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Biomedical subjects

A Sedallian

Publications and source records attributed to A Sedallian.

At least 37 records · Page 2Linked to original sources

[Activity of cefotetan against anaerobic bacteria].

We determined the susceptibility to antibiotics of 64 strains of obligate anaerobes. Tested bacterial strains were as follows: 28 Bacteroides fragilis, 22 Fusobacterium nucleatum, 10 Clostridium perfringens, and 4 Bacteroides bivius. Tested antibiotics were cefotetan, cefoxitin and piperacillin. Cefotaxime was tested against 20 Bacteroides fragilis strains. Bacteroides fragilis, which is the most resistant species, was susceptible to cefotetan, cefoxitin and piperacillin, with comparable MICs for these three drugs (0.5 to 16 micrograms/ml); cefotaxime was less effective (MICs = 0.5 to 128 micrograms/ml). Fusobacterium nucleatum and Clostridium perfringens were highly susceptible to cefotetan, cefoxitin and piperacillin.

Bacteroides↗

[Sensitivity of anaerobes to 8 antibiotics].

We studied the susceptibility of 282 obligate anaerobes to 8 antibiotics. The strains were isolated from clinical specimens taken during 1983 and 1984. Minimal inhibitory concentrations (MICs) were determined using a microplate method for 245 strains and agar dilution for 33 Bacteroides asaccharolyticus strains. Tested strains were as follows: 85 Bacteroides fragilis, 71 Clostridium, 19 Fusobacterium nucleatum, 35 Peptostreptococcus, 39 Bacteroides oralis and Bacteroides bivius and 33 Bacteroides asaccharolyticus. Tested antibiotics were: metronidazole, clindamycin, minocycline, cefoxitin, cefotaxime, moxalactam, keflin and carbenicillin. For Bacteroides fragilis, the three most active antibiotics were metronidazole (inhibition of all strains with 8 micrograms/ml), minocycline and clindamycin (inhibition of 95% of strains by MICs less than or equal to 0.5 microgram/ml). However, four strains were resistant to clindamycin (MICs greater than 8 micrograms/ml). The other anaerobic strains tested were susceptible. However, a few Bacteroides bivius strains were resistant to keflin (MIC greater than or equal to 64 micrograms/ml for 5% of strains).

Anti-Bacterial Agents↗

[Isolation and identification of Gardnerella vaginalis].

Thirty-four strains of Gardnerella vaginalis were studied. They were isolated from non specific vaginitis. A presumptive identification can be based on colonial morphology, Gram stain characteristics, negative catalase and oxidase test. The differentiation of Gardnerella vaginalis from other negative catalase coccobacilli is based on the acid formation of carbohydrates, enzymatic test, analysis of short chain volatile and non volatile end products of fermentation in GLC. All Gardnerella strains produce acid from glucose, maltose, starch and are hippurate and alpha glucosidase positive. They are sulfonamide resistant, acetic, lactic and succinic acids are detected by gas liquid chromatography.

Actinomyces↗

Evolution in antibiotic susceptibility of Bacteroides fragilis group strains in France based on periodic surveys.

Anaerobic antibiotic susceptibility testing with standardized methods enabled the authors to speculate on the evolution of antibiotic resistance within the Bacteroides fragilis group strains. Cefoxitin resistance was stable (0-5%) until 1985 and gradually increased later. Clindamycin resistance emerged in 1980 with a stable 10% resistance rate until 1986. An increase in clindamycin resistance developed in three institutions in 1987. No change was detected for imipenem and metronidazole, while piperacillin resistance increased since 1986. A comparison of antibiotic resistance rates is discussed for anaerobes in different countries.

Bacteroides↗

A collaborative study of French laboratories to assess any evolution of antibiotic resistance within the Bacteroides fragilis group.

Antibiotic susceptibility testing of anaerobes by a same methodology allows the authors to draw up suggestions about the evolution of antibiotic resistance within the B. fragilis group. Cefoxitin resistance rates were stable until 1985 and were slowly increasing later. Until 1985 piperacillin was able to inhibit all tested strains. In 1987 the two groups noticed an increasing resistance to piperacillin (4 to 9%). During the 1970's clindamycin resistance was a minor event (less than 1%) then the resistance rate increased rapidly to 10% in 1980. MICs determinations from 1981 to 1985 demonstrated well that clindamycin resistance was stable at this 10% rate. Since 1987 the clindamycin resistance was again increasing and reached respectively 14 to 19% for the two groups of investigators. Metronidazole has kept a good activity against Bacteroides fragilis group strains but some strains with reduced susceptibility (MIC 2 to 8 mg/l) have been described since 1983. Three strains with MIC greater than 8 mg/l were recently described by one of the groups. Until 1987, the clavulanic amoxicillin combination was able to inhibit all strains of the B. fragilis group but only imipenem remained still active on all investigated strains with no change at all for the values of MIC50 and MIC90 determined by the investigators of this study. All these results emphasize the need for periodical surveys within the B. fragilis group in each country.

Bacteroides fragilis↗