Strains Of Bacteroides Gingivalis Research Articles

Glycosaminoglycan-depolymerizing enzymes produced by anaerobic bacteria isolated from the human mouth

A number of obligately anaerobic bacteria, some implicated in periodontal disease, were screened for their ability to produce enzymes capable of degrading hyaluronic acid and chondroitin-4-sulphate. Two screening methods were used following anaerobic incubation at 37 °C for 7 days. One involved incorporating the respective substrates and bovine-serum albumin into agar plates and, after incubation, flooding the plates with 2 M acetic acid. Clear zones were produced around colonies which produced enzymes capable of depolymerizing the substrates. The second was a sensitive spectrophotometric procedure based on the ability of certain bacteria to produce eliminase enzymes, which degrade the substrates to unsaturated products having a characteristic u.v. absorption at 232 nm. Strains of Bacteroides gingivalis and Bacteroides melaninogenicus degraded both substrates whereas Bacteroides asaccharolyticus degraded neither substrate by either method. Some bacteria gave negative results with the plate method whereas the more sensitive spectrophotometric assay proved positive. The number of anaerobic bacteria capable of degrading hyaluronic acid and chondroitin-4-sulphate in vitro may therefore have been underestimated in previous studies.

Histopathological effects in the palate of the rat induced by injection with different black‐pigmented Bacteroides strains

The present investigation was carried out in order to study the histopathological effect and virulence of different black‐pigmented Bacteroides species on both soft and hard tissues in an animal model. Male Wistar rats were injected in the palate next to the first right molar with 30 μl of a bacterial suspension containing 5 × 1010 viable cells per ml. To determine the difference in virulence the histopathological effects were studied five days after injection.All strains tested caused a submucosal infiltrate at the injection site, consisting of mononuclear cells, mainly lymphocytes, monocytes and fibroblasts. These inflammatory responses were accompanied by devitalization and resorption of bone. Simultaneously active osteoblasts and bone formation were observed. Strains of Bacteroides asaccharolyticus, Bacteroides melaninogenicus, Bacteroides corporis, and Bacteroides loescheii caused a less prominent devitalization of the palatinal bone than strains of Bacteroides gingivalis and Bacteroides intermedius. Strains of the latter species caused often a nasal infiltrate and abundant bone formation at the nasal side of the palatinal bone. B. asaccharolyticus and B. melaninogenicus scarcely caused signs of a reaction at the nasal side of the palatinal bone.In a second longitudinal study the histopathological effects of B. gingivalis strain HG 66 were investigated. The inflammation was characterized by a rapid influx of polymorphonuclear cells within 2 to 4 hours. These cells gradually diminished and were replaced by a mononuclear infiltrate. One of the most characteristic features accompanying the inflammation was the disappearance of the periosteum. After two days a recovery of periosteum was observed and the osteoblasts became active in new bone formation. Devitalization from the palatinal bone started about 8 hours after injection and could be seen until 10 days after injection. No inflammatory reaction or devitalization of bone could be observed 15 days after injection.

Degradation of the human proteinase inhibitors alpha-1-antitrypsin and alpha-2-macroglobulin by Bacteroides gingivalis.

Various strains of black-pigmented Bacteroides species were grown on horse blood agar and suspended in human serum. After various times of incubation the effect of the bacteria on the serum was evaluated by polyacrylamide gel electrophoresis and "rocket" immunoelectrophoresis. The formation of trichloroacetic acid-soluble material in the suspensions and the capacity of the treated sera to inhibit the activity of trypsin were also determined. The two tested strains of Bacteroides gingivalis (W83, H185) degraded most serum proteins, including the plasma proteinase inhibitors alpha-1-antitrypsin and alpha-2-macroglobulin. They did not, however, degrade alpha-1-antichymotrypsin. Bacteroides intermedius NCTC 9336, Bacteroides asaccharolyticus NCTC 9337, and an asaccharolytic oral strain different from B. gingivalis (BN11a-f) did not degrade the plasma proteinase inhibitors. These strains were, however, able to inactivate the capacity of serum to inhibit the activity of trypsin.

The effect of culture filtrates of oral strains of black-pigmented Bacteroides on the matrix production of chick embryo cartilage cells in vitro.

Culture filtrates of strains of Bacteroides gingivalis and Bacteroides asaccharolyticus contain a heat stable factor which inhibits the production of extracellular matrix by chick embryo chondrocytes and which causes vacuolization of these chondrocytes. This morphological effect appeared to be reversible. Strains of the saccharolytic species Bacteroides melaninogenicus did not have these effects. The significance of this cytotoxic effect for the etiology of periodontal diseases is discussed.

Cytotoxic activity of Bacteroides gingivalis and Bacteroides asaccharolyticus.

Culture filtrates of all eight strains of Bacteroides gingivalis and all five strains of B. asaccharolyticus were toxic for Vero cells. Cytotoxicity was in general greater with material from cultures of B. gingivalis than from B. asaccharolyticus but none of the culture filtrates from eight strains of B. melaninogenicus showed activity in this test. The toxic material was released during prolonged incubation and more detailed study of preparations from one strain indicated that it had a molecular weight of less than 3500 and was heat stable.

API ZYM system for identification of Bacteroides spp., Capnocytophaga spp., and spirochetes of oral origin.

A total of 80 oral strains of Bacteroides gingivalis, B. asaccharolyticus, B. melaninogenicus subsp. intermedius, B. melaninogenicus subsp. melaninogenicus, Capnocytophaga, Treponema denticola, and T. vincentii were characterized with the API ZYM system for 19 enzyme activities. Comparison of anaerobic and aerobic incubation with nine reference strains of these organisms showed no important differences. The key differential tests for black-pigmented Bacteroides strains and treponemes of oral origin were trypsin, alpha-glucosidase, and N-acetyl-beta-glucosaminidase. All Capnocytophaga strains produced distinctive aminopeptidase activities but varied in their glycosidic capabilities. The presence of a trypsin-like activity in B. gingivalis, T. denticola, and a group of Capnocytophaga strains may contribute to tissue destruction in periodontal disease.

Bacteroides gingivalis, Bacteroides asaccharolyticus, andBacteroides melaninogenicus subspecies: Cell surface morphology and adherence to erythrocytes and human buccal epithelial cells

All study strains ofBacteroides gingivalis, B. asaccharolyticus, andB. melaninogenicus subspecies possessed numerous pilus-like fibers and capsule-like outer surface structures. The capsular morphology varied between the different species and subspecies.B. gingivalis strongly agglutinated 16 erythrocyte species studied.B. asaccharolyticus showed variable and weak agglutination of only a few erythrocyte species.B. melaninogenicus subsp.intermedius strains strongly agglutinated rabbit erythrocytes and exhibited variable, often weak agglutination of 8 other erythrocyte species. Preparations of capsular polysaccharide or lipopolysaccharide fromB. gingivalis failed to agglutinate human erythrocytes, while pili preparations from the same organisms possessed marked hemagglutinating activity.B. gingivalis cells adhered in high numbers to human buccal epithelial cells, whereas strains ofB. asaccharolyticus failed to show measurable adherence. Oral strains ofB. melaninogenicus subsp.intermedius feebly adhered to the buccal epithelial cells. Pretreatment ofB. gingivalis cells with serum or saliva prevented the adherence to epithelial cells. Our findings suggest that cell surfaces with distinct properties exist on the various black-pigmentedBacteroides species and subspecies and this may accout for markedly differing ability of these organisms to attach to mammalian cells.