Lipopolysaccharides of the motile aeromonads; core oligosaccharide analysis as an aid to taxonomic classification

1978 ◽  
Vol 24 (7) ◽  
pp. 864-868 ◽  
Author(s):  
Derek H. Shaw ◽  
H. J. Hodder

Twelve motile Aeromonas strains have been examined with respect to the hexose and heptose monosaccharide residues present in the core region of their cell wall lipopolysaccharides. These strains were divided into three distinctly separate groups on the basis of the various combinations of hexose and heptose residues. The assignment of a strain to any one of the three groups furnishes a distribution which is substantially the same as that recently reported in a computer-based numerical analysis. All strains tested which were previously named A. liquefaciens fall into the same group.

1983 ◽  
Vol 29 (10) ◽  
pp. 1458-1461 ◽  
Author(s):  
E. E. Ishiguro ◽  
Teresa Ainsworth ◽  
D. H. Shaw ◽  
W. W. Kay ◽  
T. J. Trust

Cell wall lipopolysaccharide (LPS) was identified as the receptor for the Aeromonas salmonicida bacteriophage strain 55R-1. Mutants of A. salmonicida resistant to phage 55R-1 were unable to adsorb phage 55R-1 and were shown to be defective in LPS structure. Purified A. salmonicida LPS inactivated phage 55R-1, but the O-polysaccharide and the core oligosaccharide portions of the LPS were ineffective. These results suggest that lipid A was required for receptor activity. Antibodies directed against LPS also inhibited phage adsorption.


2009 ◽  
Vol 191 (16) ◽  
pp. 5272-5282 ◽  
Author(s):  
Nikolay A. Paramonov ◽  
Joseph Aduse-Opoku ◽  
Ahmed Hashim ◽  
Minnie Rangarajan ◽  
Michael A. Curtis

ABSTRACT Porphyromonas gingivalis synthesizes two lipopolysaccharides (LPSs), O-LPS and A-LPS. Here, we elucidate the structure of the core oligosaccharide (OS) of O-LPS from two mutants of P. gingivalis W50, ΔPG1051 (WaaL, O-antigen ligase) and ΔPG1142 (O-antigen polymerase), which synthesize R-type LPS (core devoid of O antigen) and SR-type LPS (core plus one repeating unit of O antigen), respectively. Structural analyses were performed using one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy in combination with composition and methylation analysis. The outer core OS of O-LPS occurs in two glycoforms: an “uncapped core,” which is devoid of O polysaccharide (O-PS), and a “capped core,” which contains the site of O-PS attachment. The inner core region lacks l(d)-glycero-d(l)-manno-heptosyl residues and is linked to the outer core via 3-deoxy-d-manno-octulosonic acid, which is attached to a glycerol residue in the outer core via a monophosphodiester bridge. The outer region of the “uncapped core” is attached to the glycerol and is composed of a linear α-(1→3)-linked d-Man OS containing four or five mannopyranosyl residues, one-half of which are modified by phosphoethanolamine at position 6. An amino sugar, α-d-allosamine, is attached to the glycerol at position 3. In the “capped core,” there is a three- to five-residue extension of α-(1→3)-linked Man residues glycosylating the outer core at the nonreducing terminal residue. β-d-GalNAc from the O-PS repeating unit is attached to the nonreducing terminal Man at position 3. The core OS of P. gingivalis O-LPS is therefore a highly unusual structure, and it is the basis for further investigation of the mechanism of assembly of the outer membrane of this important periodontal bacterium.


Author(s):  
Philip D. Lunger ◽  
H. Fred Clark

In the course of fine structure studies of spontaneous “C-type” particle production in a viper (Vipera russelli) spleen cell line, designated VSW, virus particles were frequently observed within mitochondria. The latter were usually enlarged or swollen, compared to virus-free mitochondria, and displayed a considerable degree of cristae disorganization.Intramitochondrial viruses measure 90 to 100 mμ in diameter, and consist of a nucleoid or core region of varying density and measuring approximately 45 mμ in diameter. Nucleoid density variation is presumed to reflect varying degrees of condensation, and hence maturation stages. The core region is surrounded by a less-dense outer zone presumably representing viral capsid.Particles are usually situated in peripheral regions of the mitochondrion. In most instances they appear to be lodged between loosely apposed inner and outer mitochondrial membranes.


1984 ◽  
Vol 108 ◽  
pp. 257-258
Author(s):  
Michael Rosa ◽  
Jorge Melnick ◽  
Preben Grosbol

The massive H II region NGC 3603 is the closest galactic counterpart to the giant LMC nebula 30 Dor. Walborn (1973) first compared the ionizing OB/WR clusters of the two H II regions and suggested that R 136, the unresolved luminous WR + 0 type central object of 30 Dor, might be a multiple system like the core region of NGC 3603. Suggestions that the dominant component of R 136, i.e. R 136A, might be either a single or a very few supermassive and superluminous stars (Schmidt-Kaler and Feitzinger 1982, Savage et al. 1983) have recently been disputed by Moffat and Seggewiss (1983) and Melnick (1983), who have presented spectroscopic and photometric evidence to support the hypothesis of an unresolved cluster of stars. We have extended Walborn's original comparison of the apparent morphology of the two clusters by digital treatment of the images to simulate how the galactic cluster would look like if it were located in the LMC


1997 ◽  
Vol 10 (7) ◽  
pp. 926-928 ◽  
Author(s):  
Mari-Anne Newman ◽  
Michael J. Daniels ◽  
J. Maxwell Dow

Pre-treatment of leaves of pepper (Capsicum annuum) with lipopolysaccharide (LPS) preparations from enteric bacteria and Xanthomonas campestris could prevent the hypersensitive response caused by an avirulent X. campestris strain. By use of a range of deep-rough mutants, the minimal structure in Salmonella LPS responsible for the elicitation of this effect was determined to be lipid A attached to a disaccharide of 2-keto-3-deoxyoctulosonate; lipid A alone and the free core oligosaccharide from a Salmonella Ra mutant were not effective. For Xanthomonas, the core oligosaccharide alone had activity although lipid A was not effective. The results suggest that pepper cells can recognize different structures within bacterial LPS to trigger alterations in plant response to avirulent pathogens.


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