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• Letter from Japan

  Ideguchi, S; Yamamoto, K

  RESPIROLOGY ( Respirology )  29 ( 7 ) 637 - 639   2024.07

  Type of publication: Research paper (scientific journal)

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• Clinical features relating to pneumococcal colony phase variation in hospitalized adults with pneumonia

  Ideguchi, S; Yamamoto, K; Takazono, T; Fukuda, Y; Tashiro, T; Shizukuishi, S; Chang, B; Ogawa, M; Izumikawa, K; Yanagihara, K; Yatera, K; Mukae, H

  JOURNAL OF MEDICAL MICROBIOLOGY ( Journal of Medical Microbiology )  73 ( 1 )   2024 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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  Background. Streptococcus pneumoniae is a major causative bacteria of pneumonia and invasive pneumococcal disease (IPD); however, the mechanisms underlying its severity and invasion remain to be defined. Pneumococcal colonies exhibit opaque and transparent opacity phase variations, which have been associated with invasive infections and nasal colonization, respectively, in animal studies. This study evaluated the relationship between the opacity of pneumococcal colonies and the clinical presentation of pneumococcal pneumonia.Methods. This retrospective study included adult patients hospitalized with pneumococcal pneumonia between 2012 and 2019 at four tertiary medical institutions. Pneumococcal strains from lower respiratory tract specimens were determined for their serotypes and microscopic colony opacity, and the association between the opacity phase and the severity of pneumonia was evaluated. Serotypes 3 and 37 with mucoid colony phenotypes were excluded from the study because their colony morphologies were clearly different.Results. A total of 92 patients were included. Most patients were older adults (median age: 72 years) and males (67 %), and 59 % had community-acquired pneumonia. Of the 92 patients, 41 (45 %), 12 (13 %), and 39 (42 %) patients had opaque, transparent, and mixed variants in their pneumococcal colony, respectively. The opaque and non-opaque pneumococcal variants had no statistically significant difference in patient backgrounds. Although the pneumonia severity index score did not differ between the opaque and non-opaque groups, the rate of bacteremia was significantly higher in the opaque group than in the non-opaque group. Serotype distribution was similar between the groups.Conclusions. Opaque pneumococcal variants may cause pneumonia and invasive diseases in humans. This study could help elucidate IPD, and opacity assessment may serve as a predictor for IPD.

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• Infectious Pneumonia and Lower Airway Microorganisms in Patients with Rheumatoid Arthritis

  Shuhei Ideguchi, Kazuko Yamamoto, Masahiro Tahara, Tomohiro Koga, Shotaro Ide, Tatsuro Hirayama, Takahiro Takazono, Yoshifumi Imamura, Taiga Miyazaki, Noriho Sakamoto, Shimpei Morimoto, Koichi Izumikawa, Katsunori Yanagihara, Kazuto Ashizawa, Takatoshi Aoki, Atsushi Kawakami, Kazuhiro Yatera, Hiroshi Mukae

  Journal of Clinical Medicine ( MDPI AG )  10 ( 16 ) 3552 - 3552   2021.08 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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  The relationship between microorganisms present in the lower respiratory tract and the subsequent incidence of pneumonia in patients with rheumatoid arthritis is unclear. A retrospective cohort study was designed to include a total of 121 patients with rheumatoid arthritis who underwent bronchoscopy at three hospitals between January 2008 and December 2017. Data on patient characteristics, microorganisms detected by bronchoscopy, and subsequent incidences of pneumonia were obtained from electronic medical records. Patients were divided into groups based on the microorganisms isolated from the lower respiratory tract. The cumulative incidence of pneumonia was assessed using the Kaplan–Meier method, and decision tree analysis was performed to analyze the relation between the presence of microorganisms and the occurrence of pneumonia. The most frequently isolated microbes were Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae. Patients whose samples tested negative for bacteria or positive for normal oral flora were included in the control group. The rate of the subsequent incidence of pneumonia was higher in the P. aeruginosa group than in the control group (p = 0.026), and decision tree analysis suggested that P. aeruginosa and patient performance status were two important factors for predicting the incidence of pneumonia. In patients with rheumatoid arthritis, the presence of P. aeruginosa in the lower respiratory tract was associated with the subsequent incidence of pneumonia.

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• Diagnostic evaluation of serum (1, 3)-β-<scp>d</scp>-glucan levels using the Fungitec G-Test MK kit for <i>Pneumocystis jirovecii</i> pneumonia (PCP) in non-HIV patients

  Shuhei Ideguchi, Kazuko Yamamoto, Tatsuro Hirayama, Takahiro Takazono, Yoshifumi Imamura, Taiga Miyazaki, Noriho Sakamoto, Koichi Izumikawa, Katsunori Yanagihara, Shimpei Morimoto, Hiroshi Mukae

  Medical Mycology ( Oxford University Press (OUP) )  59 ( 6 ) 616 - 623   2020.12 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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  Abstract Pneumocystis jirovecii pneumonia (PCP) is an opportunistic and life-threatening pulmonary infection with an increasing prevalence among individuals who are human immunodeficiency virus (HIV)-negative. Evidence regarding diagnostic testing of PCP in this patient population is insufficient. We evaluated the performance of serum (1, 3)-β-d-glucan (BDG) using the Fungitec G-test MK kit for diagnosing PCP in non-HIV patients. We retrospectively analyzed data from 219 non-HIV adult patients who underwent bronchoscopy and were tested for P. jirovecii DNA by PCR using lavage samples from the lower respiratory tract. Fifty PCP patients and 125 non-PCP patients were included. The most common underlying diseases were malignancies and systemic autoimmune diseases. Using the serum BDG Fungitec G-test MK test to diagnose PCP, the area under the receiver operating characteristic curve (AUC) was 0.924, whereas the modified cut-off value of 36.6 pg/mL had a sensitivity and specificity of 92.0% and 84.8%, respectively. The AUC for patients with systemic autoimmune diseases was 0.873, and the accuracy of serum BDG test declined when using methotrexate (MTX). In conclusion, the serum BDG test was useful for diagnosing PCP in non-HIV patients; however, the results should be carefully interpreted in case of MTX administration.

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• An adult case of invasive pneumococcal disease due to serotype 12F-specific polysaccharide antibody failure following a 23-valent polysaccharide vaccination.

  Yasuhiro Tanaka, Kazuko Yamamoto, Yuichi Fukuda, Asuka Umemura, Masataka Yoshida, Shuhei Ideguchi, Nobuyuki Ashizawa, Tatsuro Hirayama, Masato Tashiro, Takahiro Takazono, Yoshifumi Imamura, Taiga Miyazaki, Koichi Izumikawa, Katsunori Yanagihara, Bin Chang, Hiroshi Mukae

  Emerging microbes & infections   9 ( 1 ) 2266 - 2268   2020.12 [ Peer Review Accepted ]

  Type of publication: Research paper (other science council materials etc.)

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  A 68-year-old Japanese man was admitted to our hospital for an acute febrile illness with shivering and impaired consciousness. He was a previous smoker and had a history of chronic obstructive pulmonary disease, for which he inhaled steroid with a long-acting bronchodilator. He had received a 23-valent pneumococcal polysaccharide vaccination 2 years previously. He was intubated and placed on a ventilator in intensive care unit because of acute respiratory failure and hypercapnia. Streptococcus pneumoniae was grown from his blood, sputum, and urine cultures, and he was diagnosed with invasive pneumococcal disease with acute renal failure. He was treated with intravenous beta-lactam and macrolide with continuous hemodiafiltration and was discharged 3 months later. The pneumococcus was identified as serotype 12F, and his serotype-specific IgG and opsonophagocytic index against serotype 12F indicating a lack of protection from IPD among PPV23 serotypes. This case highlights that some individuals may have a serotype-specific polysaccharide antibody failure that makes them susceptible to serotype 12F invasive pneumococcal disease. This case also illustrates the need for serotype-specific IgG and opsonophagocytic index titre cut-offs for each specific pneumococcal serotype in available vaccines to understand the vaccination protection for individual patients better.

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Other Papers 【 display / non-display 】

• 肺炎球菌株のマクロファージNF-κB活性誘導能がもつ臨床的な意義

  井手口 周平, 山本 和子, 高園 貴弘, 西條 知見, 今村 圭文, 宮崎 泰可, 柳原 克紀, 福田 雄一, 一門 和哉, 矢寺 和博, 常 彬, 迎 寛

  日本呼吸器学会誌 ( (一社)日本呼吸器学会 )  8 ( 増刊 ) 140 - 140   2019.03

   

• 非結核性抗酸菌種別のマクロファージNF-κB活性誘導能の検討

  巌水 慧, 山本 和子, 井手口 周平, 井手 昇太郎, 武田 和明, 高園 貴弘, 宮崎 泰可, 泉川 公一, 柳原 克紀, 迎 寛

  結核 ( (一社)日本結核病学会 )  94 ( 3 ) 297 - 297   2019.03

   

• 下気道微生物と関節リウマチの疾患活動性との関連性の検討

  井手口 周平, 山本 和子, 高園 貴弘, 西條 知見, 今村 圭文, 宮崎 泰可, 遠藤 友志郎, 古賀 智裕, 川上 純, 迎 寛

  日本内科学会雑誌 ( (一社)日本内科学会 )  108 ( Suppl. ) 201 - 201   2019.02

   

• 緑膿菌の気道定着と関節リウマチ患者の予後との関連性についての検討

  井手口 周平, 山本 和子, 高園 貴弘, 西條 知見, 今村 圭文, 宮崎 泰可, 迎 寛

  日本化学療法学会雑誌 ( (公社)日本化学療法学会 )  66 ( Suppl.A ) 382 - 382   2018.04

   

• 飛蚊症が契機で診断に至った結核性ぶどう膜炎合併肺結核の2例

  石岡 泰知, 井手口 周平, 梅村 明日香, 山本 和子, 高園 貴弘, 今村 圭文, 宮崎 泰可, 福島 喜代康, 迎 寛, 井上 大輔

  結核 ( (一社)日本結核病学会 )  93 ( 4 ) 307 - 307   2018.04

   

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• Elucidating mechanism of invasive pneumococcal disease by using opacity transformed colonies

  Grant-in-Aid for Scientific Research(C)

  Project Year: 2021.04  -  2024.03 

  Direct: 3,300,000 (YEN)  Overheads: 4,290,000 (YEN)  Total: 990,000 (YEN)

• Neutrophils in mediastinal lymph node mediates innate immune response during pneumococcal pneumonia.

  Grant-in-Aid for Scientific Research(C)

  Project Year: 2017.04  -  2020.03 

  Investigator(s): YAMAMOTO Kazuko 

  Direct: 3,700,000 (YEN)  Overheads: 4,810,000 (YEN)  Total: 1,110,000 (YEN)

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  Mediastinal lymph nodes (MLN) are secondary lymphoid organs of the lung. Lymphatic vessels link lung to MLN and MLN to blood. We postulate that innate immune activities in the MLN interrupt bacterial passage, preventing disseminated infection during pneumonia. Our objective was to determine whether neutrophils migrate into MLNs during pneumonia, and to evaluate whether neutrophils in MLN affect bacteremia during pneumonia. Our data showed that neutrophils migrate to MLN during pneumococcal pneumonia, mediated by CXCL1 and CXCL5 in lymphatic endothelial cells, and to prevent bacterial dissemination from the lung via lymphatics. Neutrophils in MLN present MHC class II to stimulate acquired immune response. MLN neutrophils prevent bacteremia during pneumonia.