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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Macaca arctoides monkeys develop periodontal disease, and they harbor a periodontopathic indigenous flora largely similar to that of humans. This study showed that various Haemophilus isolates and H2O2-splitting asaccharolytic Bacteroides melaninogenicus strains constituted major segments of the monkey periodontal microflora. These organisms have not been previously identified among human isolates. Furthermore, the present data revealed that asaccharolytic B. melaninogenicus strains increased in proportion from a few percent to about 66% of the total isolates concomitant with the development of a significant loss of alveolar bone mass. Hence, this study strongly implicates B. melaninogenicus subsp. asaccharolyticus and closely related strains as important pathogens in actively destructive periodontal disease.
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PMID:Longitudinal study of experimentally induced periodontal disease in Macaca arctoides: relationship between microflora and alveolar bone loss. 3 2

A study on the predominant cultivable microorganisms inhabiting gingival crevices affected with a chronic gingivitis was carried out using the roll tube culture technique. Samples were obtained from nine individuals 25--42 years of age. Gram-positive rods make up 29.1% of the isolates and included mainly Actinomyces naeslundii, Actinomyces israelii, and Actinomyces viscosus. Streptococcus mitis and Streptococcus sanguis together made up 26.8% of the cultivable organisms. Peptostreptococcus averaged 3.0% of the organisms recovered. Gram-negative anaerobic rods constituted 25.0% of the total isolates with Fusobacterium nucleatum, Bacteroides melaninogenicus ss. intermedius. Bacteriodes ochraceus, other Bacteroides species, Selenomonas sputigena, and Campylobacter sputorum as the most predominant isolates. Haemophilus parainfluenzae averaged about 14% and Veillonella species 4.3% of the cultivable microflora. The data presented indicate that the subgingival microflora of a chronic gingivitis differs from those of healthy periodontium and advanced adult and juvenile periodontis. This might suggest that different infectious processes may be operative in various clinical entities of periodontal disease.
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PMID:Microbiota of gingivitis in man. 27 16

Actinobacillus actinomycetemcomitans is a Gram-negative coccobacillus which can cause certain severe extra-oral infections as well as forms of human periodontal disease such as localized juvenile periodontitis. In contrast to many prokaryotic and eukaryotic species which exhibit an intact 23S ribosomal RNA (rRNA) molecule, examination of six A. actinomycetemcomitans strains--including three serogroup representative strains and two strains from non-human primates--revealed that this micro-organism does not produce an intact 23S ribosomal RNA (rRNA) molecule but, rather, two smaller forms of 1.8 kb and 1.2 kb designated as 23S alpha and 23S beta fragments. On the other hand, 14 other strains of Actinobacillus, Haemophilus, and Pasteurella species demonstrated intact 23S rRNA. The sequence of the region of the 23S rRNA gene in A. actinomycetemcomitans strain ATCC 43718 containing the cleavage site was determined by dideoxynucleotide sequencing, while the location of the 3' and 5' termini of the 23S alpha and 23S beta fragments was resolved by S1 nuclease mapping and cDNA primer-extension. A deletion of 112 bases was noted in comparisons of base sequences from A. actinomycetemcomitans rRNA and rDNA. The DNA intervening sequence was localized to nucleotide 1180 of the Escherichia coli 23S rRNA map. While the primary structure of the gap region showed little homology with the gap regions described in other organisms, the secondary structure was similar to that previously described in the parasitic helminth Schistosoma japonicum. Restriction enzyme and nucleotide sequence analysis of the gap region in eight other A. actinomycetemcomitans strains showed it to be highly conserved.
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PMID:Identification and analysis of the gap region in the 23S ribosomal RNA from Actinobacillus actinomycetemcomitans. 138 32

Recent studies of microbial epidemiology emphasizing the genetic organization and distribution of organisms associated with orofacial infections have led to new insights into the possible origins of pathogenicity. Studies into genetic heterogeneity, acquisition and transmission of these organisms have been markedly advanced by the utilization of the powerful technique of genomic DNA fingerprinting. Characteristic fingerprints for each bacterial isolate can be produced by cleavage of high molecular weight genomic DNA by restriction endonucleases. It is assumed that each DNA fingerprint represents a clonal type. In this report, we review and analyze studies of the epidemiology of bacteria associated with orofacial infections with an emphasis on periodontal disease. Studies of nontypable (NT) Haemophilus influenzae associated with recurrent otitis media illustrate the utility of this technique. DNA fingerprinting clearly demonstrates genetic heterogeneity of NT H. influenzae isolates, and clonality of infection of any individual. Furthermore, DNA fingerprinting has shown that the same clonal type is seen in siblings concurrently suffering from otitis media, suggesting horizontal transmission within the family. Studies of mutans Streptococci also show extensive genetic heterogeneity and show vertical transmission of a predominant clonal type only from mother to infant, but not from father to infant. Studies of Actinobacillus actinomycetemcomitans show considerable genetic heterogeneity among monkey isolates. Thus far, three clonal types have been reported with DNA fingerprinting among isolates from periodontal patients, but additional genetic heterogeneity can be found using specific DNA fragments as probes in hybridization experiments. Intrafamilial transmission of A. actinomycetemcomitans has been demonstrated. Porphyromonas (Bacteroides) gingivalis shows extensive genetic heterogeneity and case reports suggest clonal infection of any one individual. In contrast, results with DNA fingerprinting of Eikenella corrodens, Fusobacterium nucleatum, and Bacteroides intermedius show that individuals may be infected with 2 or more clonal types. These studies point to the great potential of DNA fingerprinting for investigating the epidemiology of putative orofacial pathogens. Such studies with periodontal microorganisms will likely reveal steps in the acquisition, intraoral and person-to-person transmission, which then could possibly be inhibited or interfered with to prevent periodontal disease or its recurrence.
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PMID:The use of genomic DNA fingerprinting in studies of the epidemiology of bacteria in periodontitis. 189 Feb 19

The prevalence and distribution of Haemophilus actinomycetemcomitans (H.a.) were studied in 3292 specimens of subgingival plaque on the four subgingival aspects of all teeth of the dental arch, 150 specimens from the mucosal surface (tongue and cheek) and 30 saliva specimens in 30 subjects. The sample population of 30 subjects was subdivided into three groups: 10 normal subjects, 10 subjects with localised juvenile periodontitis (SLJP) and 10 subjects with adult chronic periodontitis (SACP). The prevalences of H.a. in subgingival areas of each group mentioned were 30%, 90% and 60% respectively. Scores for prevalence obtained with other types of specimens proved to be lower except for saliva specimens which appear to be a less representative marker of subgingival prevalence of H.a.. Histograms for the distribution of H.a. revealed a predominance of this microorganism on the proximal surface of molar teeth in the three groups of patients. Only the SLJP also exhibited a high prevalence on the proximal aspect of the incisor teeth. The wide distribution of H.a. in all of the clinical groups studied suggests that this bacterium is not a good marker of periodontal disease and that it is necessary to define the most characteristic phenotypes and genotypes.
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PMID:[The distribution and prevalence of Haemophilus actinomycetemcomitans in the oral cavity]. 193 44

We have studies the role that interleukin-1 (IL-1) and IL-1-like cytokine play in the mechanism of bone resorption that occurs in periodontal disease. To determine whether the bone cell itself produces IL-1-like cytokine, we examined bone cells migrating from fragments of newborn mouse calvaria. These bone cells were cultured in alpha-MEM with of without fetal calf serum. IL-1-like cytokine activity was measured by incorporation of [3H] thymidine into C3H/HeJ thymocytes treated with lipopolysaccharide (LPS) from Haemophilus actinomycetemcomitans, a bacterium found in juvenile periodontopathy. The bone cells produced a significant amount of IL-1-like cytokine. The maximum production of IL-1-like cytokine was observed at 24 hours with the LPS in serum-free alpha-MEM. IL-1-like cytokine production stimulated by LPS was marked in the bone cells from LPS high-responder C3H/HeN mice, but not in those from low-responder C3H/HeJ mice. Peak of IL-1-like cytokine activity in culture supernatants of the bone cells was detected in fractions with a molecular weight corresponding to 15,000 daltons.
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PMID:[Production of IL-1 like cytokine by cultured bone cells: inducing effect of Haemophilus actinomycetemcomitans lipopolysaccharide on the cytokine production]. 248 80

Periodontal disease is thought to be initiated by a bacterial infection and subsequently developed by immunopathological mechanisms thorough host-parasite interactions. The macrophage and lymphocyte are the major functional cell types in the lesion of the disease and participate in tissue destruction and alteration of the periodontal connective tissue as well as in host defense mechanisms. However, the detailed implications of macrophages in development of the disease is still unclear. The aim of this study was to gain more understanding of the functional role of macrophages in periodontal disease. In this study, we examined the inducing effects of sonicated extracts from some gram-negative and gram-positive bacteria associated with the pathogenesis of periodontal disease, including Bacteroides gingivalis, Fusobacterium nucleatum, Haemophilus actinomycetemcomitans, and Actinomyces viscosus, on activation of macrophage functions and IL-1 production by the macrophages from the mouse peritoneum. At a dose as low as 1 microgram/ml (dry weight) sonicated extracts from B. gingivalis induced an increase in acid phosphatase activity and in glucose consumption of mouse peritoneal macrophages in vitro. A significant increase in the acid phosphatase and in glucose consumption was observed in the cultures at 24 h and 48 h, respectively, after the addition of the sonicate. Sonicated extracts from A. viscosus, a gram-positive bacterium, as well as B. gingivalis, F. nucleatum, and H. actinomycetemcomitans, gram-negative ones, were able to induce the increase in acid phosphatase activity and in glucose consumption of the macrophages. These periodontopathic bacteria were found to strongly induce IL-1 production by the macrophages as early as 24 h after addition of the sonicates. A significant increase in the IL-1 production was observed at a dose of 1 microgram/ml of the sonicates. The inducing ability was equivalent to 1 microgram/ml Escherichia coli lipopolysaccharide. The highest production of IL-1 was observed in the macrophages treated with H. actinomycetemcomitans among these sonicates. Sonicated extracts from both gram-negative and gram-positive bacteria were able to induce the IL-1 production by macrophages from C3H/HeJ mice, which are LPS low-responders. These results suggest that periodontopathic bacteria have potent ability to induce macrophage activation and IL-1 production and that the activated macrophages may play an important role in development of periodontal disease.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Inducing effect of periodontopathic bacteria on activation of macrophage functions and production of interleukin-1 by mouse peritoneal macrophages]. 260 96

While Actinobacillus actinomycetemcomitans has been associated with rapidly progressive periodontal destruction in man, the closely related Haemophilus aphrophilus has not been related to periodontal disease. This may be due to differences in composition and structure of the lipopolysaccharides (LPS) of these dental-plaque bacteria, since LPS probably exerts a series of detrimental effects on the periodontium. LPS was prepared by the phenol-water procedure from the type strains of A. actinomycetemcomitans and H. aphrophilus, purified by hexane extraction and ultracentrifugation, and analyzed with gas chromatography and gas chromatography-mass spectrometry. While the lipid content of LPS from A. actinomycetemcomitans constituted 35.4%, it was only 18.4% in H. aphrophilus: 3-hydroxytetradecanoic and tetradecanoic acids were 21.1 and 14.3% in A. actinomycetemcomitans and 10.9 and 7.5% in H. aphrophilus. There were qualitative and quantitative differences in the polysaccharide portions of their LPS. A actinomycetemcomitans contained both D-glycero-D-mannoheptose and L-glycero-D-mannoheptose (7.8 and 11.3%); H. aphrophilus contained only L-glycero-D-mannoheptose (17.4%). The rhamnose, fucose, galactose, glucose, and glucosamine/galactosamine contents in A. actinomycetemcomitans were 2.6, 5.2, 10.1, 22.4, and 5.2%, respectively; in H. aphrophilus, they were 2.1, 2.6, 19.4, 36.4, and 3.7%. Chemical differences in LPS from A. actinomycetemcomitans and H. aphrophilus may contribute to the divergence in periodontopathogenic potential of these organisms and help taxonomic differentiation.
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PMID:Chemical differences in lipopolysaccharides from Actinobacillus (Haemophilus) actinomycetemcomitans and Haemophilus aphrophilus: clues to differences in periodontopathogenic potential and taxonomic distinction. 277 74

The topical application of hydrogen peroxide (H2O2) and sodium bicarbonate (NaHCO3), individually and in combination, has been used empirically in the treatment of periodontal diseases. In this study, we examined both minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of these disinfectants individually and in combination against selected facultative, Gram-negative oral bacteria in a microtiter dilution assay. The bacteria studied included Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, Eikenella corrodens, and Capnocytophaga gingivalis. These bacteria exhibited MBC (one hr) values ranging from 75 mumol/L to greater than 10 mmol/L and MIC from less than 5 to 500 mumol/L for H2O2. The tested bacteria exhibited MIC values for NaHCO3 of from 23 to 182 mmol/L, and the MBC (one hr) exceeded 728 mmol/L for most of the strains examined. At sublethal (sub-MIC) concentrations, sodium bicarbonate antagonized the ability of H2O2 to inhibit bacterial growth in MIC assays, but sublethal concentrations of H2O2 had no effect on the MIC values of NaHCO3. Lethal concentrations of H2O2 and NaHCO3 exhibited synergistic antimicrobial activity in combination in one-hour bactericidal assays. Since the bactericidal properties of these antimicrobial agents are synergistic, we conclude that it may be rational to use them in combination to treat certain forms of periodontal disease. Also, lower and perhaps safer concentrations of H2O2 can be used in combination with NaHCO3 when oxidative antimicrobial chemotherapy is indicated.
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PMID:Antimicrobial properties of hydrogen peroxide and sodium bicarbonate individually and in combination against selected oral, gram-negative, facultative bacteria. 301 51

Lipopolysaccharide (LPS) purified from Haemophilus actinomycetemcomitans stimulates resorption and inhibits collagen synthesis in mouse calvaria bones in vitro. Addition of polymyxin B caused a dose-related inhibition of LPS-stimulated bone resorption and reversal of the inhibition of collagen synthesis. A polymyxin B to LPS ratio of 2:1 prevented bone resorption and restored collagen synthesis to control levels. The activity of polymyxin B was specific for LPS as bone resorption induced by prostaglandin E2 or parathyroid hormone was unaffected at similar concentrations. These results indicate that polymyxin B and its analogues may have potential in the treatment of periodontal disease by reducing bone loss induced by lipopolysaccharides.
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PMID:In vitro inhibition of lipopolysaccharide-induced bone resorption by polymyxin B. 302 92


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