Rough strain

It must also be pointed out that the QACs are eonsiderably less aetive against wild-type than against deep rough strains of E. coli and Sal. typhimurium. It is elear, then, that the outer membrane must act as a permeability barrier against these eompounds. 

It is obvious from the work of Papa et al.185 and Belisle and Brennan186 that the LOSs of M. kansasii are antigenic in the laboratory sense. Belisle and Brennan used this property to demonstrate that rough strains of M. kansasii were devoid of the LOSs, an observation that may be important in the context of the infectivity and persistence of some strains of M. kansasii in some hosts.186 M. tuberculosis, M. leprae, and M. avium are intracellular parasites able to proliferate inside macro-... 

Using erythrocyte-adsorbed lipopolysaccharides from a series of rough strains of Pasteurella psevdotvberculom, it was possible to show that, although their composition was very similar, their specificities differed a little—in such a way that they could be arranged in a spectrum of overlapping specificities where the two opposite-end members of the series failed to cross-react. ... 

Russell AD, Furr JR. Comparitive sensitivity of smooth, rough and deep rough strains of Escherichia coli to chlorhexidine, quaternary ammonium compounds and dibromopropamidine isethionate. Int J Pharm 1987 36 191-197. 

The hydrated nature of amino acid residues lining the porin channels presents an energetically unfavourable barrier to the passage of hydrophobic molecules. In rough strains, the reduction in the amount of polysaccharide on the cell surface allows hydrophobic molecules to approach more closely the surface of the outer membrane and cross the outer membrane lipid bilayer by passive diffusion. This process is greatly facilitated in deep rough and heptose-less strains which have phospholipid molecules on the outer face of their outer membranes as well as on the inner face. The exposed areas of phospholipids favour the absorption and penetration of the hydrophobic agents. 

Since LPS varies in chemical composition from one bacterial species to another, different methods are used for its extraction. LPS is generally extracted from smooth strains of bacteria in a mixture of phenol and water (PW) at 68°C as described by Westphal and Jann (19). After extraction, the solution is allowed to cool and partition. Nearly all proteins remain in the phenol phase or interphase, while polysaccharides, LPS, and nucleic acids remain in the aqueous phase. In some instances, the LPS from certain organisms (i.e. Brucella abortus) remain in the phenol phase. Lipopolysaccharide is extracted from rough strains of bacteria in a mixture of phenol, chloroform, and petroleum ether (PCP) at room temperature as described by Galanos, et (20). After extraction, the chloroform and petroleum ether are removed by rotary evaporation and the LPS is then precipitated from the phenol with water. With some bacteria, PW or PCP will not extract sufficient quantities of LPS (21) and EDTA (22), chloroform-methanol (23), or butanol (11) must be used. 

The C-substance, a common constituent of all pneumococci, was first isolated by Tillett and Francis from a rough strain of Pneumococcus. 

Glycoside produced by deacylation of the main glycolipid from the rough strain of Pneumococcus Type 1. Constit. of the glycolipid of Lactobacillus casei. 

Polysaccharide moiety. The polysaccharide portion of lipopolysaccharide is known to be important in the virulence of many bacteria. Strains lacking polysaccharide side chains (rough strains) are invariably less virulent than those containing such structures. 

Olsthoom et al. to obtain a PSD spectrum from the LPS from a rough strain (lacking the O-specific chain) of Klebsiella pneumoniae. Many other examples can be found in the literature. 

Olsthoorn, M. M. A. Haverkamp, L TIiomas-Oaies, 1. E. Mass spectrometric analysis of Klebsiella pneumoniae ssp. pneumoniae rough strain R20 (01 (-) K20(-)) lipopolysaccharide preparations Identification of novel core oUgosaccharide components and three 3-deoxy-D-monno-oct-2-ulopyranosonic artefacts. J. Mass Spectrom. 1999,34, 622-636. 

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