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Biomedical subjects

L V Holdeman

Publications and source records attributed to L V Holdeman.

At least 37 records · Page 2Linked to original sources
PubMed1982

Bacteriology of experimental gingivitis in young adult humans.

From replicate trials of experimental gingivitis in four periodontally healthy subjects, 166 bacterial species and subspecies were detected among 3,034 randomly selected isolates from 96 samples. Of these bacteria, Actinomyces naeslundii (serotype III and phenotypically similar strains that were unreactive with available antisera), Actinomyces odontolyticus (serotype I and phenotypically similar strains that were unreactive with available antisera), Fusobacterium nucleatum, Lactobacillus species D-2, Streptococcus anginosus, Veillonella parvula, and Treponema species A appeared to be the most likely etiological agents of gingivitis. Statistical interpretations indicated that the greatest source of microbiological variation of the total flora observed was person-to-person differences in the floras. The next greatest source of variation was the inflammatory status of the sample sites. Person-to-person differences were smallest at experimental day 4. The floras became more diverse with time and as gingivitis developed and progressed. Analyses indicated that sequential colonization by certain species was repeatable and therefore probably predictable. Variation was relatively small between replicate trials, between two sites on the same teeth sampled on the same day, and between the same sites sampled at the same relative time in a replicate trial.

Actinomyces↗
PubMed1982

Bacteriology of severe periodontitis in young adult humans.

A total of 78 bacteriological samples were taken from the supragingival tooth surface after superficial cleaning with toothpicks or from the periodontal sulci of 42 affected sites in 21 adolescents or young adults with severe generalized periodontitis. Of 190 bacterial species, subspecies, or serotypes detected among 2,723 isolates, 11 species exceeded 1% of the subgingival flora and were most closely associated with the diseased sulci. Eleven others were also sufficiently frequent to be suspect agents of tissue destruction. Many of these species are known pathogens of other body sites. In addition, 10 species of Treponema were isolated. One of these and the "large treponeme" were also more closely associated with severe periodontitis than they were with healthy sites or gingivitis. There were highly significant differences between the composition of the flora of the affected sulci and the flora of (i) the adjacent supragingival tooth surface, (ii) the gingival crevice of periodontally healthy people, and (iii) sites with a gingival index score of 0 or 2 in experimental gingivitis studies. The floras of different individuals were also significantly different. There was no statistically detectable effect of sampling per se upon the composition of the flora of subsequent samples from the same sites. The composition of the supragingival flora of the patients with severe generalized periodontitis that had serum antibody to Actinobacillus actinomycetemcomitans was significantly different from the supragingival flora of patients without this serum antibody. However, there was no statistically significant difference in the composition of their subgingival floras.

Actinobacillus↗
PubMed1982

Electrophoretic study of Clostridium species.

Polyacrylamide gel electrophoretic analysis of soluble cellular proteins (without sodium dodecyl sulfate) of 70 Clostridium species indicated that the procedure was readily applicable to the differentiation of species in the genus. The protein patterns correlated well with the available DNA homology data and with most accepted differential tests. Results indicated that several earlier names for species were synonyms of those of accepted species and that two accepted species may be synonymous.

Bacterial Proteins↗
PubMed1981

Polyclonal B-cell activation induced by extracts of Gram-negative bacteria isolated from periodontally diseased sites.

The objective of this research was to determine whether gram-negative bacteria frequently isolated from periodontally diseased sites contained polyclonal B-cell activators. Polyclonal B-cell activation, which results in nonspecific activation of multiple B-cell clones was analyzed by a hemolysis-in-gel assay designed to detect a broad range of antibody specificities. Extracts from numerous bacterial strains, including Bacteroides gingivalis, Bacteroides melaninogenicus subsp. melaninogenicus, B. melaninogenicus subsp. intermedius, Fusobacterium nucleatum, Selenomonas sputigena, Capnocytophaga ochracea, and Actinobacillus actinomycetemcomitans, were tested. Extracts of the above organisms were found to stimulate polyclonal antibody responses in cultures of normal human peripheral blood lymphocytes, although the magnitude of stimulation varied among the extracts. Optimal antibody-forming cell responses were found at stimulator doses between 5 and 1,000 micrograms/ml. We conclude that the resident gram-negative subgingival flora associated with periodontal lesions possesses potent polyclonal B-cell activators. These activators may contribute to disease pathogenesis by inducing B lymphocytes to produce antibody, osteolytic factors, or both and possibly other mediators of inflammation.

Actinobacillus↗
PubMed1980

Polyacrylamide slab gel electrophoresis of soluble proteins for studies of bacterial floras.

A polyacrylamide slab gel electrophoresis procedure was used to compare cellular proteins from bacterial isolates of gingival crevice floras. Isolates with identical protein patterns consistently were shown to be members of the same species. When used to screen isolates, the procedure reduced total analytical time and expense without sacrificing accuracy, and it provided additional verification of the identity of strains characterized by conventional phenotypic tests.

Journal Article↗
PubMed1980

Production of indole-3-propanoic acid and 3-(p-hydroxyphenyl)propanoic acid by Clostridium sporogenes: a convenient thin-layer chromatography detection system.

Indole-3-propanoic acid (IPA), 3-(p-hydroxyphenyl)propanoic acid (HPPA), and 3-phenylpropanoic acid (PPA) were present in the spent bacterial media of Clostridium sporogenes (20/20 strains) and C. cylindrosporum (1/1 strains), but absent in 32 other clostridial species (74 strains) tested. Both IPA and HPPA (but not PPA) could be readily detected by thin-layer chromatography and p-hydroxybenzaldehyde spray reagent. IPA forms a scarlet complex with p-hydroxybenzaldehyde which shifts to purple and remains stable for up to 6 weeks. IPA can be detected in acidified extracts of C. sporogenes by a simple spot test. The structures of IPA and HPPA were confirmed by nuclear magnetic resonance (nmr) and mass spectroscopy and their formation was detected by the absorbance at 280 nm. Addition of one of the precursor amino acids (L-tryptophan, L-tyrosine, or L-phenylalanine) to the medium greatly enhanced formation of the corresponding deaminated acid and depressed the formation of the other two acids. The products IPA, HPPA, and PPA, at 10(-3) M, and spent bacterial media were negative in the direct Ames's assay for mutagenicity and noncytotoxic towards MRC-S cells.

Cells, Cultured↗
PubMed1979

New markers for Eubacterium lentum.

Of 37 strains of Eubacterium lentum and phenotypically similar organisms, 26 (70%) synthesized a corticoid 21-dehydroxylase and/or a 3 alpha-hydroxysteroid dehydrogenase. It appeared that the corticoid 3 alpha-hydroxysteroid dehydrogenase was identical to the bile acid 3 alpha-hydroxysteroid dehydrogenase. Steroid-metabolizing enzymes were found both in E. lentum and in phenotypically similar organisms. E. lentum is characterized by nitrate reduction and enhanced growth in the presence of arginine. Many phenotypically similar organisms possess either one or the other of the two markers. In contrast, using the steroid-metabolizing enzymes as markers, a "steroid-active" and a "steroid-inactive" group were established with minimal overlapping of metabolic characteristics. Synthesis of the steroid enzymes was positively correlated with production of gas from H2O2 and formation of H2S. A simple method for the detection of corticoid 21-dehydroxylase and 3 alpha-hydroxysteroid dehydrogenase, one or both of which were present in 92% of the steroid-active group, is described.

3-Hydroxysteroid Dehydrogenases↗
PubMed1979

Bile salt 3 alpha- and 12 alpha-hydroxysteroid dehydrogenases from Eubacterium lentum and related organisms.

Thirty-two strains of Eubacterium lentum and phenotypically similar anaerobic gram-positive bacilli were screened for intracellular bile salt 3alpha- and 12alpha-hydroxysteroid dehydrogenase (HSDHase) activities. These organisms were categorized into four groups: (A) those containing 12alpha-HSDHase only (10 strains), (B) those containing 3alpha- and 12alpha-HSDHase (13 strains), (C) those containing 3alpha-HSDHase only (2 strains), and (D) those devoid of any measurable HSDHase activity (7 strains). Of the respective four groups, 9/10, 13/13, 0/2, and 0/7 were like the neotype strain of E. lentum (ATCC 25559) in that they produced H(2)S in a triple sugar iron agar butt, reduced nitrate to nitrite, and weakly decomposed hydrogen peroxide. The other strains were variable for nitrate reduction and activity on hydrogen peroxide, but all the organisms in the first three categories (with one exception) were H(2)S producers (triple sugar iron agar butt) and all (with one exception) were designated E. lentum, whereas the organisms of category B were non-H(2)S producers (triple sugar iron agar butt). Five of these seven were not stimulated by arginine and are designated "phenotypically similar organisms." Thin-layer chromatography of extracted spent bacterial medium of four representative strains from each group grown in the presence of cholate revealed the presence of (A) 12-oxo product, (B) 12-oxo and 3-oxo products, (C) 3-oxo product, and (D) the absence of any of these products. The 12alpha-HSDHase of category B organisms was unstable unless 10(-3) M dithioerythritol was added to the buffer. With the exception of 3 out of 32 strains, there was a positive correlation between the production of measurable amounts of 12alpha-HSDHase and H(2)S production. Growth curves and the effect of arginine on growth and the production of 3alpha- and 12alpha-HSDHase were examined in representative strains of categories A, B, and C. Both enzymes were shown to bind onto a nicotinamide adenine dinucleotide-Sepharose column and could be eluted by high-ionic-strength buffer, resulting in approximately 25-fold and 18-fold purification, respectively. Molecular weight estimations by Sephadex G-200 gave values of 205,000 and 125,000 for the 3alpha- and 12alpha-HSDHase, respectively. Purified 12alpha-HSDHase was investigated with respect to pH requirement, substrate specificity, and enzyme kinetics.

3-Hydroxysteroid Dehydrogenases↗
PubMed1979

Synonymy of strains of Center for Disease Control group DF-1 with species of Capnocytophaga.

Of eight strains of Center for Disease Control group DF-1 examined, seven had 62 to 87% deoxyribonucleic acid homology with the neotype strain of Capnocytophaga ochracea and one had 72% deoxyribonucleic acid homology with the type strain of C. gingivalis. Deoxyribonucleic acid homology of four strains of Bacteroides ochraceus with the neotype strain of C. ochrecea was 76 to 86%.

Bacteroides↗
PubMed1978

Some current concepts in intestinal bacteriology.

Quantitative studies of the fecal flora of populations at different risk of colon cancer indicate that the relative proportions of some particular species of bacteria rather than of different genera of bacteria may be correlated with colon cancer incidence. Since the metabolic activity of different species in each genus varies widely, a shift in proportions of species could cause a major change in total metabolic activity in the individual. In samples taken from various areas of the intestinal tract and in scrapings from the intestinal wall, the composition of the flora remained relatively constant from the ascending colon to the rectum. Therefore, the bacteria in feces do reflect the flora of the large colon. The composition of the flora was not significantly affected by drastic changes in diet, but statistically significant shifts in the proportions of some species were noted in individuals under conditions of anger or fear stress. Although diet may not change the flora the individual maintains, the bacteria present may convert the different substrates provided by a high-fat diet as opposed to a high-fiber diet into metabolites that are potentially carcinogenic. The conversion of dietary components to carcinogenic compounds, identification of the bacteria capable of effecting such conversions, and the conditions favoring the proliferation of such bacteria will be investigated in greater detail.

Animals↗
PubMed1978

Superoxide dismutase in anaerobes: survey.

Superoxide dismutase (SOD) was present in 23 of 28 strains of the genus Bacteroides tested. Several clostridia, anaerobic cocci, and anaerobic, grampositive, nonsporing rods contained measureable SOD, but the frequency of SOD occurrence was much lower than in the bacteroides. These data indicate that there is a large variation in SOD levels between genera and among species within a genus of anaerobic bacteria. There was also no correlation between source of isolate, SOD levels, and presumed pathogenicity of the isolate.

Anaerobiosis↗
PubMed1977

Urease assay and urease-producing species of anaerobes in the bovine rumen and human feces.

A growth medium and test were developed for rapid detection of urease in fermentative anaerobic bacteria. Using nonselective rumen fluid roll-tube agar medium and the new test, it was confirmed that Peptostreptococcus productus is often the most numerous urease-forming species in human feces. Also, some fecal strains of Ruminococcus albus, Clostridium innocuum, and Clostridium beijerinckii produced urease. Single strains of Fusobacterium prausnitzii, Coprococcus catus, and Streptococcus mitis that were strongly ureolytic on isolation later lost this ability. Urease activity was also detected in many strains of nonselectively isolated rumen species. They include Succinivibrio dextrinosolvens, Treponema sp., Ruminococcus bromii (not previously known to be present in the rumen), Butyrivibrio sp., Bifidobacterium sp., Bacteroides ruminicola, and P. productus. Most P. productus strains contain urease; however, the uniformity of this feature in the other species noted above is not known. The urease in many of these species was not detected if the growth medium contained 0.2% or more (each) yeast extract and Trypticase.

Ammonia↗
PubMed1977

Bile salt degradation by nonfermentative clostridia.

Eight strains of nonfermentative clostridia were characterized on the basis of their intracellular nicotine adenine dinucleotide- and nicotinamide adenine dinucleotide phosphate-dependent hydroxysteroid dehydrogenase (HSDH) content, ability to deconjugate taurocholate, growth characteristics, and metabolic products, including utilization of lactate and pyruvate. Two cultures of Clostridium sporosphaeroides (representing one strain obtained from two different sources), one strain of Clostridium irregularis, four strains of an unnamed species (Clostridium group SPH-1), and one strain of an unnamed species (Clostridium group P) were studied. Both cultures of C. sporosphaeroides contained low amounts of 7alpha-HSDH; C. irregularis contained only a low amount of 3alpha-HSDH. All four strains of Clostridium SPH-1 contained both 12alpha- and 7alpha-HSDH in the ratio of approximately 10:1. The strain of Clostridium group P contained only 12alpha-HSDH and was devoid of any other bile salt oxidoreductases. The enzyme preparation from Clostridium group P was useful in spectrophotometric quantitative studies of 12alpha-OH groups. Correlation of bile salt degradative activities with other phenotypic tests for characterization of and differentiation among such organisms is discussed.

3-Hydroxysteroid Dehydrogenases↗
PubMed1977

Isolation and characteristics of a skatole-producing Lactobacillus sp. from the bovine rumen.

A bacterium that is capable of decarboxylating indoleacetic acid to skatole (3-methylindole) has been isolated from an L-tryptophan enrichment of bovine rumen fluid. The bacterium is a gram-positive, nonmotile, nonsporeforming rod. It is an obligate anaerobe, and strains predominatly produce D-(-)-lactic acid, with smaller amounts of L-(+)-lactic acid and acetic acid, from sugar. All four strains isolated gave a negative reaction to the indole test because they cannot form skatole directly from tryptophan. This is the first report of indoleacetic acid decarboxylation to skatole in pure culture and the demonstration of skatole production by a Lactobacillus species.

Acetates↗
PubMed1977

Production and some properties of catalase and superoxide dismutase from the anaerobe Bacteroides distasonis.

The catalase level of Bacteroides distasonis (ATCC 8503, type strain) varied with the amount of hemin supplied to the medium when the cells were grown in either a prereduced medium containing 0.5% peptone, 0.5% yeast extract, and 1% glucose or in a prereduced, defined heme-deficient medium. The effect of hemin on catalase production could not be duplicated by ferrous sulfate or ferrous ammonium citrate. Catalase activity reached peak values in late log phase, whereas superoxide dismutase specific activity remained constant throughout the culture growth cycle. The catalase was a nondialyzable, cyanide and azide-sensitive, heat-labile protein that coeluted with bovine erythrocyte catalase from Sepharose 6 B. Analysis of polyacrylamide gels stained for catalase activity and for heme showed a correspondence between the single catalytic activity band and one of three heme-protein bands. These data suggest a heme-protein of approximately 250,000 molecular weight. The superoxide dismutase was a cyanide-insensitive protein of approximately 40,000 molecular weight that migrated electrophoretically on acrylamide gels as a single band of activity.

Azides↗
PubMed1976

Human fecal flora: variation in bacterial composition within individuals and a possible effect of emotional stress.

Data are presented on the distribution of 101 bacterial species and subspecies among 1,442 isolates from 25 fecal specimens from three men on: (i) their normal diet and normal living conditions, (ii) normal living conditions but eating the controlled metabolic diet designed for use in the Skylab simulation and missions, and (iii) the Skylab diet in simulated Skylab (isolation) conditions. These bacteria represent the most numerous kinds in the fecal flora. Analyses of the kinds of bacteria from each astronaut during the 5-month period showed more variation in the composition of the flora among the individual astronauts than among the eight or nine samples from each person. This observation indicates that the variations in fecal flora reported previously, but based on the study of only one specimen from each person, more certainly reflect real differences (and not daily variation) in the types of bacteria maintained by individual people. The proportions of the predominant fecal species in the astronauts were similar to those reported earlier from a Japanese-Hawaiian population and were generally insensitive to changes from the normal North American diet to the Skylab diet; only two of the most common species were affected by changes in diet. However, one of the predominant species (Bacteroides fragilis subsp. thetaiotaomicron) appeared to be affected during confinement of the men in the Skylab test chamber. Evidence is presented suggesting that an anger stress situation may have been responsible for the increase of this species simultaneously in all of the subjects studied. Phenotypic characteristics of some of the less common isolates are given. The statistical analyses used in interpretation of the results are discussed.

Adult↗
PubMed1976

Clinical isolates of anaerobic gram-negative rods with a formate-fumarate energy metabolism: Bacteroides corrodens, Vibrio succionogenes, and unidentified strains.

Strains of anaerobic, gram-negative bacteria, isolated from human clinical specimens and from studies of human normal flora, that have energy metabolism similar to Vibrio succinogenes are described. Included are four human isolates of V. succinogenes, five similar strains of motile straight rods, three strains of Bacteroides corrodens, and two unidentified strains. All strains studied grew poorly in usual anaerobic broth media but produced good turbidity in overnight broth cultures in media containing fromate and fumarate, indicating that all have an energy metabolism similar to V. succinogenes: they gain energy by the transfer of electrons from formate or hydrogen to fumarate.

Asparagine↗