Search results for "Actinomycetes."

Mutations in the rpoB and katG Genes Leading to Drug Resistance in Mycobacterium tuberculosis in Latvia

2002

ABSTRACT To characterize the genetic basis of drug resistance in Mycobacterium tuberculosis in Latvia, mutations involved in rifampin ( rpoB gene) and isoniazid ( katG gene) resistance in DNA from 19 drug-susceptible and 51 multidrug-resistant M. tuberculosis complex isolates were analyzed. The most frequent rpoB gene mutations found by the Line Probe assay were the S531L (14 of 34 isolates), D516V (7 of 34), H526D (4 of 34), and D516Y plus P535S (4 of 34) mutations. Direct sequencing of seven isolates with unclear results from Line Probe assay showed the presence of the L533P mutation and the Q510H plus H526Y (1 of 34) and D516V plus P535S (4 of 34) double mutations, neither of which has b…

Snapshot of Moving and Expanding Clones of Mycobacterium tuberculosis and Their Global Distribution Assessed by Spoligotyping in an International Stu…

2003

ABSTRACT The present update on the global distribution of Mycobacterium tuberculosis complex spoligotypes provides both the octal and binary descriptions of the spoligotypes for M. tuberculosis complex, including Mycobacterium bovis , from >90 countries (13,008 patterns grouped into 813 shared types containing 11,708 isolates and 1,300 orphan patterns). A number of potential indices were developed to summarize the information on the biogeographical specificity of a given shared type, as well as its geographical spreading (matching code and spreading index, respectively). To facilitate the analysis of hundreds of spoligotypes each made up of a binary succession of 43 bits of information, …

Production of Antibacterial Compounds from Actinomycetes

2016

Actinomycetes are soil-dwelling Gram-positive bacteria, industrially relevant as producers of a wide range of bioactive secondary metabolites, including many antibiotics of clinical and commercial importance.The understanding of actinomycete biology has been based on extensive studies on the model organism Streptomyces coelicolor over many years and on the availability of its complete genome sequence. This bacterium has an unusual complex developmental cycle that includes programmed cell death phenomena that make this bacterium a multicellular prokaryotic model.Morphological differentiation in S. coelicolor is strictly related to physiological differentiation: indeed the onset of morphologi…

Identification and characterization of new prolylendopeptidases (PEPs) from Actinomycetes

2011

Unraveling the functional role of Streptomyces coelicolor trpX, an intriguing small orf

2013

NovelAmycolatopsis balhimycinabiochemical abilities unveiled by proteomics

2014

Amycolatopsis balhimycina DSM5908 is an actinomycete producer of balhimycin, an analogue of vancomycin, the antibiotic of ‘last resort’ against multidrug-resistant Gram-positive pathogens. Most knowledge on glycopeptide biosynthetic pathways comes from studies on A. balhimycina as this strain, among glycopeptide producers, is genetically more amenable. The recent availability of its genome sequence allowed to perform differential proteomic analyses elucidating key metabolic pathways leading to antibiotic production in different growth conditions. To implement proteomic data on A. balhimycina derived from 2-DE approaches and to identify novel components, a combined approach based on protein …

Coupling Proteomics and Fermentation Technology for the Improvement of Bioactive Molecule Production Yield in Actinomycetes

2013

Copyright: © 2013 Gallo. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Most bioactive molecules (like anticancers, antitumors, antibiotics, immunosuppressants, insecticidals, antivirals, herbicidals, antifungals) with valuable industrial and market value are naturally produced by actinomycetes [1-4], Gram-positive filamentous bacteria widespread in both terrestrial and aquatic environments [5,6]. Out of thousands of bioactive molecules, also known as secondary metabolites since they are not essential for…

Isolation of Gram-positive n-alkane degraders from a hydrocarbon-contaminated Mediterranean shoreline.

2007

Aims: To investigate the petroleum hydrocarbon (HC)-degrading potential of indigenous micro-organisms in a sandy Mediterranean coast, accidentally contaminated with petroleum-derived HCs. Methods and Results: Using culturable methods, a population of Gram-positive n-alkane degraders was detected in the contaminated soil. Five isolates, identified as one Nocardia, two Rhodococcus and two Gordonia strains, were able to degrade medium- and long-chain n-alkanes up to C36 as assessed by growth assays and gas chromatography-mass spectrometry analysis. Diverging alkane hydroxylase-encoding genes (alkB) were detected by PCR, using degenerated primers, in all the strains; multiple sequences were obt…

Regulation of the biosynthesis of the glycopeptide antibiotic A40926 in Nonomuraea ATCC39727

2011

The actinomycete Nonomuraea produces the glycopeptide A40926, precursor of dalbavancin. Dalbavancin is a novel lipoglycopeptide agent against emerging resistant Gram-positive cocci with superior pharmacodynamics properties compared to vancomycin. Chemically, a glycopeptide antibiotic consists of a heptapeptide core constituted by proteinogenic and nonproteinogenic amino acids such as 3,5-dihydroxyphenylglycine (DPG) and 4-hydroxyphenylglycine (HPG). The heptapeptide is assembled by a nonribosomal peptide synthetase and modified by oxidative cross-linking of the electron-rich aromatic side chains, halogenation, sulfation, methylation, acylation, and glycosylation. The A40926 biosynthetic gen…