日本における基質特異性拡張型β-ラクタマーゼ産生肺炎桿菌の分子遺伝学的特徴：CTX-M-15の優位性と高病原性クローンの出現

Objective: To provide data on the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae clinical isolates in Japan. Methods: A total of 100 clinical isolates of ESBL-producing K. pneumoniae collected throughout Japan between June and July 2018 were studied. ESBL genes were analyzed using PCR and DNA sequencing. Transferability of ESBL genes was investigated by conjugation experiments. Plasmid replicon types, virulence genes (rmpA, rmpA2, iucA, iroB, and peg-344) associated with hypervirulent K. pneumoniae (hvKp), and capsule types were detected using PCR. Genotyping was performed using multilocus sequence typing. Results: All ESBL-producing isolates carried blaCTX-M genes. The most predominant CTX-M-type identified was CTX-M-15 (n=55). We identified 24 sequence types (STs) among the CTX-M-15 producers, with ST25 (n=8) being the most common. Most of the transconjugants carrying blaCTX-M-15 contained the FIIk replicon. Of the 100 ESBL-producing isolates, 31 were hvKp defined by the presence of the virulence genes. These ESBL-producing hvKp isolates belonged to eight STs (STs 23, 25, 36, 65, 86, 268, 412, and 4492), with five capsule types (K1, K2, K20, K57, and undefined). Conclusions: CTX-M-15 was the predominant ESBL among K. pneumoniae isolates from Japan. This study shows that ESBL-producing hvKp strains comprising various clones are emerging in Japan.博士（医学）・甲第769号・令和3年3月15日© 2020 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Extreme hyperglycemia and diabetic ketoacidosis occurring in a patient on chronic dialysis

Department of Urology, North medical center, Kyoto prefectural university of medicine, Kyoto, Japan.Department of Nephrology and Urology, Nishijin Hospital, Kyoto, Japan.Department of Internal medicine, Nishijin Hospital, Kyoto, Japan.Diabetic ketoacidosis (DKA) is a complication that is rarely reported in patients on chronic dialysis. Herein, we describe the case of a patient on chronic hemodialysis who presented to us with acute onset diabetic ketoacidosis. A 50-year-old man with insulin-dependent diabetes mellitus, who was on hemodialysis for 2 years, presented to us with altered consciousness. Laboratory data revealed the following results: blood sugar, 110.1 mmol/L (1984 mg/dL); serum sodium, 107 mmol/L; β -hydroxybutyric acid, 1991 μ M; pH, 7.048. A diagnosis of diabetic ketoacidosis was made, and insulin therapy and hemodialysis were initiated, following which his parameters including blood glucose, and serum potassium and sodium improved. High osmotic dehydration was not observed in our patient owing to his renal dysfunction. The patient’s consciousness normalized following the correction of hyperglycemia and DKA. This case report highlights the importance of early diagnosis of DKA, and prompt initiation of insulin therapy and hemodialysis in patients on chronic dialysis. Therefore, in patients with end stage renal disease, the blood glucose correction should be followed by the restoration of sodium and osmolality, guided by corrected sodium concentration and effective osmolality, and by the appropriate adjustment of insulin and dialysis

奈良における侵襲性GBS感染症における臨床的特徴と分子疫学的特徴(2007～2016年)

Invasive Streptococcus agalactiae (GBS) infections are increasingly common among neonates and the elderly. Therefore, GBS surveillance for better antibiotic treatment and prophylaxis strategies are needed. We retrospectively evaluated the clinical aspects of invasive infections and the phenotypic and genetic diversity of infectious isolates from Nara, Japan, collected between 2007 and 2016, by using information from hospital records. GBS strains collected from the blood and cerebrospinal fluid cultures were evaluated for capsular types, multi-locus sequence typing (MLST), antibiotic susceptibility, antibiotics resistance gene, and pulsed-field gel electrophoresis. Forty GBS isolates (10 from children and 30 from adults) were analyzed, and the distribution of molecular serotype and allelic profiles varied between children and adults. We found the rates of early-onset disease in neonates with birth complications to be higher than that of previous reports, indicating that there could be relevance between complications at birth and early-onset disease. Standard antibiotic prophylaxis strategies may need to be reconsidered in patients with birth complications. In adults, the mean age of the patients was 68 years (male: 63%). Primary bacteremia was the most common source of infection. In the neonates, six had early-onset diseases and four had late-onset diseases. The most frequently identified strains were molecular serotype Ia ST23 (40%) and molecular serotype Ib ST10 (20%) in children and molecular serotype Ib ST10 (17%), molecular serotype VI ST1 (13%), and molecular serotype V ST1 (13%) in adults. Levofloxacin-resistant molecular serotype Ib strains and molecular serotypes V and VI ST1 were common causes of GBS infection in adults but were rarely found in children. Furthermore, pulsed-field gel electrophoresis in our study showed that specific clone isolates, that tend to have antibiotics resistance were widespread horizontally for a decade. Continuous surveillance and molecular investigation are warranted to identify the transmission route and improve antibiotic treatment strategies.博士（医学）・甲第773号・令和3年3月15日Copyright: © 2020 Hirai et al. This is an open access article distributed under the terms of the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

本邦で分離されたカルバペネマーゼ産生肺炎桿菌の分子遺伝学的解析

Carbapenemase-producing Enterobacteriaceae represent a serious public health threat worldwide. Carbapenemase genes, harbored on a transferable plasmid, have been isolated globally with distinct geographical features. Klebsiella pneumoniae, included in Enterobacteriaceae, also produces carbapenemase and often shows hypervirulence. Overlapping carbapenem resistance and hypervirulence in K. pneumoniae have been reported, but such strains have not yet been found in Japan. Here, we screened 104 carbapenemase-producing K. pneumoniae isolates collected from 37 hospitals and outpatient clinics in Japan between September 2014 and July 2015. PCR and DNA sequencing demonstrated IMP-1 in 21 isolates and IMP-6 in 83 isolates, 77 of which coharbored CTX-M-2. Most of the isolates showed low MICs toward imipenem and meropenem but high MICs toward penicillin and cephalosporins. Conjugation experiments with an Escherichia coli J53 recipient showed that most of the plasmids in IMP-6 producers were transferable, whereas only one-half of the plasmids in IMP-1 producers were transferable. PCR-based replicon typing and multiplex PCR identified five isolates belonging to the CG258 non-tonB79 cluster and no isolate belonging to the CG258-tonB79 cluster or sequence type 307 (ST307). Four K1-ST23 isolates, 10 K2-ST65 isolates, and 7 K2-ST86 isolates were detected that harbored virulence genes. The resistance genes in 85 isolates were transferable, but the virulence genes were not transferred. These results demonstrate the acquisition of IMP-type carbapenemase genes and CTX-M-type genes among hypervirulence isolates in Japan, warranting further attention and countermeasures. In this study, we have determined the molecular characteristics and epidemiology of IMP-6 producers that coharbored various CTX-M genes in Japan.IMPORTANCE Carbapenems serve as a last resort for the clinical treatment of multidrug-resistant infections. Therefore, the rapid spread of carbapenemase-producing strains represents a serious public health threat, further limiting antibiotic choices. The current findings of hypervirulent carbapenemase-producing Klebsiella pneumoniae clinical isolates in Japan demonstrate the potential broad spread and transfer of these genes, necessitating close surveillance.博士（医学）・乙第1509号・令和3年3月15日Copyright © 2020 Yonekawa et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license(https://creativecommons.org/licenses/by/4.0/)

General characterization of Antarctic micrometeorites collected by the 39th Japanese Antarctic Research Expedition: Consortium studies of JARE AMMs (III)

From November 1998 to January 1999,the 39th Japanese Antarctic Research Expedition (JARE-39) undertook Japanese first large-scale collection of Antarctic micrometeorites (AMMs), with sizes larger than 10μm, at the Meteorite Ice Field around the Yamato Mountains in Antarctica (at three different locations, for a total of 24 collection sites). The number of collected AMMs larger than 40μm is estimated to be about 5000. Here we present the general characterization (i.e., micro-morphology and surface chemical composition using SEM/EDS) of ∿810 AMMs chosen from 5 of the 24 sites. Additionally, the mineral composition of 61 out of 810 AMMs was determined by Synchrotron X-ray radiation. Preliminary results on mineralogical and chemical compositions show similarities with that of previous studies, even though a pronounced alteration of some AMMs is noticed. A correlation is found between the Mg/Si ratio at the sample\u27s surfaces of unmelted AMMs and the age of snow/ice in which the AMMs are embedded

Protocol for a multicentre, prospective, cohort study to investigate patient satisfaction and quality of life after immediate breast reconstruction in Japan: the SAQLA study

Introduction The aim of breast reconstruction (BR) is to improve patients' health-related quality of life (HRQOL). Therefore, measuring patient-reported outcomes (PROs) would clarify the value and impact of BR on a patient's life and thus would provide evidence-based information to help decision-making. The Satisfaction and Quality of Life After Immediate Breast Reconstruction study aimed to investigate satisfaction and HRQOL in Japanese patients with breast cancer who undergo immediate breast reconstruction (IBR). Methods and analysis This ongoing prospective, observational multicentre study will assess 406 patients who had unilateral breast cancer and underwent mastectomy and IBR, and were recruited from April 2018 to July 2019. All participants were recruited from seven hospitals: Okayama University Hospital, Iwate Medical University Hospital, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Showa University Hospital, University of Tsukuba Hospital, Osaka University Hospital and Yokohama City University Medical Center. The patients will be followed up for 36 months postoperatively. The primary endpoint of this study will be the time-dependent changes in BREAST-Q satisfaction with breast subscale scores for 12 months after reconstructive surgery, which will be collected via an electronic PRO system. Ethics and dissemination This study will be performed in accordance with the Ethical Guidelines for Medical and Health Research Involving Human Subjects published by Japan's Ministry of Education, Science and Technology and the Ministry of Health, Labour and Welfare, the modified Act on the Protection of Personal Information and the Declaration of Helsinki. This study protocol was approved by the institutional ethics committee at the Okayama University Graduate School of Medicine, Dentistry, on 2 February 2018 (1801-039) and all other participating sites. The findings of this trial will be submitted to an international peer-reviewed journal

Molecular Characteristics of Extended-Spectrum Beta-Lactamases and qnr Determinants in Enterobacter Species from Japan

The incidence of extended-spectrum β-lactamases (ESBLs) has been increasing worldwide, but screening criteria for detection of ESBLs are not standardized for AmpC-producing Enterobacteriaceae such as Enterobacter species. In this study, we investigated the prevalence of ESBLs and/or AmpC β-lactamases in Japanese clinical isolates of Enterobacter spp. and the association of plasmid-mediated quinolone resistance (PMQR) determinants with ESBL producers. A total of 364 clinical isolates of Enterobacter spp. collected throughout Japan between November 2009 and January 2010 were studied. ESBL-producing strains were assessed by the CLSI confirmatory test and the boronic acid disk test. PCR and sequencing were performed to detect CTX-M, TEM, and SHV type ESBLs and PMQR determinants. For ESBL-producing Enterobacter spp., pulsed-field gel electrophoresis (PFGE) was performed using XbaI restriction enzyme. Of the 364 isolates, 22 (6.0%) were ESBL producers. Seven isolates of Enterobacter cloacae produced CTX-M-3, followed by two isolates producing SHV-12. Two isolates of Enterobacter aerogenes produced CTX-M-2. Of the 22 ESBL producers, 21 had the AmpC enzyme, and six met the criteria for ESBL production in the boronic acid test. We found a significant association of qnrS with CTX-M-3-producing E. cloacae. The 11 ESBL-producing Enterobacter spp. possessing blaCTX-M, blaSHV, or blaTEM were divided into six unique PFGE types. This is the first report about the prevalence of qnr determinants among ESBL-producing Enterobacter spp. from Japan. Our results suggest that ESBL-producing Enterobacter spp. with qnr determinants are spreading in Japan

建学の精神の徹底を図る初年次教育の実践と課題 ―ホスピタリティ概論の分析から―

本研究は、2017年度から始まった本学の初年次教育を定着させるとともに、新入生が大学での教育を理解し、建学の精神に代表される理念やディプロマポリシーを自分のものとして捉え、その実現に向けた主体的な学修の基盤を構築するという初年次教育の目標の達成を図ることにある。このためには、彼らの特性をとらえるとともに、彼らが初年次教育をどのように捉え、理解したかを把握しなければならない。そこで初年次教育の科目の一つとして開設された「ホスピタリティ概論」を活用して、全受講生を対象とした2つの調査を3年間実施した。1つ目の調査は入学当初の学生像をとらえ授業展開に生かすために学生の特徴を把握するものであり、第1回目の授業で実施された。2つ目の調査は授業内容の理解度を評価するものであり、第10回目に実施された。これらの回答を年度と学科毎に集計、分析した。その結果、次のことが明らかになった。①オープンキャンパスへの参加や進学希望状況などの本学入学に至る経緯が学科によって異なること、そして、入学当初には心身に不安を抱いている学生が、どの学科にも相当数存在すること。3年間の調査によって各学科の学生の特色が明らかになり、学科毎の適切な学修支援方策の作成に向けた示唆が得られたこと。②この講義を受けて、建学の精神であるホスピタリティの獲得に大学が力を入れており、その実現が求められていると多くの学生が認識していること、及び、本科目の重点目標である多様性の理解力の育成につながる他学科の学生とのコミュニケーションの機会に意義を見出していること等から、授業の目標達成に向けた順調な歩みが見られること。これらの結果及び他の科目の報告から、初年次教育が定着しつつあること、そして、その目標達成に向けた歩みが順調であると判断した。ただ、更なる充実のための課題も浮かび上がっている

Plasmodium knowlesi thioredoxin peroxidase 1 binds to nucleic acids and has RNA chaperone activity

Malaria parasites are under oxidative attack throughout their life cycle in human body and mosquito vector. Therefore, Plasmodium antioxidant defenses are crucial for its survival and being considered as interesting target for antimalarial drug design. Plasmodium knowlesi has emerged recently from its simian host to human in Southeast Asia and has been recognized as the fifth Plasmodium species that can cause human malaria. In this study, we cloned and characterized thioredoxin peroxidase 1 from P. knowlesi (PkTPx-1). PkTPx-1 gene was cloned, and recombinant protein was produced by heterologous overexpression in Escherichia coli. The recombinant protein was used for evaluation of enzymatic activity and polyclonal antibody production. Using the recombinant PkTPx-1 protein, its antioxidant activity was confirmed in a mixed-function oxidation assay where PkTPx-1 prevented nicking of DNA by hydroxyl radicals. PkTPx-1 was able to bind to double-strand DNA and RNA and had RNA chaperone activity in a nucleic acid melting assay indicating new function of PkTPx-1 other than antioxidant activity. Using specific polyclonal antibodies, it was indicated that PkTPx-1 is expressed in the cytoplasm of the parasite. Altogether, these results suggest that PkTPx-1 not only protects the parasite from the adverse effects of reactive oxygen species but also has RNA chaperone activity