bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism Determining the Host Specificity of Tobacco Mosaic Virus
Authors: Kiho Yukio , Machida Haruhiko , Oshima Nobuyuki 
Published: November 2013

ABSTRACTIn order to know the mechanism controling the host specificity of tobacco mosaic virus (TMV), three species of plants showing various degrees of resistance to TMV or TMV‐RNA infection were selected and the fate of infecting viral genome was studied. Extract was obtained from leaves 0.5–6 hr after inoculation of 32P‐TMV or 32P‐TMV‐RNA and analyzed by sucrose density gradient centrifugation. It was found that polysomes containing infecting 32P‐RNA were formed in plants resistant to TMV to the same extent as in susceptible tobacco plants, suggesting that the host specificity of TMV is determined at a stage of viral multiplication later than the step of translation of infecting viral genome.
Extracellular Crystalline Lattice Material of Corynebacterium diphtheriae Revealed by Electron Microscopy
Authors: Kawata Tomio , Masuda Kuniyoshi 
Published: November 2013

ABSTRACTCrystalline material showing square lattice arrays attached to the cell envelope of Corynebacterium diphtheriae grown in liquid cultures was demonstrated under the electron microscope using negative staining and sectioning techniques. Two types of lattice patterns could be found in the crystal. One was a square lattice consisting of parallel lines (about 3.2 nm in diameter) with an average distance between their centers of 5.3 nm. The second type of lattice pattern was composed of thinner parallel lines (approximately 2.2 nm in diameter) with a closer periodicity being about 3.5 nm. The two types of lattice patterns appeared to intersect each other at an angle of 45 degrees. The lattice arrays were disorganized and disappeared upon treatment with proteolytic enzymes, alkali and sodium dodecyl sulfate. This crystalline material seemed to be composed of protein(s) but not to be related to diphtheria toxin.
Immune Response against Hamster Erythrocytes in the Low‐Responder Mouse Strains
Authors: Nomoto Kikuo , Makidono Reiko , Takeya Kenji 
Published: November 2013

ABSTRACTIt was confirmed by passive transfer experiments that the function of thymus‐derived cells specific for hamster erythrocytes (HRBC) was deficient in the low‐responder mouse strains. 1) Antibody production against HRBC was enhanced by passive transfer of thymus cells from normal SL mice (high‐responder) to normal C57BL/6 mice (low‐responder). 2) The enhancing effect of passive transfer of thymus cells from SL mice was abrogated by pre‐sensitization of the recipients (C57BL/6) with thymus cells from SL mice. 3) In C57BL/6 mice, antibody production against HRBC was enhanced by the transfer of lymph node or spleen cells from C57BL/6 mice which had been sensitized with HRBC in Freund's complete adjuvant or hamster lymphoma cells.
Isolation and Characterization of Spontaneous Mutants of Staphylococcus aureus S6 Possessing Quantitative Differences in Enterotoxin B Production
Authors: Kondo Masaomi , Katsuno Shingo 
Published: November 2013

ABSTRACTSpontaneous mutants possessing quantitative differences in enterotoxin B production were isolated from the parent strain of Staphylococcus aureus S6 by using NZ‐amine agar plate which contained anti‐enterotoxin B antiserum. A shake‐flask culture of S. aureus S6 715H, a high enterotoxin B‐producing strain, extracellularly produced 370 μg/ml of enterotoxin B after 16 hr of incubation at 37 C. A shake‐flask culture of S. aureus S6 715NH, a low enterotoxin B‐producing strain, produced 22 μg/ml of enterotoxin B under the same conditions. The difference in the ability to produce enterotoxin B among the strains resulted from differences in their activities of de novo enterotoxin B synthesis. A quantitative difference in the production of individual extracellular proteins existed in the strains. S. aureus S6 715H produced higher levels of α‐and δ‐hemolysins, alkaline phosphatase, ribonuclease and staphylokinase (fibrinolysin) than S. aureus S6 715NH. These results suggest that the production of enterotoxin B and most of the other extracellular proteins, at least the above five toxins or enzymes, may be dependent upon some coordinated control mechanisms in S. aureus S6.
Ampicillin‐Resistant R Factors Derived from Shigella Strains
Authors: Tanaka Tokumitsu , Hashimoto Hajime , Mitsuhashi Susumu 
Published: November 2013

ABSTRACTSixteen Shigella strains resistant to ampicillin(APC) were isolated from 3760 strains examined in 1965. Five strains among these isolates were resistant to tetracycline(TC), chloramphenicol (CM), streptomycin(SM) and sulfanilamide(SA) in addition to APC, and transferred their APC resistances by conjugation together with the aforementioned four drugs. The 5‐drug resistance was transferred to an Escherichia coli strain and the resistance was analyzed by both conjugation and transduction. Three out of the five Shigella strains transferred a single type of R(TC.CM.SM.SA.APC) factor, but the linkage relationship between the resistant markers were different from each other. The ampicillin gene, however, was always linked close to the genes governing both transfer and replication. The 5‐drug resistance was transferred to an E. coli strain from the remaining two Shigella strains. According to the genetic studies of E. coli strains which had acquired the 5‐drug resistance, it was concluded that the two parent Shigella strains carried two types of R factors in a cell, i.e., fi+R(TC.CM.SM.SA) and fi‐(SM.APC). These two R factors in a cell sometimes recombined and formed a recombinant R factor possessing the 5‐drug resistance in which the ampicillin gene was linked close to the transfer gene. The enzymological properties of the five penicillinases coded by R factors possessed by the five Shigella strains were all similar to each other and of the type 1 penicillinase, which was demonstrated from Klebsiella pneumoniae and mediated by most of the R factors.
Genetic Structure of an R Factor Conferring Ampicillin Resistance
Authors: Hashimoto Hajime , Tanaka Tokumitsu , Mitsuhashi Susumu 
Published: November 2013

ABSTRACTAn R factor carrying resistant genes, ampicillin (amp), tetracycline (tet), chloramphenicol (cml), dihydrostreptomycin (sir), and sulfanilamide (sul), was analyzed by three genetic techniques: spontaneous segregation, transduction, and recombination. The R factor was stable in Shigella and Escherichia coli, but in Salmonella the (cml.str.sul) genes were spontaneously lost at a high frequency. Almost all of the transductants with Pl contained the five drug markers, but a very small number of them carried both tet and amp genes, or the (amp.cml.str.sul) genes. In conjugal transfer from a strain carrying a single type of R factor to R+ recipient, the recombination took place between the amp and tet, amp and cml, and between the cml and str genes, at a frequency of 23.5, 39.5, and 3.0%, respectively. Crossover between the amp and transfer (tra) loci was not observed. A circular genetic model is proposed in which the genes are arranged in the order –tet9–tet1‐tra.amp–cml–str–.
Cephalexin‐Induced Morphological Alterations in the Surface Structures of Staphylococcus aureus and Escherichia coli Demonstrated by Scanning Electron Microscopy
Authors: Nishino Takeshi , Nakazawa Shozo 
Published: November 2013

ABSTRACTThe scanning electron microscope was used to investigate the alterations in surface morphology of Staphylococcus aureus 209P and Escherichia coli NIH induced by the action of cephalexin known to interfere with cell‐wall synthesis. Exposure to cephalexin produced a series of changes on the surface morphology in proportion to the concentrations of cephalexin added. Untreated S. aureus cells had smooth contours. Exposure to 1 μg/ml of cephalexin during the logarithmic phase of growth in S. aureus did not produce any detectable changes. Upon exposure of S. aureus to 5 μ/ml or 10 μg/ml, some cells were larger than normal and showed abnormal cell division‐like structures in part. When S. aureus was exposed to 50 μg/ml, cell division was completely inhibited, and no formation of grape‐like clusters was observed. Untreated E. coli cells appeared to have smooth and regular contours. E. coli propagated almost normally upon exposure of the organisms to 1 μg/ml of cephalexin. Filamentous structures were observed with the exposure of E. coli to 12.5 μg/ml or 25 μg/ml, but spheroplast‐like structures were not observed. Exposure to 100 μg/ml of cephalexin resulted in the formation of marked filamentous cells and spheroplast‐like structures having multiple small saccular outpouchings. Scanning electron microscope demonstrated more completely the morphological abnormalities induced by cephalexin.
Transformability of Group H Streptococcus Challis
Authors: Ito Takako , Hirano Toyo , Tomura Tsuneko , Yoshioka Morimasa 
Published: November 2013

ABSTRACTTwo types of hemolysis, α and β were formed by group H streptococcus wild type strain Challis on horse blood agar, and both of the hemolytic markers could be transformed in each. α‐Hemolysis‐acquired transformants lost the competence‐provoking factor producibility (CPF–). When DNAs, obtained from strains Challis α, dihydrostreptomycin sulfate‐resistant Challis α, and Wicky, were used CPF– transformants appeared in high frequencies. DNAs from incompetent β cells grown in ET3 medium for 6 hr or in heated ET3 medium for 2 hr also transferred the CPF–. CPF producibility (CPF+) was transformed with DNA from competent Challis β, while it was not transformed to Challis β with DNA from Wicky cells in competent and incompetent phases. Among β transformants obtained there were (1) those having CPF+ and competency, (2) those having competency but CPF–, and also (3) those defective in both. Based upon these results, the transformability is discussed regarding close relation to DNA receptor site or CPF attachment and also on the probable transfer of itself by transforming DNA.
The Incidence of R Factors in Bordetella bronchiseptica Isolated from Pigs
Authors: Terakado Nobuyuki , Azechi Hayami , Ninomiya Kiyoji , Fukuyasu Tsuguaki , Shimizu Takeshi 
Published: November 2013

ABSTRACTBordetella bronchiseptica strains isolated from the nasal cavities of young pigs in Japan from 1969 to 1972 were surveyed for drug resistance and distribution of R factors. Of 304 strains examined, 71 (23%) were resistant to either one or more of following three drugs, streptomycin (SM), sulfadimethoxine (SA), and aminobenzyl penicillin (APC). Triple (SM.SA.APC)‐resistance was most frequent among these resistant strains. Strains of double (SM. SA)‐ or single (SM)‐ and (SA)‐resistance were also isolated, but were very few in numbers. Of the 71 drug‐resistant strains, 61 (86%) were found to carry R factors which were capable of conjugal transfer. All of these R factors had the triple (SM.SA.APC)‐resistant markers and were identified as fi– (no fertility inhibition) type. The (SM.SA.APC)‐resistant strains carrying R factors had been isolated from pigs reared on various farms in different districts, and consequently the prevalence of B. bronchiseptica strains carrying R factors was considered to be relatively wide‐spread in young pigs.
Studies on the Growth Conditions of Campylobacter fetus
Authors: Miyamae Takeo 
Published: November 2013

ABSTRACTThe optimal growth pH and conditions necessary to give a full manifestation of the effect of reductants upon the growth of Campylobacter fetus were investigated using static cultivation. The multiplication of cells was limited to a narrow range of added reductants. Thioglycollate supplemented without heating produced heavy growth in combinations of 0.05% at pH 6.80 or 0.1% at pH 6.60, and 0.2% at pH 7.00 or 7.20. Although the stimulating effect depended upon the time between the addition of the supplement and inoculation, two prominent peaks in the growth curve always appeared with both alkaline and acidic pH ranges of the medium. Autoclaving the medium with some SH compounds brought about this growth only at around pH 6.50. Consequently there was a uniform decrease in the initial pH. l‐Cysteine and ascorbic acid also gave similar effects. Glucose remarkably prevented the growth promotion due to SH compounds. Optimal initial reduction potential for growth in a semisolid medium was considered to be −0.05 to −0.08 volt at an initial pH of 6.60. SH compounds supplemented without heating brought about a marked longevity of the culture in comparison with a culture in an autoclaved medium of the same composition. For the growth of C. fetus in semisolid medium, it was important to avoid decreasing the growth‐promoting activity of some of the supplemented SH compounds by not heating but adding the supplement aseptically. Also a rigid regulation of the pH, the concentration of the added reductants, and the time of inoculation into the fresh medium were important.
Isolation of a Common Cell Wall Antigen from the Proteolytic Strains of Clostridium botulinum
Authors: Takumi Kenji , Kawata Tomio 
Published: November 2013

ABSTRACTA protein‐rich antigen was extracted from the cell walls of Clostridium botulinum type A strain 190L by relatively mild treatments with detergents, tryptic digestion or cell wall autolysis. The cell wall antigen was relatively labile, and destroyed by acid or formamide hydrolysis. Immunodiffusion studies with the trypsin‐treated cell wall extracts from various strains of C. botulinum indicated that the antigenic cell wall polymers among the proteolytic strains of types A, B and F but not among the nonproteolytic strains of C. botulinum shared a common antigenic specificity.
β‐Lactamase Formation and Resistance of Proteus morganii to Various Penicillins and Cephalosporins
Authors: Yaginuma Satoshi , Sawai Tetsuo , Yamagishi Saburo , Mitsuhashi Susumu 
Published: November 2013

ABSTRACTTen strains of Proteus morganii were selected and the production of β‐lactamase was studied. The cellular level of β‐lactamase from P. morganii was regulated by the concentration of the inducer in the growth media, and the enzyme activity appeared within 10 min while its highest value was obtained 2 hr after the addition of benzylpenicillin as the inducer. The resistance level to cephaloridine was generally related to the amount of β‐lactamase activity among the ten strains of P. morganii, but no relation was found between the ampicillin susceptibilities and the amounts of β‐lactamase in their cell‐free preparations. The maximum rate of hydrolysis of cephalosporin C and several other derivatives of 7‐aminocephalosporanic acid by a crude enzyme was five times higher than that of benzylpenicillin. Semisynthetic penicillins were resistant to hydrolysis and exhibited competitive inhibition. Among the semisynthetic penicillins, dicloxacillin and carbenicillin were powerful competitive inhibitors of the β‐lactamase from P. morganii.
A Capillary Tube Method for Counting Viable Cells of Bifidobacterium bifidum Grown in a Solid Medium1
Authors: Nakamura Hiroshi , Samejima Keijiro , Tamura Zenzo 
Published: November 2013

ABSTRACTA method which permitted counting viable cells of Bifidobacterium bifidum N4 in a solid medium was developed. A piece of the solid medium (0.7 ml) was quantitatively obtained with the aid of an agar‐puncher device and was homogenized in a Potter–Elvehjem homogenizer after the addition of 9.3 ml of sterile physiological saline. A 10‐fold dilution of the homogenate was repeated several times to make a series of dilutions. An aliquot (0.2 ml) of the appropriate dilution was used for counting the viable cells using a capillary tube method. The accuracy and the reproducibility of the method were comparable with those of the conventional plate counting method. By using established procedures the behaviors of B. bifidum N4 in a solid medium were studied. Viability of the organism in a solid medium lacking an energy source (lactose) was generally correlated to the period of preculture; the longer the period of preculture, the shorter was the span of cell life.
Biochemical Studies on Germination of Bacterial Spores
Authors: Watabe Kazuhito , Ichikawa Tomio , Kondo Masaomi 
Published: November 2013

ABSTRACTThe initiating mechanism in the germination of Bacillus thiaminolyticus spores was studied with 14C‐L‐alanine. A characteristic pattern of incorporation of L‐alanine into the spores was observed during the early stages of germination with two incorporation peaks, one occurred just after contact with L‐alanine (first incorporation) and the other 5 min later (second incorporation). L‐Glutamine, L‐valine, or L‐serine substituted for the incorporation of L‐alanine during the first stage of germination. Although, L‐alanine taken up during the first incorporation phase was extractable with trichloroacetic acid (TCA), that taken up during the second incorporation phase was not extractable. The distribution of radioactivity showed that incorporated L‐alanine was located in the spore coat, mainly in the paracrystal fraction. The radioactive material which remained in the germination medium or was extractable from the spore coat fraction with TCA treatment or pronase digestion was identified as alanine. Significance of incorporation of L‐alanine and its location in the spore in reference to the initiation of germination is discussed.
Model System for the Adsorption of Tobacco Mosaic Virus
Authors: Kiho Yukio 
Published: November 2013

ABSTRACTMaterials which can adsorb tobacco mosaic virus (TMV) were isolated from tobacco leaves and studied for applicability as a model system for TMV adsorption. Leaves were homogenized and fractionated by sucrose density gradient centrifugation. One fraction adsorbed TMV in the presence of polyornithine. Deduced from its sensitivity to trypsin and detergent as well as from its manner of isolation, the material responsible for adsorption of TMV seemed to be cytoplasmic membrane. Membrane derived from light particulate, as well as cytoplasmic membrane, seemed to be capable of adsorbing TMV. Shorter rods obtained by sodium dodecyl sulfate or sonic treatment of TMV could adsorb to membrane as efficiently as TMV. Viral protein subunit could not adsorb whereas helical rods made of viral protein aggregates could. A two‐step nature of the adsorption of TMV was suggested: a salt‐sensitive and a subsequent salt‐resistant steps. In the first step, ionic bonding plays a main role in the combination between TMV and membrane. Adsorption of 14C‐labeled TMV was inhibited by an excess amount of non‐labeled TMV or cucumber green mottle mosaic virus but not by potato virus X or rice dwarf virus, suggesting the specific nature of adsorption. In contrast to the observed specificity on the part of virus, a membrane fraction isolated from various plants, including non‐hosts for TMV, could adsorb TMV. This may imply that adsorption and injection are not the determinant of host specificity in plant viral infection.
Effect of Calcium on the Cell Infectivity of Virulent Shigella flexneri 2a
Authors: Osada Yasuaki , Une Tsutomu , Ikeuchi Tora , Ogawa Hidemasa 
Published: November 2013

ABSTRACTEffect of calcium ions (Ca++) on the virulence of Shigella flexneri 2a was examined with reference to its infectivity to cultured cells, the guinea pig eye, and the ligated small intestine of rabbits. The organism grown in a calcium‐containing medium showed a significantly higher ability to penetrate HeLa cells than that of organism grown in a calcium‐deficient medium. This ability was constantly maintained in the presence of Ca++, while readily lost in the absence of Ca++. Similarly, its pathogenicity for the guinea pig eye and the ligated small intestine of rabbits was more or less greater in cases with Ca++ than in cases without Ca++. Ca++ seemed to play an important role in bacterial adhesion to the cell membrane, by which the cellular engulfment was induced. The presence of Ca++ in the environment of bacterial growth was emphasized on development and maintenance of virulence of S. flexneri 2a.
Drug Resistance and Distribution of R Factors among Escherichia coli Strains
Authors: Tanaka Tokumitsu , Kobayashi Akio , Ikemura Kengo , Hashimoto Hajime , Mitsuhashi Susumu 
Published: November 2013

ABSTRACTThree hundred and thirty‐eight strains of Escherichia coli from clinical sources were examined for their drug resistances and R factors in 1971. With reference to four drugs, i.e., tetracycline(TC), chloramphenicol(CM), streptomycin(SM) and sulfanilamide(SA), the SA‐resistant strains were isolated most frequently followed by SM‐, TC‐ and CM‐resistant ones in decreasing order. Among those resistant to the aforementioned four drugs, 20.3, 19.0, 7.7 and 18.3% were single‐, double‐, triple‐ and quadruple‐resistant, respectively. The R factors were demonstrated at a frequency of 29.2% among these resistant strains. From the strains possessing quadruple‐resistance, the conjugationally transferable R factors were demonstrated most frequently (60.5%) followed by triple‐ (59.1%), double‐ (21.7%) and single‐resistant strains (4.5%). The isolation frequencies of strains resistant to kanamycin (KM) and ampicillin (APC) were 1.5 and 4.7%, respectively; being fewer in numbers compared with those resistant to the four drugs. Strains resistant to cephaloridine, nalidixic acid, Colistin, gentamicin C complex and furatridine were not isolated. Strains resistant to KM and APC were demonstrated mostly from those possessing multiple resistance with reference to the aforementioned four drugs. Among the strains carrying either APC‐ or KM‐resistance, 76.9 and 100% respectively, were found to carry R factors, indicating that most of the APC‐ and KM‐resistances were conferred by the R factors. Twenty percent of the R+ strains with reference to resistance to the four drugs carried two types of R factors in a cell, being in a hetero‐R state, and 66.7% of the strains carrying R factors with APC‐ or KM‐resistance were in a hetero‐R state.
Studies on Complement‐Fixation Reaction in Equine Infectious Anemia
Authors: Nakamura Junji , Kuroda Sadao , Ueda Susumu , Samejima Togo 
Published: November 2013

ABSTRACTComplement‐fixing (CF) and complement fixation‐inhibiting (CFI) antibodies were investigated sequentially in three horses infected with equine infectious anemia (EIA) virus. The CF activity was first demonstrated 6 or 8 days after onset of the first pyrexia. The CFI activity developed a short period later, and caused a decrease of apparent CF titer of the whole serum. However, both antibodies tended to increase with advance of the disease course in two persistently infected horses, whereas they became completely undetectable during the late‐stage in the remaining horse which showed no evidence for recurrence of pyrexia or persistence of viremia. The CF activities determined with varying dilutions of serum were distinctly different in pattern between the early‐stage serum having the CF activity alone and the late‐stage serum having both the CF and the CFI activities. The CF antibody was precipitated by 27–30% saturation with ammonium sulfate (SAS) while the CFI activity distributed in a wider range of precipitates formed by 26–32% SAS. The CFI activity was demonstrated to a higher titer when a relatively small amount of antigen was sensitized with CFI antibody prior to addition of reference CF antibody than when the three reagents were mixed at one time. The late‐stage serum with a strong CFI activity against EIA antigen had no effect on the CF reaction of other viral antigen–antibody systems such as equine influenza and equine rhinopneumonitis.