A new test based on ‘salting out’ to measure relative hydrophobicity of bacterial cells

Lindahl, Mattias; Faris, Ahmed; Wadström, Torkel; Hjertén, Stellan

doi:10.1016/0304-4165(81)90261-0

Cited by 413 publications

(199 citation statements)

References 24 publications

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“…The surface hydrophobicity of the bacterial cells was determined in triplicate by the salt aggregation test (SAT) (Lindahl et al 1981) and by the microbial adhesion to hydrocarbons (MATH) test (Rosenberg et al 1980). The bacterial cells grown on TYES agar for 3 d were suspended in 2 mM NaH 2 PO 4 , pH 6.8 (SAT test) or phosphate urea magnesium sulfate (PUM) buffer (MATH test; 100 mM K 2 HPO 4 × 3H 2 O, 50 mM KH 2 PO 4 , 30 mM urea, 1 mM MgSO 4 × 7H 2 O, pH 7.1) to an optical density (OD) of 1.1 ± 0.05 at 590 nm (Møller et al 2003).…”

Section: Bacterial Isolates and Growth Conditions Thementioning

confidence: 99%

Phase variation in Flavobacterium psychrophilum: characterization of two distinct colony phenotypes

Högfors‐Rönnholm

Wıklund²

2010

Dis. Aquat. Org.

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Four 'smooth' and 4 'rough' colony phenotypes of the Gram-negative fish pathogen Flavobacterium psychrophilum isolated from rainbow trout Oncorhynchus mykiss were characterized using biochemical, physiological, molecular and virulence tests to better understand the pathogenesis of the bacterium. Biochemically, the 2 cell types did not react significantly differently. Physiologically, the 2 phenotypes had distinct characteristics, and, when grown in broth, the smooth cells were found to be autoagglutinating and able to switch into the non-agglutinating rough phenotype. The rough cells did not switch into the smooth phenotype under any growth conditions tested, indicating that the phase variation from the smooth to rough phenotype is irreversible or that the conditions for the reversible switch are still to be found. Smooth cells were hydrophobic and more adhesive compared to the hydrophilic rough cells, suggesting that the phase variation most probably involves one or several surface structures other than outer membrane proteins and lipopolysaccharides that were found to be similar in both types. Analysis of extracellular products produced by the 2 cell types indicated furthermore that a difference in enzymatic activities could exist. Both cell types were virulent for rainbow trout in an intramuscular challenge; thus, the distinct physiological characteristics of the phenotypes do not seem to be directly associated with virulence, when the body surface of the fish is disregarded. The results suggest that phase variation occurs in F. psychrophilum, but that the importance of the 2 phenotypes for the pathogenesis of the bacterium has still to be investigated.

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Section: Bacterial Isolates and Growth Conditions Thementioning

confidence: 99%

Phase variation in Flavobacterium psychrophilum: characterization of two distinct colony phenotypes

Högfors‐Rönnholm

Wıklund²

2010

Dis. Aquat. Org.

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“…Cell surface hydrophobicity was assayed by a modification of the salting-out method described by Lindahl et al (1981). Mid-log phase cells were suspended in 2 mmol l -1 KPB (pH 7AE0) at approximately 1AE0 · 10 9 cells ml -1 , and the suspension was gently shaken for 30 min at room temperature with different concentrations of ammonium sulphate.…”

Section: Assay Of Cell Surface Hydrophobicitymentioning

confidence: 99%

Characterization of a cationic surfactant-resistant mutant isolated spontaneously from Escherichia coli

et al. 2002

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“…MRHA tests with bovine, sheep, pig, rabbit, guinea-pig, chicken, rat, and mouse red blood cells were performed as with human erythrocytes (3). The hydrophobicity was measured by 'salting out' test of Lindahl and co-workers (9). P fimbriae were detected by latex-bead agglutination test (BACH test, Sockerbolaget, Arl6v, Sweden).…”

Section: Methodsmentioning

confidence: 99%

Lack of association ofEscherichia coliexhibiting both mannose-resistant haemagglutination and diffuse adherence to Hep-2 cells with acute diarrhoea in children

et al. 1990

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SUMMARYStool specimens from 631 children with acute diarrhoea and from 277 healthy controls were tested for the presence of non-enteropathogenic, non-enterotoxigenic Escherichia coli strains which mediated mannose-resistant haemagglutination of human erythrocytes (MRHA +). Fifty-nine (349%) of 169 isolated MRHA + strains but none of 210 MRHA-strains exhibited diffuse adherence (DA+) to HEp-2 cells. DA + strains were found in 37 (5-9 %) children with diarrhoea and in 22 (7-9%) controls. MRHA+/DA+ strains in comparison to MRHA+/DAstrains significantly less frequently expressed P fimbriae (10-7 vs. 736 %), haemolysin production (12-5 vs. 63-2 %), and MRHA of other species erythrocytes (214 vs. 84%).These data demonstrate that E. coli which exhibit the diffuse pattern of adherence to HEp-2 cells also cause MRHA of human erythrocytes. Since these strains were found with similar frequencies in children with and without diarrhoea it seems that DA is not a marker of enteropathogenicity of E. coli.

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A new test based on ‘salting out’ to measure relative hydrophobicity of bacterial cells

Cited by 413 publications

References 24 publications

Phase variation in Flavobacterium psychrophilum: characterization of two distinct colony phenotypes

Phase variation in Flavobacterium psychrophilum: characterization of two distinct colony phenotypes

Characterization of a cationic surfactant-resistant mutant isolated spontaneously from Escherichia coli

Lack of association ofEscherichia coliexhibiting both mannose-resistant haemagglutination and diffuse adherence to Hep-2 cells with acute diarrhoea in children

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