Persistent properties of Brucella abortus isolated from various sources

Persistence factors in 70 B. abortus strains isolated from different sources were studied. Depending on the source of the isolation of B. abortus, the spread of their antilysozyme, anticomplementary, antiintercidal activity was determined and intraspecific differences in the manifestation of these signs were established. The highest spread and manifestation of persistence factors was registered in B. abortus populations isolated from brucellosis patients and from cattle.     

Immunochemical studies on sialic acid-containing lipopolysaccharides from enterobacterial species

Abstract Lipopolysaccharides with sialic acid as a component were isolated from six bacterial serovars of the family Enterobacteriaceae . SDS-polyacrylamide gel electrophoresis, immunoblotting and passive haemagglutination demonstrated that epitopes are localized in the O-specific polysaccharide of lipopolysaccharides. The strains were tested for a serological relationship; the only distinct cross-reactivity recorded was between Escherichia coli serovars O24 and O56. The molecular mimicry phenomenon was found for Citrobacter freundii serovar O37 which shared epitopes with horse as well as human red blood cells.     

Biological properties of lipopolysaccharides from Bordetella species

Biological activities of lipopolysaccharides (LPS) extracted from Bordetella pertussis, B. parapertussis and B. bronchiseptica were compared with those of Escherichia coli LPS. The LPS preparations from B. pertussis showed biological activities comparable to those of E. coli LPS in terms of lethal toxicity in galactosamine-sensitized mice, pyrogenicity in rabbits, mitogenicity in C3H/He spleen cell cultures, macrophage activation, and induction of tumour necrosis factor. All the activities of LPS preparations from B. parapertussis, except mitogenicity, were lower than those of E. coli LPS. LPS from B. parapertussis gave the greatest mitogenic action of all those tested. Biological activities stronger than or comparable to those of E. coli LPS were observed for LPS from B. bronchiseptica.     

Electrophoretic analysis of lipopolysaccharide isolated from opaque and translucent colony variants of Vibrio vulnificus using various extraction methods

Lipopolysaccharides (LPS) from an opaque and a translucent colony variant of Vibrio vulnificus were isolated by several methods and the electrophoretic profiles were analysed. The phenol-water extraction method provided a better yield compared to the phenol-chloroform-petroleum ether method. In addition, two rapid micro-assays were used to isolate LPS for electrophoretic analysis. The electrophoretic pattern was the same for all LPS extracts and was similar in both variants. No high molecular weight bands, characteristic of smooth LPS, were detected in the LPS of this organism. This was in contrast to the smooth nature of the LPS of another member of the Vibrionaceae examined, V. cholerae. The result of this study showed no correlation between LPS and colony morphology in V. vulnificus.     

Immunobiological properties of lipopolysaccharides isolated from Fusobacterium nucleatum and F. necrophorum

Lipopolysaccharides (LPSs) were isolated from Fusobacterium nucleatum ATCC 10953 and F. necrophorum ATCC 25286 by the hot phenol/water procedure. F. nucleatum LPS was composed of 16% (w/w) carbohydrate, 10% (w/w) hexosamine and 40% (w/w) fatty acid, while F. necrophorum LPS was composed of 26% (w/w) carbohydrate, 12% (w/w) hexosamine and 28% (w/w) fatty acid. These LPS preparations induced mitogenic responses in spleen cells of BALB/c, BALB/c (nu/nu) and C3H/HeN mice, and these responses were suppressed by the addition of polymyxin B. The preparations also induced the polyclonal responses of C3H/HeN spleen cells. In addition, enhanced glucose utilization and interleukin-1 production by murine peritoneal macrophages were demonstrated. Neither spleen cells nor macrophages from the 'LPS-nonresponsive' C3H/HeJ mouse were activated by LPSs from the Fusobacterium species.     

Diversity of Rhizobia isolated from various Hedysarum species

Cultural and physiological properties, serology, plasmid profiles and infective traits were determined for 23 strains of rhizobia isolated from various Hedysarum species: H. coronarium (common name: sulla) (16), H. carnosum (1), H. alpinum (3), H. mackenzii (2) and H. pallens (1) from Portugal, Spain, Tunisia, Alaska and Israel. Strains isolated from H. alpinum, H. mackenzii and H. pallens have slow growth rates on yeast-extract mannitol medium and were unable to nodulate H. coronarium plants, whereas the latter were effectively nodulated by all sixteen fast growing strains from sulla. Regardless of the country of origin all H. coronarium strains fell into one serogroup and were not serologically related with strains of other Hedysarum species. The RAPD (random amplified polymorphic DNA) fingerprinting method which was carried out on five H. coronarium and three H. alpinum strains allowed distinction to be made among serologically related rhizobia. No particular plasmid profile pattern was observed in relation to the host or geographical origin of the strains.     

Chemical and serological properties of lipopolysaccharides from Vibrio parahaemolyticus O-untypeable strains isolated from patients

Chemical and serological studies have been carried out on the O-antigenic lipopolysaccharides (LPS) of six strains, U-6443, W-90144, X-3972, AD-7999, 90A-6611 and KX-V212, of Vibrio parahaemolyticus isolated from patients. The O-serotypes of these strains have not been identified because they were not agglutinated by any diagnostic antisera against known O-serotype strains. A compositional sugar analysis of their LPS revealed that out of the six O-untypeable (OUT) strains, U-6443, W-90144 and AD-7999 strains belonged to chemotype II (chemotype of O2), 90A-6611 and KX-V212 strains to chemotype III (chemotype of O3, O5, O11 and O13) and X-3972 strain to chemotype IV (chemotype of O4). A structural analysis of LPS isolated from KX-V212 revealed that the inner core region of the LPS consisted of only one mole of 2-keto-3-deoxy-D-manno-octonic acid, which carried a phosphate group at position C4 and the outer core at position C5. In passive hemolysis tests performed by using LPS as the antigen to sensitize sheep red blood cells (SRBC), and diagnostic antisera (O1 to O11) or anti-whole-cell rabbit antisera raised against O12, O13 and the six OUT strains, strong cross-reactivity was observed among LPS derived from the strains belonging to chemotype II (U-6443, W-90144, AD-7999 and O2). Strong cross-reactivity was also observed between X-3972 (chemotype IV) and O4 LPS. In contrast, LPS from two of the strains belonging to chemotype III (90A-6611 and KX-V212) did not react with any of the antisera raised against known O-serotypes. Cross-absorption tests showed that the O-antigens of U-6443, W-90144 and AD-7999 were identical to that of O2, and the O-antigen of X-3972 to that of O4. On the other hand, after the absorption of antisera raised against 90A-6611 and KX-V212 with O2 cells, the hemolytic activities against SRBC sensitized with homologous LPS were still retained at a high titer, whereas the hemolytic activities against SRBC sensitized with LPS from other O-serotype strains were completely eliminated. A cross-absorption test revealed that the O-antigens of these two strains were identical to each other. Thus, it was demonstrated that the O-serotype of OUT strains 90A-6611 and KX-V212 was not involved in the known O-serotypes; rather it represented a novel serotype which has not hitherto been reported.     

Purification and characterization of smooth and rough lipopolysaccharides from Brucella abortus.

In an attempt to obtain pure and well characterized smooth lipopolysaccharide (S-LPS) and rough lipopolysaccharide (R-LPS), smooth and rough strains of Brucella abortus were extracted by two different modifications of the phenol-water method. S-LPS was obtained in the phenol phase, and R-LPS was obtained in the aqueous phase. Further purification was accomplished by treatment with enzymes, detergents, NaI as a chaotropic agent to separate non-covalently bound contaminants, and by gel filtration. The degree of purity of the molecules was determined by chemical and immunological analysis and by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Lipid identification by gas-liquid chromatography showed seven major fatty acids. Palmitic acid accounts for about 50%, stearic acid accounts for about 10%, and hydroxylated fatty acids account for less than 5% of total fatty acids. 2-Keto-3-deoxyoctonate but not heptose was detected in the sugar analysis. Protein was found to be firmly bound to S-LPS but not to R-LPS.     

Pseudomonas syringae lipopolysaccharides: Immunochemical characteristics and structure as a basis for strain classification

Lipopolysaccharide (LPS) preparations of 34 Pseudomonas syringae strains of 19 pathovars were prepared by saline extraction from wet cells and purified by repeated ultracentrifugation. The preparations reacted with homologous O-antisera, obtained by rabbit immunization with heat-killed bacterial cells. Through inhibition of homologous reactions between LPS preparations of heterologous strains (enzyme immunoassay, EIA), it was established for the first time that high serological affinity between strains is observed only if their LPS contains O-specific polysacc haride chains (OPS) comprised of completely identical rather than partially similar units. The central linear part of the OPS was found to be serologically inert when shielded with side groups. Data on immunochemical characteristics of the LPS and OPS structure are analyzed in relation to the design of P. syringae classification scheme.     

Serological properties and immunobiological activities of lipopolysaccharides from black-pigmented and related oral Bacteroides species

Lipopolysaccharides (LPS) from five species of oral Bacteroides, B. gingivalis strains 381 and ATCC 33277, B. oralis ATCC 33269, B. loescheii ATCC 15930, B. intermedius ATCC 25611 and B. corporis ATCC 33547, were extracted from whole cells by the phenol/water procedure, and subsequently purified by treatment with nuclease and ultracentrifugation. The LPS were composed of hexoses, glucosamine, fatty acids and phosphorus. Heptose and 2-keto-3-deoxyoctonate were not detected. The LPS preparations from B. gingivalis strains 381 and ATCC 33277 presented very similar SDS-polyacrylamide gel electrophoresis patterns when stained with ammoniacal silver. They produced a fused precipitin band against an antiserum to B. gingivalis 381 LPS in immunodiffusion tests. Antisera raised against the LPS from B. loescheii and B. intermedius reacted with the LPS prepared from all the oral Bacteroides strains except those of B. gingivalis. All the LPS preparations were mitogenic for spleen cells of BALB/c (nu/nu) mice, but not for thymus cells from C3H/HeN mice. The LPS induced marked mitogenic responses and polyclonal B cell activation for spleen cells of not only C3H/HeN (LPS responder) mice, but also C3H/HeJ (LPS nonresponder) mice. The mitogenic responses were not suppressed significantly upon addition of polymyxin B to the reaction mixture. These LPS also enhanced interleukin-1 production by murine peritoneal macrophages and mouse cell line J744. 1 macrophages. Hydrolysis of B. gingivalis ATCC 33277 LPS in 1 m-HCl at 100 degrees C for 1 h yielded lipid and polysaccharide. The lipid portion was largely composed of fatty acids and glucosamine, and was mitogenic for spleen cells from C3H/HeJ as well as C3H/HeN mice, while the polysaccharide portion induced no significant mitogenic responses under similar experimental conditions.