For the purpose of clarifying an active principle of antitumor activity of Bifidobacteria, we isolated purified cell wall (whole peptidoglycan, WPG) from Bifidobacterium infantis ATCC 15697, and then examined its antitumor effect on the syngeneic tumors, Meth A and Meth 1 fibrosarcoma and colon 26 adenocarcinoma in BALB/c mice. In this experiment, B. infantis was grown in semi-synthetic medium containing casein hydrolysate and lactose as main components to avoid contamination of antigenic components derived from culture medium with the organisms. WPG thus obtained was demonstrated to have bag-shaped structure by electron microscopic observation. WPG showed antitumor effect the sameas whole cells against Meth A fibrosarcoma. Furthermore, the marked therapeutic effect was seen in mice given consecutive injections of WPG at the tumor growing site. WPG also induced significant antitumor effect on the growth of Meth 1 fibrosarcoma and colon 26 adenocarcinoma. These effects were dosage dependent. From these results, it was concluded that cell wall fraction was active principle of antitumor activity of whole cells.

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In feces of six patients with antibiotics-associated colitis, Klebsiella oxytoca was purely detected without culture of Clostridium difficile. Representative strains of K. oxytoca from each patient were reserved. Endoscopic biopsy-specimens in active stage showed significant decrease of secreting component (SC) and IgA in the diseased portions but not in the healthy portions, according to the immunofluorescent method. At the same time, the same specimens in active stage showed significant decrease of mucus (glycoproteins) in the diseased portions but not in the healthy portions using the anti-human mucusantisera in the indirect immunofluorescent method. After recovery, further endoscopic biopsy-specimens in the previously diseased portions were obtained; epithelial cells were then scraped from the specimens and were suspended in the phosphate buffer. K. oxytoca from each patient and the corresponding epithelial cells were incubated. Adherence of bacteria on cells was observed under a phase-contrast microscope and numbers of adhesive bacteria were counted. Compared with control bacteria, K. oxytoca showed remarkable attachment on colonic epithelial cells. The fluorescent microscopic examination of the colonic lesions of the patients showed remarkable decrease in SC, IgA, and mucus. These results suggested the possibility of colonization of the bacteria on the epithelial cells as an offensive factor and breakdown of mucosal barriers as a defensive factor. Whether initiation of breakdown of barriers is produced by the bacteria is not conclusive. However, K. oxytoca might have a relationship with pathogenesis of antibioticsassociatedcolitis.

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The Auto Microbic system Anaerobes Identification Card (Vitek Systems, McDonnell Douglas, Inc., U.S.A.), a fully automated and computer-assisted method for identifying anaerobic bacteria based on 29 biochemical reactions, was compared with the conventional method, using 112 strains of anaerobic bacteria (8 genera and 21 species) isolated from human feces. In addition to comparison with conventional method, the following parameters were tested using selected isolates: (i) the effect of composition of media for growth of strains tested, (ii) the effect of variation in inoculum size, and (iii) reproducibility of the identification of anaerobic bacteria. In the present study, the inoculum was prepared with some colonies on the surface of Brucella HK agar and the inoculum size was more than McFarland No.4. The reproducibility of identification of anaerobic bacteria by ANI Card was feasible and accurate. There was a 34.8% correlation and a 30.4% incorrelation between the ANI Card and conventional methods. Of 37 strains of the Bacteroides fragilis group, 33 strains were identified (89.2%). Each species of Eubacterium aerofaciens, Lactobacillus gasseri, L.reuteri, Clostridium innocuum, and C.clostridiiforme was not identified by ANI Card. The reactions of genus Bifidobacterium and anaerobic gram-positive cocci by this system were firstly determined. These findings suggested that VITEK Systems was feasible and accurate for the identification of the B.fragilis group as predominant anaerobes of human intestine, but not Eubacterium, Lactobacillus, and Clostridium.

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O-β-D-galactopyranosyl-(1 → 4)-O-Β-D-galactopyranosyl-(1 → 4)-D-glucopyranose (hereinafter designated as 4'GL) is produced from lactose with Cryptococcus laurentii. The ratio of cecal microflora to the total bacteria during 4'GL intake was studied in rats. Male rats of the Sprague-Dawley strain at seven weeks of age (weighing about 250g) were given experimental diets supplemented with 10% 4'GL for 20 days. The percentage of Lactobacillus spp. and Enterobacteriaceae were decreased during the 4'GL intake, whereas the percentage of Bifidobacterium spp. was increased by Day 10 of the feeding. The pH values of cecal contents during feeding were lower than those of the control group.

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