants and native PZase structures were subjected to comprehensive computational molecular dynamics (MD) simulations at 100 nanoseconds in apo and drug‐bound form. Mutants and native PZase binding pocket were compared to observe the consequence of mutations on the binding pocket size. Hydrogen bonding, Gibbs free energy, and natural ligand Fe +2 effect were also analyzed between native and mutants. A significant variation between native and mutant PZase structure activity was observed. The native PZase protein docking score was found to be the maximum, showing strong binding affinity in comparison with mutants. MD simulations explored the effect of the variants on the biological function of PZase. Hydrogen bonding, metal ion Fe +2 deviation, and fluctuation also seemed to be affected because of the mutations L19R, R140H, and E144K. The variants L19R, R140H, and E144K play a significant role in PZA resistance, altering the overall activity of native PZase, including metal ion Fe +2 displacement and free energy. This study offers valuable evidence for better management of drug‐resistant tuberculosis.

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“…Whereas the mechanism of action of PZA remains partially unknown, the primary mechanism of PZA resistance in clinical isolates is well established (4,5). Because PZA is a prodrug that requires conversion to pyrazinoic acid (POA) for its antimicrobial effect, mutations of the gene encoding the mycobacterial PncA amidase (pncA) result in PZA resistance (4)(5)(6)(7). Approximately 78% of PZA-resistant isolates harbor mutations in pncA (3).…”

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confidence: 99%

High Systemic Exposure of Pyrazinoic Acid Has Limited Antituberculosis Activity in Murine and Rabbit Models of Tuberculosis

Lanoix

Tasneen

O'Brien

et al. 2016

Antimicrob Agents Chemother

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e Pyrazinamide (PZA) is a prodrug requiring conversion to pyrazinoic acid (POA) by an amidase encoded by pncA for in vitro activity. Mutation of pncA is the most common cause of PZA resistance in clinical isolates. To determine whether the systemic delivery of POA or host-mediated conversion of PZA to POA could circumvent such resistance, we evaluated the efficacy of orally administered and host-derived POA in vivo. Dose-ranging plasma and intrapulmonary POA pharmacokinetics and the efficacy of oral POA or PZA treatment against PZA-susceptible tuberculosis were determined in BALB/c and C3HeB/FeJ mice. The activity of host-derived POA was assessed in rabbits infected with a pncA-null mutant and treated with PZA. Median plasma POA values for the area under the concentration-time curve from 0 h to infinity (AUC 0 -ؕ ) were 139 to 222 g·h/ml and 178 to 287 g·h/ml after doses of PZA and POA of 150 mg/kg of body weight, respectively, in mice. Epithelial lining fluid POA concentrations in infected mice were comparable after POA and PZA administration. In chronically infected BALB/c mice, PZA at 150 mg/kg reduced lung CFU counts by >2 log 10 after 4 weeks. POA was effective only at 450 mg/kg, which reduced lung CFU counts by ϳ0.7 log 10 . POA had no demonstrable bactericidal activity in C3HeB/FeJ mice, nor did PZA administered to rabbits infected with a PZA-resistant mutant. Oral POA administration and host-mediated conversion of PZA to POA producing plasma POA exposures comparable to PZA administration was significantly less effective than PZA. These results suggest that the intrabacillary delivery of POA and that producing higher POA concentrations at the site of infection will be more effective strategies for maximizing POA efficacy.T he control of tuberculosis (TB) is jeopardized by the increasing prevalence of multidrug-resistant TB (MDR-TB) caused by strains which are resistant to at least rifampin (RIF) and isoniazid (INH) (1). Unfortunately, resistance to the other key sterilizing drug, pyrazinamide (PZA), is commonly present in MDR-TB isolates (2). Compounding this problem are the well-recognized challenges in performing PZA susceptibility testing, resulting in the common therapeutic conundrum of whether to include PZA in MDR-TB treatment regimens without certainty of its potential contribution (3). Whereas the mechanism of action of PZA remains partially unknown, the primary mechanism of PZA resistance in clinical isolates is well established (4, 5). Because PZA is a prodrug that requires conversion to pyrazinoic acid (POA) for its antimicrobial effect, mutations of the gene encoding the mycobacterial PncA amidase (pncA) result in PZA resistance (4-7). Approximately 78% of PZA-resistant isolates harbor mutations in pncA (3). However, since pncA mutations do not affect susceptibility to POA in vitro, direct administration of POA or delivery in a form that does not require PncA for the generation of POA inside Mycobacterium tuberculosis could circumvent this mechanism of resistance.The MIC of POA against M. tube...

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Characterization of pncA mutations in pyrazinamide-resistant Mycobacterium tuberculosis isolates from Korea and analysis of the correlation between the mutations and pyrazinamidase activity

Cited by 28 publications

References 36 publications

Impact of the host environment on the antitubercular action of pyrazinamide

Impact of the host environment on the antitubercular action of pyrazinamide

Pyrazinamide resistance and mutations L19R, R140H, and E144K in Pyrazinamidase of Mycobacterium tuberculosis

High Systemic Exposure of Pyrazinoic Acid Has Limited Antituberculosis Activity in Murine and Rabbit Models of Tuberculosis

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