記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Mycobacterium intracellulare is a major etiological agent of Mycobacterium avium-intracellulare pulmonary disease (MAC-PD). However, the characteristics of the virulence of M. intracellulare and the in vivo chemotherapeutic efficacy remain unclear. In this study, we examined the virulence of nine M. intracellulare strains with different clinical phenotypes and genotypes in C57BL/6 mice. RESULTS: We classified three types of virulence phenotypes (high, intermediate, and low) based on the kinetics of the bacterial load, histological lung inflammation, and neutrophilic infiltration. High virulence strains showed more severe neutrophilic infiltration in the lungs than intermediate and low virulence strains, with 6.27-fold and 11.0-fold differences of the average percentage of neutrophils in bronchoalveolar lavage fluid, respectively. In particular, the high virulence strain M.i.198 showed the highest mortality in mice, which corresponded to the rapid progression of clinical disease. In mice infected with the drug-sensitive high virulence strain M019, clarithromycin-containing chemotherapy showed the highest efficacy. Monotherapy with rifampicin exacerbated lung inflammation with increased lymphocytic and neutrophilic infiltration into the lungs. CONCLUSIONS: The virulence phenotypes of clinical strains of M. intracellulare were diverse, with high virulence strains being associated with neutrophilic infiltration and disease progression in infected mice. These high virulence strains were proposed as a useful subject for in vivo chemotherapeutic experiments.

DOI： 10.1186/s12866-023-02831-y

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41598-022-08228-7

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その他リンク： https://www.nature.com/articles/s41598-022-08228-7

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1128/aac.00171-22

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1111/febs.16412

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その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/febs.16412

記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41598-021-90156-z

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記述言語：日本語   出版者・発行元：(一社)日本結核・非結核性抗酸菌症学会  

[目的]全ゲノム解析を用いて,早期発症者と長期潜伏後発症者から分離した結核菌北京株のゲノム変異を解析した。[方法]1999年に中学校で発生した結核集団感染の接触者と二次感染者のうち2009年までに結核を発症した患者より分離した結核菌北京株6株と,別の事例で初発時と再発時の患者より分離した結核菌北京株2株の計8株の全ゲノム解析を行った。結核菌の突然変異率は,初発から1年以内に発症した早期発症者と1年以上の潜伏期を経てから発症または再燃した長期潜伏後発症者の2群間で比較した。[結果]結核菌北京株の突然変異率は,Lineage 4に属する結核菌よりも高く,結核菌北京株の高い病原性や薬剤耐性の要因である可能性が示唆された。遺伝子多型解析では,酸化的損傷に起因すると推定されている突然変異が長期潜伏後発症群のほうに多く,潜伏期間中にも薬剤耐性変異が起こる可能性が示唆された。[結論]結核菌北京株の高頻度の薬剤耐性化を防ぐためには,感染した結核菌の系統により治療法を検討する必要性も考えられた。今後,結核菌系統の特性を理解し,治療法を工夫することで結核の薬剤耐性化や重篤化を防ぐ有効な対策の構築につながることが期待される。(著者抄録)

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：日本語   出版者・発行元：日本細菌学会  

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記述言語：英語  

[This corrects the article DOI: 10.1371/journal.pone.0204160.].

DOI： 10.1371/journal.pone.0256946

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41598-020-62287-2

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その他リンク： http://www.nature.com/articles/s41598-020-62287-2

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41598-020-75028-2

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その他リンク： http://www.nature.com/articles/s41598-020-75028-2

記述言語：日本語   出版者・発行元：(一社)日本結核・非結核性抗酸菌症学会  

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1128/aac.01755-19

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：日本語   出版者・発行元：日本細菌学会  

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記述言語：日本語   出版者・発行元：日本細菌学会  

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記述言語：日本語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature Publishing Group  

The architecture of the genome influences the functions of DNA from bacteria to eukaryotes. Intrinsically disordered regions (IDR) of eukaryotic histones have pivotal roles in various processes of gene expression. IDR is rare in bacteria, but interestingly, mycobacteria produce a unique histone-like protein, MDP1 that contains a long C-terminal IDR. Here we analyzed the role of IDR in MDP1 function. By employing Mycobacterium smegmatis that inducibly expresses MDP1 or its IDR-deficient mutant, we observed that MDP1 induces IDR-dependent DNA compaction. MDP1-IDR is also responsible for the induction of growth arrest and tolerance to isoniazid, a front line tuberculosis drug that kills growing but not growth-retardated mycobacteria. We demonstrated that MDP1-deficiency and conditional knock out of MDP1 cause spreading of the M. smegmatis genome in the stationary phase. This study thus demonstrates for the first time a C-terminal region-dependent organization of the genome architecture by MDP1, implying the significance of IDR in the function of bacterial histone-like protein.

DOI： 10.1038/s41598-018-26463-9

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0204160

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PUBLISHING GROUP  

Bacteria can proliferate perpetually without ageing, but they also face conditions where they must persist. Mycobacteria can survive for a long period. This state appears during mycobacterial diseases such as tuberculosis and leprosy, which are chronic and develop after long-term persistent infections. However, the fundamental mechanisms of the long-term living of mycobacteria are unknown. Every Mycobacterium species expresses Mycobacterial DNA-binding protein 1 (MDP1), a histone-like nucleoid associated protein. Mycobacterium smegmatis is a saprophytic fast grower and used as a model of mycobacterial persistence, since it shares the characteristics of the long-term survival observed in pathogenic mycobacteria. Here we show that MDP1-deficient M. smegmatis dies more rapidly than the parental strain after entering stationary phase. Proteomic analyses revealed 21 upregulated proteins with more than 3-fold in MDP1-deficient strain, including DnaA, a replication initiator, NDH, a NADH dehydrogenase that catalyzes downhill electron transfer, Fas1, a critical fatty acid synthase, and antioxidants such as AhpC and KatG. Biochemical analyses showed elevated levels of DNA and ATP syntheses, a decreased NADH/NAD(+) ratio, and a loss of resistance to oxidative stress in the MDP1-knockout strain. This study suggests the importance of MDP1-dependent simultaneous control of the cellular functions in the long-term survival of mycobacteria.

DOI： 10.1038/s41598-017-06480-w

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER TAIWAN  

A 15-year-old boy, who had had a furuncle on his femur, developed femoral pyomyositis and osteomyelitis complicated by septic pulmonary embolism. Panton-Valentine leukocidin-positive (PVL+) ST59 methicillin-susceptible Staphylococcus aureus (MSSA) was isolated from pus and blood. Chemotherapy was started with cefazolin, followed by combination therapy with meropenem/vancomycin with surgery. The MSSA (strain KS1) was positive for increased levels of cytolytic peptide (psm alpha and hld) and staphylococcal enterotoxin B (SEB), and manifested IS1216V-mediated multidrug resistance (to erythromycin, clindamycin, kanamycin, streptomycin, and chloramphenicol), similar to a genome-analyzed reference strain (PM1) of ST59/SCCmecV(5C2&5) community-associated methicillin-resistant S. aureus (Taiwan CA-MRSA), but unlike another reference strain (M013) of Taiwan CA-MRSA in terms of resistance. The data suggest that CA-MSSA KS1, characterized by PVL, increased levels of cytolytic peptide, SEB, and multidrug resistance, is a possible ancestral strain of Taiwan CA-MRSA and causes the unique association of osteomyelitis and septic pulmonary embolism, requiring complicated management. Copyright (C) 2014, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. All rights reserved.

DOI： 10.1016/j.jmii.2014.04.015

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER TAIWAN  

An 89-year-old man suffered from and died of necrotizing pneumonia with rapid progression and cavity formation due to methicillin-resistant Staphylococcus aureus (MRSA). He was at no risk for hospital-acquired MRSA infection. His MRSA exhibited genotype ST5/spa2(t002)/agr2/SCCmecII/coagulaseII and was negative for Panton-Valentine leukocidin, indicating the New York/Japan clone (the predominant epidemic hospital-acquired MRSA clone in Japan). However, this strain expressed the cytolytic peptide (phenol-soluble modulin or delta-hemolysin) genes at high level, similar to USA300 (the most common community-acquired MRSA in the United States), indicating a variant of the New York/Japan clone with an important feature of community-acquired MRSA. Copyright (C) 2012, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. All rights reserved.

DOI： 10.1016/j.jmii.2012.09.004

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER JAPAN KK  

Iliopsoas abscesses (IPAs) from methicillin-resistant Staphylococcus aureus (MRSA) are rare; however, IPAs from community-associated MRSA (CA-MRSA) may be increasing. In Japan, we previously described an adolescent athlete case of Panton-Valentine leukocidin (PVL)-positive ST30 CA-MRSA (strain NN12). In this study, we describe an IPA and discitis case from a variant of the successful PVL-negative CA-MRSA clone (ST8 CA-MRSA/J) in Japan. The patient was a 62-year-old man with intractable eczema, who had been diagnosed with IPAs and discitis (L1-L2). CA-MRSA (strain NN55) was isolated from blood, pus, and joint fluid. The invasive infections seemed to have originated in his intractable eczema, and the characteristics of this case, systemic myalgia and marked thrombocytopenia, seemed to have been caused by an exotoxin. Molecular genetic analysis revealed that NN55 possessed genotype ST8/spa606(t1767)/agr1/CoaIII and SCCmecIV of a novel subtype (encoding new cell-wall-anchored surface protein/J [CWASP/J]), exhibited enhanced expression of the cytolytic peptide genes, psm alpha and hld, and was resistant to gentamicin (caused by aacA-aphD), similar to ST8 CA-MRSA/J; however, NN55 lacked pathogenicity island SaPIj50 [carrying tst, encoding toxic shock syndrome toxin-1 (TSST-1)] of ST8 CA-MRSA/J, suggesting a variant (ST8 CA-MRSA/Jv). Strains NN12 and NN55 both caused bacteremia, IPAs, and adjacent musculoskeletal infections, preceded by intractable skin infections, and possessed high potential for adherence and enhanced expression of psm alpha and hld. The data suggest the role of a combination of CA-MRSA adhesin/cytolytic peptides (not PVL or TSST-1) in the pathogenesis of IPAs (and perhaps of systemic myalgia and marked thrombocytopenia).

DOI： 10.1007/s10156-013-0561-5

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The ST5 lineage of methicillin-resistant Staphylococcus aureus (MRSA) is one of the most globally disseminated hospital-associated MRSA (HA-MRSA) lineages. We isolated a new local variant (designated ST764) over at least 5 years that causes invasive infections, including necrotizing fasciitis, and is carried by medical students, as well as household members. Analysis of the genome sequence of one isolate compared to that of the reference ST5 strain revealed that ST764 had acquired virulence traits similar to those of community-associated MRSA (CA-MRSA) through the acquisition of two new mobile genetic elements, ACMEII and SaPInn54, which carried ACME arcA and the staphylococcal enterotoxin B gene (seb), respectively, and through enhanced expression of cytolytic peptide genes, although ST764 was negative for Panton-Valentine leukocidin. Other differences between ST764 and ST5 included the acquisition of an ACMEII-related cassette (cJR1), prophage φ2 NN54, and streptococcal Tn5251 and decreased numbers of copies of Tn554. As for superantigen genes, although the two possessed seg, sei, sem, sen, and seo, ST764 lacked tst, sec, sel, and sep. The data suggest that ST764 MRSA is a novel hybrid variant of ST5 HA-MRSA with the characteristics of CA-MRSA and that the evolution of ST764 includes multiple steps, e.g., acquisition of novel or nonstaphylococcal mobile elements. Copyright © 2013, American Society for Microbiology. All Rights Reserved.

DOI： 10.1128/AAC.01147-12

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Methicillin-resistant Staphylococcus aureus (MRSA) emerged in 1961, just after the introduction of methicillin as a countermeasure against penicillinase-producing " multidrug-resistant" S. aureus, a threat at that time. Since then, MRSA has posed a continuous threat to medical care as a major multidrug-resistant pathogen in hospitals. In 1997-1999, severe invasive infection with MRSA occurred in the community, and this attracted attention as community-associated MRSA (CA-MRSA). The evolutionary steps include species-to-species transfer and salvage of key genetic structures, responsible for community spread, virulence, and resistance. The MRSA epidemic, including invasive diseases, in the community is dynamic. © 2012.

DOI： 10.1016/j.biomed.2012.12.001

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

A 17-year-old female patient (a basketball player) suffered from recurrent pelvic abscesses from methicillin-resistant Staphylococcus aureus (MRSA). The first episode, from strain NN12, occurred in October 2004. Her cutaneous abscesses complicated into systemic progression to osteomyelitis and multifocal pelvic abscesses, adjacent to the sacroiliac joint. The second episode, abscesses at tissues adjacent to the sacroiliac joint from strain NN31A, occurred late in February 2005. The third episode, from strain NN31B, occurred on July 30, 2005, repeating the second episode. Three MRSA strains were identical in terms of genotypes (belonging to Panton-Valentine leukocidin [PVL]-positive ST30 community-acquired MRSA, CA-MRSA), pulsed-field gel electrophoresis patterns, and peptide cytolysin gene (psm) expression levels. The three MRSA strains exhibited superior THP-1 cell invasion ability over hospital-acquired MRSA (New York/Japan clone). The data suggest that PVL-positive ST30 CA-MRSA, with high levels of cell invasion and peptide cytolysins, causes recurrence of pelvic abscesses in a healthy adolescent.

DOI： 10.1111/j.1442-200X.2012.03612.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MICROBIOL RES FOUNDATION  

DOI： 10.2323/jgam.59.147

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

The mechanisms for the cytotoxicity of staphylococcal PantonValentine leukocidin (PVL), a pore-forming toxin consisting of LukS-PV and LukF-PV, in human immune cells are still unclear. Because LukS-PV binds to ganglioside GM1, a constituent of detergent-resistant membrane microdomains (DRMs) of the plasma membrane, the role of DRMs in PVL cytotoxicity was examined in human polymorphonuclear neutrophils (PMNs), monocytes, HL-60 cells, and THP-1 cells. PVL binding capacities in HL-60 and THP-1 cells were higher than those in PMNs and monocytes; however, the PVL concentration to obtain more than 80% cell lysis in HL-60 cells was 10 times higher than that in PMNs and PVL even at such concentration induced < 10% cell lysis in THP-1 cells. After incubation of PMNs with LukS-PV, more than 90% of LukS-PV bound to the detergent-soluble membranes. Subsequent incubation with LukF-PV at 4 degrees C induced the accumulation of more than 70% of PVL components and 170- to 220-kDa complex formation in DRMs in an actin-independent manner. However, only 30% of PVL was found, and complex formation was under detectable level in DRMs in HL-60 cells. PVL did not accumulate in DRMs in THP-1 cells. Our observations strongly indicate that PVL accumulation in DRMs is essential for PVL cytotoxicity.

DOI： 10.1111/j.1574-695X.2012.01027.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BIOMEDICAL RESEARCH PRESS LTD  

Methicillin-resistant Staphylococcus aureus (MRSA) includes hospital-acquired MRSA (HA-MRSA) and community-acquired MRSA (CA-MRSA). Panton-Valentine leukocidin (PVL)-positive multilocus sequence type 30 (ST30) MRSA is one of worldwide CA-MRSA, which has also persisted in Japan since the 1980s. However, unexpectedly, it was not the same ST30 clone throughout. Before 2000, it was HA-MRSA with spa43 and phi Sa3sea (phage Sa3 carrying the sea gene) and only one PVL-positive MRSA in Japan; in the 1980s, ST30 MRSA accounted for 23.5% of HA-MRSA, showed multidrug resistance, had high MICs for oxacillin and imipenem, and caused decubitus and pneumonia in hospitalized patients. A dynamic clonal change (spa43/phi Sa3sea -> spa19) occurred around 2000-2002. A rare spa43/phi Sa3sea/SCCinecI-IE25923 genotype also emerged. After 2002, the prevalent.vpa19 clone was CA-MRSA; it accounted for only 0.3% (or less) of MRSA in hospitals but 7.6% of CA-MRSA. Since 2007, PVL-positive CA-MRSA with other ST types (such as ST8, ST22, and ST59) also emerged in Japan, albeit at a low frequency. ST30/spo19 CA-MRSA occasionally caused severe invasive infections and a novel ST1335/spa19 genotype emerged. These ST30/spa19 CA-MRSA and variants were identified by pulsed field gel electrophoresis. Further analysis revealed that PVL-positive ST30/spa19 CA-MRSA is a highly-virulent, successful clone, having a potential of clonal expansion.

DOI： 10.2220/biomedres.33.97

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER TOKYO  

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), which often produces Panton-Valentine leukocidin (PVL), is an emerging threat in the community. In Japan, for example, PVL-positive ST8 CA-MRSA (USA 300), which originated from the United States, persisted in families for a year and caused severe invasive infection in a child. In this study, we describe a long-term familial infection cluster caused by novel PVL-positive CA-MRSA, which most probably originated from India. This MRSA persisted in related families for more than 2 years with colonization of, for example, the nares and cheek. At least 6 of 12 members (50%) developed deep cutaneous abscesses, including recurrent and multifocal abscesses, every 1.2 months on average. All MRSA isolates from colonization and abscesses were the same, albeit with a variant in pulsed-field gel electrophoresis analysis. The MRSA exhibited the genotype ST22/spa113(t005)/SCCmecIVa/coagulase gene (coa) novel type and strong hemolysis activity. Moreover, the MRSA exhibited high biofilm formation (which was markedly enhanced by sub-MICs of oxacillin). Some patients were treated with levofloxacin, with successful MRSA eradication even from the whole body surface sites; however, short-term patient follow-up was not sufficient to demonstrate eradication of the familial infection cluster. The data suggest that PVL-positive novel ST22 CA-MRSA emerged in Japan, causing a long-term familial infection cluster, and that the success of ST22 CA-MRSA as both a colonizer and a pathogen could result from the combination of its strong biofilm formation and other virulence factors. A long-term patient (or carrier) follow-up is needed in the community.

DOI： 10.1007/s10156-011-0316-0

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER JAPAN KK  

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a major concern worldwide. In the United States, ST8 CA-MRSA with SCCmecIVa (USA300) has been predominant, affecting the entire United States. In this study, we investigated Japanese ST8 CA-MRSA with new SCCmecIVl (designated ST8 CA-MRSA/J), which has emerged in Japan since 2003. Regarding community spread and infections, ST8 CA-MRSA/J spread in 16.2-34.4% as a major genotype in the community in Japan, and was associated with skin and soft tissue infections (SSTIs), colitis, and invasive infections (sepsis, epidural abscesses, and necrotizing pneumonia), including influenza prodrome cases and athlete infections, similar to USA300. It spread to even public transport and Hong Kong through a Japanese family. Regarding genetic diversity, ST8 CA-MRSA/J included ST and spa variants and was classified into at least three pulsed-field gel electrophoresis types, ST8 J alpha to gamma. Of those, ST8 J beta was associated with severe invasive infections. As for genomics, ST8 CA-MRSA/J showed high similarities to USA300, but with marked diversity in accessory genes; e.g., ST8 CA-MRSA/J possessed enhanced cytolytic peptide genes of CA-MRSA, but lacked the Panton-Valentine leukocidin phage and arginine catabolic mobile element, unlike USA300. The unique features of ST8 CA-MRSA/J included a novel mosaic SaPI (designated SaPIj50) carrying the toxic shock syndrome toxin-1 gene with high expression; the evolution included salvage (through recombination) of hospital-acquired MRSA virulence. The data suggest that ST8 CA-MRSA/J has become a successful native clone in Japan, in association with not only SSTIs but also severe invasive infections (posing a threat), requiring attention.

DOI： 10.1007/s10156-012-0379-6

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

The effects of Lactobacillus johnsonii La1 (LC1) on Helicobacter pylori colonization in the stomach were investigated. H. pylori colonization and gastritis in LC1-inoculated Mongolian gerbils were significantly less intense than those in the control animals. LC1 culture supernatant (>10-kDa fraction) inhibited H. pylori motility and induced bacterial aggregation in human gastric epithelial cells, suggesting the potential of clinical use of LC1 product.

DOI： 10.1271/bbb.110921

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

Methicillin-resistant Staphylococcus aureus (MRSA) not only causes disease in hospitals, but also in the community. The characteristics of MRSA transmission in the environment remain uncertain. In this study, MRSA were isolated from public transport in Tokyo and Niigata, Japan. Of 349 trains examined, eight (2.3%) were positive for MRSA. The MRSA isolated belonged to sequence types (STs) 5, 8, 88, and 89, and included community infection-associated ST8 MRSA (with novel type IV staphylococcal cassette chromosome mec) and the ST5 New York/Japan hospital clone. The data indicate that public transport could contribute to the spread of community-acquired MRSA, and awareness of this mode of transmission is necessary.

DOI： 10.1111/j.1348-0421.2011.00397.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER SOC MICROBIOLOGY  

A total of 293 strains of Helicobacter pylori, including strains resistant to levofloxacin, clarithromycin, metronidazole, or amoxicillin, were examined for in vitro susceptibility to 10 antimicrobial agents. Among these agents, sitafloxacin (a fluoroquinolone) showed the greatest activity (MIC(90), 0.06 mu g/ml), with high bactericidal activity and synergy in sitafloxacin-lansoprazole (a proton pump inhibitor) combination. In a Mongolian gerbil model with a H. pylori ATCC 43504 challenge, marked eradication effects were observed at >= 1 mg/kg for sitafloxacin, >= 10 mg/kg for levofloxacin, and >= 10 mg/kg for lansoprazole, reflecting MIC levels for each agent (0.008, 0.25, and 2 mu g/ml, respectively). The therapeutic rates were 83.3% for the sitafloxacin (0.3 mg/kg)lansoprazole (2.5 mg/kg) combination and 0% for either sitafloxacin or lansoprazole alone. The maximum serum concentration (C(max)) of sitafloxacin was 0.080 +/- 0.054 mu g/ml at 30 min, when orally administered at 1 mg/kg. The simultaneous administration of lansoprazole resulted in no difference. In the resistance development assay, MICs of levofloxacin increased 64- to 256-fold with gyrA mutations (Ala88Pro and Asn87Lys), while MICs of sitafloxacin only up to 16-fold with the Asn87Lys mutation. The data suggest that sitafloxacin exhibited superior anti-H. pylori activity with low rates of resistance development in vitro and that, reflecting high in vitro activities, sitafloxacin-lansoprazole combination exhibited strong therapeutic effects in Mongolian gerbils with a C(max) of sitafloxacin that was 10-fold higher than the MIC value at a 1-mg/kg administration.

DOI： 10.1128/AAC.01105-10

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：FEDERATION AMER SOC EXP BIOL  

Murine M phi that phagocytose CMP develop into M1; this response depends on the size and the chemical composition of the particles. In contrast, recent studies concluded that chitin particles induce M2 and eosinophil migration, promoting acquired Th2 immune responses against chitin-containing microbes or allergens. This study examined whether these apparently inconsistent responses to chitin could be induced by variation in the size and chemical composition of the chitin particles. We compared the responses of M phi with CMP, LCB, and Sephadex G-100 beads (>40 mu m). Beads were given i.p. to WT mice and to mice deficient in a CRTH2, a receptor for the eosinophil chemoattractant PGD(2). In contrast to the M1 activation induced by CMP, i.p. administration of LCB or Sephadex beads induced within 24 h a CRTH2-dependent peritoneal eosinophilia, as well as CRTH2-independent activation of peritoneal M phi that expressed Arg I, an M2 phenotype. LCB-induced M phi exhibited elevated Arg I and a surface MR, reduced surface TLR2 levels, and no change in the levels of CHI3L1 or IL-10 production. Our results indicate that the effects of chitin in vivo are highly dependent on particle size and that large, nonphagocytosable beads, independent of their chemical composition, induce innate eosinophilia and activate M phi expressing several M2, but not M1, phenotypes. J. Leukoc. Biol. 90: 167-176; 2011.

DOI： 10.1189/jlb.1110624

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER TOKYO  

In 2008 we isolated methicillin-resistant Staphylococcus aureus (MRSA) from an 11-month-old Japanese girl who lived in Saitama, Japan, and suffered from cellulitis of the lower thigh and sepsis. The MRSA (strain NN47) belonged to multilocus sequence type (ST) 8 and exhibited spa363 (t024), agr1, staphylococcal cassette chromosome mec (SCCmec) type IVa, and coagulase type III. It was positive for Panton-Valentine leukocidin (PVL) and the arginine catabolic mobile element (ACME). Pulsed-field gel electrophoresis (PFGE) demonstrated that the MRSA was the USA300 clone, which is the predominant community-acquired MRSA (CA-MRSA) in the US. Strain NN47 was divergent, in terms of the spa type and patterns of PFGE and plasmids, from the USA300-0114 type strain or USA300 strain NN36, previously isolated from a visitor (Indian girl) from the US. Strain NN47 was resistant to erythromycin, in addition to beta-lactam agents (e.g., oxacillin). These data demonstrate the first emergence of the USA300 clone in Japanese children who have never been abroad and have had no contact with foreigners (and therefore, the first USA300 spread in Japan), and also emergence of multiple divergent strains of the USA300 clone in Japan. Because the USA300 clone is highly transmissible and virulent, surveillance of the USA300 clone is needed.

DOI： 10.1007/s10156-010-0051-y

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Methicillin-resistant Staphylococcus aureus (MRSA) is able to persist not only in hospitals (with a high level of antimicrobial agent use) but also in the community (with a low level of antimicrobial agent use). The former is called hospital-acquired MRSA (HA-MRSA) and the latter community-acquired MRSA (CA-MRSA). It is believed MRSA clones are generated from S. aureus through insertion of the staphylococcal cassette chromosome mec (SCCmec), and outbreaks occur as they spread. Several worldwide and regional clones have been identified, and their epidemiological, clinical, and genetic characteristics have been described. CA-MRSA is likely able to survive in the community because of suitable SCCmec types (type IV or V), a clone-specific colonization/infection nature, toxin profiles (including Pantone-Valentine leucocidin, PVL), and narrow drug resistance patterns. CA-MRSA infections are generally seen in healthy children or young athletes, with unexpected cases of diseases, and also in elderly inpatients, occasionally surprising clinicians used to HA-MRSA infections. CA-MRSA spreads within families and close-contact groups or even through public transport, demonstrating transmission cores. Re-infection (including multifocal infection) frequently occurs, if the cores are not sought out and properly eradicated. Recently, attention has been given to CA-MRSA (USA300), which originated in the US, and is growing as HA-MRSA and also as a worldwide clone. CA-MRSA infection in influenza season has increasingly been noted as well. MRSA is also found in farm and companion animals, and has occasionally transferred to humans. As such, the epidemiological, clinical, and genetic behavior of CA-MRSA, a growing threat, is focused on in this study.

DOI： 10.1007/s10156-010-0045-9

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

Campylobacter jejuni has recently been noted as the most common cause of bacterial foodborne diseases in Japan. In the present study, we determined ST types of C. jejuni and Campylobacter coli isolated from chickens and patients with enteritis or GBS in Japan and Thailand. C. jejuni from chickens, enteritis, and GBS exhibited divergent ST types and included several novel types in addition to worldwide common types. C. coli from enteritis was also divergent. Novel ST types may represent unidentified native clones in each country. Pulsed-field gel electrophoresis confirmed the above typing and demonstrated long-term persistence and transmission.

DOI： 10.1111/j.1348-0421.2010.00222.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL PUBLISHING, INC  

Background:
Streptococcus pneumoniae and Haemophilus influenzae infections in children with influenza have been noted because of the severity of co-infection. In Japan, vaccination against S. pneumoniae and H. influenzae infections has been listed in the vaccine program in 2008, but the characteristics of the two organisms, colonizing at the initial stage of influenza infection, have not been investigated in detail.
Methods:
Nasopharyngeal swabs from children with influenza (flu+) (n = 236; mean age, 6.2 years) were examined for bacterial pathogens, including S. pneumoniae and H. influenzae. They were then examined for serotypes, drug susceptibilities, and resistance genes (or gene mutations). As a reference, children with upper respiratory tract infection (URTI+, flu-; n = 189; mean age, 6.2 years) were also examined.
Results:
S. pneumoniae, beta-streptococci (groups A, B, and G), methicillin-susceptible and -resistant S. aureus, Moraxella catarrhalis, and H. influenzae were isolated. For S. pneumoniae, nine serotypes were detected with prevalent types of 3, 6, 19 and 23. Penicillin resistance was detected in types 19 and 23, while resistance to macrolide and clindamycin was found in various types. For H. influenzae, only b serotype was detected, with marked ampicillin resistance. The majority was non-typeable. Very similar results were obtained even in URTI+ (flu-) cases.
Conclusion:
Multiple drug-resistant S. pneumoniae with major serotypes, for example, 19 and 23 and H. influenzae with serotype b were already present at the initial stage of influenza infection, similar to URTI+ flu- cases. They could be prevented by current vaccines, but drug-resistant non-typeable H. influenzae is troubling.

DOI： 10.1111/j.1442-200X.2009.02861.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：OXFORD UNIV PRESS INC  

Intelectin is an extracellular animal lectin found in chordata. Although human and mouse intelectin-1 recognize galactofuranosyl residues included in cell walls of various microorganisms, the physiological function of mammalian intelectin had been unclear. In this study, we found that human intelectin-1 was a serum protein and bound to Mycobacterium bovis bacillus Calmette-Guerin (BCG). Human intelectin-1-binding to BCG was inhibited by Ca(2+)-depletion, galactofuranosyl disaccharide, ribose, or xylose, and was dependent on the trimeric structure of human intelectin-1. Although monomeric, mouse intelectin-1 bound to BCG, with its C-terminal region contributing to efficient binding. Human intelectin-1-transfected cells not only secreted intelectin-1 into culture supernatant but also expressed intelectin-1 on the cell surface. The cell surface intelectin-1 was not a glycosylphosphatidylinositol-anchored membrane protein. Intelectin-1-transfected cells captured BCG more than untransfected cells, and the BCG adherence was inhibited by an inhibitory saccharide of intelectin-1. Intelectin-1-preincubated cells took up BCG more than untreated cells, but the adhesion of intelectin-1-bound BCG was the same as that of untreated BCG. Mouse macrophages phagocytosed BCG more efficiently in medium containing mouse intelectin-1 than in control medium. These results indicate that intelectin is a host defense lectin that assists phagocytic clearance of microorganisms.

DOI： 10.1093/glycob/cwp013

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER TOKYO  

Pediatric outpatients and healthy children in the community were examined for nasal methicillin-resistant Staphylococcus aureus (MRSA) in Japan. MRSA isolation frequencies were 0.7% (3/426) and 3.7% (5/136), respectively, in pediatric outpatients and healthy children in the community (overall frequency, 1.4%). The frequency of MRSA isolation was higher in children 5-9 years of age compared with the other age groups. All eight MRSA strains isolated were Panton-Valentine leukocidin-negative. Of these, three with the genotype multilocus sequence type (ST) 8/spa606/SCCmecIV (2 cases) and ST88/spa999/SCCmecIV/exfoliative toxin A gene (eta) were identical or similar to MRSA from bullous impetigo, determined by pulsed-field gel electrophoresis. One strain with ST764 (ST5 variant)/spa2/SCCmecII/staphylococcal enterotoxin B gene seb2 (seb variant) was similar to MRSA from bacteremia, and one with ST5/spa2/SCCmecII was the Pandemic New York/Japan clone. The remaining three strains, with ST22/spa998/SCCmecI, ST380/spa799/SCCmecIV, and ST857/spa416/SCCmecII, have not been identified. All MRSA strains were resistant to one or more non-beta-lactam antibiotics, and the ST5 and ST764 strains were multidrugresistant. Family analysis demonstrated parent-to-child transmission (for ST8 and ST764), as well as acquisition from outside the family (for ST8 and ST380). The data suggest that young school-age children have a higher carriage rate of nasal MRSA than children of other ages, and that not only community-acquired MRSA strains but also MRSA strains with characteristics of hospital-acquired MRSA are spreading in the community.

DOI： 10.1007/s10156-009-0668-x

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER TOKYO  

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), which is often positive for Panton-Valentine leucocidin (PVL), is increasingly noted as an emerging pathogen worldwide. In Japan, PVLpositive CA-MRSA belonging to multilocus sequence type (ST) 30 has spread and caused, for example, pediatric death due to community-acquired pneumonia and severe pelvic abscesses in an athlete. In this study, we investigated a new rapid screening method for PVL-positive ST30 CA-MRSA and its related clone by a combination of multiplex polymerase chain reaction (M-PCR) and pulsed-field gel electrophoresis (PFGE). For M-PCR, the targets of the assay were the five genes for PVL, collagen adhesin, bone sialoprotein adhesin, methicillin resistance, and S. aureus-specifi c thermostable nuclease. Only PVL-positive ST30 CA-MRSA strains produced all five bands in M-PCR. With PFGE, Japanese strains and most foreign strains of PVLpositive ST30 CA-MRSA shared the same pattern. Moreover, PFGE distinguished current PVL-positive CA-MRSA ST30/spa19 strains from previous PVL-positive MRSA ST30/spa43 strains (which were isolated at the time of nosocomial MRSA outbreaks in the late 1980s and early 1990s) in Japan. Thus, the M-PCR assay rapidly, and the M-PCR/PFGE combination assay more precisely, discriminated between PVL-positive ST30 CA-MRSA (or its related clone) and PVL-positive CA-MRSA belonging to other ST types such as ST1, 8, 59, and 80, PVL-negative CA-MRSA, hospital-acquired MRSA, methicillin-susceptible S. aureus, or coagulase-negative staphylococci (CNS), including MRCNS. This screening method is more useful than genotyping for routine work in many clinical laboratories.

DOI： 10.1007/s10156-009-0667-y

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSIOLOGICAL SOC  

When macrophages phagocytose chitin (N-acetyl-D-glucosamine polymer) microparticles, mitogen-activated protein kinases ( MAPK) are immediately activated, followed by the release of Th1 cytokines, but not IL-10. To determine whether phagocytosis and macrophage activation in response to chitin microparticles are dependent on membrane cholesterol, RAW264.7 macrophages were treated with methyl-beta-cytodextrin (MBCD) and stimulated with chitin. These results were compared with the corresponding effects of bacterial components including heat-killed (HK) Mycobacterium bovis bacillus Calmette-Guerin (BCG) and an oligodeoxynucleotide (ODN) of bacterial DNA (CpG-ODN). The MBCD treatment did not alter chitin binding or the phagocytosis of chitin particles 20 min after stimulation. At the same time, however, chitin-induced phosphorylation of cellular MAPK was accelerated and enhanced in an MBCD dose-dependent manner. The increased phosphorylation was also observed for chitin phagosome-associated p38 and ERK1/2. In contrast, CpG-ODN and HK-BCG induced activation of MAPK in MBCD-treated cells at levels comparable to, or only slightly more than, those of control cells. We also found that MBCD treatment enhanced the production of tumor necrosis factor-alpha (TNF-alpha) and the expression of cyclooxygenase-2 (COX-2) in response to chitin microparticles. In neither MBCD- nor saline-treated macrophages, did chitin particles induce detectable IL-10 mRNA synthesis. CpG-ODN induced TNF-alpha production, and COX-2 expression were less sensitive to MBCD treatment. Among the agonists studied, our results indicate that macrophage activation by chitin microparticles was most sensitive to cholesterol depletion, suggesting that membrane structures integrated by cholesterol are important for physiological regulation of chitin microparticle-induced cellular activation.

DOI： 10.1152/ajpcell.00446.2007

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

Over 25 years ago, it was observed that peritoneal macrophages (M phi) isolated from mice given heat-killed Mycobacterium bovis bacillus Calmette-Guerin (HK-BCG) i.p. did not release PGE(2).. However, when peritoneal M 5 from untreated mice are treated with HK-BCG in vitro, cyclooxygenase 2 (COX-2), a rate-limiting enzyme for PGE(2) biosynthesis, is expressed and the release of PGE2 is increased. The present study of peritoneal M phi obtained from C57BL/6 mice and treated either in vitro or in vivo with HK-BCG was undertaken to further characterize the cellular responses that result in suppression of PGE2 release. The results indicate that M phi treated with HK-BCG in vivo express constitutive COX-1 and inducible COX-2 that are catalytically inactive, are localized subcellularly in the cytoplasm, and are not associated with the nuclear envelope (NE). In contrast, M phi treated in vitro express catalytically active COX-1 and COX-2 that are localized in the NE and diffusely in the cytoplasm. Thus, for local M(P activated in vivo by HK-BCG, the results indicate that COX-1 and COX-2 dissociated from the NE are catalytically inactive, which accounts for the lack of PGE2 production by local M(P activated in vivo with HK-BCG. Our studies further indicate that the formation of catalytically inactive COX-2 is associated with in vivo phagocytosis of HK-BCG, and is not dependent on extracellular mediators produced by in vivo HK-BCG treatment. This attenuation of PGE2 production,may enhance M phi-mediated innate and Th1-acquired immune responses against intracellular infections which are suppressed by PGE(2).

DOI： 10.4049/jimmunol.179.10.7072

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：OXFORD UNIV PRESS INC  

Human intelectin-1 (hITLN-1) is a 120-kDa lectin recognizing galactofuranosyl residues found in cell walls of various microorganisms but not in mammalian tissues. Although mouse intelectin-1 (mITLN-1) has been identified previously, its biochemical properties and functional characteristics have not been studied. Therefore, we have compared structures and saccharide-binding specificities of hITLN-1 and mITLN-1 using recombinant proteins produced by mammalian cells. Recombinant hITLN-1 is a trimer, disulfide-linked through Cys-31 and Cys-48, and N-glycosylated at Asn-163. Despite 84.9% amino acid identity to hITLN-1, recombinant and intestinal mITLN-1 are unglycosylated 30-kDa monomers. Recombinant hITLN-1, as well as recombinant and intestinal mITLN-1 were purified by Ca2+-dependent adsorption to galactose-Sepharose. In competitive binding studies, hITLN-1 was eluted from galactose-Sepharose by 100 mM 2-deoxygalactose, a galactofuranosyl disaccharide, D-xylose, and both D- and L-ribose. In contrast, mITLN-1 was partially eluted by the galactofuranosyl disaccharide, and only minimally by the other saccharides indicating that the two intelectins have different saccharide-binding specificities. When the N- and C-terminal regions of hITLN-1 were replaced, respectively, with those of mITLN-1, galactose-Sepharose binding was associated with the C-terminal regions. Finally, hITLN-1 binding to galactose-Sepharose was not affected by the substitution of the Cys residues in the N-terminal region that are necessary for oligomer formation, nor was it affected by the removal of the N-linked oligosaccharide at Asn-163. Although both hITLN-1 and mITLN-1 recognize galactofuranosyl residues, our comparative studies, taken together, demonstrate that these intelectins have different quaternary structures and saccharide-binding specificities.

DOI： 10.1093/gob/cwm075

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSIOLOGICAL SOC  

Cyclooxygenase2 (COX-2)-mediated prostaglandin E-2 (PGE(2)) biosynthesis by macrophages downregulates microbicidal activities in innate and acquired immune responses against intracellular bacteria. Previous studies in mice showed that intraperitoneal administration of heat-killed Mycobacterium bovis bacillus Calmette-Guerin (HK-BCG) resulted in induction of splenic PGE2-releasing macrophages in 7 - 14 days. In contrast, HK-BCG induced catalytically inactive COX-2 at relatively high levels in the macrophages within 1 day. In the present study, we found that COX-2 was localized subcellularly in the nuclear envelope (NE) 7 and 14 days after HK-BCG treatment, whereas COX-2 was dissociated from the NE 1 day after treatment. At 1 day after treatment, the majority of COX-2-positive macrophages had phagocytosed HK-BCG. In contrast, no intracellular HK-BCG was detected 7 and 14 days after treatment in COX-2-positive macrophages, where COX-2 was associated with the NE. However, when macrophages phagocytosed HK-BCG in vitro, all COX-2 was associated with the NE. Thus the administration of HK-BCG induces the biphasic COX-2 expression of an NE-dissociated catalytically inactive or an NE-associated catalytically active form in splenic macrophages. The catalytically inactive COX-2-positive macrophages develop microbicidal activities effectively, since they lack PGE(2) biosynthesis.

DOI： 10.1152/ajpcell.00346.2006

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Although immunocompetent hosts develop protective type I helper T cell (Th1) responses in mycobacterial infections, sercepidemiologic studies show that patients with atherosclerosis commonly express high antibody titers against mycobacterial heat shock protein (HSP) 65 and may develop a nonprotective type 2 helper T cell (Th2) response and advanced disease. These studies were undertaken to define mycobacterial dose requirements and kinetics for development of antibodies to HSP65, the Th1 to Th2 shift of immune response, and calcified atherosclerotic lesion development in the apo E-/- mouse. Fourteen-week apo E-/- female mice were treated intraperitoneally (ip) with heat-killed M. bovis Bacillus Calmette-Guerin (BCG), and 14 days later, cross-sections from the ascending aortas were stained for measurement of lesion size and calcium deposition. At 14 days, 0.01 -mg BCG induced Th1 responses against HSP65. In contrast, 1-mg BCG induced splenic PGE(2)-releasing macrophages with a Th1-to-Th2 shift of responses to HSP65, which was PGE(2)-dependent. Treatment with I -mg BCG significantly lowered bone density with increases in marrow osteoclastogenesis and development of calcified lesions in the aorta. At 14 days, 0.01 -mg BCG induced Th1-dependent HSP65 responses and did not advance atherosclerosis. In contrast, for 1-mg BCG, a PGE(2)-dependent Th1-to-Th2 shift of responses to HSP65 and evidence of bone resorption are associated with advanced calcified atherosclerotic lesions.

DOI： 10.1016/j.trsl.2006.08.008

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：FEDERATION AMER SOC EXP BIOL  

Previous studies have shown that prostaglandin E-2 (PGE(2)) release by splenic F4/80(+) cyclooxygenase (COX)-2(+) macrophages (M circle divide) isolated from mice, treated with mycobacterial components, plays a major role in the regulation of immune responses. However, splenic M circle divide, isolated from untreated mice and treated in vitro with lipopolysaccharide and interferon-gamma, express COX-1 and COX-2 within I day but release only minimal amounts of PGE2 following elicitation with calcium ionophore A23187. For further characterization of in vivo requirements for development of PGE(2)-releasing M circle divide (PGE(2)-M circle divide), C57B1/6 [wild-type (WT)], and interleukin (IL)-10-deficient (IL-10(-/-)) mice were treated intraperitoneally with heat-killed Mycobacterium bovis bacillus Calmette-Guerin (HK-BCG). One day following injection, COX-2 was induced in splenic M circle divide of both mouse strains. However, PGE2 biosynthesis by these M circle divide was not increased. Thus, expression of COX-2 is not sufficient to induce PGE2 production in vivo or in vitro. In sharp contrast, 14 days after HK-BCG treatment, PGE2 release by COX-2(+) splenic M circle divide increased as much as sevenfold, and a greater increase was seen in IL-10-/- cells than in WT cells. To further determine whether the 14-day splenic PGE(2)-M circle divide could be derived from bone marrow precursors, we established a chimera in which bone marrow cells were transfused from green fluorescent protein (GFP)-transgenic donors to WT mice. Donors and recipients were treated with HK-BCG simultaneously, and marrow transfusion was performed on Days I and 2. On Day 14 after BCG treatment, a significant number of spleen cells coexpressed COX-2 and GFP, indicating that bone marrow-derived COX-2+ M circle divide may be responsible for the increased PGE(2) production.

DOI： 10.1189/jlb.1205737

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Staphylococcal leukocidin (Luk) consists of LukS and LukF, which cooperatively lyse human polymorphonuclear leukocytes (HPMNLs), monocytes, and macrophages. Here we found that LukS and LukF assembles into hetero-oligomeric pore complexes on the detergent-resistant membrane microdomains, lipid rafts of HPMNLs. When HPMNLs were treated with LukS alone, 24% of the added LukS was localized in lipid rafts. Furthermore, in HPMNLs treated with both LukS and LukF simultaneously, about 90% of high molecular-mass complexes of 100 kDa, which consists of LukS and LukF, were detected in the lipid raft fractions. In contrast, in HPMNLs treated with LukF alone, LukF was not localized in lipid rafts despite binding to the target cell membranes. Ten mm methyl-beta-cyclodextrin, a dysfunctioning agent of lipid rafts, completely inhibited assembly of Luk on lipid rafts, and resulted in null leukocytolytic activity of Luk. Hence, we concluded that assembly of LukS and LukF into the pore-complex occurs in lipid rafts in HPMNLs and that LukF can bind to LukS, which had already bound to lipid rafts, to assemble into hetero-oligomers.

DOI： 10.1271/bbb.50499

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.cellimm.2006.04.003

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：FEDERATION AMER SOC EXP BIOL  

Different populations of mononuclear phagocytes (MO) show considerable diversity of cellular function including prostaglandin E-2 (PGE(2)) biosynthesis. Certain bacterial components enhance PGE2 biosynthesis differentially in selected populations of MO. Interleukin (IL)-10 is proposed to inhibit modulation of PGE(2) biosynthesis by down-regulating prostaglandin G/H synthase-2 (PGHS-2) expression. To assess whether IL-10 regulates PGE2 biosynthesis and PGHS-2 expression, splenic and bone marrow MO were isolated from IL-10-deficient (IL-10(-/-)), C57B1/6 [wild-type (WT) control], and Balb/c (comparison control) mice and were treated with lipopolysaccharide (LPS) and/or interferon-gamma (IFN-gamma) as a model of bacterial inflammation. LPS-induced PGHS-2 expression was similar for splenic MO isolated from the three strains of mice. However, PGE(2) released by LPS-treated splenic MO was significantly higher in IL-10-/- and Balb/c than in WT cells. In the presence of LPS and IFN-gamma, PGHS-2 expression and PGE(2) release by IL-10(-/-) and Balb/c splenic MO were enhanced compared with stimulation with LPS alone or IFN-gamma alone. However, there was no significant increase in PGE2 release from WT splenic MO treated with LPS plus IFN-gamma despite increased PGHS-2 expression. In sharp contrast, PGHS-2 expression and PGE(2) release by bone marrow MO were greatly enhanced in IL-10-/- cells compared with control cells. Our results indicate that IL-10 regulation of MO PGE(2) biosynthesis and PGHS-2 expression is compartment-dependent and that PGE(2) production is not linked directly to PGHS-2 levels. Furthermore, our findings emphasize strain-specific differences between C57B1/6 and Balb/c mice, and Balb/c appears more similar to the IL-10-/- than to the C57B1/6 with respect to prostanoid production.

DOI： 10.1189/jlb.0504311

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Luk-I produced by Staphylococcus intermedius was found to be a new member of the staphylococcal bi-component pore-forming toxin family, in which staphylococcal leukocidin, Panton-Valentine leukocidin, and gamma-hemolysin are included. Luk-I consists of LukS-I and LukF-I. From the deduced amino acid sequence of LukS-I, a 4-residue sequence, K135K136I137S138, at the root of the stem region was found to be identical with that of the phosphorylated segment of a protein phosphorylated by protein kinase A. A mutant of LukS-I (MLSI-SA), in which the Ser138 residue was replaced by an alanine residue, was created, purified, and assayed for its leukocytolytic and pore-forming activities with LukF-I. Both LukS-I and MLSI-SA formed a ring-shaped complex with LukF-I on rabbit erythrocytes and human polymorphonuclear leukocytes (HPMNLs) membrane. However, MLSI-SA showed no leukocytolytic activity with LukF-I. LukS-I was phosphorylated by protein kinase A in the presence of [gamma-P-32] ATP in a cell-free system, but MLSI-SA was not phosphorylated significantly. A potent and selective inhibitor of protein kinase A (N- [2(p-bromocinnamylamino) ethyl]-5-isoquinolinesulfonamide (H-89)) showed 50% inhibition of the Luk-I-induced cell lysis at 0.5 nm. Thus, it is concluded that the phosphorylation of the Ser138 residue in the 4-residue segment K135K136I137S138 of LukS-I is important for the leukocytolysis of HPMNLs.

DOI： 10.1271/bbb.66.328

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Staphylococcal leukocidin (Luk) consists of two protein components, LukF and LukS, which cooperatively lyse human and rabbit polymorphonuclear leukocytes. Here, we demonstrate that the phosphorylation of LukS by protein kinase A is crucial for the LukS-specific leukocytolytic function of Luk on HPMNLs by using N-[2(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H-89), which is a potent and selective inhibitor of protein kinase A. At 0.5 mu M H-89 completely prevented the Luk-induced cell lysis accompanied by blocking of the incorporation of exogenous P-32-H3PO4 into LukS on HPMNLs, However, with LukS and LukF together, 0.5 mu M H-89 did not inhibit the cell swelling which takes place before the cell lysis. HPMNLs also became swollen upon treating with both LukF and LukS mutants which could not be phosphorylated.

DOI： 10.1271/bbb.62.1834

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Staphylococcal leukocidin nd gamma-hemolysin consist of LukF and LukS for leukocidin and LukF and HIg2 for gamma-hemolysin. In this report, we identify the minimum segment responsible for the LukS-specific function of leukocidin. After chemical analysis and homology study of the amino acid sequence of the C-terminal region between LukS and HIg2, we found a unique 5-residue sequence (IKRST246)-K-242-R-243-S-244-T-245 in LukS in which the 4-residue KRST is identical with that of the phosphorylated segment of a protein phosphorylated by protein kinase A. To elucidate whether the 5-residue segment is essential for the LukS function, we created plasmids containing a series of mutant genes corresponding to the 5-residue sequence and expressed them in Escherichia coli. The mutant proteins were purified and assayed for their leukocytolytic activity with LukF. The mutant MLS-TS, in which the T-246 in the 5-residue sequence was replaced by S, showed leukocidin activity 10 times higher than that of the intact LukS. However, neither mutant MLS-TY nor MLS-TA, in which T-246 was replaced by Y or A, respectively, showed leukocidin activity. The 5-residue segment was found to be deleted in HIg2. The mutant of HIg2, in which the 5-residue segment was inserted at the position that the segment is deleted, showed leukocidin activity. The boiled LukS, MLS-TS, and MHS-Z were strongly phosphorylated with [gamma-P-32]ATP in the presence of protein kinase A in a cell-free system. Thus, we conclude that the 5-residue segment (IKRST246)-K-242-R-243-S-244-T-245 is the pivotal segment of LukS responsible for the LukS function of staphylococcal leukocidin. (C) 1997 Federation of European Biochemical Societies.

DOI： 10.1016/S0014-5793(97)01100-9

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記述言語：日本語   出版者・発行元：日本細菌学会  

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J-GLOBAL

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J-GLOBAL

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記述言語：日本語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：(一社)日本感染症学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：英語   出版者・発行元：日本細菌学会  

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記述言語：日本語   出版者・発行元：新潟医学会  

【目的】消化管手術の周術期には、黄色ブドウ球菌などの皮膚常在菌による創部感染、絶食による腸内細菌叢の攪乱に伴うBacterial translocation、抗菌薬使用に伴うmethicillin-resistant Staphylococcus aureus(MRSA)などの薬剤耐性菌の出現が起こりうる。このような状況に対して応用的プロバイオティクスによる周術期感染制御を視野に、ヨーグルト製品のもつ抗菌効果の特性を微生物学的に解析した。【方法】新潟県で開発され市販されているヤスダヨーグルト(以下、YYG)に注目して、1)抗菌活性スペクトル(被験株:methicillin-sensitive Staphylococcus aureus(MSSA)ならびにMRSA臨床分離株、大腸菌株DH5α)、2)配合菌株の異なる他の5種の市販ヨーグルト製品との抗菌活性の相違、3)YYG各配合菌種(Yc-x11およびYc-180)の示す抗菌作用、および4)抗菌活性を示す分離画分について、ディスク法による阻止円形成により検討した。【結果】YYGは大腸菌に比してMSSAに優位な抗菌活性を示した。また、YYGはMRSA臨床分離株に対しても抗菌活性を示した。他製品との比較において、YYGは最も高い抗菌活性を示した。YYG配合菌種は、通常の低塩濃度培地上では抗菌活性を示したものの高塩濃度条件下では、その効果は減弱あるいは消失した。YYGの抗菌活性は、上清ではなく沈殿画分に認めた。【結論】YYGはMRSAを含む黄色ブドウ球菌に対する直接的な抗菌活性を示した。その抗菌効果は、特有の配合菌種に依拠する抗菌活性物質によることが示唆された。ヨーグルトの中でもYYGは極めて有望な抗菌性機能食品として、周術期感染制御に貢献できる可能性がある。(著者抄録)

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記述言語：日本語   出版者・発行元：(株)医薬ジャーナル社  

結核は三大感染症の一角であり、代表的な再興感染症である。病原体である結核菌はアフリカの東岸に5〜10万年前に出現し、人類の出アフリカにともない世界に伝播した。通常、菌は飛沫核感染で肺を侵入門戸として生体に侵入し感染するが、すみやかに発症に至るケースは5%程度とまれである。一方、感染成立後、ヒトの免疫系は菌を生体から駆逐することはできず、感染は宿主の命が果つるまで継続する。このような無症候感染者は人類の1/3に及び、一部は再燃により結核が発症する。このため無症候感染は潜在性結核と呼ばれる。このような事実は、病原体の源泉である潜在性結核の対処が結核の制御に重要であることを示しており、潜伏感染機構の理解はそのよりどころとなるだろう。本稿では、結核菌の潜伏感染機構についての知見と、潜在性結核の解析をベースにした新しい制御法開発の可能性について述べる。(著者抄録)

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記述言語：日本語   出版者・発行元：新潟医学会  

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その他リンク： http://search.jamas.or.jp/link/ui/2013320239

記述言語：日本語   出版者・発行元：新潟医学会  

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記述言語：日本語   出版者・発行元：EDIXi出版部  

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その他リンク： http://search.jamas.or.jp/link/ui/2010163447

記述言語：日本語   出版者・発行元：新潟医学会  

Helicobacter pyloriは胃癌の細菌性リスク因子で, H. pyloriが分泌するCagAタンパク質のEPIYAモチーフでのリン酸化レベルがH. pyloriの発癌作用に関連すると考えられている. 今回, H. pyloriロシア株のCagAタンパク質EPIYAモチーフについてDNA解析した結果, 日本(新潟)のH. pylori株と同様の結果が得られた. ロシア株は日本株と同様で, 発癌能力の高い強毒株である可能性がある.

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：FEDERATION AMER SOC EXP BIOL  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：FEDERATION AMER SOC EXP BIOL  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：FEDERATION AMER SOC EXP BIOL  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：FEDERATION AMER SOC EXP BIOL  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：FEDERATION AMER SOC EXP BIOL  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：ポスター発表  

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記述言語：英語   会議種別：ポスター発表  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：ポスター発表  

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