Bacteriostatic and Bactericidal Activities of Various Antibiotics Against
            <i>Bacteroides fragilis</i>

Zabransky, R.J.; Johnston, John; Hauser, Kathrin

doi:10.1128/aac.3.2.152

Cited by 44 publications

(19 citation statements)

References 10 publications

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“…32) Furthermore, the MANG strain was susceptible to b-lactam type antibiotics (ampicillin and penicillin G), lincomycin, chloramphenicol and tetracycline with MICs in the range of 2-15mg/ml.…”

Section: Isolation and Characterization Of A Bacterium That Transformmentioning

confidence: 99%

Isolation of a Human Intestinal Bacterium That Transforms Mangiferin to Norathyriol and Inducibility of the Enzyme That Cleaves a C-Glucosyl Bond

Sanugul

Akao

et al. 2005

Biological & Pharmaceutical Bulletin

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C-Glucosides, which are widely distributed among plants, are more resistant towards acid, alkaline and enzyme hydrolysis than O-glucosides. Even prolonged exposure to acid does not cleave the glucosyl bond of C-glucosides, in which glucose is attached by a carbon-carbon bond to the aglycone, to give the aglycone. 1) However, intestinal bacteria from human feces can cleave C-glucosyl bonds in various C-glucosides such as mangiferin, abrusin 2Љ-O-b-D-apioside, aloeresin A, aloesin, barbaloin, bergenin, homoorientin, puerarin and safflor yellow B. 2-8)Mangiferin (2-b-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone), was originally isolated from Mangifera indica L. (Anacardiaceae). It is distributed among at least sixteen plant families including Anacardiaceae, Iridaceae and Gentianaceae. Studies in vitro have shown that mangiferin has antiviral activity against herpes simplex virus 9) as well as antioxidant, 10) and anti-HIV activity. 11) Mangiferin orally administered to rats or mice exerts biological antitumor, 11) antidiabetic, 12) antioxidant, 13) hepatoprotective 14) and immunomodulative 15) activities. However, the pharmacokinetic studies in rats given oral mangiferin have failed to detect mangiferin in plasma, 16) suggesting poor absorption. On the other hand, appreciable amounts of euxanthone (1,7-dihydroxyxanthone) and its glucuronides are excreted into the urine of rabbits given oral mangiferin, 17) indicating a unique metabolic transformation that involves elimination of a Cglucosyl chain and two phenolic hydroxyl groups. The transformation of mangiferin to norathyriol by human fecal flora in vitro ( Fig. 1) 5) indicates an important role of mangiferinmetabolizing bacteria in the disposition of norathyriol and its subsequent metabolites in vivo, as well as in the pharmacological activities of mangiferin. Norathyriol also exerts antiinflammatory, 18,19) vasorelaxation 20) and antiplatelet 21) activities. Therefore, the biotransformation of mangiferin should be thoroughly investigated.Here, we isolated and characterized a bacterium that transforms mangiferin to norathyriol. Furthermore, the novel enzyme that cleaved C-glucosyl was selectively inducible with mangiferin and apparently differs from a-and b-glucosidases. The C-glucosyl bond of C-glucosides generally tolerates acid and enzymatic hydrolysis. Many C-glucosides are cleaved by human intestinal bacteria. We isolated the specific bacterium involved in the metabolism of mangiferin (2-b b-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone), C-glucosyl xanthone, from a mixture of human fecal bacteria. The anaerobic Bacteroides species named MANG, transformed mangiferin to the aglycone, norathyriol, suggesting cleavage of a C-glucosyl bond. However, B. sp. MANG cleaved C-glucosyl in a dose-and time-dependent manner only when cultivated in the presence of mangiferin. Cleavage was abolished by inhibitors of RNA and protein syntheses, such as rifampicin and chloramphenicol, respectively, indicating that the enzyme that cleaves C-glucosyl is induced by mangiferin....

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Section: Isolation and Characterization Of A Bacterium That Transformmentioning

confidence: 99%

Isolation of a Human Intestinal Bacterium That Transforms Mangiferin to Norathyriol and Inducibility of the Enzyme That Cleaves a C-Glucosyl Bond

Sanugul

Akao

et al. 2005

Biological & Pharmaceutical Bulletin

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“…Metronidazole appears to be more consistently bactericidal against susceptible strains of Bacterioides fragilis than other antibiotics which are more variable in this regard (6,15,16). The purpose of this study was to compare its time-related bactericidal effects with those of penicillin, carbenicillin, and clindamycin against strains of two commonly isolated pathogens, B. fragilis and Clostridium perfringens.…”

mentioning

confidence: 99%

“…The in vitro susceptibilities of anaerobic bacteria have been extensively reported, especially in recent years, with the increasing recognition of the pathogenicity of these organisms and the resistance of certain anaerobes to commonly used antibiotics (4,5,12,16). Metronidazole appears to be more consistently bactericidal against susceptible strains of Bacterioides fragilis than other antibiotics which are more variable in this regard (6,15,16).…”

mentioning

confidence: 99%

Unique Bactericidal Action of Metronidazole Against Bacteroides fragilis and Clostridium perfringens

Ralph

Kirby

1975

Antimicrob Agents Chemother

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The comparative bactericidal activity of penicillin G, carbenicillin, clindamycin, and metronidazole against eight susceptible strains of Bacteroides fragilis and four strains of Clostridium perfringens was determined by performing colony counts anaerobically of cultures incubated in brucella broth. With the B. fragilis strains, there was a lag phase of growth of approximately 8 h, during which time metronidazole did not reduce the colony counts. However, within 4 h of the onset of exponential growth, metronidazole caused an abrupt decrease in counts to less than 100 colonies per ml in all strains tested. Moreover, in two strains in which the bactericidal rate was followed hourly, a 3-to 6-log decrease occurred over 1 h or less. In contrast, penicillin G and carbenicillin caused a gradual decline in colony counts from the start of approximately 1 log for each 8-h interval and were bactericidal for all strains tested. Clindamycin demonstrated the slowest bactericidal activity and for 25% of the strains was only bacteriostatic. With the C. perfringens strains, after a lag phase of 4 h, an abrupt decrease in colony counts also occurred with metronidazole, whereas penicillin and clindamycin again demonstrated more gradual killing effects. These studies showed a unique, time-related bactericidal action of metronidazole as compared with the other three antimicrobial agents.

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“…However, the bactericidal or "lethal" concentration varies according to the definitions used by various authors; e.g., that producing a 99% kill12), 99.9 % kill1,3--5,13) 99.99 % kills), or complete kill13, 14) Further work will be necessary before a more complete understanding of this area can be attained.…”

Section: Discussionmentioning

confidence: 99%

Timed bacteriostatic and bactericidal activities of selected antimicrobial agents against Bacteroides fragilis isolated from clinical specimens.

Masuda

1984

J. Antibiot.

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Bacteriostatic and Bactericidal Activities of Various Antibiotics Against Bacteroides fragilis

Abstract: The minimal inhibitory concentrations and minimal bactericidal concentrations of seven antibiotics were determined by broth dilution tests for 50

Cited by 44 publications

References 10 publications

Isolation of a Human Intestinal Bacterium That Transforms Mangiferin to Norathyriol and Inducibility of the Enzyme That Cleaves a C-Glucosyl Bond

Isolation of a Human Intestinal Bacterium That Transforms Mangiferin to Norathyriol and Inducibility of the Enzyme That Cleaves a C-Glucosyl Bond

Unique Bactericidal Action of Metronidazole Against Bacteroides fragilis and Clostridium perfringens

Timed bacteriostatic and bactericidal activities of selected antimicrobial agents against Bacteroides fragilis isolated from clinical specimens.

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