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Colonic bacterial activity and serum lipid risk factors for cardiovascular disease.

Antibiotics are being proposed for the treatment of cardiovascular disease. In the past, antibiotics were advocated for the control of hypercholesterolemia. We have therefore investigated the relation between colonic bacterial activity and serum lipids. In a four-phase randomized crossover study, we fed a different starch supplement during each 2-week phase to 24 healthy subjects. In two phases, supplements containing resistant starches were fed that reach the colon and are largely fermented by colonic bacteria. Fecal starch recovery therefore reflects the metabolic activity of colonic microflora. The control treatments were conventional starches. Blood lipid levels were obtained at the start and 4-day fecal collections at the end of each phase. Resistant starch supplements increased fecal starch excretion by 3.8 +/- 1.2 g/d more than conventional starches (P = .006). Mean starch excretion was related positively to pretreatment serum high-density lipoprotein (HDL) cholesterol (r = -.57, P = .003) and negatively to low-density lipoprotein (LDL) cholesterol (r = -.57, P = .004), apolipoprotein B:AI (r = -.56, P = .005), and fecal output of fusobacteria (r = -.73, P = .003) and bacteroides (r = -.72, P = .003). The ratio of fusobacteria to total anaerobes was also related to pretreatment LDL cholesterol (r = .56, P = .037). Differences in starch excretion between healthy subjects, as a measure of bacterial activity, accounted for 32% of the variation in pretreatment LDL cholesterol. The activity of colonic microflora therefore appears to influence serum lipid levels. Alterations of bacterial number and activity may provide an additional strategy to control serum lipid risk factors for cardiovascular disease.

Adult↗

Pericoronitis: a reappraisal of its clinical and microbiologic aspects.

Pericoronitis is an infectious disease of the operculum overlying an erupting or semi-impacted tooth. It manifests itself mainly in late adolescence and young adulthood and nearly always occurs around the lower third molar. The distinctive location, age, clinical picture, and link with predisposing factors warranted a reappraisal of pericoronitis and its etiology. Spirochetes and fusobacteria proved prevalent at all stages of the disease. The presence of these microbacteria may provide a clue as to the late appearance, particular location, and singular clinical picture of pericoronitis. The fact that spirochetes and fusobacteria are also found in acute necrotizing ulcerative gingivitis, and have been associated with alveolar osteitis, indicates a possible relationship between these disorders and pericoronitis.

Adolescent↗

Experimental observations on the pathogenesis of necrobacillosis.

Earlier studies showed that the minimum infective dose (greater than 10(6) organisms) of a virulent strain of Fusobacterium necrophorum could be greatly reduced by suspending the fusobacteria in sub-lethal doses of cultures of other bacteria such as Escherichia coli before inoculating mice subcutaneously. In the present study the infective dose of the same strain of F. necrophorum was reduced by a factor of greater than 10(3) by suspending the fusobacteria in sub-lethal doses of 5% homogenate of gaur or wallaby faeces. Sterile faecal filtrate had no such effect. The sites of low grade infection produced by the prior subcutaneous injection of E. coli culture or gaur faecal suspension were susceptible to superinfection by doses of F. necrophorum far below those required to infect normal tissue. This work helps to explain the production of necrobacillosis by the faecal contamination of small wounds. It proved impossible, however, to produce necrobacillosis in mice by the subcutaneous injection of faecal suspensions from 33 farm cattle. This suggests that the proportion of cattle with virulent F. necrophorum in their faeces is low.

Animals↗

Sequence conservation and distribution of the fusobacterial immunosuppressive protein gene, fipA.

Fusobacterium nucleatum is a gram-negative anaerobe involved in various diseases, including periodontitis. Recently, other investigators isolated the F. nucleatum FDC 364 fusobacterial immunosuppressive protein (FIP). One subunit, FipA, impairs T-cell activation in vitro and shows homology with beta-ketothiolases. However, its distribution and variability among fusobacteria was not reported. Cloned fipA gene sequences from F. nucleatum ssp. polymorphum (ATCC 10953) and F. nucleatum ssp. nucleatum (ATCC 23726) shared 89 and 92% identity, respectively, with FDC 364 fipA, and 90 and 94% identity, respectively, with the FDC 364 FipA predicted amino acid sequence. Southern blot analyses of chromosomal DNA from fusobacterial strains, including F. nucleatum and other Fusobacterium species, were performed using partial fipA sequences as probes. The results indicate that fipA is highly conserved among the F. nucleatum strains examined and that fipA homologues are widely distributed among fusobacteria. A clear relationship between immune suppression, metabolism and the FipA protein remains to be determined.

Acetyl-CoA C-Acetyltransferase↗

Comparative effects of moxifloxacin and clarithromycin on the normal intestinal microflora.

Twelve healthy male subjects age range 24-40 y participated in the investigation. The trial was divided into 2 35-d periods. The 2 treatment regimens were: (i) 1 x 400 mg moxifloxacin tablet in the morning and 1 placebo tablet in the evening for 7 d; and (ii) 1 x 500 mg clarithromycin tablet in the morning and 1 x 500 mg clarithromycin tablet in the evening for 7 d. Each subject received firstly I treatment regimen and secondly the other treatment regimen. The wash-out period was 6 weeks between the two treatment regimens. Moxifloxacin caused significant decreases of enterococci and enterobacteria during the administration period while the numbers of staphylococci, streptococci, Bacillus and Candida were not affected. No impact on peptostreptococci, lactobacilli, Veillonella, Bacteroides or fusobacteria was observed, while bifidobacteria and clostridia decreased during moxifloxacin administration. The microflora was normalized after 35 d. Clarithromycin caused significant reduction of Escherichia coli while the numbers of enterococci, Enterobacter, Citrobacter, Klebsiella and Pseudomonas increased markedly. No significant changes in the numbers of staphylococci, streptococci, Bacillus and Candida were noticed. In the anaerobic microflora bifidobacteria, lactobacilli and clostridia were suppressed, while no changes in peptostreptococci, Veillonella, Bacteroides and fusobacteria were found. The microflora was normalized in all volunteers after 35 d.

Administration, Oral↗

Patterns of susceptibility to fluoroquinolones among anaerobic bacterial isolates in the United States.

The activity of the fluoroquinolone antibiotics against anaerobic bacteria has generally been moderate to poor. Nalidixic acid and cinoxacin show poor activity against almost all anaerobes. Norfloxacin and enoxacin exhibit poor anaerobic activity (MIC90, 8- > 256 micrograms/mL) except against Clostridium perfringens, Bacteroides ureolyticus, and some eubacteria. Norfloxacin is slightly more active than enoxacin against some Bacteroides species. While ciprofloxacin is more active than earlier fluoroquinolones against anaerobes such as Bacteroides fragilis (MIC90, 4-16 micrograms/mL), fusobacteria, and peptostreptococci, its activity is often variable and its MIC90 is frequently close to the maximal level attainable in serum. Ofloxacin is active against B. fragilis (MIC90, 4-8 micrograms/mL) but not against other species of the B. fragilis group (MIC90, 8-32 micrograms/mL); other anaerobes (e.g., peptostreptococci and fusobacteria) are generally susceptible to < or = 8 micrograms of ofloxacin/mL. Several newer quinolones exhibit improved anaerobic activity (although the studies yielding relevant data have often used diverse methods, small numbers and varieties of isolates, and different breakpoints). CI-960 and WIN 57273 inhibit 95% of strains tested at < or = 2 micrograms/mL. CI-990, sparfloxacin, and temafloxacin inhibit most anaerobes at < or = 2 micrograms/mL, but clustering around the breakpoint and strain variability have been noted. CI-990 is active against more than 85% of B. fragilis strains (MIC90, 4 micrograms/mL), but other species of the B. fragilis group often require > 4 micrograms/mL for inhibition; Prevotella bivia, Fusobacterium varium, and Fusobacterium ulcerans are usually resistant.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Infective Agents↗

Review of the in vitro activity of gemifloxacin against gram-positive and gram-negative anaerobic pathogens.

Published reports on the in vitro activity of gemifloxacin mesylate (SB 265805), a new fluoronaphthyridone, against anaerobic pathogens are reviewed here. The studies used a variety of media, inocula and antimicrobial agents. Using a proposed breakpoint of 0.5 mg/L, these studies showed that gemifloxacin had generally higher potency against Gram-positive anaerobes (Clostridium perfringens, all Peptostreptococcus spp.) and fusobacteria (Fusobacterium nucleatum, Fusobacterium necrophorum) and moderate but variable potency against Gram-negative anaerobes. Bacteroides stercoris, Bacteroides tectum and many Bacteroides fragilis isolates were inhibited by concentrations of < or =0.5 mg/L, while the other species of the B. fragilis group required higher concentrations for inhibition. Species variability was evident: Porphyromonas asaccharolytica, Porphyromonas canoris, Porphyromonas gingivalis, Porphyromonas macaccae, Prevotella heparinolytica and Prevotella intermedia were susceptible to 0.5 mg/L of gemifloxacin while most other Porphyromonas and Prevotella spp. were not. These data suggest that gemifloxacin may have a clinical role in the treatment of certain dental, head and neck and pleuropulmonary infections in which Gram-positive anaerobes, fusobacteria and some Prevotella and Porphyromonas spp. may predominate.

Anti-Infective Agents↗

Pathways of glutamate catabolism among Fusobacterium species.

Glutamate is a major source of energy for Fusobacterium species but its mode of catabolism has not hitherto been elucidated. Cell suspensions of F. nucleatum and F. varium, as representative species from the oral cavity and gastrointestinal tract, respectively, both decarboxylated position-labelled glutamate but by different pathways. 14CO2 was released only from C-5 by F. nucleatum whereas F. varium decarboxylated glutamate at either C-1 or C-5. In both species, 2 mols of glutamate fermented yielded 2 mols of acetate and 1 mol of butyrate, suggesting the possibility of three metabolic pathways: the 2-oxoglutarate, mesaconate and 4-aminobutyrate pathways. Enzymes representative of the three pathways were assayed for in cell-free extracts of fusobacteria. All species tested possessed high levels of both glutamate dehydrogenase and 2-oxoglutarate reductase, indicating the presence of the 2-oxoglutarate pathway. Enzymes representative of the mesaconate pathway were detected in F. sulci, F. ulcerans, F. mortiferum and F. varium, while the latter two species also possessed the 4-aminobutyrate pathway. The pathways of glutamate catabolism therefore bore no relationship to the site of isolation of the fusobacteria tested but instead correlated with their chemotaxonomic properties. Thus, F. varium, F. mortiferum, F. ulcerans and F. sulci, which possess a peptidoglycan structure based on diaminopimelic acid, have either two or three pathways for glutamate catabolism whereas F. nucleatum and other species that have a lanthionine-based murein metabolized glutamate solely by the 2-oxoglutarate pathway.

Fermentation↗

Antimicrobial susceptibility of non-Bacteroides fragilis group anaerobic Gram-negative bacilli in Europe.

OBJECTIVE: To investigate the in vitro activity of a range of anti-anaerobe antimicrobials against non-Bacteroides fragilis group anaerobic Gram-negative bacilli isolated in Europe. METHODS: Isolates from 15 laboratories in 13 countries were identified by conventional methods. The MICs of 20 antibiotics were determined by an agar dilution method. RESULTS: There were 488 Prevotella spp., 174 fusobacteria, 69 Porphyromonas spp., 33 Bacteroides spp., 28 Bilophila wadsworthia and 16 Campylobacter spp. isolates, one Sutterella wadsworthensis isolate and four unidentified isolates. Penicillin resistance (and diminished susceptibility to piperacillin) was most common in Prevotella spp. and Bilophila wadsworthia but was also seen in many other species. All isolates, except three of Bilophila wadsworthia, were susceptible to amoxycillin/clavulanate. Most isolates were susceptible to cefoxitin (except Bilophila wadsworthia) and all were susceptible to the carbapenems. Clinafloxacin was the most active quinolone, followed by trovafloxacin and then sparfloxacin. Most fusobacteria were inherently resistant to the macrolides, as expected, but resistance to macrolides and a ketolide in other species was uncommon. Most Fusobacterium varium isolates were resistant to clindamycin, but resistance to clindamycin in all other species was rare. Tetracycline resistance was common but this did not affect the glycylcyclines. There was one isolate of Bacteroides putredinis resistant to chloramphenicol, and three isolates, a Bacteroides ureolyticus isolate, the Sutterella wadsworthensis isolate and one of the unnamed isolates, were metronidazole resistant. Rifampicin was active against most Prevotella and Porphyromonas spp., but not against many other genera. CONCLUSIONS: Penicillin resistance has increased in Europe among non-Bacteroides fragilis anaerobic Gram-negative bacilli, much of it due to beta-lactamase. Acquired resistance to other beta-lactams, macrolides and rifampicin has not significantly increased, and chloramphenicol and metronidazole are unaffected. However, resistance to tetracycline is common. The new compounds, a ketolide (HMR 3647), the glycylcyclines and clinafloxacin, are highly active.

Journal Article↗

Changes in the bacterial flora of the neoterminal ileum after ileocolonic resection for Crohn's disease.

OBJECTIVE: Bacterial agents have been implicated in the early recurrence of Crohn's disease after ileocolectomy. The aim of our study was to identify and quantify bacteria associated with the ileal mucosa in patients and controls and to correlate specific bacteria with recurrence. METHODS: The predominant bacterial microflora of the ileum were enumerated and identified, aerobically and anaerobically, in biopsies obtained at the time of surgery or by endoscopy from 61 patients with Crohn's disease and 10 ileocolectomy controls. The 61 specimens were comprised of 13 ileal biopsies taken from resection specimens, seven taken after ileostomy, and 41 taken after ileocolectomy. RESULTS: Ileocolectomy induced a significant increase in bacterial counts and variety in the neoterminal ileum in both patients and controls that was not observed in ileostomy biopsies. Comparison between patients and controls revealed greater numbers of Escherichia coli and enterococci in Crohn's disease and of bifidobacteria and ruminococci in controls. Early recurrence was associated with high counts of E. coli and bacteroides and the frequent isolation of fusobacteria. CONCLUSION: After ileocolectomy, colonization of the neoterminal ileum is increased. Our data suggest that increases in the populations of specific bacteria such as E. coli, enterococci, bacteroides, and fusobacteria may be important in postoperative recurrence of Crohn's disease.

Adult↗

Susceptibilities of 394 Bacteroides fragilis, non-B. fragilis group Bacteroides species, and Fusobacterium species to newer antimicrobial agents.

The susceptibilities of 374 selected beta-lactamase-producing gram-negative anaerobes (including 22 cefoxitin-resistant strains and 36 strains refractory to the enhancing effect of beta-lactamase inhibitors) and 20 beta-lactamase-negative strains were tested by agar dilution against selected new agents. The organisms included 217 Bacteroides fragilis group strains, 137 non-B. fragilis group Bacteroides spp., and 40 fusobacteria. All strains were susceptible to piperacillin-tazobactam, imipenem, and meropenem. For the B. fragilis group, 96% were susceptible to ampicillin-sulbactam, 95% were susceptible to amoxicillin-clavulanate and cefoperazone-sulbactam, 94% were susceptible to tosufloxacin, 91% were susceptible to cefoxitin, 88% were susceptible to trospectomycin, and 73% were susceptible to cefotetan. For the beta-lactamase-positive non-B. fragilis group Bacteroides spp., greater than or equal to 94% were susceptible to cefoxitin, amoxicillin-clavulanate, ampicillin-sulbactam, cefoperazone-sulbactam, and trospectomycin, 90% were susceptible to cefotetan, and 85% were susceptible to tosufloxacin (the most resistant strains were B. bivius and B. disiens). For the beta-lactamase-positive fusobacteria, greater than or equal to 97% were susceptible to amoxicillin-clavulanate, ampicillin-sulbactam, cefoperazone-sulbactam, trospectomycin, and cefoxitin, 90% were susceptible to cefotetan, and 89% were susceptible to tosufloxacin. All agents showed excellent activity against beta-lactamase-negative strains (for trospectomycin, 95% were susceptible; for all other drugs, 100% were susceptible). Overall, both carbapenems and piperacillin-tazobactam were most active. Amoxicillin-clavulanate, ampicillin-sulbactam, and cefoperazone-sulbactam lacked activity against some cefoxitin-resistant B. fragilis group strains but had excellent activity against other organisms. Tosufloxacin, a new quinolone, had very good activity against B. fragilis group strains (94% susceptible), good activity against other beta-lactamase-positive strains (less than or equal 85% susceptible), and excellent activity against beta-lactamase-negative strains (100% susceptible; MIC for 90% of strains, 0.5 microgram/ml). Trospectomycin was active against >90% of all strains except for B. fragilis group strains (88% susceptible; MIC for 90% of strains, 32 microgram/ml). Clinical studies are required to delineate the role of newer agents in the therapy of anaerobic infections.

Anti-Bacterial Agents↗

Susceptibilities of 428 gram-positive and -negative anaerobic bacteria to Bay y3118 compared with their susceptibilities to ciprofloxacin, clindamycin, metronidazole, piperacillin, piperacillin-tazobactam, and cefoxitin.

The susceptibilities of 428 gram-negative and gram-positive anaerobes (including selected cefoxitin-resistant strains) to Bay y3118 (a new fluoroquinolone), ciprofloxacin, clindamycin, metronidazole, cefoxitin, piperacillin, and piperacillin-tazobactam were tested. Organisms comprised 115 Bacteroides fragilis group, 116 non-B. fragilis Bacteroides, Prevotella, and Porphyromonas spp., 40 fusobacteria, 58 peptostreptococci, 48 gram-positive non-spore-forming rods, and 51 clostridia. beta-Lactamase production was demonstrated in 87% of the gram-negative rods but in none of the gram-positive organisms. Overall, Bay y3118 was the most active agent, with all organisms inhibited at an MIC of < or = 2.0 micrograms/ml (MICs for 50% [MIC50] and 90% [MIC90] of strains tested, 0.125 and 0.5 microgram/ml, respectively). By contrast, ciprofloxacin was much less active, with only 42% of strains susceptible at a breakpoint of 2.0 micrograms/ml (MIC50, 4.0 micrograms/ml; MIC90, 16.0 micrograms/ml). Metronidazole was active against all gram-negative rods, but 7% of peptostreptococci, 83% of gram-positive non-spore-forming rods, and 4% of non-Clostridium perfringens, non-Clostridium difficile clostridia were resistant to this agent (MICs, > 16.0 micrograms/ml). Clindamycin was active against 94% of Bacteroides, Prevotella, and Porphyromonas spp., 91% of peptostreptococci, and 100% of gram-positive non-spore-forming rods, but was active against only 70% of fusobacteria and 53% of clostridia. Cefoxitin was active against > or = 90% of all groups except the B. fragilis group and non-Propionibacterium acnes gram-positive non-spore-forming rods (both 85%) and C. difficile (20%). Significant enhancement of piperacillin by tazobactam was seen in all beta-lactamase-positive strains (99% susceptible; MIC90, 8.0 micrograms/ml), and all beta-lactamase-negative strains were susceptible to piperacillin (MIC90, 8.0 micrograms/ml). Clinical studies are required to delineate the role of Bay y3118 in the treatment of anaerobic infections.

Anti-Infective Agents↗

In vitro activity of gemifloxacin (SB 265805) against anaerobes.

Gemifloxacin mesylate (SB 265805), a new fluoronaphthyridone, was tested against 359 recent clinical anaerobic isolates by the National Committee for Clinical Laboratory Standards reference agar dilution method with supplemented brucella blood agar and an inoculum of 10(5) CFU/spot. Comparative antimicrobials tested included trovafloxacin, levofloxacin, grepafloxacin, sparfloxacin, sitafloxacin (DU-6859a), penicillin G, amoxicillin clavulanate, imipenem, cefoxitin, clindamycin, and metronidazole. The MIC(50) and MIC(90) (MICs at which 50 and 90% of the isolates were inhibited) of gemifloxacin against various organisms (with the number of strains tested in parentheses) were as follows (in micrograms per milliliter): for Bacteroides fragilis (28), 0.5 and 2; for Bacteroides thetaiotaomicron (24), 1 and 16; for Bacteroides caccae (12), 1 and 16; for Bacteroides distasonis (12), 8 and >16; for Bacteroides ovatus (12), 4 and >16; for Bacteroides stercoris (12), 0.5 and 0.5; for Bacteroides uniformis (12), 1 and 4; for Bacteroides vulgatus (11), 4 and 4; for Clostridium clostridioforme (15), 0.5 and 0.5; for Clostridium difficile (15), 1 and >16; for Clostridium innocuum (13), 0.125 and 2; for Clostridium perfringens (13), 0.06 and 0.06; for Clostridium ramosum (14), 0.25 and 8; for Fusobacterium nucleatum (12), 0.125 and 0.25; for Fusobacterium necrophorum (11), 0.25 and 0.5; for Fusobacterium varium (13), 0.5 and 1; for Fusobacterium spp. (12), 1 and 2; for Peptostreptococcus anaerobius (13), 0.06 and 0.06; for Peptostreptococcus asaccharolyticus (13), 0.125 and 0.125; for Peptostreptococcus magnus (14), 0.03 and 0.03; for Peptostreptococcus micros (12), 0.06 and 0.06; for Peptostreptococcus prevotii (14), 0.06 and 0.25; for Porphyromonas asaccharolytica (11), 0.125 and 0.125; for Prevotella bivia (10), 8 and 16; for Prevotella buccae (10), 2 and 2; for Prevotella intermedia (10), 0.5 and 0.5; and for Prevotella melaninogenica (11), 1 and 1. Gemifloxacin mesylate (SB 265805) was 1 to 4 dilutions more active than trovafloxacin against fusobacteria and peptostreptococci, and the two drugs were equivalent against clostridia and P. asaccharolytica. Gemifloxacin was equivalent to sitafloxacin (DU 6859a) against peptostreptococci, C. perfringens, and C. ramosum, and sitafloxacin was 2 to 3 dilutions more active against fusobacteria. Sparfloxacin, grepafloxacin, and levofloxacin were generally less active than gemifloxacin against all anaerobes.

Anti-Bacterial Agents↗

Lectinlike interactions of Fusobacterium nucleatum with human neutrophils.

Fusobacterium nucleatum expresses lectinlike adherence factors which mediate binding to a variety of human tissue cells. Adherence is selectively inhibited by galactose, lactose, and N-acetyl-D-galactosamine. In this study, adherence of F. nucleatum to human peripheral blood polymorphonuclear neutrophils (PMNs) was investigated. The results indicated that the fusobacteria adhered to live and metabolically inactivated or fixed PMNs. Adherence of F. nucleatum resulted in activation of PMNs as determined by PMN aggregation, membrane depolarization, increased intracellular free Ca2+, superoxide anion production, and lysozyme release. Transmission electron micrographs showed that F. nucleatum was phagocytized by the PMNs. Microbicidal assays indicated that greater than 98% of F. nucleatum organisms were killed by PMNs within 60 min. Adherence to and activation of PMNs by F. nucleatum were inhibited by N-acetyl-D-galactosamine or lactose greater than galactose, whereas equal concentrations of glucose, N-acetyl-D-glucosamine, mannose, and fucose had little or no effect on F. nucleatum-PMN interactions. Pretreatment of the fusobacteria with heat (80 degrees C, 20 min) or proteases inhibited adherence to and activation of PMNs, but superoxide production was also stimulated by heated bacteria. The results indicate that interaction of F. nucleatum with PMNs is lectinlike and is probably mediated by fusobacterial proteins which bind to other human tissue cells. Adherence of F. nucleatum to PMNs in the absence of serum opsonins, such as antibodies and complement, may play an important role in PMN recognition and killing of F. nucleatum in the gingival sulcus and in the subsequent release of PMN factors associated with tissue destruction.

Bacterial Adhesion↗

Time-Lapse Photomicrography of Lashing, Flexing, and Snapping Movements in Escherichia coli and Corynebacterium Microcultures.

Hoffman, Heiner (New York University, New York, N.Y.), and Michael E. Frank. Time-lapse photomicrography of lashing, flexing, and snapping movements in Escherichia coli and Corynebacterium microcultures. J. Bacteriol. 90:789-795. 1965.-A series of four consecutive photomicrographs of snapping by an Escherichia coli cell pair indicates that this maneuver consists initially of lashing movements of one cell unattached to the underlying surface and consequent flexion of the second cell, which is strongly attached to the underlying surface at its distal end. This is followed by a final unidirectional movement of the unattached cell which carries the attached cell with it. Lashing movements were also observed in microcultures of fusobacteria and a Corynebacterium, and photomicrographs were obtained of the latter. The observations cannot be interpreted to support the conventional hypothesis that snapping is a response to partial rupture of the capsule during cell division. A new hypothesis is suggested which is based upon motile intracellular granules that have been observed to break out of E. coli, corynebacteria, and fusobacteria cells, typically from the cell ends. Photomicrographs of the minute granules were obtained for both E. coli and the Corynebacterium.

Journal Article↗

New medium selective for Fusobacterium species and differential for Fusobacterium necrophorum.

Fusobacterium egg yolk agar is a new medium selective for Fusobacterium species and differential for Fusobacterium necrophorum. The medium is a Brucella Agar base (Difco Laboratories, Detroit, Mich.) containing vancomycin, neomycin, josamycin, and egg yolk. All species of fusobacteria grew with only minimal inhibition. The mean log difference in counts between Fusobacterium egg yolk agar and control media for 30 strains of seven species of fusobacteria was 0.1922. F. necrophorum typically showed a strong lipase reaction. Most other organisms were significantly inhibited by the medium.

Agar↗

The antimicrobial effect of a triclosan/copolymer dentifrice on oral microorganisms in vivo.

BACKGROUND: The authors compared the in vivo antimicrobial effects on microorganisms from dental plaque, saliva and the tongue in subjects who used a triclosan/copolymer dentifrice and a fluoride dentifrice (control). METHODS: The authors assigned 15 subjects randomly to the control dentifrice or the triclosan/copolymer dentifrice for twice-daily use for one week. They collected samples of plaque, saliva and tongue scrapings six and 12 hours after the final brushing. They analyzed colony-forming units of Veillonella species, Fusobacteria species, total cultivable anaerobes and hydrogen sulfide (H(2)S)-producing bacteria. A one-week washout followed. The authors repeated the protocol with the second dentifrice. RESULTS: The results showed no differences at baseline. Significant reductions (88 to 96 percent) in oral anaerobic bacteria were observed in the triclosan/copolymer group six and 12 hours after brushing compared with the control group (P = .001). Fusobacteria decreased by 77 to 92 percent and Veillonella decreased by 84 to 89 percent six and 12 hours after brushing in the triclosan/copolymer group versus the control group. The triclosan/copolymer group also demonstrated a significant decrease in H(2)S-producing bacteria six and 12 hours after brushing (74 to 85 percent) (P = .001). CONCLUSIONS: Brushing with the triclosan/copolymer dentifrice resulted in significant reductions in microorganisms from the three sites compared with the control dentifrice. CLINICAL IMPLICATIONS: The triclosan/copolymer dentifrice produced sustained effects on oral bacteria for 12 hours.

Adult↗

Preterm birth: associations with genital and possibly oral microflora.

Opportunistic pathogenic microbes are indigenous to the female lower genital tract and etiologic in many types of pelvic infections and, apparently, a portion of preterm birth (PTB) cases. Bacterial vaginosis (BV) is a clinical syndrome based on an altered genital microflora in which Gardnerella vaginalis; anaerobic species primarily among Prevotella, Porphyromonas, Bacteroides, Peptostreptococcus, and Mobiluncus; Mycoplasma hominis; and Ureaplasma urealyticum become predominant in vaginal secretions. This BV complex of microbes, compared to a normal vaginal microflora dominated by facultative lactobacilli, is associated with significantly increased risks for preterm labor, preterm premature rupture of membranes, PTB, and other perinatal infectious complications. Pathogenetic mechanisms include an ascending route of infection and/or inflammatory process due to microbial products and maternal and/or fetal response(s) with production of prostaglandins and cytokines. In the presence of periodontal disease, oral opportunistic pathogens and/or their inflammatory products also may have a role in prematurity via a hematogenous route. Fusobacterium nucleatum, a common oral species, is the most frequently isolated species from amniotic fluid cultures among women with preterm labor and intact membranes. Also, the species and subspecies of fusobacteria identified from amniotic fluid most closely match those reported from healthy and diseased subgingival sites, namely F. nucleatum subspecies vincentii and F. nucleatum subspecies nucleatum, compared to strains identified from the lower genital tract. Although these fusobacteria also could be acquired through cunnilingus from a partner, new data associating maternal periodontal disease with preterm low birth weight taken with the isolation of F. nucleatum, Capnocytophaga, and other oral species from amniotic fluid support further study of a possible additional route, oral-hematogenous, to PTB.

Amniotic Fluid↗