Seiken Matayoshi

Purification of a κ-Carrageenase from Marine Cytophaga Species

A mixture of extracellular carrageenases was isolated from the cell‐free medium of a culture of marine Cytophaga sp. 1k‐C783 grown on ZoBell 2216 E broth with 0.1% commercial carrageenan. A single active peak of k‐carrageenase was separated and purified from the mixture by ammonium sulfate precipitation, ion‐exchange chromatography, and Sephadex G‐200 gel filtration chromatography. Molecular weight of the purified k‐carrageenase was estimated as 100,000 by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). The purified k‐carrageenase had pH optimum 7.6 and temperature optimum 25 C.

Serological evidence that the Q fever agent (Coxiella burnetii) has spread widely among dairy cattle of Japan.

Serological examination of bovine and human sera for antibodies against Coxiella burnetii was carried out by the immunofluorescence technique. Twenty to 30%o of the cows examined were antibody‐positive. Sera from two veterinarians also had antibody against C. burnetii. These results suggest an increase in the number of infected cows with C. burnetii in Japan since 1954, and also imply the possibility of the prevalence of acute Q fever in the human population, which had been underestimated and undiagnosed for the last three decades.

Relationship between the production of spirosomes and anaerobic glycolysis activity in Escherichia coli B.

The effects of culture conditions (aerobic or anaerobic) and glucose in the medium on the production of spirosomes in Escherichia coli B were studied by SDS-PAGE and electron microscopy. The Mr of the spirosome of E. coli B was estimated to be 97,000. Electron microscopy revealed that the amount of spirosomes derived from anaerobic cultures was about eightfold larger than that from aerobic cultures. In SDS-PAGE, the bands of spirosome protein derived from anaerobic cultures were more intense than those derived from aerobic cultures, either in peptone water or in Davis-Mingiolis minimal medium. With increased glucose concentration under aerobic conditions, the intensity of the band of spirosome protein was similar to that observed under anaerobic conditions in basal media. These results suggest that spirosome production by E. coli B is related to its anaerobic glycolysis activity.

A heat-stable component of Bartonella henselae upregulates intercellular adhesion molecule-1 expression on vascular endothelial cells

Bartonella henselae upregulated the expression of intercellular adhesion molecule‐1 (ICAM‐1) on human umbilical vein endothelial cells (HUVECs). The induction level of ICAM‐1 depended on the inoculation bacterial dose. ICAM‐1 expression began increasing 4 h after infection and reached a sustained peak beginning at 12 h after B. henselae infection; this time course was similar to that of lipopolysaccharide (LPS) of Escherichia coli. The stimulatory effect was abolished when live B. henselae were separated from HUVECs by a filter membrane. The nonpiliated strain, which is unable to invade endothelial cells, induced ICAM‐1 expression to the same extent as the piliated strain. Inactivation of B. henselae by ultraviolet (UV) irradiation, heat (56 °C, 30 min), or sonication did not alter its stimulatory activity. Polymyxin B, which strongly inhibited the effect of LPS, did not exert any influence on the stimulatory activity of B. henselae. Furthermore, the effect of sonicated B. henselae was not inhibited even by boiling, which was also the case with LPS. Our data suggest that some heat‐stable component of B. henselae binds to the endothelial cell surface, inducing ICAM‐1 expression. Though the participation of LPS could not be completely ruled out, we suppose that some unidentified heat‐stable proteins, lipids, or polysaccharides may be the stimulatory factor(s). The ability of B. henselae to enhance the expression of adhesion molecules on endothelial cells may be an important mechanism in the pathogenesis of B. henselae infection.

The presence of Angiostrongylus cantonensis in Viti Levu, Fiji

Wild rats and molluscs were examined for Angiostrongylus cantonensis infection on Viti Levu, Fiji. A. cantonensis were recovered from 29.6% (16/54) of Rattus rattus and 59.5% (25/42) of R. exulans. A. cantonensis-like larval nematodes were found in all of four slugs, Laevicaulis alte, and ten of 20 unidentified land snails. The larvae developed to adult A. cantonensis in the pulmonary arteries of laboratory rats 40 to 42 days after ingestion. This is the first record of A. cantonensis in Fiji.

Observations on the transmission of Angiostrongylus cantonensis from snail to rodent

A survey of Angiostrongylus cantonensis was carried out to investigate the mode of transmission from mollusc to rat in a fixed study area of Yoron Island from 1979 to 1982. Rattus rattus was found to be infected with a small number of worms in spite of heavy infection with third-stage larvae in Achatina fulica and an abundance of this snail in the area. Natural infection and/or susceptibility with A. cantonensis were confirmed in three small snail species. Bradybaena circulus, Fruticicola despecta and Luchuena reticulata. Young A. fulica was found to be infected with fewer third-stage larvae than mature A. fulica. It was concluded that molluscs which were infected with a small number of third-stage larvae of A. cantonensis play an important role in maintaining the life cycle of A. cantonensis. The percentage of rat stomachs containing mollusc tissue was relatively low, and the incidence and infection was low in rats. Infection with A. cantonensis did not occur very often in R. rattus in nature.

CD14-Mediated Induction of Interleukin-8 and Monocyte Chemoattractant Protein-1 by a Heat-Resistant Constituent of Porphyromonas gingivalis in Endothelial Cells

Viable and inactivated Porphyromonas gingivalis dose‐dependently induced interleukin‐8 (IL‐8) and monocyte chemoattractant protein‐1 (MCP‐1) secretion in human umbilical vein endothelial cells (HUVECs). The inactivated P. gingivalis, in comparison with viable bacteria, tended to enhance the production of both chemokines more strongly. The production of MCP‐1 protein began increasing immediately after stimulation by P. gingivalis, and there was a nearly linear increase from 0 to 8 h of incubation, whereas IL‐8 production showed a linear increase between 4 and 12 h of incubation. The IL‐8 and MCP‐1 mRNA expressions in HUVECs as determined by reverse transcriptase‐polymerase chain reaction (RT‐PCR) or Quantikine mRNA colorimetric quantification kits were found to be enhanced by P. gingivalis. Furthermore, the time courses of IL‐8 and MCP‐1 mRNA expressions were in accordance with those of protein production. Addition of polymyxin B or boiling did not weaken the stimulatory effect of P. gingivalis, which inhibited the effect of Escherichia coli lipopolysaccharide (E. coli LPS) and tumour necrosis factor‐α (TNF‐α), respectively. In contrast, the induction of IL‐8 and MCP‐1 by P. gingivalis was significantly reduced by anti‐CD14 antibody. Our results suggest that some heat‐stable component of P. gingivalis, including LPS, may be responsible for the induction of IL‐8 and MCP‐1 in HUVECs by a CD14‐dependent mechanism. These effects might be involved in the accumulation and activation of neutrophils and monocytes at an early stage of the periodontal pathogenesis.

Detection of Fine Spiral Structures (Spirosomes) by Weak Sonication in Some Bacterial Strains

Fine spiral structures (spirosomes) were observed in cell suspensions of five species of bacteria just after weak sonication. The structure is morphologically indistinguishable from the spirosome reported for Lactobacillus species. The molecular weight of the protein of the spirosomes from nine strains was about 94,000 to 95,000 as determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The difference in the molecular weight among these spirosomes was not very great, but there were slight differences among the strains from which the spirosomes were derived.

The induction of intercellular adhesion molecule-1 on human umbilical vein endothelial cells by a heat-stable component of Porphyromonas gingivalis

Live Porphyromonas gingivalis enhanced the expression of intercellular adhesion molecule-1 (ICAM-1) on the surface of human umbilical vein endothelial cells (HUVECs) in a bacterial dose-dependent manner. Inactivation of P. gingivalis by ultraviolet (UV), heat (56°C, 30 min), or sonication did not alter its stimulatory activity. ICAM-1 expression began to increase at 4 h after stimulation, reached a maximum at 12 h, and remained at the maximum for at least the next 8 h. This time course was similar to that of expression by Escherichia coli LPS. Furthermore, the effect of UV-inactivated P. gingivalis was not inhibited by boiling or polymyxin B treatment. In addition, the effect of P. gingivalis strain W83 on ICAM-1 expression was stronger than that of strain ATCC 33277. Our results suggested that some unidentified, heat-stable proteins, polysaccharides, or lipids may be the stimulatory factor(s), although the participation of LPS could not be completely ruled out. The ability of P. gingivalis to stimulate ICAM-1 expression on endothelial cells may play an important role in the pathogenesis of periodontal disease.