Stimulation of macrophages by lipopolysaccharide of Vibrio parahaemolyticus

The effect of lipopolysaccharide (LPS) from Vibrio parahaemolyticus on the biochemical and phagocytic activities of murine peritoneal macrophages was determined. Intraperitoneal treatment with different doses (0.5-25 micrograms) of V. parahaemolyticus LPS markedly increased the cellular RNA content as well as lysosomal enzyme activities of peritoneal macrophages. The treatment also stimulated the phagocytic activities of macrophages. These observations suggest that V. parahaemolyticus LPS causes stimulation of murine peritoneal macrophages.     

Immunomodulation of macrophages by radio-detoxified lipopolysaccharide of Salmonella typhimurium

Lipopolysaccharide (LPS) and ratio-detoxified LPS (Rd-LPS) from Salmonella typhimurium were analysed for their ability to stimulate murine peritoneal exudate cells (PEC) and macrophages. Rd-LPS induced much more inflammatory response as compared to LPS. PEC numbers/mouse obtained were significantly higher (3-fold) in response to Rd-LPS than LPS. The haemorrhage was induced in mice by LPS but not by Rd-LPS. Activation of macrophages in vivo by Rd-LPS was significantly higher as compared to LPS. This was evident from the increase levels of their lysosomal enzymes and cytokines. Rd-LPS induced 10-fold increase in acid phosphatase contents of macrophages as compared to controls while only 7-fold increase was obtained with LPS. Arylsulfatase and beta-glucuronidase increased by about 2-fold by Rd-LPS and LPS. Macrophages incubated with Rd-LPS in vitro showed 16-fold and 20-fold increase in the cell associated levels of arylsulfatase and beta-glucuronidase respectively as compared to unstimulated cells. On the other hand, only 6-fold increase was observed in response to LPS in the levels of both the enzymes. TNF-[symbol: see text] and IL-1 secreted by macrophages increased considerably in response to Rd-LPS as compared to those released by LPS. Rd-LPS, thus seems to be a better immunomodulator than untreated LPS.     

Chemical structure of the carbohydrate backbone of Vibrio parahaemolyticus serotype 012 lipopolysaccharide.

The chemical structure of the saccharide portion of Vibrio parahaemolyticus serotype 012 lipopolysaccharide was studied. Using chemical degradation and modification, as well as methylation analysis in combination with GLC-MS, laser-desorption mass spectrometry and 1H-NMR and 13C-NMR spectroscopy, the carbohydrate backbone of the lipopolysaccharide was characterized as a branched decasaccharide with the following structure: (formula; see text) In the native lipopolysaccharide two additional phosphate groups are present and 3-deoxy-D-threo-hexulosonic acid and D-galacturonic acid are bound via acid-labile linkages.     

Demonstration of the presence of alditols and galacturonic acid in Vibrio parahaemolyticus O10 lipopolysaccharide

Abstract Identification of 4 unidentified neutral substances (X₁, X₂, X₃ and X₄) in lipopolysaccharides of Vibrio parahaemolyticus (Miyano et al. (1980) FEMS Microbiol. Lett. 8, 23–28, and 14, 145–148) was attempted. X₁ (1,4-anhydroribitol) was found to be formed from ribitol-5-phosphate during hydrolysis. X₂ was identified to be 2- O -methylribitol. X₃ and X₄ were found to be formed during hydrolysis of galacturonic acid and D-glycero-L-mannoheptose (or L-glycero-D-mannoheptose), respectively. The chemical structures of X₃ and X₄ remain to be determined.     

副溶血弧菌的致病机制

副溶血性弧菌是引发微生物食源性疾病的首要病原菌,其在临床上主要引起3种疾病,即胃肠炎、伤口感染和败血症。经过多年的研究,人们对副溶血性弧菌的致病机制有了一定的认识。我们着重介绍副溶血性弧菌的主要毒力因子、毒力基因表达调控及常用的毒力表型研究方法。     

Serovars of Vibrio parahaemolyticus

Seashore water samples collected along the coastline in Bulgaria and Rumania contained in large numbers OK serovars of V. parahaemolyticus; some of these had been isolated repeatedly over an extended time period: 01 K32, 03 K30, 03 K48, 04 K37, 04 K53, 05 K17, 05 K30. The serovar 05 K17 was virtually present in all water samples and was also isolated from a case of purulent ear infection in a child from Burgas. In contrast, strains recovered from Asian and African coastal water had different K antigens and were never identified in Europe. Two strains of V. parahaemolyticus (serovars 05 K15 and 07 K10) had positive swarming growth resembling that of V. alginolyticus. The first of these was Kanagawa-positive and was isolated from a case of severe diarrhea in Brazzaville. Vibrio parahaemolyticus isolates came from marine or brackish water specimens collected on sand banks, 3 strains were recovered from marine or brackish water in Africa. Vibrio harveyi, a sucrose-negative species important from differential diagnostic aspects, has been isolated from seashore water samples collected on coarse-sand or pebbly beaches.     

Hemolytic activity of and lethal toxin production by environmental strains of Vibrio parahaemolyticus

Repeated subculturing of Kanagawa-negative strains of Vibrio parahaemolyticus on Wagatsuma agar induced the production of a hemolysin which was not the thermostable direct hemolysin. Crude hemolysin exhibited a 30 to 40% lethal toxicity in mice after intraperitoneal injection. A 21-kilodalton protein band was observed with all the environmental isolates in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results suggested that a certain percentage of environmental strains of V. parahaemolyticus is responsible for pathogenesis.     

Medium for Isolation and Differentiation of Vibrio parahaemolyticus and Vibrio alginolyticus

Trypticase soy agar supplemented with sucrose, sodium chloride, bile salts, and triphenyltetrazolium chloride is an improved plating medium for the isolation of Vibrio parahaemolyticus from samples of seawater, permitting better differentiation of this organism from Vibrio alginolyticus and other bacteria.     

Isolation and partial characterization of a compound with siderophore activity from Vibrio parahaemolyticus

A compound with siderophore activity was purified by successive column and thin layer chromatographic procedures from Dowex 1 x 8 extracts of culture supernatants of Vibrio parahaemolyticus AQ 3354. The strain synthesized the compound in culture media containing less than 2 microM added FeCl3. Hydrolysis of the compound yielded alanine, ethanolamine, citric acid and 2-ketoglutaric acid. The 1H-NMR spectrum exhibited the presence of a residue from each of these components in the intact molecule. The fast-atom bombardment mass spectrum of the methyl ester derivative indicated a prominent ion at m/z 477, probably corresponding to [M + 1] ion. Other strains of V. parahaemolyticus were also found to produce this compound when grown in an iron-limited medium.     

Medium for isolation and differentiation of Vibrio parahaemolyticus and Vibrio alginolyticus

Trypticase soy agar supplemented with sucrose, sodium chloride, bile salts, and triphenyltetrazolium chloride is an improved plating medium for the isolation of Vibrio parahaemolyticus from samples of seawater, permitting better differentiation of this organism from Vibrio alginolyticus and other bacteria.     

The multiple identities of Vibrio parahaemolyticus

Vibrio parahaemolyticus is a ubiquitous marine bacterium and human pathogen. The organism possesses multiple cell types appropriate for life under different circumstances. The swimmer cell, with a single polar flagellum, is adapted to life in liquid environments. The polar flagellum is powered by the sodium motive force and can propel the bacterium at fast speeds. The swarmer cell, propelled by many proton-powered lateral flagella, can move through highly viscous environments, colonize surfaces, and form multicellular communities which sometimes display highly periodic architecture. Signals that induce differentiation to the surface-adapted cell type are both physical and chemical in nature. Surface-induced gene expression may aid survival, whether attached to inanimate surfaces or in a host organism. Genetic rearrangements create additional phenotypic versatility, which is manifested as variable opaque and translucent colony morphotypes. Discovery that a LuxR homolog controls the opaque cell type implicates intercellular signaling as an additional survival strategy. The alternating identities of V. parahaemolyticus may play important roles in attachment and detachment, how bacterial populations adapt to growth on surfaces, form structured communities, and develop biofilms.