bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epidemiologic Typing of Methicillin‐Resistant Staphylococcus aureus in Neonate Intensive Care Units Using Pulsed‐Field Gel Electrophoresis
Authors: Saito Yumi , Seki Keiko , Ohara Tomoko , Shimauchi Chieko , Honma Yoko , Hayashi Mutsumu , Masuda Shogo , Nakano Masayasu 
Published: November 2013

AbstractTo elucidate the mode of dissemination of methicillin‐resistant Staphylococcus aureus (MRSA) in neonate intensive care units (NICUs), a total of 223 isolates from 3 separate hospitals were investigated between 1994 and 1996 by a DNA fingerprinting technique with pulsed‐field gel electrophoresis (PFGE). Exoprotein profiles of some strains were also examined using SDS‐polyacrylamide gel‐electrophoresis (SDS‐PAGE) and the assessment of enzyme/toxin production such as coagulase, enterotoxin and TSST‐1. Judging from the strain typing data from PFGE results and the epidemiological data, 2 different types of PFGE patterns (A and B) and their subtypes (A′, A″ and B′) were identified. The A type including A′ and A″ (comprising approximately 95% of the isolates) was markedly dominant. Only 5% of the isolates belonged to type B and subtype B′. On the other hand, MRSA isolated from adult patients admitted to the same hospital showed many different PFGE patterns. The results strongly suggested that some strain(s) with specific PFGE pattern(s) is prevalent in NICUs. Furthermore, isolates which expressed the same PFGE pattern did not always express the same SDS‐PAGE pattern. There were some isolates with different abilities to produce coagulase, enterotoxin C and toxic‐shock syndrome toxin (TSST)‐1, and the abilities had no relation with a particular type of PFGE pattern. Therefore, a combination of PFGE analysis and biochemical analyses of coagulase, enterotoxin C and TSST‐1 may provide us with more detailed information for the epidemiological study of MRSA in NICUs.
A Rapid Latex Agglutination Assay for the Detection of Penicillin‐Binding Protein 2′
Authors: Nakatomi Yasuo , Sugiyama Junichi 
Published: November 2013

AbstractA simple and rapid slide latex agglutination assay was developed to detect penicillin‐binding protein 2′ (PBP2′) from isolates of staphylococi. PBP2′ present in the membranes of methicillin‐resistant Staphylococcus aureus (MRSA) or methicillin‐resistant coagulase negative staphylococci (MRCNS) was rapidly extracted by alkaline treatment and, by combining with a slide agglutination reaction using latex particles sensitized with monoclonal antibodies raised against it, PBP2′ could be detected from a single loopful of cells taken from agar plates not containing beta‐lactum antibiotics within 15 min. In a study of clinical isolates previously characterized as either MRSA or methicillin‐susceptible Staphylococcus aureus (MSSA) by antibiotic susceptibility testing, 231 specimens of 232 MRSA were PBP2′ positive by latex agglutination, and the 87 specimens of MSSA were all negative. One specimen identified as MRSA by susceptibility testing but PBP2′ negative by latex agglutination was confirmed as mecA gene negative by PCR. This simple and rapid slide latex reagent should be useful in clinical diagnostics.
Protective Effects of a Culture Supernatant of Lactobacillus acidophilus and Antioxidants on Ileal Ulcer Formation in Rats Treated with a Nonsteroidal Antiinflammatory Drug
Authors: Bing Shan Ruo , Kinouchi Takemi , Kataoka Keiko , Kuwahara Tomomi , Ohnishi Yoshinari 
Published: November 2013

AbstractIleal ulcers and thiobarbituric acid (TBA)‐reactive substances in the ileal mucosa were induced in rats treated with a nonsteroidal antiinflammatory drug, 5‐bromo‐2‐(4‐fluorophenyl)‐3‐(4‐methylsulfonylphenyl)thiophene (BFMeT), at a dose of 1,000 mg/kg administered with tap water as drinking water. However, the formation of ileal ulcers and TBA‐reactive substances in the ileal mucosa was repressed by giving the animals a culture supernatant of Lactobacillus acidophilus as drinking water. We measured the antioxidative activity of the culture supernatant and found that the supernatant inhibited the formation of t‐butyl hydroperoxide‐induced TBA‐reactive substances in erythrocyte membrane ghosts. Therefore, the effects of various known antioxidative compounds on the ileal ulcer formation induced by BFMeT were investigated. While α‐tocopherol, t‐butyl‐1,4‐hydroxyanisole and allopurinol did not repress ulcer formation after BFMeT treatment, ascorbic acid, dimethyl sulfoxide, glutathione and β‐carotene significantly inhibited formation. Among these compounds, ascorbic acid was the most effective. Accumulation of TBA‐reactive substances in the ileal mucosa after BFMeT treatment also decreased significantly in rats treated with ascorbic acid. In addition, the percentage of Gram‐negative rods in the ileal contents of rats treated with BFMeT and tap water was dramatically increased, but it was not increased in rats treated with BFMeT and these antioxidants. A positive correlation between the percentage of Gram‐negative rods and the number of ileal ulcers was also observed. These results suggest that lipid peroxidation mediated by oxygen radicals plays an important role in the induction of ileal ulcers by BFMeT in rats, and that lipopolysaccharide‐activated neutrophils probably produce highly reactive hypochlorous acid and hydrogen peroxide, which are inactivated by ascorbic acid and glutathione, respectively.
Anti‐Candida Activity of Cal protect in in Combination with Neutrophils or Lactoferrin
Authors: Okutomi Takafumi , Tanaka Takashi , Yui Satoru , Mikami Masaaki , Yamazaki Masatoshi , Abe Shigeru , Yamaguchi Hideyo 
Published: November 2013

AbstractThe effect of an anti‐microbial protein, calprotectin, in combination with neutrophils on the growth of Candida albicans was investigated. The growth inhibition of C. albicans by murine neutrophils was augmented by the addition of a low concentration of calprotectin prepared from rat peritoneal exudate cells. The concentrations of calprotectin causing 50% inhibition of growth of C. albicans in the absence or presence of neutrophils at an effector‐to‐target (E/T) ratio of 30 and 60 were estimated to be 0.45, 0.34 and 0.28 U/ml, respectively. The anti‐Candida activity of calprotectin was completely inhibited by 2 μM of zinc ion, while it only partially lowered the activity of the combination of calprotectin and neutrophils. Lactoferrin, which is an anti‐microbial protein released from neutrophils, strongly inhibited the growth of C. albicans in combination with calprotectin. These results suggest that calprotectin and lactoferrin released from neutrophils may cooperate to inhibit the growth of C. albicans at a local lesion of the infection where there is an accumulation of neutrophils.
Detection of Genes Encoding Cholera Toxin (CT), Zonula Occludens Toxin (ZOT), Accessory Cholera Enterotoxin (ACE) and Heat‐Stable Enterotoxin (ST) in Vibrio mimicus Clinical Strains
Authors: Shi Lei , Miyoshi Shin‐ichi , Hiura Mieko , Tomochika Ken‐ichi , Shimada Toshio , Shinoda Sumio 
Published: November 2013

AbstractA total of 51 clinical strains of Vibrio mimicus were searched for the presence of virulence‐associated genes, like ctx, zot or ace genes which locate in “cholera virulence cassette,” and the st gene by polymerase chain reaction. Moreover, the pathological potential of each clinical strain was also examined by rabbit ileal loop (RIL). Three strains showed to have the ctx gene, of which only one strain was zot gene‐positive. Meanwhile, one other strain was zot+ but ctx−. All of these four strains were found to have the ace gene and to belong to serogroup O115. Nine strains showed to carry the st gene. However, none of these ST‐gene‐positive strains was indicated to contain the genes located in the “cholera virulence cassette.” It is of interest to note that all of the RIL‐positive and/or virulence gene‐positive strains were restricted to three serogroups, O20, O41 and O115. These results suggest a significant association between O antigens and enterotoxic activities in V. mimicus clinical strains, and clearly demonstrate multifactorial virulence potentials of this human pathogen.
New Evidence That the Tyr‐157 and Tyr‐159 Residues of Staphylococcal Exfoliative Toxin B Are Essential for Its Toxicity
Authors: Sakurai Susumu , Suzuki Hitoshi , Saito Shinobu , Konishi Yasuhiko , Machida Katsuhiko , Kohno Minoru 
Published: November 2013

AbstractTo determine the active site of exfoliative toxin B (sETB) of Staphylococcus aureus, the etb gene was cloned from an S. aureus SU strain obtained from a patient with impetigo. We prepared a frame shift mutant protein from a recombinant plasmid with a BglII linker inserted into the Tyr‐155 codon of the ETB gene (pETB/BglIIL). The recombinant mutant protein (ETB/BglIIL) obtained from Escherichia coli containing pETB/BglIIL showed no toxicity in neonatal mice and no agglutination activity. The 20‐kDa ETB/BglIIL contained 185 amino acid residues. Site‐directed mutagenesis was used to introduce mutations at either Tyr‐155, Tyr‐157, Tyr‐159, or Tyr‐162. Substitution of any of the Tyr residues decreased exfoliative activity compared with that of native sETB (4,000 EU/ml). Substitution of Tyr‐155 with a Phe (ETB/Y155) decreased activity 5‐fold (800 EU/ml). Substitution of Tyr‐157 with Leu (ETB/Y157) decreased activity 80‐fold (50 EU/ml) and decreased agglutination titer 5‐fold compared with that of native sETB (400,000). Substitution of Tyr‐159 with Leu (ETB/Y159)decreased activity 4‐fold (1,000 EU/ml). When both Tyr‐157 and Tyr‐159 were mutated (ETB/Y157‐159), both toxicity and antigenicity were completely lost. On an immunodiffusion test, ETB/Y157 showed a faint precipitation line, but ETB/BglIIL and ETB/Y157‐159 had no activity, showing that the Tyr‐157 and Tyr‐159 residues are essential for the toxicity and antigenicity of ETB.
Role of Endogenous Tumor Necrosis Factor Alpha and Gamma Interferon in Resistance to Corynebacterium pseudotuberculosis Infection in Mice
Authors: Lan Dinh Thi Bich , Taniguchi Shunji , Makino Sou‐ichi , Shirahata Toshikazu , Nakane Akio 
Published: November 2013

AbstractThe production and roles of endogenous tumor necrosis factor alpha (TNF‐α) and gamma interferon (IFN‐γ) in the infection of Corynebacterium (C.) pseudotuberculosis were investigated in mice. The maximum levels of TNF‐α and IFN‐γ were detected on day 4 after infection. The administration of anti‐TNF‐α monoclonal antibody (mAb) as well as anti‐IFN‐γ mAb increased bacterial proliferation in the organs, leading to the death of infected mice, but anti‐IFN‐γ mAb showed a less marked effect than anti‐TNF‐α mAb. The suppressive effect of anti‐TNF‐α and anti‐IFN‐γ mAbs on anticorynebacterial resistance was augmented by the simultaneous administration of these antibodies. Anti‐TNF‐α mAb was found to be highly effective when administered on day 0 and day 4, suggesting that TNF‐α produced during the early stage of infection is critical for the generation of resistance. Histologically, many microabscesses, severe follicular swelling and lymphocyte destruction were observed in mice treated with anti‐TNF‐α or anti‐IFN‐γ mAb. Injection of anti‐CD4 or anti‐CD8 mAb also resulted in significantly increased mortality and a marked suppression of IFN‐γ production, but had no effect on TNF‐α production. Carrageenan also showed a marked effect on the exacerbation of infection. Taken together, these results suggest that endogenously produced TNF‐α and IFN‐γ are both essential to the host defense against C. pseudotuberculosis infection and that these cytokines may have an additive effect.
The Gene Encoding the Prepilin Peptidase Involved in Biosynthesis of Pilus Colonization Factor Antigen III (CFA/III) of Human Enterotoxigenic Escherichia coli
Authors: Taniguchi Tooru , Yasuda Yoko , Tochikubo Kunio , Yamamoto Koichiro , Honda Takeshi 
Published: November 2013

AbstractThe assembly of pilus colonization factor antigen III (CFA/III) of human enterotoxigenic Escherichia coli requires the processing of CFA/III major pilin (CofA) by a peptidase, likely another type IV pilus formation system. Western blot analysis of CofA reveals that CofA is produced initially as a 26.5‐kDa preform pilin (prepilin) and then processed to 20.5‐kDa mature pilin by a prepilin peptidase. This processing is essential for exportation of the CofA from the cytoplasm to the periplasm. In this experiment, the structural gene, cofP, encoding CFA/III prepilin peptidase which cleavages at the Gly‐30‐Met‐31 junction of CofA was identified, and the nucleotide sequence of the gene was determined. cofP consists of 819 bp encoding a 273‐amino acid protein with a relative molecular mass of 30,533 Da. CofP is predicted to be localized in the inner membrane based on its hydropathy index. The amino acid sequence of CofP shows a high degree of homology with other prepilin peptidases which play a role in the assembly of type IV pili in several gram‐negative bacteria.
Absence of Cecal Secondary Bile Acids in Gnotobiotic Mice Associated with Two Human Intestinal Bacteria with the Ability to Dehydroxylate Bile Acids In Vitro
Authors: Narushima Seiko , Itoh Kikuji , Takamine Fusae , Uchida Kiyohisa 
Published: November 2013

AbstractGerm‐free mice were orally inoculated with human intestinal 7α‐dehydroxylating bacterial strains to evaluate their ability to transform bile acids in vivo. Three weeks after inoculation of the bacteria, cecal bile acids were examined. Among free‐form bile acids, only β‐muricholic acid was detected in the cecal contents of gnotobiotic mice associated with Bacteroides distasonis strain K‐5. No secondary bile acid was observed in the cecal contents of any of the gnotobiotic mice associated with 7α‐dehydroxylating bacteria, Clostridium species strain TO‐931 or Eubacterium species strain 36S.
Facilitated Expansion of Pneumococcal Colonization from the Nose to the Lower Respiratory Tract in Mice Preinfected with Influenza Virus
Authors: Takase Hiroyuki , Nitanai Hironobu , Yamamura Eiko , Otani Tsuyoshi 
Published: November 2013

AbstractA strain of Streptococcus pneumoniae, when inoculated intranasally in 2 μl of suspension into BALB/c mice preinfected with influenza virus, colonized first in the nose, and several days thereafter also colonized significantly in the trachea and lungs with purulent inflammation. Pneumoccocal colonization was also observed in the noses of normal mice after the same bacterial inoculation, but not apparently in the lower respiratory tract. These results suggest that pneumococcal infection may develop from the upper to the lower respiratory tract as a possible sequence preferentially in influenza virus‐infected subjects.
Growth Conditions of and Emetic Toxin Production by Bacillus cereus in a Defined Medium with Amino Acids
Authors: Agata Norio , Ohta Michio , Mori Masashi , Shibayama Keigo 
Published: November 2013

AbstractThe growth and emetic toxin (cereulide) production of Bacillus cereus strains in defined culture media were studied. We found that a fully synthetic medium (CADM) allowed the production of emetic toxin and the addition of glucose enhanced it. By subtracting each amino acid from CADM, we found that only three amino acids, valine, leucine and threonine, were essential for growth and toxin production by B. cereus. The addition of high levels (50 mM) of leucine, isoleucine and glutamic acid decreased the toxin production. Other amino acids had no effect at this concentration.
Comparison of Substrate Specificities against the Fusion Glycoprotein of Virulent Newcastle Disease Virus between a Chick Embryo Fibroblast Processing Protease and Mammalian Subtilisin‐Like Proteases
Authors: Fujii Yutaka , Sakaguchi Takemasa , Kiyotani Katsuhiro , Yoshida Tetsuya 
Published: November 2013

AbstractThe fusion (F) protein precursor of virulent Newcastle disease virus (NDV) strains has two pairs of basic amino acids at the cleavage site, and its intracellular cleavage activation occurs in a variety of cells; therefore, the viruses cause systemic infections in poultry. To explore the protease responsible for the cleavage in the natural host, we examined detailed substrate specificity of the enzyme in chick embryo fibroblasts (CEF) using a panel of the F protein mutants at the cleavage site expressed by vaccinia virus vectors, and compared the specificity with those of mammalian subtilisin‐like proteases such as furin, PC6 and PACE4 which are candidates for F protein processing enzymes. It was demonstrated in CEF cells that Arg residues at the −4, −2 and −1 positions upstream of the cleavage site were essential, and that at the −5 position was required for maximal cleavage. Phe at the +1 position was also important for efficient cleavage. On the other hand, furin and PC6 expressed by vaccinia virus vectors showed cleavage specificities against the F protein mutants consistent with that shown by the processing enzyme of CEF cells, but PACE4 hardly cleaved the F proteins including the wild type. These results indicate that the proteolytic processing enzymes of poultry for virulent NDV F proteins could be furin and/or PC6 but not PACE4. The significance of individual contribution of the three amino acids at the −5, −2 and +1 positions to cleavability was discussed in relation to the evolution of virulent and avirulent NDV strains.
Characterization of Serotypes and Outer Membrane Protein Profiles in Enteroaggregative Escherichia coli Strains
Authors: Suzart Sérgio , Gomes Tânia Aparecida Tardelli , Guth Beatriz Ernestina Cabilio 
Published: November 2013

AbstractTwenty‐four Escherichia coli strains mainly isolated from children with diarrhea in São Paulo, and showing characteristics of enteroaggregative E. coli (EAEC), were characterized by serotyping and outer membrane protein (OMP) profiles. The relationship between these characteristics was evaluated, as well as the usefulness of OMP profiles in the clonal analysis of EAEC strains. All strains presented aggregative adherence to HeLa cells and were classified in two groups based on their interaction with the EAEC DNA probe. A diversity of serotypes and OMP profiles was observed in both groups studied. Although no significant correlation between serotypes and OMP profiles was observed, unique OMP profiles were identified in 80% of the probe‐positive strains which were distributed in only 4 OMP profiles. This result may indicate the presence of a few clones in the probe‐positive group. On the other hand, probe‐negative strains seem to constitute a more diverse group. In general, the observed heterogeneity in serotypes and OMP profiles described in the present study suggest a great genetic diversity in EAEC isolates of either the same or different serotypes and in strains presenting the same EAEC markers identified in our community.
Abscess Forming Ability of Streptococcus milleri Group: Synergistic Effect with Fusobacterium nucleatum
Authors: Nagashima Hiroyuki , Takao Ayuko , Maeda Nobuko 
Published: November 2013

AbstractThe abscess forming abilities of “Streptococcus milleri” strains (Streptococcus constellatus, Streptococcus anginosus, and Streptococcus intermedius) isolated from dentoalveolar abscesses and the synergistic effect of Fusobacterium nucleatum co‐inoculated with the isolates were examined on a mouse subcutaneous abscess model. Five days after inoculation, all S. milleri strains formed abscesses, which showed less pathological spread to surrounding connective tissues than those formed by Staphylococcus aureus 209P strain and were similar to those by F. nucleatum ATCC25586. When each S. milleri strain and F. nucleatum were co‐inoculated, abscess sizes and each bacterial number recovered from abscesses increased in comparison to those treated by bacterial mono‐inoculation of each S. milleri strain or F. nucleatum alone. The strongest synergistic effect was observed in the combination of S. constellatus and F. nucleatum. In a time course experiment with this combination, the recovery of S. constellatus subsequently decreased after the decrement of F. nucleatum, and it appeared that the association with F. nucleatum maintained the bacterial number of S. constellatus in the abscess. The cell‐free supernatant of F. nucleatum had a tendency to increase the abscess size caused by S. constellatus in this model. When S. constellatus was cultured with F. nucleatum culture supernatant in vitro, growth enhancement in the early phase was observed. Furthermore, the phagocytic killing of S. constellatus by human polymorphonuclear leukocytes (PMNs) was significantly suppressed and the PMN membranes appeared to be injured by addition of the F. nucleatum culture supernatant. These results suggest that the pathogenicity of S. milleri strains in odontogenic infections may be enhanced by the co‐existence of F. nucleatum.
Antigenic Relationship among the Eight Prototype and New Serotype Strains of Orientia tsutsugamushi Revealed by Monoclonal Antibodies
Authors: Kang Jae‐seung , Chang Woo‐hyun 
Published: November 2013

AbstractOrientia tsutsugamushi, the etiologic agent of tsutsugamushi disease, exhibits great antigenic variation. Three classical strains (Karp, Gilliam, and Kato) and new antigenic types from Thailand (TA686, TA678, TA716, TA763, and TH1817) have been used as prototype strains of O. tsutsugamushi in many studies. In this study, monoclonal antibodies to the five Thailand strains were produced, and their reactivity against prototype strains and newly identified isolates from Korea and Japan was tested. With a panel of these monoclonal antibodies, we could analyze the antigenic relationship among various strains of O. tsutsugamushi from Thailand, Japan, and Korea. Twelve strains of the O. tsutsugamushi tested showed various reactivities to monoclonal antibodies, and no distinct pattern of reactivity was found according to their location of isolation. Although the Boryong and Kuroki strains were similar in reactivities to most monoclonal antibodies, several monoclonal antibodies could differentiate the two strains. These results indicate that the immunofluorescence antibody test using monoclonal antibodies used in this study is valuable for analyzing the antigenic relationship and classification of O. tsutsugamushi.
Intracellular Behavior of Rabies Virus Matrix Protein (M) Is Determined by the Viral Glycoprotein (G)
Authors: Nakahara Koichiro , Ohnuma Hiroki , Sugita Shigeo , Yasuoka Kayou , Nakahara Tomomi , Tochikura Tadafumi S. , Kawai Akihiko 
Published: November 2013

AbstractTo investigate the nature and intracellular behavior of the matrix (M) protein of an avirulent strain (HEP‐Flury) of rabies virus, we cloned and sequenced the cDNA of the protein. Using expression vectors pZIP‐NeoSV(X)1 and pCDM8, the cDNA was transfected to animal cells (BHK‐21 and COS‐7) with or without coexpression of viral glycoprotein (G). When M protein alone was expressed in the cells, it displayed homogeneous distribution in the whole cell including the nucleus. In contrast, coexpression with G protein resulted in the abolishment of nuclear distribution of M antigen, and both of the antigens displayed a colocalized distribution in the cell, especially at the cellular membrane as seen in the virus‐infected cells, while the distribution of G antigen was not affected by coexpressed M antigen. Immunoprecipitation studies revealed that M protein was coprecipitated with G protein by anti‐G antibody, and vice versa, although cross‐linking with dithiobis(succinimidyl propionate) was necessary for coprecipitation because of their easier dissociation in the presence of sodium deoxycholate. These results suggest that M protein intimately associates with G protein, which may affect or regulate the behavior (e.g., intracellular localization) of M protein. Studies with deletion mutants of M protein indicate that an internal region around the amino acids from 115 to 151 is essential for the M protein to preserve its binding ability to G protein.