PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Bacteroidetes”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

336 records · Page 19Linked to original sources
PubMed2006

Phylogenetic and morphological diversity of Bacteroidales members associated with the gut wall of termites.

The microbial community adherent directly or indirectly to the gut wall of termites is distinct from that of the other habitats in the gut. The bacterial 16S rRNA genes were identified from the fractionated gut walls of two termite species, Hodotermopsis sjoestedti and Neotermes koshunensis, and compared with those previously identified from Reticulitermes speratus. Surprisingly, the bacterial constituents were almost entirely different among the termites at the phylotype level (the criterion of the phylotype was >97% nucleotide identity). Bacteria in the order Bacteroidales, which were commonly abundant symbionts on gut walls, were phylogenetically analyzed. They were dispersed in a number of clusters formed by phylotypes from the guts of various termites. In situ hybridization with probes specific for some phylotypes and a phylogenetic cluster detected the cells of several Bacteroidales members with a significant variety of cell morphology in the gut wall fractions, which reflects the phylogenetic diversity of this order.

Animals↗
PubMed1994

FR901451, a novel inhibitor of human leukocyte elastase from Flexibacter sp. I. Producing organism, fermentation, isolation, physico-chemical and biological properties.

A novel human leukocyte elastase (HLE) inhibitor, FR901451 was discovered in the fermentation broth of a bacteria. The bacteria was identified as Flexibacter sp. No. 758. FR901451 has a molecular weight of 1269 and a molecular formula of C60H79N13O18. The mode of inhibition against HLE is competitive, with a Ki value of 9.8 x 10(-9) M.

Animals↗
PubMed1994

FR901451, a novel inhibitor of human leukocyte elastase from Flexibacter sp. II. Pharmacological effect of FR901451.

Intratracheal (i.t.) or intravenous (i.v.) administration of FR901451, a potent inhibitor of human leukocyte elastase (HLE) prevented HLE-induced lung hemorrhage in hamsters with ED50 values of 10.5 micrograms/site and 8.1 mg/kg, respectively. alpha 1-Antitrypsin (alpha 1-AT) also showed inhibitory effect in this model. However, the ED50 value by i.t. injection of FR901451 was 20-fold lower than that of alpha 1-AT. Moreover, FR901451 i.t. significantly modulated porcine pancreas elastase (PPE)-induced changes of the respiratory mechanics in hamsters. The ED50 values were 529 micrograms/site and 244 micrograms/site, which were expressed by static lung compliance (Cst) and vital capacity (VC) of the lungs, respectively. These results suggest that FR901451 could be clinically useful agent for the treatment of the destructive lung disease such as pulmonary emphysema.

Animals↗
PubMedDate not supplied

[An unusual lipid A from a marine bacterium Chryseobacterium scophtalmum CIP 104199T].

The hydrolysis of defatted cells of the marine bacterium Chryseobacterium scophtalmum CIP 104199T with 10% acetic acid (3 h, 100 degrees C) led to an unusual lipid A (LA) (yield 0.6%), obtained for the first time. Using chemical analysis, FAB MS, and NMR spectroscopy, it was shown to be D-glucosamine 1-phosphate acylated with (R)-3-hydroxy-15-methylhexadecanoic and (R)-3-hydroxy-13-methyltetradecanoic acids at the C2 and C3 atoms, respectively. It is similar to the monosaccharide biosynthetic precursor of lipopolysaccharide (LPS), so-called lipid X (LX). Unlike LX, LA can be isolated by the treatment of bacteria with organic solvents only after the preliminary acidic hydrolysis of the cells, which suggests that LA might be strongly, probably chemically, linked to other components of the outer membrane. However, LPS cannot be such a component, because extraction with phenol-water or phenol-chloroform-petroleum ether mixtures in high yields (5.34% and 0.5%, respectively) leads to preparations that do not contain 3-deoxy-D-manno-oct-2-ulopyranosonic acid, 3-hydroxyalkanoic acids, or LA.

Bacteroidetes↗
PubMedDate not supplied

Cytologic manifestation of an unusual bacterial form, Simonsiella species.

Puzzling rodlike structures overlying benign squamous cells in exfoliative cytologic specimens from the upper gastrointestinal and respiratory tracts were initially considered to be fungi, protozoa, bronchodilator crystals, hemoglobin tactoids or plastic fragments. Their morphologic similarity to Simonsiella, a gram-negative bacteria frequently found in the oral cavity, was ultimately recognized. Further studies of smears and cultures obtained from the oral cavities of the authors and from the American Type Culture Collection confirmed the nature of the original findings. These giant bacterial forms were usually found in caterpillarlike side-by-side arrangements of 10 to 12 organisms. Cytologists should be aware of their appearance to avoid possible confusion with pathogenic organisms.

Bacteroidetes↗
PubMed1994

Lysis of cyanobacteria with Flexibacter spp isolated from domestic sewage.

Five species of filamentous cyanobacteria and two species of Flexibacter were isolated from domestic sewage. Cells and filtrates of F. flexilis and F. sancti lysed the cyanobacterium Oscillatoria williamsii. Inhibition of the photosynthetic electron transport reactions, and glycolate dehydrogenase and nitrogenase activity of O. williamsii due to its incubation with F. flexilis, were observed. Scanning electron micrographs revealed the attachment of F. flexilis to the sheaths of O. williamsii which resulted in the excretion of lysozyme and lysis of the cyanobacterium. Seasonal variations of Flexibacter spp showed that they were more abundant in the aeration tanks during June compared with sewage effluents.

Bacterial Adhesion↗
PubMed1997

Immunization with bacterial antigens: Flavobacterium and Flexibacter infections.

Seven bacterial species belonging to the Flavobacterium-Cytophaga group are currently considered to be pathogenic for fish. Because they were only recently described and/or because the disease they provoke has little economic significance, no study has been performed concerning immunization against Chryseobacterium scophthalmum, Flavobacterium johnsoniae and Flexibacter ovolyticus. Immunization with Flexibacter maritimus has not been investigated, and fish surviving a natural infection appear to remain equally susceptible to the disease during subsequent outbreaks. On the other hand, interesting data are available concerning immunization against Flavobacterium branchiophilum, Flavobacterium columnare and Flavobacterium psychrophilum because these bacterial species have been known for many years and are responsible for heavy losses in many countries. Surviving fish are usually protected against further infection by the same pathogens. Extensive serological studies have been performed and virulence mechanisms have also been investigated. The review of immunization trials against these three bacterial species shows important variations depending on the species of fish and the route of administration, but in several cases vaccinated fish were successfully protected by high titre of specific antibodies. However, no vaccine is commercially available.

Animals↗