Influence of the growth conditions on the hydrophobicity of Renibacterium salmoninarum evaluated by different methods

Abstract

The influence of medium and salinity on the cell surface hydrophobicity of Renibacterium salmoninarum was investigated using three different methods: bacterial adherence to hydrocarbons (BATH), salt agglutination test (SAT), and binding to nitrocellulose filters (NCF). The possible relationship among hydrophobicity, haemagglutination and adherence to cell lines was also evaluated. R. salmoninarum showed to be highly hydrophobic regardless of the growth conditions or technique employed. Nevertheless, slight differences can be detected depending on the method used. In the SAT and NCF assays very uniform values were obtained within the strains. All the R. salmoninarum isolates agglutinated in (NH4)2SO4 in a range of 0.05-0.2 M and displayed a 77-100% of adherence to nitrocellulose filters. However, more variable results were observed in the BATH method depending on the hydrocarbon, buffer and strain employed. Although all of the isolates produced haemagglutinins for homeotherm erythrocytes, the majority of them failed to agglutinate poikilothermic red blood cells and were unable to adhere to fish cell lines. Therefore, a general correlation among hydrophobicity, agglutinating capacity for fish erythrocytes and adherence to fish cells can not be established for R. salmoninarum.

Effect of serum factors on the survival of Renibacterium salmoninarum within rainbow trout macrophages

“…Although the addiThe ability of Renibacterium salmoninarum strains tion of heat-inactivated antiserum (antibody alone) opsonized with immune and non-immune rainbow favoured bacterial persistence (data not shown), the trout serum to survive within macrophages was detersunrival was notably enhanced when both antibody ten'um salmoninarum is efficiently ingested by trout phagocytes in the absence of serum factors, which is in contrast with results reported by Rose & Levine (1992). Phagocytosis in the absence of serum suggests a direct cell-bacterium interaction and the hydrophobic surface of R. salmoninarum (Daly & Stevenson 1987, Bruno 1988, Bandin et. al.…”

The detection of two antigenic groups among Renibacterium salmoninarum isolates

“…R. salmoninan+m isolates have been reported to be relatively homogeneous in a number of characteristics such as cell wall composition [11], cell surface hydrophobicity [12][13][14] and low extracelhdar enzymatic production [15]. In addition, they were described to be closely related serologieai!y [7,[16][17][18].…”

An Azorhizobium caulinodans ORS571 locus involved in lipopolysaccharide production and nodule formation on Sesbania rostrata stems and roots

“…The surface hydrophobicity of bacteria was quantitated by the hydrocarbon adhesion assay as described elsewhere (1,22). Briefly, after overnight growth to early stationary phase in defined medium (9), bacteria were resuspended in PUM buffer (23) to a final optical density at 520 nm (OD520) of 1.…”