Disease-associated Bacteria Research Articles

Nanomaterial Based Affinity Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry for Biomolecules and Pathogenic Bacteria

This paper describes mass spectrometry (MS) using nanoparticles (NPs) for the analysis of biomolecules such as aminothiol compounds, drugs, peptides, proteins, and bacteria. Papers and patents dealing with preparation and use of several NPs in MS have been briefly reviewed, including carbon nanotubes, gold NPs, and magnetic NPs. The NPs or bioconjugated NPs were used for selective concentration and/or assisted matrices for desorption and ionization of analytes of interest. When compared to conventional organic matrixes, the NPs provide low MS background in low-mass region and low shot-to-shot variation. MS techniques using NPs and bioconjugated NPs for the analysis of disease-associated biomarkers and bacteria in real samples such as blood and urine are highlighted, showing the advantages of high sensitivity, reproducibility, and simplicity.

Periodontal Bacterial DNA Suppresses the Immune Response to Mutans Streptococcal Glucosyltransferase

Certain CpG motifs found in bacterial DNA enhance immune responses through Toll-like receptor 9 (TLR-9) and may also demonstrate adjuvant properties. Our objective was to determine if DNA from bacteria associated with periodontal disease could affect the immune response to other bacterial antigens in the oral cavity. Streptococcus sobrinus glucosyltransferase (GTF), an enzyme involved in dental caries pathogenesis, was used as a test antigen. Rowett rats were injected with aluminum hydroxide (alum) with buffer, alum-GTF, or alum-GTF together with either Escherichia coli DNA, Fusobacterium nucleatum DNA, or Porphyromonas gingivalis DNA. Contrary to expectation, animals receiving alum-GTF plus bacterial DNA (P. gingivalis in particular) demonstrated significantly reduced serum immunoglobulin G (IgG) antibody, salivary IgA antibody, and T-cell proliferation to GTF compared to animals immunized with alum-GTF alone. A diminished antibody response was also observed after administration of alum-GTF with the P. gingivalis DNA either together or separately, indicating that physical complexing of antigen and DNA was not responsible for the reduction in antibody. Since TLR triggering by DNA induces synthesis of prospective suppressive factors (e.g., suppressor of cytokine signaling [SOCS]), the effects of P. gingivalis DNA and GTF exposure on rat splenocyte production of SOCS family molecules and inflammatory cytokines were investigated in vitro. P. gingivalis DNA significantly up-regulated SOCS1 and SOCS5 expression and down-regulated interleukin-10 expression by cultured splenocytes. These results suggested that DNA from periodontal disease-associated bacteria did not enhance, but in fact suppressed, the immune response to a protein antigen from cariogenic streptococci, potentially through suppressive SOCS components triggered by innate mechanisms.

Innate immune peptide LL-37 displays distinct expression pattern from beta-defensins in inflamed gingival tissue

Anti-microbial peptides produced from mucosal epithelium appear to play pivotal roles in the host innate immune defence system in the oral cavity. In particular, human beta-defensins (hBDs) and the cathelicidin-type anti-microbial peptide, LL-37, were reported to kill periodontal disease-associated bacteria. In contrast to well-studied hBDs, little is known about the expression profiles of LL-37 in gingival tissue. In this study, the anti-microbial peptides expressed in gingival tissue were analysed using immunohistochemistry and enxyme-linked immunosorbent assay (ELISA). Immunohistochemistry revealed that neutrophils expressed only LL-37, but not hBD-2 or hBD-3, and that such expression was prominent in the inflammatory lesions when compared to healthy gingivae which showed very few or no LL-37 expressing neutrophils. Gingival epithelial cells (GEC), however, expressed all three examined anti-microbial peptides, irrespective of the presence or absence of inflammation. Moreover, as determined by ELISA, the concentration of LL-37 in the gingival tissue homogenates determined was correlated positively with the depth of the gingival crevice. Stimulation with periodontal bacteria in vitro induced both hBD-2 and LL-37 expressions by GEC, whereas peripheral blood neutrophils produced only LL-37 production, but not hBD-2, in response to the bacterial stimulation. These findings suggest that LL-37 displays distinct expression patterns from those of hBDs in gingival tissue.

Involvement of periodontopathic biofilm in vascular diseases.

Oral bacteria inhabit biofilms, which are firm clusters adhering in layers to surfaces and are not easily eliminated by immune responses and are resistant to antimicrobial agents. Dental plaque is one such biofilm. In the past 10 years, subgingival plaque bacteria forming biofilms have been increasingly reported to be involved in systemic diseases. A close relationship between microbial infections and vascular disease has also been reported in the past two decades. The present review discusses the significance of the ecologic characteristics of biofilms formed by periodontopathic bacteria in order to further clarify the associations between periodontal disease and systemic disease. We focus on the relationships between periodontal disease-associated bacteria forming biofilms and vascular diseases including atherosclerosis and carotid coronary stenotic artery disease, and we discuss the direct and indirect effects on vascular diseases of lipopolysaccharides as well as heat shock proteins produced by periodontopathic bacteria.

The characteristics of periodontal disease in respect to biofilm disease

The purpose of the present study was to examine whether bacterial biofilm concerned with bacterial colonization and growth of subgingival plaque. We observed subgingival plaque of 95 severe adult periodontitis-affected teeth by scanning electron microscope. In the coronal one-third zone of subgingival plaque, cocci, rods and others established biofilm by glycocalyx-like structure. In the middle one-third zone, several kinds of bacterial species were coaggregated. Film-like microcolonies were also observed in this zone. We detected filamentous microorganisms appeared to come out from the film-like colonies, and observed holes which microorganisms had been passed through the colonies. In the apical one-third zone, several kinds of bacterial species aggregated by glycocalyx-like structures, which comprised netlike and mucoidal structure. In the “plaque-free zone”, two types of bacterial colonization were observed : bacterial cell wall directly contacted with the root surface, and microorganisms adhered to the root surface mediated by glycocalyx netlike materials. In this zone, five periodontal disease-associated bacteria, including Porphyromonas gingivalis, were detected using back-scattered electron imaging modes. The results of the present study suggested that bacterial biofilms were partially related to colonization and growth of subgingival plaque.

Identification of periodontal disease-associated bacteria in the "plaque-free zone".

Subgingival plaque bacteria live within a biofilm covered with glycocalyx, and little is known of the bacterial species associated with biofilm formation at the bottom of human periodontal pockets, the so-called "plaque-free zone"(PFZ). Seventy-seven extracted teeth from 56 patients with severe advanced adult periodontitis were examined. Porphyromonas gingivalis, Campylobacter rectus, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Treponema denticola, Prevotella nigrescens, and Actinomyces viscosus were examined by scanning immunoelectron microscopic techniques, using both secondary and back-scattered imaging, with rabbit antibodies specific for each bacteria. Secondary electron images showed that rods, filaments, and spirochete-shaped bacteria formed small aggregates in the PFZ. Some of the bacteria were covered with an amorphous film-like structure. By back-scattered electron imaging, positive reactions with anti-P. gingivalis were found in 8 of 13 samples examined, and film-like structures coated several cells of 6 positive samples examined. Labeled cells with anti-C. rectus, anti-T. denticola and anti-P. nigrescens were detected in 3 of 11, 5 of 10, and 1 of 8 samples examined. A. viscosus were found in 6 of 11 of the samples. A. viscosus tended to overlay the amorphous capsula and aggregate. F. nucleatum and A. actinomycetemcomitans were not detected in any samples examined. These findings indicated that P. gingivalis, C. rectus, T. denticola, P. nigrescens, and A. viscosus were present in the PFZ, and that some specified bacteria were possibly related to plaque-biofilm formation of subgingival plaque.

Anti-adhesive activity of sulphated exopolysaccharides of microalgae on attachment of red sore disease-associated bacteria and helicobacter pylori to tissue culture cells.

Because of the affinity of certain bacterial species for sulphated glycoconjugates exposed on the epithelial cells of susceptible hosts, we hypothesized that sulphated exopolysaccharides of microalgae can be used in anti-adhesive therapies against bacterial infections, both in cold- and warm-blooded animals. In this study we found that adhesion of the human pathogen Helicobacter pylori to the HeLa S3 cell line, and adhesion of the fish pathogens Vibrio campbellii, V. ordalii, Streptococcus saprophyticus, and Aeromonas veronii to spotted sand bass primary tissue culture cells, can be effectively blocked with the various sulphated exopolysaccharides used.

Preparation and characterization of an Actinomyces naeslundii aggregation factor that mediates coaggregation with Porphyromonas gingivalis.

Intergeneric coaggregation is responsible for the complexity of the microbiota in human dental plaque and is believed to be important in the initial bacterial colonization of the human oral cavity. Actinomyces naeslundii, an early colonizer of the tooth surface, may enhance subsequent colonization by Porphyromonas gingivalis which is associated with adult periodontitis. The purpose of this study was to isolate and characterize the A. naeslundii aggregation factor (AnAF) that mediates coaggregation with P. gingivalis. AnAF was isolated from A. naeslundii sonic extract (SE) by gel filtration on a Sephacryl S-400HR, by hydrophobic interaction chromatography on a HiTrap Octyl Sepharose 4FF, and by ion exchange chromatography on a HiTrap Q. The specific activity increased 12-fold with a yield of 2.5%. SDS-PAGE analysis of AnAF revealed a protein band of high molecular weight in excess of 200 kDa. Carbohydrate was detected as the only material coinciding with the protein band, indicating that the AnAF was a glycoprotein. Immunoblotting analysis indicated that AnAF directly bound to P. gingivalis cells. AnAF was sensitive to sodium metaperiodate treatment but not to heat or protease treatments. These results suggest that the AnAF carbohydrate component mediated coaggregation with P. gingivalis cells. AnAF also inhibited coaggregation with other periodontal disease-associated bacteria such as Prevotella intermedia, Fusobacterium nucleatum, Capnocytophaga ochracea, but not streptococci.

Short chain carboxylic acids decrease human gingival keratinocyte proliferation and increase apoptosis and necrosis.

Epithelia are key barriers to infections. In periodontal disease, the gingival sulcular epithelium becomes ulcerated. In this report, we test the hypothesis that short-chain carboxylic acids (SCCA) inhibit keratinocyte proliferation, increase necrosis and apoptosis, and may thus promote ulceration. SCCA produced by bacteria are present at millimolar concentrations in the periodontal pockets of subjects with periodontal disease. SCCA concentrations are higher in subjects with severe disease than in those with mild disease, and are not detectable in healthy subjects. Cell proliferation is critical for maintenance of epithelial barrier function. All SCCA tested, when neutralized, decreased epithelial cell proliferation (as measured by 3H-thymidine incorporation) in a dose-dependent manner. We found that epithelial cell viability decreased with increasing SCCA concentrations, accounting at least partly for the decreased 3H-thymidine incorporation. For all conditions we tested, SCCA-induced apoptosis preceded and exceeded necrosis. While the molecular mechanism(s) for these effects remain to be determined, the results indicate that SCCA derived from caries- or periodontal disease-associated bacteria could alter gingival barrier function.

Association of oral spirochetes from periodontally healthy sites with development of gingivitis.

The purpose of this investigation was to determine whether the presence of selected disease-associated bacteria in health-associated plaque correlated with future gingivitis. Sites of periodontal health were identified in 65 adults. Six months later (recall 1) plaque was collected from sites that remained in periodontal health, and 5 species of specific bacteria and pathogen-related oral spirochetes were detected using monoclonal antibodies in a microscopic assay. Members of the spirochete morphogroup were also identified by phase contrast microscopy. The relationship between site-specific detection of bacteria at recall 1 and development of gingivitis at recall 2 or 3 was evaluated by means of logistic regression using generalized estimating equations, from which odds ratios (OR) were estimated. Significance was conservatively defined as OR > 2.0 and P < 0.05. We found that 488 of 1,424 healthy sites developed gingivitis over the 12-month interval between recall 1 and 3. Only the spirochete morphogroup (OR =2.04; P=0.002) was significantly associated with the transition from health to gingivitis. The association of Treponema socranskii with future gingivitis was higher than expected (OR=2.27), but the relationship was not statistically significant (P=0.163). Campylobacter rectus, Eikenella corrodens, Porphyromonas gingivalis, and pathogen-related oral spirochetes did not correlate well with gingivitis (OR < 2.0). Health-associated plaque from 5 sites contained Treponema denticola, and all 5 sites progressed to gingivitis. An OR could not be calculated because T. denticola was not detected in health-associated plaque from stable healthy sites. These findings indicated that the presence of T. denticola and unidentified spirochetes in health-associated plaque was associated with increased susceptibility to gingival inflammation. Future studies assessing a larger panel of dental plaque microorganisms, with shorter intervals between baseline and follow-up assessment, are necessary to more fully evaluate the association between detection of specific organisms at healthy sites and risk for gingivitis.

Association of oral spirochetes from sites of periodontal health with development of periodontitis.

The purpose of this investigation was to determine whether the presence of disease-associated bacteria in health-associated plaque correlated with susceptibility to periodontitis over time. Sites of periodontal health were identified in 65 adults. Six months later (recall 1), plaque was collected from sites that remained in periodontal health, and specific bacteria were detected using monoclonal antibodies in a microscopic assay. The spirochete morphogroup was identified by phase contrast microscopy. The relationship between detection at recall 1 and development of periodontitis over two successive 6-month intervals (recalls 2 and 3) was evaluated by means of logistic regression using generalized estimating equations (GEE), from which odds ratios (OR) were estimated and tested for significance. Significant relationships were defined as those having ORs with P < 0.05. Ninety-three of 1,032 sites developed signs of early periodontitis over the 12-month interval between recall 1 and recall 3. The spirochete morphogroup (OR = 3.13, P < 0.001) and pathogen-related oral spirochetes (PROS) (OR = 3.68, P < 0.001) were significantly associated with healthy sites that developed periodontitis. The association of Treponema socranskii was not significant (OR = 3.62, P = 0.0918). Odds ratios for Campylobacter rectus, Eikenella corrodens, and Porphyromonas gingivalis were less than 2.0 and not significant. Treponema denticola was not detected in health-associated plaque from stable health sites and was detected in only three sites that progressed to periodontitis. These findings indicate that the presence of PROS and some unidentified spirochetes in health-associated plaque is associated with increased susceptibility to periodontitis.

Cultivation of Whipple bacillus: the irony and the ecstasy

For 90 years investigators (including George Whipple) have been unable to propagate the microbe responsible for Whipple's disease, despite many published and probably many more unpublished attempts. 1 Whipple GH A hitherto undescribed disease characterized anatomically by deposits of fat and fatty acids in the intestinal and mesenteric lymphatic tissues. Johns Hopkins Hosp Bull. 1907; 18: 382-391 Google Scholar Evidence that a bacterium causes Whipple's disease has accumulated in recent decades. Light and electron microscopy show rod-shaped bacilli in the affected tissues of these patients, usually free in the lamina propria of the small bowel but also as partly degraded structures within macrophage vacuoles. 2 Trier JS Phelps PC Eidelman S Rubin CE Whipple's disease: light and electron microscopic correlation of jejunal mucosal histology with antibiotic treatment and clinical status. Gastroenterology. 1965; 48: 684-707 PubMed Scopus (95) Google Scholar On the basis of histology, investigators have suggested that these organisms propagate extracellularly, 3 Silva MT Macedo PM Moura NJ Ultrastructure of bacilli and the bacillary origin of the macrophagic inclusions in Whipple's disease. J Gen Microbiol. 1985; 131: 1001-1013 PubMed Google Scholar although intact organisms have been detected within several types of cells. 4 Dobbins W Kawanishi H Bacillary characteristics in Whipple's disease: an electron microscopic study. Gastroenterology. 1981; 80: 1468-1475 PubMed Scopus (77) Google Scholar A molecular phylogenetic approach provides evidence that the Whipple bacillus is a member of the actinomycete taxon of bacteria. 5 Relman DA Schmidt TM MacDermott RP Falkow S Identification of the uncultured bacillus of Whipple's disease. N Engl J Med. 1992; 327: 293-301 Crossref PubMed Scopus (1031) Google Scholar , 6 Wilson KH Blitchington R Frothingham R Wilson JA Phylogeny of the Whipple's-disease-associated bacterium. Lancet. 1991; 338: 474-475 Summary PubMed Scopus (302) Google Scholar DNA from this microbe, unofficially named Tropheryma whippelii, is almost invariably present in patients who have Whipple's disease, but disappears with effective antibiotic treatment. 7 Ramzan NN Loftus EJ Burgart LJ et al. Diagnosis and monitoring of Whipple disease by polymerase chain reaction. Ann Intern Med. 1997; 126: 520-527 Crossref PubMed Scopus (209) Google Scholar Using both histological and molecular data, G Schoedon and colleagues 8 Schoedon G Goldenberger D Forrer R et al. Deactivation of macrophages with IL-4 is the key to the isolation of Tropheryma whippelii. J Infect Dis. 1997; 176: 672-677 Crossref PubMed Scopus (156) Google Scholar now provide evidence of the successful propagation of T whippelii in cell culture. Interleukin-4 (IL-4) was critical for rendering peripheral blood monocytes and monoblastic cell-lines permissive for intracellular growth of the organism.

An immunohistochemical study on the localization of Porphyromonas gingivalis, Campylobacter rectus and Actinomyces viscosus in human periodontal pockets.

The localization and distribution of Porphyromonas gingivalis, Campylobacter rectus and Actinomyces viscosus were studied in human periodontal pockets. After obtaining voluntary consent from 9 patients, 12 teeth and their surrounding periodontal tissue with advanced adult periodontitis were extracted carefully so as not to change the structure of the periodontal pockets. The specimens were processed into serial sections. One of the sections was stained with Brown & Brenn-modified Gram stain to observe the distribution of bacteria. The others were stained immunohistochemically by the Labelled Streptavidin Biotin method (LSAB method) using specific rabbit antibodies against selected bacteria. Some bacteria could be found within epithelial cells. P. gingivalis was found in 9/12 of the samples examined. Small aggregates of P. gingivalis were scattered in all parts of the periodontal pockets, and some of these aggregates could be seen in close contact with the epithelium. Conversely, C. rectus was observed in 5/12 of the samples examined and was predominantly located in the middle and deep pocket zones. C. rectus tended to form large clumps in both the tooth-attached and epithelium-associated plaque area. A. viscosus was observed in 7/12 of the samples examined and was localized predominantly in the tooth-attached plaque area, especially in the shallow and middle pocket zones. Although unexpected spills of unattached plaque from periodontal pockets was possible, immunohistochemical staining with species-specific antibodies was extremely sensitive and revealed the localization and the distribution of periodontal disease-associated bacteria in human periodontal pockets.

Microbial colonization of dental implants in partially edentulous subjects

This study assessed the colonization of Brånemark dental implants by periodontopathic bacteria in four partially edentulous patients with a total of 10 implants. Marginal and subgingival plaque on the implants was sampled 14 days and 28 days after second-stage surgery and compared with plaque from three teeth closest to the implant sites sampled before second-stage surgery (baseline) and at 14 and 28 days. Slot immunoblot assay was used to determine the presence or absence of bacterial antigen to six different periodontopathic microorganisms. In general, colonization of marginal implant plaque occurred within 14 days, whereas subgingival colonization took longer and occurred within 28 days. It appears that Brånemark dental implants placed in partially edentulous patients may be colonized by disease-associated bacteria within 14 days of second-stage surgery.

A sensitive enzymatic method (SK-013) for detection and quantification of specific periodontopathogens.

Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola have been found to predominate in periodontal pockets of patients with adult periodontitis. These microorganisms hydrolyze the synthetic peptide N-benzoyl-DL-arginine-2-naphthylamide (BANA). In this study, we developed an enzymatic method, designated SK-013, to detect the existence of these microorganisms in subgingival plaque bacteria. This enzymatic method was based on the observation of the hydrolysis of N-carbobenzoxy-glycyl-glycyl-arginyl-3,5-dibromo-4-hydroxyaniline (N-CBz-Gly-Gly-Arg-DBHA) and made more sensitive by adding an enhancing system. The SK-013 was specifically positive for P. gingivalis, B. forsythus, T. denticola, and some strains of Capnocytophaga species, but was not specific for any of the other bacterial strains tested. This SK-013 system may be valuable for detection and quantification of periodontal disease-associated bacteria in subgingival plaque and thus for diagnosis of periodontal infections.

Phylogeny of the Whipple's-disease-associated bacterium

Efforts to culture and identify the intracellular bacteria associated with Whipple's disease have been unsuccessful. Nucleotide sequencing and amplification by the polymerase chain reaction was done on the bacterial 16 S ribosomal DNA present in a small-bowel biopsy specimen taken from a patient with Whipple's disease. A search by computer for similar rRNA sequences filed in databases showed the Whipple's-associated organism to be most similar to bacteria of the Rhodococcus, Streptomyces, and Arthrobacter genera, and more weakly related to mycobacteria. The biopsy specimen was estimated to contain around 10 7 cells of the organism. The probable aetiological agent for our patient's illness has not been identified previously in a patient with Whipple's disease.

Adherence to experimental pellicle of rough‐type lipopolysaccharides from subgingival plaque bacteria

The adherence of lipopolysaccharides (LPSs) from periodontal disease-associated bacteria to saliva-coated hydroxyapatite (S-HA) and serum-coated HA beads was examined by chromogenic Limulus activity (toxicolor test). Phenol-water extracted LPS preparations from Bacteroides intermedius, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Eikenella corrodens, and rough-type LPS from Escherichia coli adhered to S-HA and serum-coated beads and agglutinated human erythrocytes. The adhered LPSs to S-HA and serum-coated HA beads were not removed by vigorous washing with distilled water. LPSs from Bacteroides (Porphyromonas) gingivalis strains and wild-type E. coli did not adhere to S-HA, serum-coated HA beads or show hemagglutinating activity. SDS-PAGE patterns stained with silver stain showed that LPSs adhered to S-HA, and serum-coated HA beads and erythrocytes possessed a distinct fast-migrating band similar to rough-type LPS. B. gingivalis LPSs possessed slow-migrating and repeating ladder bands similar to wild-type LPS.

Microbiological evaluation of initial preparation for adult periodontitis patients

The microbial flora from 46 adult periodontitis lesions of 23 patients and 18 sites in 9 healthy persons were examined and levels of serum IgG antibody to gram negative periodontal disease-associated bacteria were measured by enzyme-linked immunosorbent assay. Plaque samples and serum samples were taken 40-50 days after initial preparation consisting of scaling and root planing. To evaluate the effects of the therapy on 10 patients with adult periodontitis, changes in clinical parameters were compared with alterations of the microbial flora and serum IgG antibody levels. Black-pigmented Bacteroides species, mainly Bacteroides gingivalis, were found to be predominant in periodontitis lesions. A significant relationship was found between the prevalence of B. gingivalis and elevated titers of serum IgG antibody against the microorganism. No relationships between Bacteroides intermedius, Actinobacillus actinomycetemcomitans and elevated titers of serum IgG antibody to them were detected. The fact that there was no marked reduction of serum IgG antibody to B. gingivalis after initial preparation suggests that a more extended, longitudinal study is required. Although brushing resulted in a significant reduction of the number of total cultivable organisms in samples from periodontal pockets, no significant proportional changes in gram-negative bacteria in the lesional flora were found. Initial preparation was not effective in eliminating gram-negative bacteria from deep periodontal pockets. However, the microbiological shifts, especially the reduction in the proportion and frequency of detection of B. gingivalis in periodontal pockets, was paralleled by significant improvement in the clinical parameters.

Indicators of periodontal disease activity: an evaluation.

It is becoming increasingly apparent that the traditional clinical criteria are inadequate for: determining active disease sites in periodontitis, monitoring quantitatively the response to therapy or measuring the degree of susceptibility to future breakdown. In an attempt to develop objective measures, a wide variety of studies have been undertaken using saliva, blood, plaque and gingival crevicular fluid (GCF) as the specimen source. Examination has included: specific bacteria and their products; host cells and their products (enzymatic and antibacterial, both immunologic and non-immunologic); products of tissue injury derived from local epithelial and connective tissues and bone. Although most of the work to date has failed to provide reliable aids to the clinician, refinements in techniques for sampling and the availability of more sophisticated analytic techniques give cause for optimism. Methods proposed for detection of disease-associated bacteria in subgingival plaque vary in their sensitivity and specificity. Dark field microscopy shows some correlation with existing disease; however, the limited specificity of this method imposes severe restrictions on its usefulness. Highly specific polyclonal and monoclonal antisera to suspected pathogens Bacteroides gingivalis and Actinobacillus actinomycetemcomitans have been developed and improved methods of identification of these microbes in plaque by ELISA immunofluorescence and flow cytometry are under development. With respect to the host response, a strong correlation between antibody patterns to specific bacteria and periodontal disease categories appears to be emerging. Although most studies have focused on serum antibody derived from peripheral blood, a shift to detection of local antibody response appears to be likely. Techniques of measurement that are exquisitely sensitive have been developed for detection of major immune recognition proteins such as antibody and complement in crevicular fluid. Research efforts attempting to correlate local antibody response to local disease activity are underway. Measurement of GCF flow rate, endotoxin, H2S, butyrate and a variety of enzymes (e.g., collagenase, arylsulfatase, B-glucuronidase) show good correlation with levels of gingivitis. In periodontitis, the most promising markers of tissue breakdown are prostaglandins of the E series, the enzymes collagenase and aspartate aminotransferase, sulfated glycosaminoglycans, osteoclastic activating factor and bone resorptive capacity of crevicular cells. Assay of the migration of crevicular leucocytes in vivo can serve as an indicator of a defect in host resistance.(ABSTRACT TRUNCATED AT 400 WORDS)