Effect of host responses on the pathogenicity of strains of <i>Porphyromonas gingivalis</i>

Katz, Jannet; Ward, Dawn; Michalek, Suzanne M.

doi:10.1111/j.1399-302x.1996.tb00187.x

Cited by 59 publications

(61 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Like that in many encapsulated pathogenic bacteria, capsule expression in P. gingivalis is linked to pathogenicity. Interestingly, strains that produce a capsule have been shown to cause a spreading type of infection in mice, with recovery of the organism from blood, spleen, and kidneys (16,52), while infections with strains that do not synthesize capsule (strains 381 and 33277) typically attach and result in localized abscesses (43,52), suggesting that encapsulation is linked to dissemination and not attachment. Our results show that capsule expression in P. gingivalis blocks biofilm formation and hence could enhance dissemination.…”

Section: Discussionmentioning

confidence: 99%

Enhanced Biofilm Formation and Loss of Capsule Synthesis: Deletion of a Putative Glycosyltransferase inPorphyromonas gingivalis

Davey¹,

Duncan²

2006

J Bacteriol

112

104

View full text Add to dashboard Cite

Periodontitis is a biofilm-mediated disease. Porphyromonas gingivalis is an obligate anaerobe consistently associated with severe manifestations of this disease. As an opportunistic pathogen, the ability to proliferate within and disseminate from subgingival biofilm (plaque) is central to its virulence. Here, we report the isolation of a P. gingivalis transposon insertion mutant altered in biofilm development and the reconstruction and characterization of this mutation in three different wild-type strains. The mutation responsible for the altered biofilm phenotype was in a gene with high sequence similarity (ϳ61%) to a glycosyltransferase gene. The gene is located in a region of the chromosome that includes up to 16 genes predicted to be involved in the synthesis and transport of capsular polysaccharide. The phenotype of the reconstructed mutation in all three wild-type backgrounds is that of enhanced biofilm formation. In addition, in strain W83, a strain that is encapsulated, the glycosyltransferase mutation resulted in a loss of capsule. Further experiments showed that the W83 mutant strain was more hydrophobic and exhibited increased autoaggregation. Our results indicate that we have identified a gene involved in capsularpolysaccharide synthesis in P. gingivalis and that the production of capsule prevented attachment and the initiation of in vitro biofilm formation on polystyrene microtiter plates.The clinical importance of dental plaque and its accessibility for in vivo research makes it one of most studied and bestunderstood biofilm communities. It is now well documented that gram-negative anaerobic bacteria play a significant role in the development of periodontitis, with Porphyromonas gingivalis being implicated as one of the major players in the progression of this chronic disease (10,19,30,61). A number of factors are associated with the virulence of the organism, including a variety of proteases, endotoxins, and collegenases and the production of surface structures, such as fimbriae and capsular polysaccharide (38). This opportunistic pathogen also attaches to and invades human epithelial cells (18,53,56,57), connective tissue, and endothelial cells (15,17,55), and invasion has been shown to be mediated by the expression of fimbriae and a variety of surface adhesins. It is evident that the growth of P. gingivalis within the subgingival plaque is central to the disease process; however, although there have been numerous studies of the pathogenicity of the organism and its interactions with other organisms within the biofilm community, little is known about the molecular-genetic basis of biofilm formation in P. gingivalis.Research on oral biofilms has focused on determining the spatial organization and complex development of plaque by examining the succession of organisms in the growing biofilm. By monitoring the development of the microbial community on the tooth surface after professional cleaning, studies have demonstrated that the early colonizers are primarily grampositive organisms and the late, o...

show abstract

Section: Discussionmentioning

confidence: 99%

Enhanced Biofilm Formation and Loss of Capsule Synthesis: Deletion of a Putative Glycosyltransferase inPorphyromonas gingivalis

Davey¹,

Duncan²

2006

J Bacteriol

112

104

View full text Add to dashboard Cite

show abstract

“…The form and partitioning of Kgp between the cell and the extracellular milieu have been reported to show variations (28) that correlate with distinct changes in the functional properties of P. gingivalis strains (12,22). Differences have also been observed in the pathogenic potential of laboratory strains, depending on the animal model (4,13) or the in vitro assay employed (10,11). The latter differences in virulence may be a function of the heterogeneity within virulence genes such as kgp.…”

mentioning

confidence: 90%

Distribution of Porphyromonas gingivalis Biotypes Defined by Alleles of the kgp (Lys-Gingipain) Gene

et al. 2004

View full text Add to dashboard Cite

Paired subgingival plaque samples representing the most-diseased and least-diseased sites were collected from 34 adult patients with diagnosed chronic periodontitis. The percentage of Porphyromonas gingivalis relative to the total anaerobic and gram-negative bacterial load at each site was determined by real-time PCR. Based on variations in the noncatalytic C terminus of the Lys-gingipain (Kgp), it was reasoned that DNA sequence variation in the 3-coding region of the kgp gene might determine functional biotypes. Perusal of the available sequence information in GenBank indicated three such forms of the kgp gene corresponding to P. gingivalis strains HG66, 381, and W83. Analysis of patient samples revealed the presence of a fourth genotype (W83v) that showed duplication of a sequence recognized by the W83 reverse primer. The four biotypes, HG66, 381, W83, and W83v, were present in the study group in the ratio 8:11:6:5, respectively. Each subject was colonized by one predominant biotype, and only three patients were colonized by a trace amount of a second biotype.

show abstract

“…While animal studies have demonstrated the pathogenicity of mono-infections of periodontopathogens such as P. gingivalis [13][14][15][16][17], in recent years, reports have been published on the effects of mixed microbial infections including P. gingivalis and A. actinomycetemcomitans [18], P. gingivalis and F. nucleatum [19] and P. gingivalis and B. forsythus [20] which resulted generally in increased levels of pathogenicity with a synergistic effect observed in the humoral and cellular host responses. In the human, F. nucleatum colonizes the plaque prior to P. gingivalis and high levels of F. nucleatum have been demonstrated in association with P. gingivalis as well as other bacteria associated with periodontal disease, such as B. forsythus, Prevotella intermedia and Eikenella corrodens [21].…”

Section: Introductionmentioning

confidence: 99%

Effect of Fusobacterium nucleatum on the T and B cell responses to Porphyromonas gingivalis in a mouse model

Gemmell

Bird

Carter

et al. 2002

Clinical and Experimental Immunology

View full text Add to dashboard Cite

Periodontal disease results from the inflammatory response to bacteria in dental plaque (reviewed in [1]). Although there are well over 300 different bacterial species in the plaque, progression to periodontitis depends not on bacterial load, but on the presence of specific periodontopathic bacteria. The major pathogens identified at the 1996 World Workshop in Periodontics as causative agents are Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Bacteroides forsythus [2]. P. gingivalis has been found in 15% of subjects in an Australian population, the prevalence increasing with increasing pocket depth [3]. In another study, Slots and Ting [4] found that 40-100% of adult periodontitis patients were positive for P. gingivalis. This high occurrence, together with the pathogenic potential of P. gingivalis, has made it a major pathogen of adult periodontitis [5].Immunohistological studies have established that a T cell/macrophage lesion identical to a delayed hypersensitivity 238 Effect of Fusobacterium nucleatum on the T and B cell responses toPorphyromonas gingivalis in a mouse model SUMMARYT cell cytokine profiles and specific serum antibody levels in five groups of BALB/c mice immunized with saline alone, viable Fusobacterium nucleatum ATCC 25586, viable Porphyromonas gingivalis ATCC 33277, F. nucleatum followed by P. gingivalis and P. gingivalis followed by F. nucleatum were determined. Splenic CD4 and CD8 cells were examined for intracytoplasmic interleukin (IL)-4, interferon (IFN)-gamma and IL-10 by dual colour flow cytometry and the levels of serum anti-F. nucleatum and anti-P. gingivalis antibodies determined by an ELISA. Both Th1 and Th2 responses were demonstrated by all groups, and while there were slightly lower percentages of cytokine positive T cells in mice injected with F. nucleatum alone compared with the other groups immunized with bacteria, F. nucleatum had no effect on the T cell production of cytokines induced by P. gingivalis in the two groups immunized with both organisms. However, the percentages of cytokine positive CD8 cells were generally significantly higher than those of the CD4 cells. Mice immunized with F. nucleatum alone had high levels of serum anti-F. nucleatum antibodies with very low levels of P. gingivalis antibodies, whereas mice injected with P. gingivalis alone produced anti-P. gingivalis antibodies predominantly. Although the levels of anti-F. nucleatum antibodies in mice injected with F. nucleatum followed by P. gingivalis were the same as in mice immunized with F. nucleatum alone, antibody levels to P. gingivalis were very low. In contrast, mice injected with P. gingivalis followed by F. nucleatum produced equal levels of both anti-P. gingivalis and anti-F. nucleatum antibodies, although at lower levels than the other three groups immunized with bacteria, respectively. Anti-Actinobacillus actinomycetemcomitans, Bacteroides forsythus and Prevotella intermedia serum antibody levels were also determined and found to be negligible. In conclusion, F. nucleatum ...

show abstract

Effect of host responses on the pathogenicity of strains of Porphyromonas gingivalis

Cited by 59 publications

References 40 publications

Enhanced Biofilm Formation and Loss of Capsule Synthesis: Deletion of a Putative Glycosyltransferase inPorphyromonas gingivalis

Enhanced Biofilm Formation and Loss of Capsule Synthesis: Deletion of a Putative Glycosyltransferase inPorphyromonas gingivalis

Distribution of Porphyromonas gingivalis Biotypes Defined by Alleles of the kgp (Lys-Gingipain) Gene

Effect of Fusobacterium nucleatum on the T and B cell responses to Porphyromonas gingivalis in a mouse model

Contact Info

Product

Resources

About