During a two-year period of observationBacteroidesspecies were isolated from specimens of pus and vaginal swabs from 115 patients in this hospital. Thirty-five representative strains proved on examination to beBacteroides fragilis.Minimal inhibitory and minimal bactericidal concentrations of six antibiotics for these strains were determined. All strains were resistant to streptomycin, neomycin, and polymyxin, slightly sensitive to penicillin and ampicillin, and fully sensitive to tetracycline, chloramphenicol, erythromycin, and lincomycin. The minimum bactericidal concentrations of chloramphenicol, erythromycin, and lincomycin were two to four times the minimal inhibitory concentrations. Tetracycline failed to exert any consistent bactericidal effect.The treatment of patients with infections caused byB. fragilisis discussed in the light of the findingsin vitro.

SYNOPSISThe effect of 10% carbon dioxide on the sensitivity to four antibiotics of 10

105AD7 is a human monoclonal antibody that mimics the complement regulatory protein, CD55, overexpressed by many solid tumours including osteosarcoma. This study was designed to assess the toxicity and efficacy of this vaccine in a young age group of patients within 1 -6 months of myleosuppressive chemotherapy. Out of 28, 20 (71%, 95% CI 51 -87%) patients showed a significant T-cell proliferation response in vitro to the 105AD7 protein but not to human IgG. Furthermore, 13 out of 22 (59%, 95% CI 36 -79%) patients showed antigen-specific gIFN secretion (range 20 -370 U/ml). Nine out of 28 (32%, 95% CI 16 -52%) patients made weak antibody responses to CD55. This study showed that 105AD7 was well tolerated in younger patients with osteosarcoma. In addition, two patients with possible clinical responses were given compassionate permission to continue immunisation quarterly for 2 years. They both remain alive and disease free 5.8 and 6.5 years from original diagnosis of osteosarcoma and showed no adverse effects of repeated immunisation. In conclusion, the majority of patients showed measurable T helper responses when vaccination was commenced within a 6-month window of intensive chemotherapy with no clinically significant toxicity. Future clinical trials incorporating immune stimulation strategies should include early introduction of vaccines during the highest risk period for relapse.

-upon-Tyne SYNOPSIS Metronidazole was found to be active against Bacteroides fragilis strains isolated from human lesions. The minimal inhibitory concentrations (MIC) were from 0-16 to 2-5 ,ug/ml and the minimal bactericidal concentrations (MBC) were from 0-16 to 2 5 ,ug/ml; usually the MIC and MBC figures were equivalent. These levels are easily attainable in the serum following normal therapeutic doses. The drug is not toxic and side effects are rare and it would therefore seem highly suitable for treating Bacteroides infections and also may be considered prophylactically in certain situations that are described.Organisms of Bacteroides species and particularly Bact. fragilis have been incriminated in a large number of infections. They are frequently observed in sepsis following gastrointestinal surgery (Gillespie and Guy, 1956), in puerperal sepsis (Rotheram and Schick, 1969), lung abscess (Tillotson and Lerner, 1968), and brain abscess (Ingham, Selkon, Codd, and Hale, 1970). Lincomycin has been shown to possess bactericidal activity in vitro against Bacteroides species (Ingham, Selkon, Codd, and Hale, 1968;Nastro and Finegold, 1972) metronidazole was determined using two-fold serial dilution in 10% blood agar incorporating the drug in the medium at a starting concentration of 50 ,ug/ml with the first isolates and at 10 p,g/ml in the later estimations. A 48-hour culture grown on 10% blood agar under anaerobic conditions at 37°C was used to inoculate the drug-containing blood agar plates. The latter were incubated overnight at 37°C in an anaerobic jar under 90 % hydrogen and 10 % carbon dioxide. The MIC values were recorded after 24 hours' incubation and the minimum bactericidal concentrations (MBC) were determined by the replica plate method of Elek and Hilson (1954) using 10% blood agar plates. The recovery plates were incubated overnight under anaerobic conditions. The criterion for bactericidal effect was that there should be no colonies on the corresponding replica plates. PATHOGENICITY EXPERIMENTSAttempts to produce lesions in animals were made. Two slopes of horse blood agar were inoculated with each strain, incubated for 48 hours, and the organisms on each slope washed off with 1I0 ml of saline. This suspension was injected in 0-03 ml amounts intracerebrally into 20 g albino mice. The remainder of the saline suspension was diluted with 5% hog mucin and iWected intraperitoneally in 0-5 ml volumes into 20 g mice. Similar slopes were inoculated and harvested and 0 5 ml volumes of the suspension injected subcutaneously into 150 g guinea pigs and into 1-5 kg rabbits.

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