A form of alpha-galactosylceramide, KRN7000, activates CD1d-restricted Valpha14-invariant (Valpha14i) natural killer (NK) T cells and initiates multiple downstream immune reactions. We report that substituting the C26:0 N-acyl chain KRN7000 with shorter, unsaturated fatty acids modifies outcome Valpha14i NKT cell activation. One analogue containing a diunsaturated C20 acid (C20:2) potently induced helper type 2-biased cytokine response, diminished IFN-gamma production reduced expansion....

Mycobacterium tuberculosis (Mtb) infection remains a global health crisis. Recent genetic evidence implicates specific cell envelope lipids in Mtb pathogenesis, but it is unclear whether these compounds affect pathogenesis through structural role the wall or as effectors that interact directly with host cells. Here we show cyclopropane modification of glycolipid trehalose dimycolate (TDM) critical for growth during first week mice. In addition, TDM by synthase pcaA was both necessary and...

Mycobacterium tuberculosis, the causative agent of has two distinguishing characteristics: its ability to stain acid-fast and cause long-term latent infections in humans. Although this distinctive staining characteristic often been attributed lipid-rich cell wall, specific dye-retaining components were not known. Here we report that targeted deletion kasB, one M. tuberculosis genes encoding distinct beta-ketoacyl- acyl carrier protein synthases involved mycolic acid synthesis, results loss...

The 16S rDNA sequence similarities between the type strains of Sphingomonas paucimobilis and 32 other species range from 90.2 to 99.6%. It might be possible divide genus into several new genera according a dendrogram drawn similarity. However, phenotypic biochemical information needed define clusters representing distinct within this group organisms was not previously available. Although cellular lipids all 28 tested contained glucuronosyl-(1 --> 1)-ceramide together with 2-hydroxymyristic...

An array of lipidic compounds that constitute the cell wall mycobacteria is recognized by host receptors. Examples include trehalose dimycolate (TDM), which a major surface-exposed glycolipid mycobacteria, interacts with macrophage inducible C-type lectin, Mincle, and exerts its highly potent adjuvant functions. Recent evidence has suggested glycerol monomycolate (GroMM), another mycolate-containing lipid species produced can stimulate innate immune cells; however, specific receptors have...

Pulmonary surfactant contains homeostatic and antimicrobial hydrolases. When Mycobacterium tuberculosis is initially deposited in the terminal bronchioles alveoli, as well following release from lysed macrophages, bacilli are intimate contact with these lung We identified measured several hydrolases human alveolar lining fluid tissue that, at their physiological concentrations, dramatically modified M. cell envelope. Independent of action time (15 min to 12 h), effects on envelope resulted a...

We have characterized the gene encoding fatty acid alpha-hydroxylase, a cytochrome P450 (P450) enzyme, from Sphingomonas paucimobilis. A database homology search indicated that deduced amino sequence of this product was 44% identical to ybdT is 48 kDa protein unknown function Bacillus subtilis. In study, we cloned and using recombinant enzyme clarify product. The carbon monoxide difference spectrum showed characteristic one P450. presence H2O2, hydroxylated myristic produce...

Four Gram-positive bacteria, strains A1-17B T , A1-22 A1-3 and A1-8, isolated from the air in Russian space laboratory Mir, were subjected to a polyphasic taxonomic study. Phylogenetic analysis of bacteria based on their 16S rDNA sequence showed that they belong genera Rothia (A1-17B ), Rhodococcus (A1-22 ) Arthrobacter (A1-3 A1-8). Morphological, physiological, chemotaxonomic genomic characteristics supported assignments these genera, but could not be classified as any existing species...

ABSTRACT Granulomatous inflammation is characterized morphologically by a compact organized collection of macrophages and their derivatives. It classified as either hypersensitivity type or foreign-body type. Lipid components the Mycobacterium tuberculosis cell wall participate in pathogenesis infection. Strains M. have cord factor (trehalose 6,6′-dimycolate [TDM]) on surface. To clarify host responses to TDM, including immunogenicity pathogenicity, we analyzed footpad reaction,...

Abstract Three mycobacterium strains isolated from clinical specimens in Japan were provisionally assigned to the genus Mycobacterium based on their phenotypical characteristics. These isolates further investigated determine specific taxonomic statuses. Mycolic acid analysis and 16S rRNA gene, rpoB , hsp65 sequence data for showed that they are most similar M. terrae complex. DNA‐DNA hybridization studies indicated three of two species distinguishable terrae, nonchromogenicum hiberniae ....

ABSTRACT The antimycobacterial activities of disulfiram (DSF) and diethyldithiocarbamate (DDC) against multidrug- extensively drug-resistant tuberculosis (MDR/XDR-TB) clinical isolates were evaluated in vitro . Both DSF DDC exhibited potent antitubercular 42 M. , including MDR/XDR-TB strains. Moreover, showed remarkable bactericidal activity ex vivo Therefore, might be a drug repurposed for the treatment MDR/XDR-TB.

Abstract Mycobacterium abscessus (MAB) is a species of nontuberculous mycobacteria (NTM) and major causative pathogen pulmonary diseases especially in patients with cystic fibrosis. MAB infection notoriously difficult to treat because its intrinsic or inducible resistance most antibiotics. The rough (R) morphotype MAB, lacking cell surface glycopeptidolipids (GPLs), associated more severe persistent than the smooth (S) type; however, mechanisms underlying R type’s virulence relation GPLs...

Abstract Based on the results of phylogenetic analysis 16S rDNA sequences and presence N ‐2′‐hydroxymyristoyl dihydrosphingosine 1‐glucuronic acid (SGL‐1) 2‐hydroxymyristic (non‐hydroxymyristic in Zymomonas ) cellular lipids, a new family, Sphingomonadaceae , for Group 4 alpha‐subclass class Proteobacteria is herein proposed description family given. The consists six genera, Sphingomonas, Erythrobacter, Erythromicrobium, Porphyrobacter, Sandaracinobacter . Thus, all validly published...

A polyphasic taxonomic study was performed on Sphingomonas sp. strain RW1T. The organism isolated from water of the River Elbe and has been known as a potent metabolizer dibenzo-p-dioxin its relatives. TLC mild alkaline hydrolysate extractable cellular lipids RW1T type strains 21 species gave spot sphingoglycolipid (SGL)-1 (glucuronosyl ceramide), which is characteristic sphingomonads. In addition, three (Sphingomonas yanoikuyae, terrae macrogoltabidus) showed second SGL (SGL-1')...

On the basis of phenotypic and genotypic characteristics 16S rRNA gene sequence analysis, novel species belonging to genera Sphingomonas Brevundimonas were identified from samples taken Russian space laboratory Mir. Strain A1-18 T was isolated air. rDNA analysis showed that strain formed a coherent cluster with sanguinis , parapaucimobilis paucimobilis roseiflava similarity 97·5–98·6 %. Similar other species, G+C content 66·1 mol%, but DNA–DNA hybridization rates at optimal temperatures...

During the serial passage of Mycobacterium bovis bacillus Calmette-Guérin (BCG) in different countries after initial seed distribution from Pasteur Institute, specific insertions and deletions genome among BCG substrains were observed speculated to result differences immunological activities. 'Early-shared strains' (Russia, Moreau, Japan, Sweden, Birkhaug), distributed by which conserve three types mycolate (alpha, methoxy, keto) cell wall, exhibited stronger activities induction nitric...

It is reported that some bacteria or bacterial components cause thymic atrophy via the apoptotic process. The present study demonstrated for first time in vivo induction of apoptosis mouse thymus by mycobacterial cord factor (CF) (trehalose 6,6'-dimycolate). When 300 microg purified CF from Mycobacterium tuberculosis was intravenously administered to BALB/c mice form water-in-oil-in-water (w/o/w) emulsion, and pulmonary granulomas were induced with a peak on day 7, whereas, liposomes, days...

It is difficult to distinguish pulmonary disease due Mycobacterium avium complex (MAC) from that other mycobacteria, such as tuberculosis and kansasii. We developed an enzyme immunoassay (EIA) for diagnosis of MAC diseases uses glycopeptidolipid (GPL) antigens specific MAC, we used it in immunocompetent patients. The mean optical densities (± standard deviation) serum immunoglobulin G antibodies GPLs patients with disease, colonization, M. kansasii healthy subjects were 0.778 ± 0.784, 0.042...

A polyphasic taxonomic study was performed on the phytopathogenic bacterial strains DAPP-PG 224(T) and 228, which cause brown spot yellow Spanish melon (Cucumis melo var. inodorus) fruits. Based presence of glucuronosyl ceramide (SGL-1) in cellular lipids, results fatty acid analysis 16S rDNA sequence comparison, had been identified as belonging to genus Sphingomonas phylogenetically related mali, pruni asaccharolytica. The levels similarity these three species strain were respectively 98.0,...

ABSTRACT We report the development of a serodiagnostic method for Mycobacterium avium complex (MAC) disease with an enzyme immunoassay (EIA) MAC-specific glycopeptidolipid (GPL) core as antigen. In this study, we confirmed by EIA that GPL antibody was in sera immunocompetent patients MAC disease. The quantifying evaluated clinical tool serodiagnosis pulmonary A significant increase antibodies (immunoglobulins G, A, and M) detected diseases when they were compared to who colonized MAC,...

ABSTRACT Bacteria coordinate assembly of the cell wall as well synthesis cellular components depending on growth state. The mycobacterial is dominated by mycolic acids covalently linked to sugars, such trehalose and arabinose, critical for pathogenesis mycobacteria. Transfer sugars necessary biogenesis mediated mycolyltransferases, which have been previously identified three antigen 85 (Ag85) complex proteins. However, regulation mechanism links state has not elucidated. Here we found that a...

Mycolic acids are unique long chain fatty found in the cell walls of mycobacteria including tubercle bacillus, Mycobacterium tuberculosis. The introduction double bonds mycolic remains poorly understood, however, genes encoding two potential aerobic desaturases have been proposed to be involved this process. Here we show that one these genes, desA1, is essential for growth saprophytic smegmatis. Depletion desA1 a M. smegmatis conditional mutant led reduction acid biosynthesis and loss...