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PubMed1983

Antigenic heterogeneity of Bacteroides intermedius as recognized by monoclonal antibodies.

Four hybrid cell lines secreting monoclonal antibodies against antigens of Bacteroides intermedius were generated by fusing murine NSI cells with splenocytes from a rat immunized with B. intermedius strain OMZ248. An enzyme-linked immunosorbent assay was used to analyze the distribution of the recognized antigens on 39 strains from various Bacteroides species and on 5 strains from other genera. Only Bacteroides species B. intermedius, B. loescheii, B. melaninogenicus, and B. corporis were found to express at least one of the recognized antigens. Strains of the two asaccharolytic black-pigmenting Bacteroides species were negative. Among the strains capable of binding to one or more of the monoclonal antibodies, five groups with different reactivity patterns could be distinguished. Two of the monoclonal antibodies were specific for B. intermedius. The B. intermedius strains were metabolically almost identical, expressed at least three of the recognized antigens, and fell into three distinct antibody reactivity groups, suggesting a tentative separation of this species into three new serogroups. Oral and nonoral isolates of B. intermedius were, however, not distinguished by the monoclonal antibodies. One monoclonal antibody was directed against an antigen strongly expressed on all saccharolytic black-pigmenting Bacteroides strains tested so far, thus confirming the previously noted antigenic relationship between the species which had emerged from the former B. melaninogenicus subsp. intermedius and B. melaninogenicus subsp. melaninogenicus groups.

Animals↗
PubMed1989

A soluble Bacteroides by-product impairs phagocytic killing of Escherichia coli by neutrophils.

The effect of Bacteroides culture filtrate on killing of Escherichia coli by neutrophils was examined as a potential mechanism for E. coli-Bacteroides microbial synergy. A low-molecular-weight heat-stable factor present in the 22-h culture filtrate of Bacteroides fragilis 9032 impaired neutrophil killing function. To determine whether short-chain fatty acids present in the filtrate could account for the inhibition, the fatty acid content of the culture filtrate was determined and sterile medium supplemented with measured concentrations of fatty acids was tested for its effect on neutrophil function. Succinic and acetic acids were measured in high concentrations, while lactic, formic, and fumaric acids were present in lower concentrations. Reconstituted media mimicked the inhibitory effect of B. fragilis filtrate on neutrophil killing capacity. In further support of the hypothesis that short-chain fatty acids were responsible for the inhibition, the filtrates of other Bacteroides strains were found to be inhibitory only after bacterial growth had entered the stationary phase, a period during which fatty acid production is maximized. Further studies investigating the mechanism of impaired neutrophil killing showed that B. fragilis 9032 culture filtrate inhibited both phagocytosis of [3H]thymidine-labeled E. coli by neutrophils and the intrinsic microbicidal functions of the neutrophil. Impairment of neutrophil superoxide production was mediated via the ability of short-chain fatty acids present in B. fragilis filtrate to reduce neutrophil cytoplasmic pH. These studies suggest that Bacteroides strains capable of reaching stationary phase in vivo may contribute to the pathogenesis of mixed infections by direct inhibition of neutrophil function.

Bacteroides↗
PubMed1989

Cloning and characterization of a Bacteroides conjugal tetracycline-erythromycin resistance element by using a shuttle cosmid vector.

The Bacteroides conjugal tetracycline resistance (Tcr) elements appear not to be plasmids. In many cases, resistance to erythromycin (Emr) is cotransferred with Tcr. Using a newly constructed shuttle cosmid, pNJR1, we cloned 44 to 50 kilobase pairs of a conjugal Tcr Emr element on overlapping cosmid clones. Cosmid libraries were made in Escherichia coli with DNA from the original clinical Bacteroides thetaiotaomicron DOT strain containing Tcr Emr-DOT or from a Bacteroides uniformis Tcr Emr-DOT transconjugant strain. The cosmid clones were mobilized from E. coli into B. uniformis in groups of 10 to 20 per filter mating, with selection for Tcr or Emr transconjugants. The Tcr and Emr genes were cloned both separately and together on 30-kilobase-pair fragments. Several of the Tcr clones also contained transfer genes that permitted self-transfer of the cosmid from B. uniformis donors to E. coli or B. uniformis recipients. Neither the Tcr nor the Emr gene conferred resistance on E. coli, and the transfer-proficient clones did not self-transfer out of E. coli. Southern blot analysis was used to compare DNA from independently isolated Bacteroides strains carrying conjugal Tcr or Tcr Emr elements and their respective B. uniformis transconjugants. Results of these analyses indicate that there are large regions of homology, including regions outside the Tcr and Emr genes, but that the elements are not identical. Some Tcr clones contained a region which hybridized to chromosomal DNA from the wild-type B. uniformis recipient strain that did not carry the Tcr Emr-DOT element. This region of homology appeared not to be a junction fragment. It was not required in a Bacteroides recipient for successful transfer of the Tcr Emr element. Although we are not sure we have cloned a junction fragment between the Tcr Emr-DOT element and the B. uniformis chromosome, the preliminary function and restriction map appears to be linear.

Bacteroides↗
PubMed1996

NBU1, a mobilizable site-specific integrated element from Bacteroides spp., can integrate nonspecifically in Escherichia coli.

NBU1 is an integrated Bacteroides element that can he mobilized from Bacteroides donors to Bacteroides recipients. Previous studies have shown that a plasmid carrying the internal mobilization region of NBU1 could be transferred by conjugation from Bacteroides thetaiotaomicron to Escherichia coli. In this report, we show that NBU1 can integrate in E. coli. Whereas integration of NBU1 in B. thetaiotaomicron is site specific, integration of NBU1 in E. coli was relatively random, and the insertion frequency of NBU1 into the E. coli chromosome was 100 to 1,000 times lower than the frequency of integration in B. thetaiotaomicron. The frequency of NBU1 integration in E. coli could be increased about 10- to 70-fold, to a value close to that seen with B. thetaiotaomicron, if the primary integration site from B. thetaiotaomicron, BT1-1, was provided on a plasmid in the E. coli recipient or the NBU1 integrase gene, intN1, was provided on a high-copy-number plasmid to increase the amount of integrase available in the recipient. When the primary integration site was available in the recipient, NBU1 integrated site specifically in E. coli. Our results show that NBUs have a very broad host range and are capable of moving from Bacteroides spp. to distantly related species such as E. coli. Moreover, sequence analysis of NBU1 integration sites provided by integration events in E. coli has helped to identify some regions of the NBU1 attachment site that may play a role in the integration process.

Bacteroides↗
PubMed1999

Activities of the Porphyromonas gingivalis PrtP proteinase determined by construction of prtP-deficient mutants and expression of the gene in Bacteroides species.

PrtP is a major cysteine proteinase of Porphyromonas gingivalis. The gene encoding this proteinase, prtP, was cloned into the Escherichia coli-Bacteroides shuttle vectors pFD288 and pFD340 and was expressed in Bacteroides cells, apparently under the control of its own promoter, when in pFD288, or a Bacteroides promoter present on pFD340. Proteolytically active PrtP was detected by fibrinogen zymography in cells or spent growth medium of several Bacteroides species harboring the recombinant plasmids. The proteinase was recovered from Bacteroides fragilis ATCC 25285(pFD340-prtP) cells by 3-[(3-cholamidopropyl)-dimethyl-ammonio]-1-propanesulfonate (CHAPS) extraction and characterized with regard to exopeptidase specificity and sensitivity to proteinase inhibitors. Lys-amidolytic activity, but not Arg-amidolytic activity, was detected. PrtP was activated by cysteine and, to a lesser extent, dithiothreitol, and it was stimulated by glycine-containing compounds. It also was inhibited by Nalpha-p-tosyl-L-lysine chloromethyl ketone (TLCK) and, to a lesser extent, H-D-Tyr-L-Pro-L-arginyl chloromethyl ketone (YPRCK) and was relatively insensitive to EDTA and leupeptin. Neither B. fragilis ATCC 25285(pFD340-prtP) cells nor the CHAPS extract effected hemagglutination of sheep red blood cells or collagen cleavage, but the cells did cleave gelatin. Furthermore, P. gingivalis W12, ATCC 33277, KDP110, and HG66 with knockout mutations in prtP were constructed by allelic replacement. Unlike the parent strains, the mutant strains produced beige colonies on plates containing sheep blood. These strains also were affected in their ability to effect hemagglutination, cleave collagen, and cleave a Lys-specific peptide substrate. This report presents the results of the first characterization of the PrtP proteinase clearly in the absence of any influence by other P. gingivalis proteins and describes the properties of P. gingivalis cells defective in the production of PrtP.

Animals↗
PubMed1966

Fine structure of bacteroids in root nodules of Vigna sinensis, Acacia longifolia, Viminaria juncea, and Lupinus angustifolius.

Dart, P. J. (University of Sydney, Sydney, Australia), and F. V. Mercer. Fine structure of bacteroids in root nodules of Vigna sinensis, Acacia longifolia, Viminaria juncea, and Lupinus angustifolius. J. Bacteriol. 91:1314-1319.-In nodules of Vigna sinensis, Acacia longifolia, and Viminaria juncea, membrane envelopes enclose groups of bacteroids. The bacteroids often contain inclusion granules and electron-dense bodies, expand little during development, and retain their rod form with a compact, central nucleoid area. The membrane envelope may persist around bacteroids after host cytoplasm breakdown. In nodules of Lupinus angustifolius, the membrane envelopes enclose only one or two bacteroids, which expand noticeably during development and change from their initial rod structure.

Acacia↗
PubMed1984

Rapid glutamic acid decarboxylase test for identification of Bacteroides and Clostridium spp.

A rapid 4-h test for glutamic acid decarboxylase is described for the identification of certain anaerobic bacteria. The test substrate consisted of 1.0 g of L-glutamic acid, 0.3 ml of Triton X-155, and 0.05 g of bromcresol green sodium salt in 1 liter of water. The substrate was dispensed in 0.5-ml amounts into test tubes, and a turbid suspension was made with the test organism. The test was then incubated aerobically at 35 degrees C for 4 h. The development of a blue color was considered positive. A total of 345 strains of clinically isolated anaerobic bacteria were tested. All isolates of Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides uniformis. Clostridium perfringens, and Clostridium sordellii gave a positive reaction. Some isolates of Bacteroides distasonis and Bacteroides vulgatus were also positive. The use of this rapid test in conjunction with other rapid methods, such as the spot indol test, will enable laboratory workers to report these pathogens on the same day on which an inoculum of pure culture growth on agar is available.

Bacteriological Techniques↗
PubMed1984

Serological identification of oral Bacteroides spp. by enzyme-linked immunosorbent assay.

A rapid method for identifying black-pigmented oral Bacteroides spp. is described. Species-specific rabbit antisera to Bacteroides gingivalis, B. intermedius, and B. melaninogenicus were used in an enzyme-linked immunosorbent assay to identify clinical isolates of black-pigmented Bacteroides spp. from humans. The results showed excellent agreement with biochemical identification of B. gingivalis and B. intermedius. Only 36% of the B. melaninogenicus isolates were identified with the enzyme-linked immunosorbent assay, suggesting that this group of black-pigmented Bacteroides spp. is made up of more than one serotype. The serological enzyme-linked immunosorbent assay should enable rapid identification of black-pigmented Bacteroides spp. isolated from sites of oral diseases and may also be used to identify the presence of these organisms in complex bacterial mixtures from oral sites.

Agar↗
PubMed1982

Characterization of Bacteroides gingivalis by direct fluorescent antibody staining and cellular fatty acid profiles.

Bacteroides gingivalis is a newly proposed species which includes strains isolated from the mouth. Thirteen strains of B. gingivalis isolated from three geographic locations in the United States and France were examined with direct fluorescent antibody staining and analysis of total cellular fatty acids and compared with 16 strains of B. asaccharolyticus of nonoral origin by the same methods. Bacteroides gingivalis strains reacted with the B. gingivalis conjugate (fluorescein isothiocyanate labeled antibody reagent) only, while the B, asaccharolyticus strains reacted with the B. asaccharolyticus conjugate only. The B. gingivalis strains showed negative fluorescence with fluorescein isothiocyanate conjugates for other black-pigmented Bacteroides species. The specificity of the B. gingivalis conjugate was demonstrated by its failure to stain 88 strains of aerobic and anaerobic bacteria other than B. gingivalis. The fatty acid profiles of B. gingivalis and B. asaccharolyticus were readily distinguishable. The B. gingivalis profile was also distinguishable from those of other pigmenting Bacteroides species on the basis of concentration ratios among the characteristic components. These results support the species separation of B. gingivalis and B. asaccharolyticus. Further, they indicate the usefulness of cellular fatty acid profiles as an adjunct to the use of specific fluorescent antibody conjugates for identification of Bacteroides species.

Bacteroides↗
PubMed1989

Relative adherence of Bacteroides species and strains to Actinomyces viscosus on saliva-coated hydroxyapatite.

The study was designed to compare the adherence of several Bacteroides species to A. viscosus. Using 3H, we labeled 24 laboratory strains, including 13 Bacteroides species and 11 fresh clinical isolates of three Bacteroides species. Their adherence to A. viscosus bound to a saliva-coated mineral surface was quantified by liquid scintillation. Adherence relative to a standard strain, B. gingivalis 2561, was compared. Among the lab bacteroides, those of B. gingivalis (eight strains) were the greatest binders (mean, 80.5 +/- 12.4%). Strains of other lab bacteroides bound less well (mean, 33.4 +/- 6.3%). The difference in means was statistically significant (p less than 0.01). The mean for B. gingivalis strains was also significantly greater than that for strains of B. intermedius (51.7 +/- 6.2%). Attachment of B. gingivalis was saturable in experiments in which either input concentration or time was the independent variable, indicating that B. gingivalis cells do not accumulate in this vitro simulation of plaque formation by binding to each other. Subculture did not seem to affect the degree of binding.

Actinomyces↗
PubMed2003

[The influence of the LPS from Bacteroides fragilis on the secretion of IL-2 and IL-4 from the peripheral blood mononuclear cells of normal volunteers].

OBJECTIVE: To investigate the influence of the LPS of Bacteroides fragilis on the secretion of IL-2 and IL-4 from the peripheral blood mononuclear cells of normal individuals, so as to elucidate the mechanism of the infection by Bacteroides fragilis. METHODS: LPS was obtained from both the strains isolated from patients and from standard NCTC9343. Peripheral blood mononuclear cells (PBMCs) were treated with different concentrations of LPS thus obtained. The supernatants from the cell culture of the PBMCs were harvested at 24 PBHs and were subjected to the determination of the IL-2 and IL-4 contents by ELISA method. RESULTS The IL-2 secretion from the PBMCs of normal volunteers was obviously inhibited by the LPS from Bacteroides fragilis (P < 0.01), and the inhibitory effect was dose-dependent. Nevertheless, the IL-4 secretion from the PBMCs of normal volunteers was significantly stimulated by the LPS from Bacteroides Fragilis (P < 0.05), and it was not concentration dependent. There was no difference between the effects of the LPSs from patients and standard strains (P < 0.05). CONCLUSION: The LPS from Bacteroides fragilis was inhibitory to the secretion of IL-2 from PBMCs and was stimulative to that of IL-4 from PBMCs of normal human persons.

Bacteroides fragilis↗
PubMed1989

[Purification and some properties of neuraminidase from the culture medium of Bacteroides loescheii ATCC 15930].

The purpose of this study is to investigate the mechanism on enhanced hemagglutination caused by neuraminidase from Bacteroides in an aspect of zeta-potential levels on erythrocytes and inhibitors on hemagglutination activity. The neuraminidase from the culture medium of Bacteroides loescheii ATCC 15930 was purified by ultrafiltration followed by DEAE-Sephacel anion exchange chromatography, fast protein, polypeptide, polynucleotide, liquid chromatography using Mono P column and finally high performance liquid chromatography using Shim-pack Diol-300 column. The purified enzyme appeared to be homogeneous by analytical polyacrylamide gel electrophoresis. The molecular weight was measured to be approximately 87,000 and the optimal pH was at 4.8. The isoelectric point was at 5.1. The enzyme showed relatively high specificity toward the linkage of NANA alpha (2----3) oligosaccharides and glycoproteins, and less toward the linkage of NANA alpha (2----6), and/or NANA alpha (2----8) oligosaccharides. When the human erythrocytes were treated by the purified enzyme, hemagglutination activities of some strains of Bacteroides gingivalis, Bacteroides denticola and Bacteroides intermedius were enhanced. Hemagglutination inhibition experiments using B. gingivalis 381 showed that the activity of hemagglutination was strongly inhibited by the arginine-containing peptides especially salmine derived from salmon, although the activity was unaffected by the sugars, amino acids and divalent cations such as Ca2+, Mn2+ and Mg2+. The zeta-potential level on asialo-erythrocytes treated by purified enzyme was considerably decreased compared to that of sialo-erythrocytes. It seems likely that the mechanism on hemagglutination by the B. gingivalis 381 may be involved in electrochemical affinity between the erythrocytes and bacterial cells with the reduction of zeta-potential, and in arginine-containing peptides as receptors of ligand-binding on erythrocytes.

Bacteroides↗
PubMedDate not supplied

[Bacteremia caused by Bacteroides. An analysis of 50 episodes].

During the 32 months between October 1984 and May 1987 there were 72,800 admissions in our center; 31,523 blood cultures were undertaken and in 3,831 of them (11.5%) at least one significant organism was recovered; 6.7% of blood cultures yielded anaerobic bacteria, and 3.1% Bacteroides spp. In the 1,478 instances of bacteremia recorded during that period, the relative frequencies of bacteremia by anaerobic bacteria and by Bacteroides were 8.6% and 3.9%, respectively. In overall 50 Bacteroides bacteremias (47 due to Bacteroides fragilis and 3 to Bacteroides spp), 32 (64%) were hospital acquired and 14 (28%) postsurgical. Their most common source was the abdominal cavity (25, 50%), followed by the skin and soft tissues (7, 14%), feminine pelvis (4, 8%), miscellaneous (8, 16%), and unknown (7, 14%). Fifteen bacteremias (30%) were polymicrobial, 20 (40%) were associated with septic shock, and 15 (30%) with renal failure. Overall mortality rate was 52%, and that directly attributable to bacteremia was 32%. Poor prognostic predictors included the source from a perforated viscus, septic shock, renal failure or gastrointestinal hemorrhage, and the absence of adequate antimicrobial therapy.

Adolescent↗
PubMed1988

Antimicrobial resistance in oral and colonic bacteroides.

Antimicrobial resistance in Bacteroides from oral and colonic flora influences the selection of antimicrobial therapy to treat infections involving these organisms. An antimicrobial susceptibility study of 49 clinical isolates of oral bacteroides to 9 drugs revealed high resistance rates for penicillin 53%, for cefaclor 45%, and for tetracycline 27%, while there were low rates (less than 10%) with cefoxitin, piperacillin, clindamycin, chloramphenicol and metronidazole. Review of our U.S. nationwide survey of the susceptibility of colonic bacteroides (Bacteroides fragilis group) reveals low resistance to clindamycin, cefoxitin, piperacillin, imipenem, chloramphenicol and metronidazole. However, the identification of clindamycin, clindamycin, cefoxitin, piperacillin, imipenem and chloramphenicol resistant isolates is worrisome. The mechanism of resistance and the resistant transfer mechanism to the different classes of drugs in the oral and colonic bacteroides are reviewed.

Bacteroides↗
PubMedDate not supplied

[Increase of anaerobic infections. Prevalence of Bacteroides. Apropos of 17 cases in abdominal surgery].

Seventeen cases of anaerobic infections in abdominal surgery are reported. Predominance of bacteroides is evident (9/17), especially bacteroides fragilis. The clinical manifestations of bacteroides infections are severe: 7 septicemias and 2 parietal infections, being the cause of the death in four patients. Bacteroides infection develops preferently in an old patient, with severe disease, in colic surgery especially in emergency. Bacteroides are characterized by their polyresistance to antibiotics: beta-lactamins, except carbenicillin, and aminosids. Metronidazole is a powerful bactericidal agent with a very low toxicity, particularly active in the treatment of these affections, as well as clindamycin. If oral route is impossible, chloramphenicol, I.V. tetracyclin, and above all carbenicillin are able to be used with success.

Abdomen↗
PubMed1988

Pathogenicity of capsulate and non-capsulate members of Bacteroides fragilis and B. melaninogenicus groups in mixed infection with Escherichia coli and Streptococcus pyogenes.

The relationships between capsulate and non-capsulate Bacteroides fragilis strains and Escherichia coli, and between capsulate and non-capsulate strains of the B. melaninogenicus group and Streptococcus pyogenes, were studied in a subcutaneous abscess model in mice. Selective antimicrobial agents directed against either aerobic or anaerobic bacteria were used alone or in combination to explore the effect of eradication of one component of the mixed infection. Single agent therapy effective against both aerobic and anaerobic flora was also employed. Single therapy of mixed infection directed at the elimination of only one organism (S. pyogenes, E. coli or Bacteroides sp.) caused significant reductions in the numbers of sensitive organisms and also smaller yet significant decreases in the numbers of insensitive organisms. However, the abscesses were not eliminated after such therapy. Combination therapy or use of a single agent (cefoxitin) directed against the aerobic and anaerobic components of the infection was more effective. Non-capsulate Bacteroides spp. became capsulate after passage in mice mixed with either S. pyogenes or E. coli. Therapy directed at the elimination of S. pyogenes and E. coli did not prevent the emergence of capsulate Bacteroides spp. These data demonstrate the synergy between all members of the B. fragilis group and E. coli and between the B. melaninogenicus group and S. pyogenes, and reiterate the need to direct antimicrobial therapy at the eradication of the aerobic and anaerobic components of mixed infections.

Abscess↗
PubMed1964

BACTEROIDES ORALIS, PROPOSED NEW SPECIES ISOLATED FROM THE ORAL CAVITY OF MAN.

Loesche, W. J. (Forsyth Dental Center and Harvard School of Dental Medicine, Boston, Mass.), S. S. Socransky, and R. J. Gibbons. Bacteroides oralis, proposed new species isolated from the oral cavity of man. J. Bacteriol. 88:1329-1337. 1964.-Twenty-seven strains of oral bacteroides were characterized and compared with a National Collection of Type Cultures strain of Bacteroides fragilis as well as strains of intestinal bacteroides. A combination of acid end products, gas production, pentose fermentation, and 10% bile tolerance afforded a basis for separation of oral strains from intestinal strains. The oral strains produced succinic, lactic, acetic, and formic acids but no gas. They were inhibited by 10% bile, and did not ferment xylose and arabinose. Intestinal strains consistent with the description for B. fragilis produced succinic, formic, acetic, and propionic acids and gas, with a few strains forming lactic acid. They were stimulated by 10% beef bile, and fermented xylose and arabinose. The oral strains are sufficiently different from intestinal strains of the B. fragilis type, so that they appear to constitute a separate species. It is proposed that they be recognized as B. oralis, sp. n.

Acetates↗