Comparative studies of the outer membranes of <i>Bacteroides gingivalis</i>, strains ATCC 33277, W50, W83,381

Kennell, W; Holt, Stanley C.

doi:10.1111/j.1399-302x.1990.tb00409.x

Cited by 43 publications

(33 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These studies also showed strong similarities between W83 and W50 but placed them in a different group from that of ATCC 33277 and 381. Evidence that the four strains may be independent comes from analyses of the protein compositions of their outer membranes, from which subtle differences could be observed (18).…”

Section: Discussionmentioning

confidence: 99%

Comparative Whole-Genome Analysis of Virulent and Avirulent Strains of Porphyromonas gingivalis

Chen¹,

Hosogi²,

Nishikawa³

et al. 2004

J Bacteriol

100

View full text Add to dashboard Cite

We used Porphyromonas gingivalis gene microarrays to compare the total gene contents of the virulent strain W83 and the avirulent type strain, ATCC 33277. Signal ratios and scatter plots indicated that the chromosomes were very similar, with approximately 93% of the predicted genes in common, while at least 7% of them showed very low or no signals in ATCC 33277. Verification of the array results by PCR indicated that several of the disparate genes were either absent from or variant in ATCC 33277. Divergent features included already reported insertion sequences and ragB, as well as additional hypothetical and functionally assigned genes. Several of the latter were organized in a putative operon in W83 and encoded enzymes involved in capsular polysaccharide synthesis. Another cluster was associated with two paralogous regions of the chromosome with a low G؉C content, at 41%, compared to that of the whole genome, at 48%. These regions also contained conserved and species-specific hypothetical genes, transposons, insertion sequences, and integrases and were located adjacent to tRNA genes; thus, they had several characteristics of pathogenicity islands. While this global comparative analysis showed the close relationship between W83 and ATCC 33277, the clustering of genes that are present in W83 but divergent in or absent from ATCC 33277 is suggestive of chromosomal islands that may have been acquired by lateral gene transfer.The identification of virulent strains of pathogenic bacteria, and consequently their virulence genes, is a basic doctrine of the microbial pathogenesis field. Historically, identification has depended on phenotypic properties, biochemical activities, and immunological classifications. Increasingly, these tests have been replaced by genomic DNA-based analyses that can be successfully adapted to identify species, strains, and even mutants within strains. The availability of complete genome sequences for many bacterial pathogens has further increased the accuracy and specificity of such tests. A new addition to the existing repertoire of DNA analyses is comparative genome profiling using DNA microarrays, and this technology has been adapted to identify genes associated with pandemic strains of Vibrio cholerae (9) and to distinguish virulent strains of group A Streptococcus (30), Helicobacter pylori (4), and Salmonella species (6).Porphyromonas gingivalis is a gram-negative oral anaerobe associated with periodontal disease in adults. The organism is the most-studied oral pathogen, partly because it produces several virulence factors that can be isolated and studied biochemically (reviewed in reference 16) and partly because it is relatively easy to grow and manipulate genetically. According to animal models of disease, strains are classified as virulent and avirulent, and studies with bacterial strains and defined mutants have validated both the models and putative virulence factors (2, 3, 11). Strains of P. gingivalis have been differentiated by restriction fragment length polymorphism analysis of...

show abstract

Section: Discussionmentioning

confidence: 99%

Comparative Whole-Genome Analysis of Virulent and Avirulent Strains of Porphyromonas gingivalis

Chen¹,

Hosogi²,

Nishikawa³

et al. 2004

J Bacteriol

100

View full text Add to dashboard Cite

show abstract

“…The pellet, designated the cell envelope fraction (CEF), was washed three times, resuspended in SB, and stored at 4°C. The outer membrane fraction (OMF) was prepared by 2% (wt/vol) N-lauryl sarcosinate treatment of the CEF for 1 h at room temperature with agitation (10,15). The insoluble OMF was pelleted by ultracentrifugation (as above), washed three times in CB, resuspended in SB, and stored at 4°C.…”

Section: Methodsmentioning

confidence: 99%

“…The treated membrane fractions were washed twice and then resuspended and stored in SB at 4°C. Protein concentrations were determined with the bicinchoninic acid assay (Pierce, Rockford, Ill.) with bovine serum albumin as a control (15).…”

Section: Methodsmentioning

confidence: 99%

Localization of the Fusobacterium nucleatum T18 adhesin activity mediating coaggregation with Porphyromonas gingivalis T22

Kinder

Holt

1993

J Bacteriol

View full text Add to dashboard Cite

Adherence of pathogenic bacteria is often an essential first step in the infectious process. The ability of bacteria to adhere to one another, or to coaggregate, may be an important factor in their ability to colonize and function as pathogens in the periodontal pocket. Previously, a strong and specific coaggregation was demonstrated between two putative periodontal pathogens, Fusobacterium nucleatum and Porphyromonas gingivalis. The interaction appeared to be mediated by a protein adhesin on the F. nucleatum cells and a carbohydrate receptor on the P. gingivalis cells. In this investigation, we have localized the adhesin activity of F. nuceatum T18 to the outer membrane on the basis of the ability ofF. nuckatum T18 vesicles to coaggregate with whole cells of P. gingivalis T22 and the ability of the outer membrane fraction of F. nuckatum T18 to inhibit coaggregation between whole cells ofF. nucleatum T18 and P. gingivalis T22. Proteolytic pretreatment of the F. nucleatum T18 outer membrane fraction resulted in a loss of coaggregation inhibition, confirming the proteinaceous nature of the adhesin. The F. nucleatum T18 outer membrane fraction was found to be enriched for several proteins, including a 42-kDa major outer membrane protein which appeared to be exposed on the bacterial cell surface. Fab fragments prepared from antiserum raised to the 42-kDa outer membrane protein were found to partially but specifically block coaggregation. These data support the conclusion that the 42-kDa major outer membrane protein of F. nuceatum T18 plays a role in mediating coaggregation with P. gingivalis T22.

show abstract

“…Protein determination. Total protein content was determined by a modification of the bicinchoninic acid protein assay (Pierce, Rockford, Ill.) (23) with human SA as the standard.…”

Section: Methodsmentioning

confidence: 99%

Roles of porphyrins and host iron transport proteins in regulation of growth of Porphyromonas gingivalis W50

1991

View full text Add to dashboard Cite

Porphyromonas gingivalis (Bacteroides gingivalis) requires iron in the form of hemin for growth and virulence in vitro, but the contributions of the porphyrin ring structure, porphyrin-associated iron, host hemin-sequestering molecules, and host iron-withholding proteins to its survival are unknown. Therefore, the effects of various porphyrins, host iron transport proteins, and inorganic iron sources on the growth of P. gingivalis W50 were examined to delineate the various types of iron molecules used for cellular metabolism. Cell envelope-associated hemin and iron stores contributed to the growth of P. gingivalis in hemin-free culture, and depletion of these endogenous reserves required eight serial transfers into hemin-free medium for total suppression of growth. Comparable growth of P. gingivalis was observed with 7.7 microM equivalents of hemin as hemoglobin (HGB), methemoglobin, myoglobin, hemin-saturated serum albumin, lactoperoxidase, cytochrome c, and catalase. Unrestricted growth was recorded in the presence of haptoglobin-HGB and hemopexin-hemin complexes, indicating that these host defense proteins do not sequester HGB and hemin from P. gingivalis. The iron chelator 2,2'-bipyridyl functionally chelated hemin-associated iron, resulting in dose-dependent inhibition of growth in hemin-restricted cultures at 1 to 25 microM 2,2'-bipyridyl concentrations. In the absence of an exogenous iron source, protoporphyrin IX did not support P. gingivalis growth. These findings suggest that the iron atom in the hemin molecule is the critical constituent for growth and that the tetrapyrrole porphyrin ring structure may represent an important vehicle for delivery of iron into the P. gingivalis cell. P. gingivalis does not have a strict requirement for porphyrins, since growth occurred with nonhemin iron sources, including high concentrations (200 muM) of ferric, ferrous, and nitrogenous inorganic iron, and P. gingivalis exhibited unrestricted growth in the presence of host transferrin, lactoferrin, and serum albumin. The diversity of iron substrates utilized by P. gingivalis and the observation that growth was not affected by the bacteriostatic effects of host iron-withholding proteins, which it may encounter in the periodontal pocket, may explain why P. gingivalis is such a formidable pathogen in the periodontal disease process.

show abstract

Comparative studies of the outer membranes of Bacteroides gingivalis, strains ATCC 33277, W50, W83,381

Cited by 43 publications

References 48 publications

Comparative Whole-Genome Analysis of Virulent and Avirulent Strains of Porphyromonas gingivalis

Comparative Whole-Genome Analysis of Virulent and Avirulent Strains of Porphyromonas gingivalis

Localization of the Fusobacterium nucleatum T18 adhesin activity mediating coaggregation with Porphyromonas gingivalis T22

Roles of porphyrins and host iron transport proteins in regulation of growth of Porphyromonas gingivalis W50

Contact Info

Product

Resources

About