A5087666815- Tuberculosis Research and Epidemiology
- Mycobacterium research and diagnosis
- Biochemical and Molecular Research
- Antibiotic Resistance in Bacteria
- Cystic Fibrosis Research Advances
- Cancer therapeutics and mechanisms
- Bacterial biofilms and quorum sensing
- Algal biology and biofuel production
- Vibrio bacteria research studies
- Bacterial Genetics and Biotechnology
- Bacteriophages and microbial interactions
- Photosynthetic Processes and Mechanisms
- Enzyme Structure and Function
- Legume Nitrogen Fixing Symbiosis
- RNA and protein synthesis mechanisms
- Trace Elements in Health
- Microbial Metabolic Engineering and Bioproduction
- Enzyme Catalysis and Immobilization
- Pneumocystis jirovecii pneumonia detection and treatment
- Plant Pathogenic Bacteria Studies
- Chemical Reactions and Isotopes
- Digital Filter Design and Implementation
- Enzyme Production and Characterization
- Diagnosis and treatment of tuberculosis
- ATP Synthase and ATPases Research
University of Pavia
2013-2023
University of Naples Federico II
1999-2013
École Polytechnique Fédérale de Lausanne
2010
University of Padua
1994-2007
Biogem
2005
University of Genoa
2000-2004
Cefriel
1992
University of Milan
1991
Institute of Genetics and Biophysics
1988-1991
New drugs are required to counter the tuberculosis (TB) pandemic. Here, we describe synthesis and characterization of 1,3-benzothiazin-4-ones (BTZs), a new class antimycobacterial agents that kill Mycobacterium in vitro, ex vivo, mouse models TB. Using genetics biochemistry, identified enzyme decaprenylphosphoryl-beta-d-ribose 2'-epimerase as major BTZ target. Inhibition this enzymatic activity abolishes formation decaprenylphosphoryl arabinose, key precursor is for cell-wall arabinans, thus...
A critical feature of Mycobacterium tuberculosis, the causative agent human tuberculosis (TB), is its ability to survive and multiply within macrophages, making these host cells an ideal niche for persisting microbes. Killing intracellular tubercle bacilli a key requirement efficient treatment, yet identifying potent inhibitors has been hampered by labor-intensive techniques lack validated targets. Here, we present development phenotypic cell-based assay that uses automated confocal...
ABSTRACT The proteins belonging to the Fur family are global regulators of gene expression involved in response several environmental stresses and maintenance divalent cation homeostasis. Mycobacterium tuberculosis genome encodes two Fur-like proteins, FurA a protein formerly annotated FurB. Since this paper we show that it represents zinc uptake regulator, refer as Zur. encoding Zur is found an operon together with second transcriptional regulator (Rv2358). In previous work demonstrated...
The benzothiazinone BTZ043 is a tuberculosis drug candidate with nanomolar whole-cell activity. targets the DprE1 catalytic component of essential enzyme decaprenylphosphoryl-β-D-ribofuranose-2'-epimerase, thus blocking biosynthesis arabinans, vital components mycobacterial cell walls. Crystal structures DprE1, in its native form and complex BTZ043, reveal formation semimercaptal adduct between an active-site cysteine, as well contacts to neighboring lysine residue. Kinetic studies confirm...
Benzothiazinones (BTZs) are antituberculosis drug candidates with nanomolar bactericidal activity against tubercle bacilli. Here we demonstrate that BTZs suicide substrates of the FAD-dependent decaprenylphosphoryl-β-D-ribofuranose 2'-oxidase DprE1, an enzyme involved in cell-wall biogenesis. reduced by DprE1 to electrophile, which then reacts a near-quantitative manner active-site cysteine thus providing rationale for extraordinary potency BTZs. Mutant enzymes from BTZ-resistant strains...
The presence of persister cells has been proposed as a factor in biofilm resilience. In the present study we investigated whether are Burkholderia cepacia complex (Bcc) biofilms, what molecular basis antimicrobial tolerance Bcc persisters is, and how can be eradicated from biofilms. After treatment biofilms with high concentrations various antibiotics often small subpopulation survived. To investigate mechanism this subpopulation, cenocepacia were treated 1024 µg/ml tobramycin. Using...
Phenotypic screening of a quinoxaline library against replicating Mycobacterium tuberculosis led to the identification lead compound Ty38c (3-((4-methoxybenzyl)amino)-6-(trifluoromethyl)quinoxaline-2-carboxylic acid). With an MIC99 and MBC 3.1 μM, is bactericidal active intracellular bacteria. To investigate its mechanism action, we isolated mutants resistant sequenced their genomes. Mutations were found in rv3405c, coding for transcriptional repressor divergently expressed rv3406 gene....
The Mycobacterium tuberculosis Rv2686c-Rv2687c-Rv2688c operon, encoding an ABC transporter, conferred resistance to ciprofloxacin and, a lesser extent, norfloxacin, moxifloxacin, and sparfloxacin smegmatis. level decreased in the presence of efflux pump inhibitors reserpine, carbonyl cyanide m-chlorophenylhydrazone, verapamil. Energy-dependent from M. smegmatis cells containing operon was observed.
The Mycobacterium tuberculosis mmpL7 gene, encoding a hypothetical resistance nodulation division transporter, confers high level to isoniazid when overexpressed in smegmatis. decreased the presence of efflux pump inhibitors reserpine and CCCP (carbonyl cyanide m-chlorophenylhydrazone). Energy-dependent from M. smegmatis cells expressing gene was observed.
Burkholderia cenocepacia J2315 is representative of a highly problematic group cystic fibrosis (CF) pathogens. Eradication B. very difficult with the antimicrobial therapy being ineffective due to its high resistance clinically relevant agents and disinfectants. RND (Resistance-Nodulation-Cell Division) efflux pumps are known be among mediators multidrug in Gram-negative bacteria. Since significance 16 systems present (named RND-1 -16) has been only partially determined, aim this work was...
The new antitubercular drug candidate 2-[2-S-methyl-1,4-dioxa-8-azaspiro[4.5]dec-8-yl]-8-nitro-6-(trifluoromethyl)-4H-1,3-benzothiazin-4-one (BTZ043) targets the DprE1 (Rv3790) subunit of enzyme decaprenylphosphoryl-beta-d-ribose 2'-epimerase. To monitor potential development benzothiazinone (BTZ) resistance, a total 240 sensitive and multidrug-resistant Mycobacterium tuberculosis clinical isolates from four European hospitals were surveyed for presence mutations in dprE1 gene BTZ...
4-Aminoquinolone piperidine amides (AQs) were identified as a novel scaffold starting from whole cell screen, with potent cidality on Mycobacterium tuberculosis (Mtb). Evaluation of the minimum inhibitory concentrations, followed by genome sequencing mutants raised against AQs, decaprenylphosphoryl-β-d-ribose 2′-epimerase (DprE1) primary target responsible for antitubercular activity. Mass spectrometry and enzyme kinetic studies indicated that AQs are noncovalent, reversible inhibitors DprE1...
The high tolerance of biofilm-grown Burkholderia cepacia complex bacteria against antimicrobial agents presents considerable problems for the treatment infected cystic fibrosis patients and implementation infection control guidelines. In present study, we analyzed planktonic sessile cenocepacia J2315 cultures examined transcriptional response cells to with chlorhexidine. At low (0.0005%) (0.05%) concentrations, chlorhexidine had a similar effect on both populations, but at intermediate...
To combat the emergence of drug-resistant strains Mycobacterium tuberculosis, new antitubercular agents and novel drug targets are needed. Phenotypic screening a library 594 hit compounds uncovered two leads that were active against M. tuberculosis in its replicating, non-replicating, intracellular states: 7947882 (5-methyl-N-(4-nitrophenyl)thiophene-2-carboxamide) 7904688 (3-phenyl-N-[(4-piperidin-1-ylphenyl)carbamothioyl]propanamide). Mutants resistant to both harbored mutations ethA...
The development and spread of Mycobacterium tuberculosis multi-drug resistant strains still represent a great global health threat, leading to an urgent need for novel anti-tuberculosis drugs. Indeed, in the last years, several efforts have been made this direction, through number high-throughput screenings campaigns, which allowed identification numerous hit compounds targets. Interestingly, independent screening assays identified same proteins as target different compounds, reason, they...
ABSTRACT The mmr gene, cloned from Mycobacterium tuberculosis , was shown to confer smegmatis resistance tetraphenylphosphonium (TPP), erythromycin, ethidium bromide, acriflavine, safranin O, and pyronin Y. gene appears code for a protein containing four transmembrane domains. Studies of [ 3 H]TPP intracellular accumulation strongly suggest that the mediated by Mmr involves active extrusion TPP.
Both intrinsic and acquired multidrug resistance play an important role in the insurgence of tuberculosis. Detailed knowledge molecular basis drug recognition transport by systems is required for development new antibiotics that are not extruded or inhibitors block transporter allow traditional to be effective. We have undertaken inventory transporters subfamily, included major facilitator superfamily (MFS), encoded complete genome Mycobacterium tuberculosis (MTB). These proteins were...