The authors made investigation on Abbott and Shannon's colicine typing scheme by means of colicinogenic strains used in the classification of colicines by Fredericq; the results were as follows. 1. Colicines produced by each colicine type were; 1A=K, 1B=? 2=I, 3=?, 3A≈D 4=I, 5=? 6=E1, 8=E (3), 9=E (3), 10=?, 11≈K1+?, 12=E (3), 13≈E1, and 14=E1+I. Among colicine types which produce two different colicines, only type 14 coincided with the inhibition pattern of colicinogenic strain (CA 62=E1+I). 2. As to the two unstable colicine types 4/14 and 11/6, type 14 produced colicine I and colicine active to E1, and type 11 produced colicine K and colicine active to E1. According to these facts, the transference of colicine types was frequently noticed. 3. Colicinogeny of 272 isolated of Shigella sonnei had two different colicines, E1+I at the rate of 64.7% (type 14) and E1+I at the rate of 8.1% (type 4/14), colicine E1 at the rate of 20.5% (type 6), colicine I at the rate of 3.3% (type 4), colicine E3 at the rate of 2.2% (type 6), colicine E3 at the rate of 0.7% (type 8) and colicine K at the rate of 0.7% (type 1A). 4. Abbott and Shannon's colicine typing method can be available even in the use of the mutants resistant to colicines.
A survey for drug resistance and distribution of R factors was conducted among the Escherichia coli strains isolated from 151 swines feeded with animal food containing tetracycline. It was found that all swines excreted resistant E. coli strains with reference to 4 drugs, tetracycline (TC), chloramphenicol (CM), streptomycin (SM) and sulfanilamide (SA), which are most common resistance pattern in transmissible drug resistance factor “R”. Among 278 resistant cultures, the resistance patterns included 13% of single resistance and 87% of multiple resistance. It was also found that about 32% of these resistant strains carried R factors. The resistance patterns of R factors included 36% of single resistance and 64% of multiple resistance.It was noticed that multiple resistant E. coli strains and R factors carrying multiple resistance patterns were isolated at high frequency, even though these swines were feeded with animal food containing a single drug, tetracycline.
We examined for the productive conditions of the extracellular antigenic glycopeptide which was excreted by Aspergillus fumigatus in culture medium and obtained the following results. Powerful antigenicity of culture filtrate of Asp. fumigatus growing on the sabouraud medium, yeast extract medium and the other synthetic media was observed after 10 days incubation especially, and it showed with appearance of a glycopeptide on the paperelectrophoretic pattern of 80% MeOH fraction of the filtrate after 3 or 4 days incubation. Total carbohydrate of the 80% MeOH fractions increased with development of culture and their sugar components were composed of galactose and mannose. From the results of the precipitin activity of the fraction eluted with water on Sephadex G-50 column, it was found that polysaccharide fraction showed high activity but protein fraction was very weak.
The mechanisms of superinfection immunity of R and F factors were studied in Escherichia coli K-12. Zygotic induction of phage γ and F-duction of gal+ were studied with an F'-gal-γ+ in recipients carrying F and R factors and found useful in elucidating the mechanisms of superinfection immunity of these episomes. The results obtained may be summarized as follows: 1) The superinfection immunity of R and F factors occurs chiefly due to the inhibition of acceptance of these episomes on the cell surface and partly due to the mutual exclusion between homologous episomes inside the recipient bacteria. Thus, the superinfection immunity of these episomes is due to mechanisms fundamentally different from that of the immunity observed in temperate phages, which are caused by repressors. 2) The superinfection immunity on the cell surface in these episomes can be reasonably accounted for by postulating specific receptors on the surface of recipient bacteria, to which the mating substances of donor bacteria are bound to form conjugation tubes.
Antibody titers and tuberculin skin reaction were compared in 2 groups of guinea pigs. One group of animals were injected with heat killed tubercle bacilli while animals of the second group received the bacilli in the form of Freund's adjuvant. Changes in antibody titers of serum and skin extract were followed by Middlebrook-Dubos hemagglutination and hemolysis during the period of 10 weeks post immunization. Test for incomplete antibody was made by the Sindo-Utahashi's method. Titers in animals injected with the adjuvant rose earlier and reached higher values than those in animals injected with tubercle bacilli alone. Generally speaking, a parallel relation was found among hemolysis, presence of incomplete antibody and tuberculin reaction as was reported earlier by Hosoda.
Properties of amino acid incorporation into proteins by cell-free preparations from Pasteurella multocida were examined and the following results were obtained. 1) Amino acid incorporation into proteins by the above system was dependent upon the presence of supernatant fluid, ribosomes, ATP and ATP generators, GTP and magnesium ion, and prevented by ribonuclease or chloramphenicol. 2) Amino acid incorporation into proteins by this system was stimulated by deoxyribonuclease. 3) Attachment of C14-leucine to soluble RNA was found. 4) Transfer of C14-leucine from C14-leucyl s-RNA to ribosomes was not found. 5) Incorporation of C14-leucine or C14-phenylalanine into proteins was stimulated by ribonucleic acid isolated from P. multocida or polyuridylic acid, respectively.
Erabu-umihebi snake (laticauda semifasciata) is a sea-snake whose venom has a strong toxicity, and 6.25γ (dry weight) of the venom will kill a mouse within an hour. The action of the venom seems to be neurotoxic: death may result from motorparalysis and respiratory failure. There is no evidence of local symptom. As no medicine could completely neutralize the toxicity of sea-snake venom, it has been considered quite difficult to produce antitoxic serum in experimental animals. The success of our experiment-immunization against toxic action of sea-snake venom in rabbits-is due to the use of the venom-gland fixed with 10% formalin. The venom-gland was taken out from living laticauda semifasciata and fixed in 10% formalin, and preserved for several months. Washing formalin off with water, the material was emulsified, and used as an immunogen. One gramme weight of the fixed antigen, together with Freund's incomplete adjuvant, was subcutaneously injected into rabbits. Four weeks after the first injection, 0.1g emulsion of toxic gland was injected as a booster. Neutralizing value of the serum from the rabbits, obtained one week after the last immunization, showed: in vitro test, 0.1ml of the blood serum can neutralize 37.5γ-50γ of the venom. And in vivo test, intravenous injection of the same amount of the serum is able to cure the symptom of paralysis in mice caused by 25γ venom. 0.1ml of the antivenin of laticauda semifasciata, thus obtained, is found to be also efficacious in neutralizing in vitro the venom of hydrophis cyanocinctus (the lethal dose for a mouse, 25γ). The fact suggests the use of laticauda semifasciata serum against the venoms of hydrophiinae sea-snakes, numerous bite cases of which have been reported in the South Seas area.