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Biomedical subjects

E Yabuuchi

Publications and source records attributed to E Yabuuchi.

At least 55 records · Page 3Linked to original sources
PubMed1991

Effects of biocidal treatments to inhibit the growth of legionellae and other microorganisms in cooling towers.

The effects of biocidal treatments for cooling towers were examined through the use of chemicals and ultraviolet irradiation to inhibit the growth of legionellae and other microorganisms. In the water of cooling towers without continuous biocidal treatments, heterotrophic bacteria and bacterivorous protozoan first appeared, and then legionellae increased up to 10(4) CFU/100 ml. When a UV sterilizer was connected to the cooling tower, the legionellae count was 1/10 or 1/100 of that in the nontreated tower water. In the water of towers supplemented continuously with the biocidal chemicals, legionellae were not found during a 4-month period. The biocidal treatments tested were proved to suppress the increase of legionellae in cooling-tower water, and thus are useful in preventing the outbreak of legionellosis due to inhalation of contaminated aerosol from the cooling tower system.

Animals↗
PubMed1991

Application of colorimetric microdilution plate hybridization for rapid genetic identification of 22 Mycobacterium species.

Quantitative microdilution plate hybridization was used to identify 22 Mycobacterium species. DNAs of clinical strains were rapidly extracted and labeled with photoreactive biotin. Labeled DNAs were distributed into wells of a microdilution plate in which reference DNAs had been immobilized. After 2 h of hybridization, hybridized DNAs were quantitatively detected with peroxidase-conjugated streptavidin and the substrate, tetramethylbenzidine. This method could differentiate among 20 of the 22 Mycobacterium species tested. The type strains of Mycobacterium tuberculosis and M. bovis were genetically highly related and could not be differentiated by this method. Of 194 biochemically identified human clinical strains, 178 (90%) were genetically identified within 3 h of the small-scale DNA extraction.

Aminosalicylic Acid↗
PubMed1991

[STAPHYOGRAM, a new rapid identification kit for the aerobic, gram-positive, catalase-positive cocci--application of fluorometric microplate hybridization for the pre-identification of 386 isolates used].

A new simplified test kit, STAPHYOGRAM plate, was developed for 4-hr identification of aerobic, Gram-positive and catalase-positive cocci. The plate has 18 wells, in which different dehydrated substrates and nutrients are fixed. An 18-hr agar-culture suspension of a test strain with a turbidity of McFarland No. 4 was distributed into all wells in 50-microliters quantities. After 4-hr incubation at 37C, the profile number was obtained by summarizing positive reactions. The ability of the plate to differentiate the type strains of the 30 species of the three genera in the family Micrococcaceae was confirmed. These three genera are Staphylococcus, Micrococcus and Stomatococcus. The applicability of the fluorometric microplate hybridization technique to identification of aerobic, Gram-positive and catalase-positive cocci was confirmed by homologous hybridization among the type strains of the 30 species. Thus, 386 isolates of human and animal origin were pre-identified by microplate hybridization and used for evaluating the STAPHYOGRAM plate. Of the 236 profile numbers thus obtained with the 386 isolates, 218 (92.4%) were species-proper each and all for the 15 species of Staphylococcus and Stomatococcus mucilaginosus. A total of 342 (88.6%) of the 386 isolates were given such profile numbers, and were identified without any additional test. Among the 15 species identified primarily by the results of STAPHYOGRAM plate culture, S. caprae, S. lugdunensis, S. gallinarum and S. delphini were validly published after Approved Lists of Bacterial Names. The identified strains of S. caprae (48), S. haemolyticus (46), S. capitis (35) numbered between those of S. epidermidis (67) and S. saprophyticus (31). Profile numbers common to two species were seven (27 strains) and that to four species was one (17 strains). These 44 strains were identified with one to three additional tests. From these results, we were convinced that the STAPHYOGRAM test plate is useful for the rapid identification of members of family Micrococcaceae. By compiling STAPHYOGRAM plate data on genetically identified strains, an exclusive list of profile numbers will soon be prepared for perfection of the kit.

Animals↗
PubMed1990

Rapid procedure to determine the DNA base composition from small amounts of gram-positive bacteria.

A universal rapid procedure to determine the DNA base composition (mol% guanine + cytosine) of Gram-positive bacteria is described. Cells of Gram-positive bacteria were lysed with achromo-peptidase and the mol% G + C of their DNAs were determined by using high performance liquid chromatography. One ml of a Gram-positive bacterial suspension which matched MacFarland No. 3 standard turbidity was sufficient to determine the mol% G + C within 3 h.

Base Composition↗
PubMed1990

Evaluation of the microplate hybridization method for rapid identification of Legionella species.

Rapid genetic identification of 23 Legionella species was performed using microdilution plate hybridization. When an isolate appeared to be a strain of the Legionella species, its DNA was quickly extracted, labelled with photobiotin and distributed to microdilution wells where 23 different DNAs had previously been immobilized. After hybridization for 90 min at 45 degrees C, the microdilution well which emitted the maximum fluorescence was determined. The criterion for interpreting results of this genetic identification method is given.

DNA, Bacterial↗
PubMed1990

Peptostreptococcus hydrogenalis sp. nov. from human fecal and vaginal flora.

We describe Peptostreptococcus hydrogenalis sp. nov., which is found in human feces and vaginal discharge. This new species was established on the basis of the results of DNA-DNA hybridization among anaerobic cocci. The results of different biochemical reactions also are given. The type strain of this species is strain GIFU 7662 (= JCM 7635).

Base Composition↗
PubMed1990

Proposals of Sphingomonas paucimobilis gen. nov. and comb. nov., Sphingomonas parapaucimobilis sp. nov., Sphingomonas yanoikuyae sp. nov., Sphingomonas adhaesiva sp. nov., Sphingomonas capsulata comb. nov., and two genospecies of the genus Sphingomonas.

Based on the partial nucleotide sequence analysis of 16S ribosomal ribonucleic acid (rRNA), presence of unique sphingoglycolipids in cellular lipid, and the major type of ubiquinone (Q10), we propose Sphingomonas gen. nov. with the type species Sphingomonas paucimobilis (Holmes et al, 1977) comb. nov. From the homology values of deoxyribonucleic acid-deoxyribonucleic acid hybridization and the phenotypic characteristics, three new species, Sphingomonas parapaucimobilis, Sphingomonas yanoikuyae, Sphingomonas adhaesiva, and one new combination, Sphingomonas capsulata, are described. S. parapaucimobilis JCM 7510 (= GIFU 11387), S. yanoikuyae JCM 7371 (= GIFU 9882), and S. adhaesiva JCM 7370 (= GIFU 11458) are designated as the type strains of the three new species. Emended description of the type strain of S. capsulata is presented.

Base Composition↗
PubMed1990

[Asymptomatic infection of Legionella pneumophila in four cases with pulmonary diseases].

In view of the wide-spread existence of legionellae in cooling-tower and other environmental water, asymptomatic infection of this organism could occur. In order to verify the possibility of colonization of legionellae at lower respiratory tract of patients with various pulmonary diseases, a total of 22,036 sputum samples from in- and out-patients at National Sanyoso Hospital were examined during a five-year period from September, 1984 to August, 1989. Four (0.073%) out of 5,502 cases were culture-positive for L. pneumophila. L. pneumophila strains were isolated from expectorated, subsequently washed sputum samples of two male and two female patients with respiratory tract diseases. The identification of the isolates was genetically confirmed by the fluorometric microplate DNA-DNA hybridization method. The serogroup (SG) and viable counts of L. pneumophila per ml of sputum of each patient were as follows: 73 y/o female K.H., SG-6, 10(3) CFU; 75 y/o male H.J., SG-5, 10(4) CFU; 61 y/o female M.S., SG-5, 10(5) CFU; and 77 y/o male M.G., not-agglutinable against SG-1-6 antisera, 10(4) CFU. None of the four patients was clinically suspected of legionellosis and antibody titer of paired sera remained 1:64 or lower than 1:32. From these findings, we concluded that L. pneumophila can cause, though quite rarely, asymptomatic infection in human respiratory tract. None of the environmental samples obtained from in- and out-side of the Hospital was culture-positive for legionellae. Thus, the source of infection has remained unknown.

Aged↗
PubMed1990

[Clinical laboratory works and taxonomy in bacteriology].

Taxonomy is the basic stand point for every field of bacteriology and provides a common language to each worker and researcher in bacteriology throughout the world. Proper identification of isolates from human pathological specimens or from hospital environments is one of the five principal fields of bacterial taxonomy. Before the establishment of classification and stabilization of nomenclature, any isolate can not be identified. Collection of unidentifiable strains is the starting point of new taxonomic investigation. Doctors in medical fields tend to be too much concerned to the infrasubspecific subdivisions, such as serological classification, toxigenicity, resistance to antimicrobics, rather ignoring the classification above the rank of subspecies. Doctors who take care patients and workers in clinical bacteriology laboratories should recognize the importance of bacterial taxonomy in general and use the necessary information in taxonomy selectively.

Bacteria↗
PubMed1988

Ornithine-containing lipids of some Pseudomonas species.

Ornithine-containing lipids purified by thin-layer chromatography were found to represent 2-15% of the total extractable cellular lipids in two or three strains each of four Pseudomonas species: P. aeruginosa, P. fluorescens, P. stutzeri and P. cepacia. The structures of the ornithine-containing lipids were elucidated by chemical analysis, thin-layer chromatography, gas-liquid chromatography, gas-liquid chromatography/mass spectrometry (electron impact or secondary ion) and infrared absorption spectroscopy. At least six molecular species of ornithine-containing lipids were present in common in all of the preparations of the four Pseudomonas species. The structure which was the most abundantly in P. fluorescens (about 60% of the total amount of the ornithine-containing lipid) was 3-hydroxyhexadecanoic acid amide-linked to ornithine and esterified to hexadecanoic acid. In addition to this structure, 3-hydroxyoctadecenoic acid amide-linked to ornithine and esterified to hexadecanoic acid was a dominant structure in the ornithine-containing lipids of P. aeruginosa, P. stutzeri or P. cepacia. In P. cepacia, another ornithine-containing lipids with a terminal polar fatty acid, 3-hydroxyhexadecanoic acid amide-linked to ornithine and esterified to 2-hydroxynonadecacyclopropanoic acid or 2-hydroxyoctadecenoic acid, was found; its content, which represented 8-11% of the total extractable cellular lipids, was higher than that of the ornithine-containing lipids with a terminal nonpolar fatty acid. These ornithine-containing lipids exhibited hemagglutinating activity. Additionally, it was very interesting that hydroxy fatty acids included in the ornithine-containing lipids were not found in the phospholipids which represented more than 80% of the total extractable cellular lipids.

Chemical Phenomena↗
PubMed1988

Small-scale DNA preparation for rapid genetic identification of Campylobacter species without radioisotope.

A simplified and rapid genetic identification method for Campylobacter species without radioisotope was established. Three different amounts of DNA (200, 50, and 12.5 ng) extracted from each type strain of Campylobacter species with standard Marmur's procedure were spotted on a nitrocellulose filter. DNA obtained from one ml bacterial suspension at a concentration of McFarland standard turbidity No. 1 of Campylobacter fetus, C. jejuni, C. coli, and C. pylori isolates were sufficiently labeled with photo-biotin within 15 min and clearly hybridized with the type strain of the corresponding species within four to six hours. Hybridized spots were visualized with alkaline-phosphatase-conjugated streptavidin color-detection method. The reaction was usually stopped within 30 min. Atypical clinical isolates such as a nitrate-negative C. jejuni, two nalidixic acid-resistant C. jejuni, and two strains of C. fetus able to grow at 42 C, which were tentatively identified as such, were definitely identified by the simplified DNA hybridization method presented here. This method will be applicable routinely for the definite identification of atypical strains of Campylobacter species and other gram-negative bacteria difficult to identify biochemically.

Campylobacter↗
PubMed1988

Intact motility as a Salmonella typhi invasion-related factor.

Invasiveness of Salmonella typhi was investigated. At first, we introduced Tn5 into the chromosome of a wild-type S. typhi strain, GIFU 10007, and screened the independent Tn5 insertion mutants for noninvasive (Inv-) strains. During the first half of this work, we obtained 4 Inv- strains from 1,338 independent Tn5 mutants. The four were either nonflagellate (Fla-), nonmotile (Mot-), or nonchemotactic (Che-). We then isolated more Fla-, Mot-, or Che- mutants and examined the invasiveness of these mutants. Sixty-three spontaneous or Tn5 insertion motility mutants, i.e., Fla-, Mot-, or Che-, were independently isolated from the wild-type strain GIFU 10007; all of them were noninvasive. Motile revertants isolated from some of these mutants showed the same invasiveness as the parent strain. P22-mediated transductional crosses were carried out between some of the motility mutants (as the recipients) and the Fla- reference strains of S. typhimurium with known deletion sites on the genome (as the donors). The mutational sites of the S. typhi mutants were assigned almost evenly to the three flagellar gene regions (regions I, II, and III) of S. typhimurium. The invasiveness of the motile recombinants obtained from the transduction assays was examined. The restoration of intact motility resulted in the restoration of invasiveness. Thus, we conclude that intact motility is an invasion-related factor of S. typhi. The relationship of Vi antigen to the invasiveness of S. typhi was also studied. Vi-negative mutants with intact motility remained invasive, whereas all 63 Inv- spontaneous or Tn5 mutants were Vi positive. Therefore, Vi antigen was not related to the invasiveness of S. typhi.

Bacterial Adhesion↗
PubMed1988

Simple genetic method to identify viridans group streptococci by colorimetric dot hybridization and fluorometric hybridization in microdilution wells.

Simple dot hybridization and fluorometric hybridization methods in microdilution wells were designed and established for rapid and routine genetic identification of viridans group streptococci. Reference DNA extracted from each strain of 24 reference Streptococcus species was fixed both on a nitrocellulose filter and in a microdilution well. A 1-ml portion of the bacterial suspension which matched the turbidity of McFarland no. 2 standard was prepared when a streptococcal strain was isolated. It was lysed with achromopeptidase, and the DNA was quickly labeled with photobiotin under a sunlamp for 15 min. Dot hybridization and fluorometric hybridization were then carried out between the labeled DNA of the unknown organism and 24 unlabeled reference DNAs. Hybridized fragments on a nitrocellulose filter were detected by using alkaline-phosphatase-conjugated streptavidin and analyzed with a color graphic analyzer. Hybridized fragments in microdilution wells were quantitatively detected by using an enzyme, streptavidin-conjugated beta-D-galactosidase, and a fluorogenic substrate, 4-methylumbelliferyl-beta-D-galactoside. Strains belonging to each genetically distinct species could be identified by this dot blot hybridization test. However, some clinical strains cross-hybridized with two or more reference species, and then they were difficult to differentiate by dot blot hybridization. In such a case, fluorometric identification provided reliable results because the fluorometric method was more quantitative than dot blot identification. By these methods, it was possible to determine species assignment within the viridans group.

Autoradiography↗
PubMed1987

An ultrastructural study of HeLa cell invasion with Salmonella typhi GIFU 10007.

Scanning electron micrograph of HeLa S3 monolayered cells, inoculated with viable bacteria of a Salmonella typhi strain GIFU 10007, revealed that the extended microvilli tangled the bacteria within 10 min after inoculation. The micrographs of HeLa cells, at 1 hr after inoculation, indicate the following: shortening of bacterium-attached microvilli, subsiding of tangled bacteria into microvilli bush, and then attachment of bacterial soma to cell surface making the cell membrane depressed. The transmission electron micrographs, at 1 hr after inoculation, demonstrated the findings of interaction between HeLa cell and S. typhi 10007, similar to those observed on scanning electron micrographs. Hair-like fine structures from the soma of challenge organisms were also observed. They were in contact with HeLa cell microvilli and cell membrane. The bacteria were first partially and then totally surrounded by the HeLa cell plasma membrane. One, two, or several bacteria with intact outer membrane were enclosed in intracytoplasmic membrane-bound vacuoles. Fragmented vacuolar membrane was still visible around the intracellularly accumulated bacteria at 24 hr after inoculation. The viable cells of S. typhi 10007 are regarded as internalizing into HeLa cells by a process of endocytosis and to multiply within the membrane-bound vacuoles.

HeLa Cells↗
PubMed1987

Effects of FLONLIZER, ultraviolet sterilizer, on Legionella species inhabiting cooling tower water.

Legionella pneumophila in sterile distilled water was not detected after ultraviolet irradiation by FLONLIZER, a new-type sterilizer, at a flow rate of 82.5 to 364.8 liters/hr. When irradiated by FLONLIZER at a flow rate of under 324.0 liters/hr, no viable cells of legionellae, other heterotrophic bacteria and bacterivorous protozoa were detected in the cooling tower water, which was found to contain L. pneumophila. No viable cells of L. pneumophila and L. bozemanii suspended in sterile distilled water were detected after the irradiation with UV-doses of over 6.16 X 10(3) micro W.sec/cm2. At the irradiation of low UV-doses under 1.06 X 10(4) micro W.sec/cm2, the viable count of legionellae recuperated by photoreactivation from UV-damage increased with the exposure time under a white fluorescent lamp. However, in the samples irradiated with UV-doses of over 3.52 X 10(4) micro W.sec/cm2, equal to the FLONLIZER, legionellae did not recuperate even after 18 hr illumination with a white fluorescent lamp. FLONLIZER is thus expected to act as a sterilizer which can control the legionellae inhabiting cooling tower systems placed in outdoor space.

Legionella↗
PubMed1986

Ecological studies of Legionella species. I. Viable counts of Legionella pneumophila in cooling tower water.

The occurrence and viable counts of Legionella pneumophila in acid-treated water samples of 62 cooling towers on the main island of Japan were determined by inoculating them onto plates of Wadowsky-Yee-Okuda (WYO) agar medium. WYO plate cultures of 39 (63%) of the samples yielded L. pneumophila with viable counts ranging from 10 to 10(4) colony-forming units per 100 ml. Of the L. pneumophila isolates, 157 were serologically identified as serogroup 1, and the remaining 21 were agglutinated by serogroup 3 (2 strains) and serogroup 6 (19 strains) antisera. In each culture-positive water sample, the pH and the number of other bacteria were found not be statistically significantly correlated with the viable counts of L. pneumophila. However, a higher rate of recovery of L. pneumophila was obtained with the water samples with a smaller number of other bacteria. Practical use of commercially available antialgal or antimicrobial agents was found not to be significantly effective for controlling the occurrence and growth of L. pneumophila in cooling tower water.

Bacteriological Techniques↗
PubMed1986

Invasiveness of Salmonella typhi strains in HeLa S3 monolayer cells.

The internalization and intracellular multiplication, i.e., the invasiveness, of Salmonella typhi strains recently isolated from typhoid fever patients were confirmed in HeLa cell monolayers. When stained with Giemsa solution, intracellular bacteria were 0.6 X 1.2 micron in size and stained purple, whereas extracellular bacteria associated or not with the HeLa cell surface were 1.0 X 3.0 micron and stained deep blue. Strain GIFU 10007 was internalized into 23% of the HeLa cells within 10 min after inoculation. About 90% of the HeLa cells were infected after 24 hr incubation in kanamycin (KM)-containing medium. Intracellular multiplication of the challenge organism was verified by a large number of intracellular bacteria after 24 hr incubation in KM-containing medium by both light-microscopy of the Giemsa stained preparation and viable counts of intracellular bacteria. The viable counts of strain 10007 showed an increase of more than 40-fold within 24 hr after inoculation, whereas in the four other less or non-infective strains, recovery of viable bacteria was poor or nil. Strains which were highly invasive usually failed to show strong adhesion. The contribution of Vi antigen to the internalization of challenge organisms was not proved. Infective strains, when killed by formalin were still adhesive, but were not internalized. The same strains, when killed by boiling, were neither adhesive nor internalized. From these findings it was concluded that the internalization and multiplication of infective S. typhi strains in cultured HeLa cells should be regarded as an invasion rather than phagocytosis by host cells, and such invasiveness could be an indicator to estimate the virulence of S. typhi strains.

Agglutination Tests↗