MICROBIOLOGY and IMMUNOLOGY
Online ISSN : 1348-0421
Print ISSN : 0385-5600
ISSN-L : 0385-5600
Volume 34, Issue 1
Displaying 1-9 of 9 articles from this issue
  • Fumiaki IKEDA
    1990 Volume 34 Issue 1 Pages 1-9
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    The minimal inhibitory concentrations (MICs) of ampicillin for fifty strains of beta-lactamase-producing Neisseria gonorrhoeae (PPNG) isolated in Japan ranged from 1.56 to 200μg/ml, and all the strains harbored a 4.5 megadalton plasmid. These strains were classified into two groups: dicloxacillin-susceptible (28%) and -resistant group (72%). A linear correlation was found in the dicloxacillin-susceptible strains between their beta-lactamase activity and the susceptibility to ampicillin, but not in the dicloxacillin-resistant strains. This suggests that the high ampicillin resistance in PPNG is due not only to acquiring the beta-lactamase producing plasmid, but also to some intrinsic resistance of the strains. To investigate a cause of the high ampicillin resistance, the beta-lactamase-producing plasmid, pTMS1, was transferred by conjugation to a penicillin-susceptible gonococcal strain as well as to its isogenic multiply antibiotic-resistant transformants, and the susceptibility of the transconjugants to ampicillin was determined. Acquisition of pTMS1 by a penicillin-susceptible strain resulted in a 32-fold increase in resistance to ampicillin, whereas the increase was 128-fold for its isogenic strains which contain some chromosomal mutations. These results suggest that reduced permeability of the outer membrane to ampicillin underlies the high ampicillin resistance of PPNG.
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  • Sei-ichi KATAYAMA, Masaki NINOMIYA, Junzaburo MINAMI, Akinobu OKABE, H ...
    1990 Volume 34 Issue 1 Pages 11-24
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    The production of heat-labile enterotoxin (LT) in 76 strains of human enterotoxigenic Escherichia coli (ETEC) varied by a factor of 100. Three ETEC strains that differ in the levels of LT production were chosen for the cloning of LT genes (toxAB) into plasmid pBR322, and the gene structure and expression were compared in E. coli HB101. The recombinant of the low LT-producing strain produced LT at the same level as that of the moderate LT-producing strain, but that of the high-level producer continued to produce at a level 14-21 times higher than the others. The restriction maps of the coding regions of the cloned LT genes (toxAB) were identical, but the flanking regions were dissimilar. The content of LT mRNA per cell, examined by Northern blot analysis, was higher in the high producer than the others by 6 times. The promoter strengths of the recombinants were all alike. LT mRNA of the high producer was more stable than that of the moderate one by 1.3 times, but the difference was not large enough to explain the difference of the content of LT mRNA. It was shown that LT production can be controlled at a transcriptional step, and DNA structure of the flanking regions may be involved in the control of the LT gene expression.
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  • Yayoi NISHIYAMA, Hideyo YAMAGUCHI
    1990 Volume 34 Issue 1 Pages 25-34
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    Filipin, a sterol-specific antibiotic, and freeze-fracture electron microscopy were used to study the presence and distribution of sterol in the cytoplasmic membrane of stable staphylococcal L-form cells. Fixed cells were treated with filipin, and then observed by freeze-fracture electron microscopy. Freeze-fractured profiles of the L-form cells treated with filipin demonstrated irregular distribution of protuberances or pits of 25-30nm, representing filipin-sterol complexes, on the protoplasmic fracture face (PF) and exoplasmic fracture face (EF) of the cytoplasmic membrane. In contrast, no such structure was detected in the filipin-treated parent cells or protoplasts. The results suggest that some sterol molecules, which are usually not found in staphylococcal or other bacterial cells, emerged on the cytoplasmic membrane after the cells were converted to the stable L-form.
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  • Kazuhiko TAKIGUCHI, Masato TASHIRO, Kiyoto NAKAMURA
    1990 Volume 34 Issue 1 Pages 35-44
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    Four-week-old rats (WKA/Hkm strain) were infected intranasally with the Ann Arbor/1/50 strain of influenza C virus and examined for clinical symptoms, virus replication, and serum antibody response. Although the animals showed no definite signs of illness, the virus replicated in the nose, and the hemagglutination inhibiting (HI) and neutralizing antibodies were produced in their sera. When the inoculum sizes of 106.2 and 103.2PFU were used, virus was recovered from nasal homogenates between days 1 and 10, and serum HI antibody became detectable by 10 days after infection. The rats infected with 101.2PFU of the virus continued to shed virus until as late as day 20 without producing serum HI antibody. The amount of virus recovered from the nose was not affected significantly by either sex, age, or strain of the rat except that a slower virus growth was seen in the LE strain. It was also observed that the rats, previously inoculated with 103.2PFU of the virus, showed no virus shedding when reinfected 7 weeks later but produced virus though in low titers when reinfected 50 to 55 weeks later. Virus was also recovered from rats once inoculated with 101.2PFU of the virus when challenged 7 weeks later. Thus repeated infections characteristic of human influenza C can be produced in rats under the restricted conditions.
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  • Yayoi NATSUHARA, Junji YOSHINAGA, Takeshi SHOGAKI, Yukie SUMI-NISHIKAW ...
    1990 Volume 34 Issue 1 Pages 45-53
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    A newly isolated mycoloyl glycolipid (Rt. GM-2) from Rhodococcus terrae 70012 was identified and the granulomagenic and antitumor activities were studied as compared with trehalose-6, 6'-dimycolate (cord factor) also from R. terrae (Rt. TDM). The alkaline hydrolysis products of Rt. GM-2 contained trehalose, methyl-α-mycolate and a less-polar ester than the usual methyl-α-mycolate, possibly β-keto mycolate (1:1:1, by mol. ratios). On the other hand, analysis of alditol acetate obtained after the mild permethylation, NaBH4 reduction, and acetylation showed the occurrence of 2, 3, 4-tri-O-methyl-6-O-acetylglucitol. Therefore, the original glycolipid (Rt. GM-2) was identified tentatively as 6-O-α-mycoloyl 6'-O-β-ketomycoloyl trehalose. Intravenous injection of Rt. GM-2 in the form of water-in-oil-in-water emulsion caused prominent granulomas in lungs and spleen of ICR and BALB/c mice. The granulomagenic effects were as strong as those caused by Rt. TDM. The lung and spleen weights reached peaks one week after an injection of Rt. GM-2 in mice and then gradually decreased. Multiple intravenous injections of Rt. GM-2 and Rt. TDM showed antitumor activity against subcutaneously implanted Sarcoma-180, and caused prominent granulomatous changes and growthsuppression of mice.
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  • Françoise GUEGUEN, Georges ROBREAU, Françoise TALBOT, Ro ...
    1990 Volume 34 Issue 1 Pages 55-64
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    A monoclonal antibody, prepared against whole cells of Clostridium tyrobutyricum, recognized a surface antigen extracted by heat treatment or by hot phenol-water treatment. This antigen, after analysis by polyacrylamide gel electrophoresis and immunoblotting, has been shown to present a regularly-spaced ladder pattern similar to those shown by the lipopolysaccharide of many gram-negative bacteria. The proteinase K has been shown to have no effect on the recognition of this epitope by the monoclonal antibody. On the contrary, the inhibition of the antigen reactivity to the monoclonal antibody after a mild periodate oxidation suggests the involvement of a carbohydrate moiety in the epitope. Moreover, the SDS-PAGE analysis of phenol-water extracts has shown an additional compound, detected by silver staining but not recognized by the monoclonal antibody.
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  • Chemical Treatment of the Cells and Teichuronic Acids on the Surface
    Toshihiko MONODANE, Michiko TOKUNAGA, Mitsuo TORII
    1990 Volume 34 Issue 1 Pages 65-72
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    Tetrads-forming mutant MT cells of Micrococcus luteus, both treated with chemical reagents and non-treated, were observed with a scanning electron microscope (SEM). The agglutinability of the cells with antiserum containing anti-teichuronic acid antibody was examined. The binding of protein A-gold particles to the cells, mediated with the antiserum, was also observed with SEM. A tetrad surface, not surface of each of four “unit monococci” constituting a tetrad, consisted of two or three smooth areas with borders. The difference in the surface features between M. luteus wild-type IFO 3333 (Monodane et al, Microbiol. Immunol. 33: 165-174, 1989) and the mutant MT cells is discussed.
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  • Eiko YABUUCHI, Yasuhiro HASHIMOTO, Takayuki EZAKI, Yoshimi IDO, Noriko ...
    1990 Volume 34 Issue 1 Pages 73-76
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    The type and eight strains of Flavobacterium indologenes were clearly differentiated from the type and two reference strains of Flavobacteriurn gleum by deoxyribonucleic acid-deoxyribonucleic acid homology data and phenotypic characteristics. Phenotypic characteristics useful to differentiate the two species are presented.
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  • Toyoko NAKAGOMI, Atsushi OHSHIMA, Kaoru AKATANI, Nobuko IKEGAMI, Norik ...
    1990 Volume 34 Issue 1 Pages 77-82
    Published: 1990
    Released on J-STAGE: March 17, 2008
    JOURNAL FREE ACCESS
    A human rotavirus strain, designated AU32, that belongs to serotype 9 was isolated and was compared by RNA-RNA hybridization with recently established two serotype 9 strains (WI61 and F45) as well as other prototype human strains. These three strains exhibited a very high degree of homology with one another and shared a high degree of homology with strains belonging to the Wa genogroup but not with strains belonging to either the DS-1 or AU-1 genogroup. These results suggest that genetic constellation of the serotype 9 strains is similar to that of the commonest human rotavirus despite the recent recognition of this serotype.
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