scholarly journals Potential Plasticity of the Mannoprotein Repertoire Associated to Mycobacterium tuberculosis Virulence Unveiled by Mass Spectrometry-Based Glycoproteomics

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2348
Author(s):  
Laure Tonini ◽  
Bashir Sadet ◽  
Alexandre Stella ◽  
David Bouyssié ◽  
Jérôme Nigou ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mycobacterium Tuberculosis ◽  
Large Scale ◽  
Therapeutic Targets ◽  
Multidrug Resistant ◽  
Host Cells ◽  
Bacterial Protein ◽  
Wild Type ◽  
In The Wild ◽  
Resistant Strains

To date, Mycobacterium tuberculosis (Mtb) remains the world’s greatest infectious killer. The rise of multidrug-resistant strains stresses the need to identify new therapeutic targets to fight the epidemic. We previously demonstrated that bacterial protein-O-mannosylation is crucial for Mtb infectiousness, renewing the interest of the bacterial-secreted mannoproteins as potential drug-targetable virulence factors. The difficulty of inventorying the mannoprotein repertoire expressed by Mtb led us to design a stringent multi-step workflow for the reliable identification of glycosylated peptides by large-scale mass spectrometry-based proteomics. Applied to the differential analyses of glycoproteins secreted by the wild-type Mtb strain—and by its derived mutant invalidated for the protein-O-mannosylating enzyme PMTub—this approach led to the identification of not only most already known mannoproteins, but also of yet-unknown mannosylated proteins. In addition, analysis of the glycoproteome expressed by the isogenic recombinant Mtb strain overexpressing the PMTub gene revealed an unexpected mannosylation of proteins, with predicted or demonstrated functions in Mtb growth and interaction with the host cell. Since in parallel, a transient increased expression of the PMTub gene has been observed in the wild-type bacilli when infecting macrophages, our results strongly suggest that the Mtb mannoproteome may undergo adaptive regulation during infection of the host cells. Overall, our results provide deeper insights into the complexity of the repertoire of mannosylated proteins expressed by Mtb, and open the way to novel opportunities to search for still-unexploited potential therapeutic targets.

scholarly journals Relationship between Pyrazinamide Resistance, Loss of Pyrazinamidase Activity, and Mutations in the pncA Locus in Multidrug-Resistant Clinical Isolates of Mycobacterium tuberculosis

1999 ◽  
Vol 43 (9) ◽  
pp. 2317-2319 ◽  
Author(s):  
M. Mestdagh ◽  
P. A. Fonteyne ◽  
L. Realini ◽  
R. Rossau ◽  
G. Jannes ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Radiometric Method ◽  
Clinical Isolates ◽  
Wild Type ◽  
Resistant Strains ◽  
Resistance Loss

ABSTRACT Sixty-two Mycobacterium tuberculosis isolates were tested for pyrazinamidase activity, and their pyrazinamide susceptibility was determined by the radiometric method. Sequencing ofpncA genes in the 23 resistant strains revealed mutations in 16 pyrazinamidase-negative strains, 11 of which had not been previously described. Six isolates containing wild-typepncA might possess alternative resistance mechanisms.

scholarly journals Activation of 2,4-Diaminoquinazoline in Mycobacterium tuberculosis by Rv3161c, a Putative Dioxygenase

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Eduard Melief ◽  
Shilah A. Bonnett ◽  
Edison S. Zuniga ◽  
Tanya Parish
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mutant Strain ◽  
Type Strain ◽  
Wild Type Strain ◽  
Type A ◽  
Wild Type ◽  
Metabolite Analysis ◽  
Content Type ◽  
Data Support ◽  
In The Wild

ABSTRACT The diaminoquinazoline series has good potency against Mycobacterium tuberculosis. Resistant isolates have mutations in Rv3161c, a putative dioxygenase. We carried out metabolite analysis on a wild-type strain and an Rv3161c mutant strain after exposure to a diaminoquinazoline. The parental compound was found in intracellular extracts from the mutant but not the wild type. A metabolite consistent with a monohydroxylated form was identified in the wild type. These data support the hypothesis that Rv3161c metabolizes diaminoquinazolines in M. tuberculosis.

scholarly journals Constraints of Drug Resistance in Mycobacterium tuberculosis - Prospects for Pharmacological Reversion of Susceptibility to Antibiotics

2017 ◽  
Vol 8 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Aleksandr I. Ilin ◽  
Murat E. Kulmanov ◽  
Ilya S. Korotetskiy ◽  
Marina V. Lankina ◽  
Gulshara K. Akhmetova ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Genetic Heterogeneity ◽  
Multidrug Resistant ◽  
Resistance Mutations ◽  
General Increase ◽  
Drug Induced ◽  
Mdr Tb ◽  
Resistant Strains

Emergence of multidrug resistant strains ofMycobacterium tuberculosis(MDR-TB) threatens humanity. This problem was complicated by the crisis in development of new anti-tuberculosis antibiotics. Induced reversion of drug resistance seems promising to overcome the problem. Successful clinical trial of a new anti-tuberculosis nanomolecular complex FS-1 has demonstrated prospectively of this approach in combating MDR-TB. Several clinical MDR-TB cultures were isolated from sputum samples prior and in the process of the clinical trial. Every isolate was tested for susceptibility to antibiotics and then they were sequenced for comparative genomics. It was found that the treatment with FS-1 caused an increase in the number of antibiotic susceptible strains among Mtb isolates that was associated with a general increase of genetic heterogeneity of the isolates. Observed impairing of phthiocerol dimycocerosate biosynthesis by disruptive mutations inppsACDsubunits indicated a possible virulence remission for the sake of persistence. It was hypothesized that the FS-1 treatment eradicated the most drug resistant Mtb variants from the population by aggravating the fitness cost of drug resistance mutations. Analysis of distribution of these mutations in the global Mtb population revealed that many of them were incompatible with each other and dependent on allelic states of many other polymorphic loci. The latter discovery may explain the negative correlation between the genetic heterogeneity of the population and the level of drug tolerance. To the best of our knowledge, this work was the first experimental confirmation of the drug induced antibiotic resistance reversion by the induced synergy mechanism that previously was predicted theoretically.

scholarly journals A Novel Cecropin D-Derived Short Cationic Antimicrobial Peptide Exhibits Antibacterial Activity Against Wild-Type and Multidrug-Resistant Strains of Klebsiella pneumoniae and Pseudomonas aeruginosa

2020 ◽  
Vol 16 ◽  
pp. 117693432093626
Author(s):  
Iván Darío Ocampo-Ibáñez ◽  
Yamil Liscano ◽  
Sandra Patricia Rivera-Sánchez ◽  
José Oñate-Garzón ◽  
Ashley Dayan Lugo-Guevara ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Health Concern ◽  
Wild Type ◽  
Cationic Antimicrobial Peptide ◽  
Promising Alternative ◽  
Resistant Strains

Infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa and Klebsiella pneumoniae are a serious worldwide public health concern due to the ineffectiveness of empirical antibiotic therapy. Therefore, research and the development of new antibiotic alternatives are urgently needed to control these bacteria. The use of cationic antimicrobial peptides (CAMPs) is a promising candidate alternative therapeutic strategy to antibiotics because they exhibit antibacterial activity against both antibiotic susceptible and MDR strains. In this study, we aimed to investigate the in vitro antibacterial effect of a short synthetic CAMP derived from the ΔM2 analog of Cec D-like (CAMP-CecD) against clinical isolates of K pneumoniae (n = 30) and P aeruginosa (n = 30), as well as its hemolytic activity. Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of CAMP-CecD against wild-type and MDR strains were determined by the broth microdilution test. In addition, an in silico molecular dynamic simulation was performed to predict the interaction between CAMP-CecD and membrane models of K pneumoniae and P aeruginosa. The results revealed a bactericidal effect of CAMP-CecD against both wild-type and resistant strains, but MDR P aeruginosa showed higher susceptibility to this peptide with MIC values between 32 and >256 μg/mL. CAMP-CecD showed higher stability in the P aeruginosa membrane model compared with the K pneumoniae model due to the greater number of noncovalent interactions with phospholipid 1-Palmitoyl-2-oleyl-sn-glycero-3-(phospho-rac-(1-glycerol)) (POPG). This may be related to the boosted effectiveness of the peptide against P aeruginosa clinical isolates. Given the antibacterial activity of CAMP-CecD against wild-type and MDR clinical isolates of P aeruginosa and K pneumoniae and its nonhemolytic effects on human erythrocytes, CAMP-CecD may be a promising alternative to conventional antibiotics.

scholarly journals Direct Detection of Pyrazinamide Resistance in Mycobacterium tuberculosis by Use of pncA PCR Sequencing

2019 ◽  
Vol 57 (8) ◽  
Author(s):  
Kingsley King-Gee Tam ◽  
Kenneth Siu-Sing Leung ◽  
Gilman Kit-Hang Siu ◽  
Kwok-Chiu Chang ◽  
Samson Sai-Yin Wong ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Direct Detection ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Activity Data ◽  
Content Type ◽  
Treatment Regimens ◽  
Mdr Tb ◽  
Resistant Strains ◽  
Respiratory Specimens

ABSTRACT An in-house-developed pncA sequencing assay for analysis of pyrazinamide (PZA) resistance was evaluated using 162 archived Mycobacterium tuberculosis complex (MTBC) isolates with phenotypic PZA susceptibility profiles that were well defined by analysis of Bactec MGIT 960 PZA kit and PZase activity data. Preliminary results showed 100% concordance between pncA sequencing and phenotypic PZA drug susceptibility test (DST) results among archived isolates. Also, 637 respiratory specimens were prospectively collected, and 158 were reported as MTBC positive by the Abbott Realtime MTB assay (96.3% sensitivity [95% confidence interval {CI}: 92.2% to 98.7%]; 100% specificity [95% CI: 99.2% to 100.0%]). Genotypic and phenotypic PZA resistance profiles of these 158 MTBC-positive specimens were analyzed by pncA sequencing and Bactec MGIT 960 PZA kit, respectively. For analysis of PZA resistance, pncA sequencing detected pncA mutations in 5/5 (100%) phenotypic PZA-resistant respiratory specimens within 4 working days. No pncA mutations were detected among PZA-susceptible specimens. Combining archived isolates with prospective specimens, 27 were identified as phenotypic PZA resistant with pncA mutation. Among these 27 samples, 6/27 (22.2%) phenotypic PZA-resistant strains carried novel pncA mutations without rpsA and panD mutations. These included 5 with mutations (a deletion [Del] at 383T [Del383T], Del 380 to 390, insertion of A [A Ins] at position 127, A Ins at position 407, and G Ins at position 508) in pncA structural genes and 1 with a mutation (T-12C) at the pncA promoter region. All six of these strains had no or reduced PZase activities, indicating that the novel mutations might confer PZA resistance. Additionally, 25/27 phenotypic PZA-resistant strains were confirmed multidrug-resistant tuberculosis (MDR-TB) strains. As PZA is commonly used in MDR-TB treatment regimens, direct pncA sequencing will rapidly detect PZA resistance and facilitate judicious use of PZA in treating PZA-susceptible MDR-TB.

scholarly journals Alterations of Metabolic and Lipid Profiles in Polymyxin-ResistantPseudomonas aeruginosa

2018 ◽  
Vol 62 (6) ◽  
Author(s):  
Mei-Ling Han ◽  
Yan Zhu ◽  
Darren J. Creek ◽  
Yu-Wei Lin ◽  
Dovile Anderson ◽  
...  
Keyword(s):  
Lipid A ◽  
Therapeutic Option ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Wild Type ◽  
Metabolomics Data ◽  
Content Type ◽  
In The Wild ◽  
High Level ◽  
Acyl Coenzyme A

ABSTRACTMultidrug-resistantPseudomonas aeruginosapresents a global medical challenge, and polymyxins are a key last-resort therapeutic option. Unfortunately, polymyxin resistance inP. aeruginosahas been increasingly reported. The present study was designed to define metabolic differences between paired polymyxin-susceptible and -resistantP. aeruginosastrains using untargeted metabolomics and lipidomics analyses. The metabolomes of wild-typeP. aeruginosastrain K ([PAK] polymyxin B MIC, 1 mg/liter) and its pairedpmrBmutant strains, PAKpmrB6and PAKpmrB12(polymyxin B MICs of 16 mg/liter and 64 mg/liter, respectively) were characterized using liquid chromatography-mass spectrometry, and metabolic differences were identified through multivariate and univariate statistics. PAKpmrB6and PAKpmrB12, which displayed lipid A modifications with 4-amino-4-deoxy-l-arabinose, showed significant perturbations in amino acid and carbohydrate metabolism, particularly the intermediate metabolites from 4-amino-4-deoxy-l-arabinose synthesis and the methionine salvage cycle pathways. The genomics result showed a premature termination (Y275stop) inspeE(encoding spermidine synthase) in PAKpmrB6, and metabolomics data revealed a decreased intracellular level of spermidine in PAKpmrB6compared to that in PAKpmrB12. Our results indicate that spermidine may play an important role in high-level polymyxin resistance inP. aeruginosa. Interestingly, bothpmrBmutants had decreased levels of phospholipids, fatty acids, and acyl-coenzyme A compared to those in the wild-type PAK. Moreover, the more resistant PAKpmrB12mutant exhibited much lower levels of phospholipids than the PAKpmrB6mutant, suggesting that the decreased phospholipid level was associated with polymyxin resistance. In summary, this study provides novel mechanistic information on polymyxin resistance inP. aeruginosaand highlights its impacts on bacterial metabolism.

scholarly journals Fluoroquinolone Resistance amongMycobacterium tuberculosisStrains from Karachi, Pakistan: Data from Community-Based Field Clinics

2010 ◽  
Vol 55 (2) ◽  
pp. 929-930 ◽  
Author(s):  
Yasraba Rafiq ◽  
Kauser Jabeen ◽  
Rumina Hasan ◽  
Sana Jafri ◽  
Rabia Laiq ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Fluoroquinolone Resistance ◽  
First Line ◽  
Sensitivity Testing ◽  
Community Based ◽  
Strain Type ◽  
Resistant Strains

ABSTRACTA fluoroquinolone (FQ) resistance rate of 5.9% is reported in 205Mycobacterium tuberculosisisolates from patients presenting to field clinics in Karachi, Pakistan (2006 to 2009). FQ resistance among multidrug-resistant (MDR) strains was 11.1% (5/45), and it was 4.9% (5/103) inM. tuberculosisstrains susceptible to all first-line agents. Spoligotyping of resistant strains did not show dominance of one strain type. Our data reflect considerable FQ-resistantM. tuberculosisisolates and the need to consider inclusion of FQ within first-line sensitivity testing in such settings.

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