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Clinical and Diagnostic Laboratory... Jul 1997Oral Prevotella and Capnocytophaga species, regularly isolated from periodontal pockets and associated with extraoral infections, secret specific immunoglobulin A1...
Oral Prevotella and Capnocytophaga species, regularly isolated from periodontal pockets and associated with extraoral infections, secret specific immunoglobulin A1 (IgA1) proteases cleaving human IgA1 in the hinge region into intact Fab and Fc fragments. To investigate whether these enzymes are subject to inhibition in vivo in humans, we tested 34 sera from periodontally diseased and healthy individuals in an enzyme-linked immunosorbent assay for the presence and titers of inhibition of seven Prevotella and Capnocytophaga proteases. All or nearly all of the sera inhibited the IgA1 protease activity of Prevotella buccae, Prevotella oris, and Prevotella loescheii. A minor proportion of the sera inhibited Prevotella buccalis, Prevotella denticola, and Prevotella melaninogenica IgA1 proteases, while no sera inhibited Capnocytophaga ochracea IgA1 protease. All inhibition titers were low, ranging from 5 to 55, with titer being defined as the reciprocal of the dilution of serum causing 50% inhibition of one defined unit of protease activity. No correlation between periodontal disease status and the presence, absence, or titer of inhibition was observed. The nature of the low titers of inhibition in all sera of the IgA1 proteases of P. buccae, P. oris, and P. loescheii was further examined. In size exclusion chromatography, inhibitory activity corresponded to the peak volume of IgA. Additional inhibition of the P. oris IgA1 protease was found in fractions containing both IgA and IgG. Purification of the IgG fractions of five sera by passage of the sera on a protein G column resulted in recovery of inhibitory IgG antibodies against all three IgA1 proteases, with the highest titer being for the P. oris enzyme. These finding indicate that inhibitory activity is associated with enzyme-neutralizing antibodies.
Topics: Adolescent; Adult; Aged; Antibodies, Bacterial; Binding, Competitive; Capnocytophaga; Humans; Immunoglobulin A; Immunoglobulin G; Middle Aged; Periodontal Diseases; Prevotella; Serine Endopeptidases; Serine Proteinase Inhibitors
PubMed: 9220164
DOI: 10.1128/cdli.4.4.458-464.1997 -
Infection and Immunity Sep 1995By using an in vitro bone-forming culture system, the chick periosteal osteogenesis (CPO) model, the direct effects on osteogenesis of sonicated extracts derived from...
By using an in vitro bone-forming culture system, the chick periosteal osteogenesis (CPO) model, the direct effects on osteogenesis of sonicated extracts derived from oral bacteria were examined. Both extracts from bacterial species having strong associations with periodontal diseases (Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Prevotella intermedia, hereinafter referred to as suspected periodontopathogens) and extracts from species not correlated with periodontal disease (Streptococcus sanguis, Veillonella atypica, and Prevotella denticola, hereinafter referred to as nonpathogenic bacteria) were tested. All bacterial cultures were grown under standard anaerobic culture conditions. Sonicated bacterial extracts were prepared from the bacterial pellet. These were added in various proportions to the CPO cultures. Parameters of osteogenesis, including alkaline phosphatase activity, calcium and P(i) accumulation, and collagen synthesis, were measured in 6-day-old cultures. Compared with controls grown in the absence of bacterial products, osteogenesis was inhibited significantly in cultures treated with extracts derived from the suspected periodontopathogens. No osteogenic inhibition was observed in cultures treated with extracts from the nonpathogenic bacteria. These results suggest that the ability to inhibit osteogenesis in vitro may be a pathogenic property shared by a limited group of species. Further characterization of the P. gingivalis extracts revealed that both proteinaceous and nonproteinaceous products, including lipopolysaccharide, were able to inhibit osteogenesis. P. gingivalis extract-mediated inhibition of osteogenesis in CPO cultures was blocked by indomethacin, implicating prostaglandins in the regulation of the bacterial effects. The bacterial extracts had either reversible or irreversible inhibitory effects on osteogenesis when added after differentiation or before/during differentiation of bone cells, respectively.
Topics: Animals; Chick Embryo; Culture Techniques; Hot Temperature; Indomethacin; Lipopolysaccharides; Osteogenesis; Periodontitis; Porphyromonas gingivalis
PubMed: 7642257
DOI: 10.1128/iai.63.9.3287-3296.1995 -
Infection and Immunity Jul 1993The classical twin model was utilized in this study in an attempt to determine the importance of host genetics to the composition of the subgingival flora.... (Comparative Study)
Comparative Study
The classical twin model was utilized in this study in an attempt to determine the importance of host genetics to the composition of the subgingival flora. Simultaneously, the effect of puberty on the flora composition was assessed. The compositions of the floras were significantly different at ages 11 and 14 in the same people, indicating that transition to an adult flora composition may be initiated during puberty. However, the numbers of subjects who had prepubertal and postpubertal testosterone levels in this study were too small to demonstrate significant differences based solely on testosterone level (P = 0.053 and 0.11 for tests of unrelated members, i.e., all twins "a," the first twin of each pair, and all twins "b," the second twin of each pair). Sixteen unrelated 11-year-old subjects had prepubertal levels of less than 30 ng of testosterone per dl of serum, and only six of these unrelated subjects had levels above 300 ng/dl by age 14. Of their twin siblings, who formed the second group of unrelated individuals, 15 had prepubertal levels and only 5 reached postpubertal levels. Unpaired t tests indicated that Veillonella atypica, Prevotella denticola, and Prevotella melaninogenica were among the species that contributed most to changes in flora composition during puberty. The compositions of subgingival floras of 11-year-old monozygous and dizygous male twins were significantly more similar than those of unrelated subjects in the study (P = 0.004 and 0.009, respectively). At 12.5 years of age, the floras of monozygous twins remained more similar than those of unrelated subjects (P = 0.001), but the dizygous-twin floras were not significantly more similar than those of unrelated people. This difference corresponded with moderate and varied testosterone levels within dizygous-twin pairs at age 12.5. By age 14 both monozygous and dizygous twins again had floras with compositions more similar than those of unrelated people (P = 0.008 and 0.002, respectively). Estimates of the genetic contributions to the increased similarity of the floras of twins as compared with floras of unrelated people indicated that the concentrations of several species in the flora may be influenced by host genetic factors. The prevalence of certain other species appeared to be controlled primarily by environment.
Topics: Adolescent; Adult; Bacteria; Child; Environment; Gingiva; Humans; Male; Puberty; Testosterone; Twins, Dizygotic; Twins, Monozygotic
PubMed: 8514392
DOI: 10.1128/iai.61.7.2891-2898.1993 -
Journal of Bacteriology Jul 1992Conjugal genetic elements in isolates of oral black-pigmented Bacteroides denticola (Prevotella denticola) and B. intermedius (P. intermedia) transfer tetracycline and...
Conjugal genetic elements in isolates of oral black-pigmented Bacteroides denticola (Prevotella denticola) and B. intermedius (P. intermedia) transfer tetracycline and penicillin resistance in the absence of plasmids. Transverse alternating-field electrophoresis of restricted chromosomal DNAs from transconjugants revealed arrangements indicating that transfer and insertion can involve more than one 60-kb copy of the elements and occurs at strongly preferred sites in the recipient chromosome.
Topics: Bacteroides; Blotting, Southern; Conjugation, Genetic; DNA, Bacterial; Penicillin Resistance; Recombination, Genetic; Tetracycline Resistance
PubMed: 1624474
DOI: 10.1128/jb.174.14.4853-4855.1992 -
Journal of Clinical Microbiology Sep 1991A rapid method for presumptive identification of black-pigmented gram-negative anaerobic rods was developed. Using filter paper spot tests for indole production,...
A rapid method for presumptive identification of black-pigmented gram-negative anaerobic rods was developed. Using filter paper spot tests for indole production, sialidase, alpha-glucosidase, beta-glucosidase, alpha-fucosidase, and trypsinlike enzyme activities, 100% of Porphyromonas gingivalis, Prevotella intermedia, and Bacteroides levii and 89% of Prevotella corporis isolates were correctly identified to the species level. Porphyromonas asaccharolytica and Porphyromonas endodontalis could not be differentiated from each other but could be distinguished from all other species tested. Similarly, Prevotella denticola, Prevotella loescheii, and Prevotella melaninogenica could not be differentiated from each other. The methods described are based on 4-methylumbelliferone derivatives of the various substrates and are simple to perform, rapid (less than 15 min), and applicable to difficult-to-cultivate anaerobic rods.
Topics: Bacteriological Techniques; Evaluation Studies as Topic; Glucosidases; Gram-Negative Anaerobic Bacteria; Hymecromone; Indoles; Neuraminidase; Pigmentation; alpha-L-Fucosidase
PubMed: 1774320
DOI: 10.1128/jcm.29.9.1955-1958.1991