Updated on 2024/05/08

写真a

 
OKA Keisuke
 
Organization
Nagoya University Hospital Center of National University Hospital for Infection Control Assistant professor of hospital
Title
Assistant professor of hospital
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Degree 1

  1. Doctor (Medicine) ( 2022.9   Nagoya University ) 

Research Interests 6

  1. 薬剤耐性菌

  2. 分子疫学

  3. 細菌

  4. Infection Control

  5. 結核菌

  6. ワクチン

Research Areas 3

  1. Life Science / Bacteriology

  2. Life Science / Hygiene and public health (laboratory)

  3. Life Science / General internal medicine

Research History 1

  1. Nagoya University   Nagoya University Hospital Center of National University Hospital for Infection Control   Assistant professor of hospital

    2021.8

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Professional Memberships 7

  1. 日本内科学会

  2. 日本感染症学会

  3. 日本化学療法学会

  4. 日本呼吸器学会

  5. 日本結核・非結核性抗酸菌症学会

  6. 日本臨床微生物学会

  7. 日本環境感染学会

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Awards 1

  1. The 19th Asia Pacific Congress of Clinical Microbiology and Infection Best Poster Presentation Awards

    2023.7   Asia Pacific Society of Clinical Microbiology and Infection   Analysis of Enterobacter cloacae complex producing IMI-type carbapenemase

    Keisuke Oka, Kazumitsu Kawamura, Tetsuya Yagi

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    Award type:Award from international society, conference, symposium, etc.  Country:Korea, Republic of

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Papers 26

  1. Clinical characteristics and treatment outcomes of carbapenem-resistant Enterobacterales infections in Japan. Reviewed International journal

    Keisuke Oka, Akane Matsumoto, Nobuyuki Tetsuka, Hiroshi Morioka, Mitsutaka Iguchi, Nobuhisa Ishiguro, Tsunehisa Nagamori, Satoshi Takahashi, Norihiro Saito, Koichi Tokuda, Hidetoshi Igari, Yuji Fujikura, Hideaki Kato, Shinichiro Kanai, Fumiko Kusama, Hiromichi Iwasaki, Kazuki Furuhashi, Hisashi Baba, Miki Nagao, Masaki Nakanishi, Kei Kasahara, Hiroshi Kakeya, Hiroki Chikumi, Hiroki Ohge, Momoyo Azuma, Hisamichi Tauchi, Nobuyuki Shimono, Yohei Hamada, Ichiro Takajo, Hirotomo Nakata, Hideki Kawamura, Jiro Fujita, Tetsuya Yagi

    Journal of global antimicrobial resistance   Vol. 29   page: 247 - 252   2022.6

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

    OBJECTIVES: The dissemination of difficult-to-treat carbapenem-resistant Enterobacterales (CRE) is of great concern. We clarified the risk factors underlying CRE infection mortality in Japan. METHODS: We conducted a retrospective, multicentre, observational cohort study of patients with CRE infections at 28 university hospitals from September 2014 to December 2016, using the Japanese National Surveillance criteria. Clinical information, including patient background, type of infection, antibiotic treatment, and treatment outcome, was collected. The carbapenemase genotype was determined using PCR sequencing. Multivariate analysis was performed to identify the risk factors for 28-day mortality. RESULTS: Among the 179 patients enrolled, 65 patients (36.3%) had bloodstream infections, with 37 (20.7%) infections occurring due to carbapenemase-producing Enterobacterales (CPE); all carbapenemases were of IMP-type (IMP-1: 32, IMP-6: 5). Two-thirds of CPE were identified as Enterobacter cloacae complex. Combination therapy was administered only in 46 patients (25.7%), and the 28-day mortality rate was 14.3%. Univariate analysis showed that solid metastatic cancer, Charlson Comorbidity Index ≥3, bloodstream infection, pneumonia, or empyema, central venous catheters, mechanical ventilation, and prior use of quinolones were significant risk factors for mortality. Multivariate analysis revealed that mechanical ventilation (OR: 6.71 [1.42-31.6], P = 0.016), solid metastatic cancers (OR: 5.63 [1.38-23.0], P = 0.016), and bloodstream infections (OR: 3.49 [1.02-12.0], P = 0.046) were independent risk factors for 28-day mortality. CONCLUSION: The significant risk factors for 28-day mortality in patients with CRE infections in Japan are mechanical ventilation, solid metastatic cancers, and bloodstream infections.

    DOI: 10.1016/j.jgar.2022.04.004

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  2. Genetic and epidemiological analysis of ESBL-producing Klebsiella pneumoniae in three Japanese university hospitals. Reviewed International journal

    Keisuke Oka, Nobuyuki Tetsuka, Hiroshi Morioka, Mitsutaka Iguchi, Kazumitsu Kawamura, Kengo Hayashi, Takako Yanagiya, Yuiko Morokuma, Tomohisa Watari, Makiko Kiyosuke, Tetsuya Yagi

    Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy   Vol. 28 ( 9 ) page: 1286 - 1294   2022.9

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    INTRODUCTION: We aimed to clarify the genetic background and molecular epidemiology of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae (K. pneumoniae) at three geographically separated university hospitals in Japan. METHODS: From January 2014 to December 2016, 118 ESBL-producing K. pneumoniae (EPKP) strains that were detected and stored at three university hospitals were collected. Molecular epidemiological analysis was performed using enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction (PCR) and multi-locus sequence typing (MLST). The ESBL type was determined using the PCR-sequence method. The presence of plasmid-mediated fluoroquinolone resistance (PMQR) genes was analyzed by PCR. We compared the relationships between PMQR gene possession/quinolone resistance-determining region (QRDR) mutation and levofloxacin (LVFX)/ciprofloxacin (CPFX) susceptibility. RESULTS: The detection rate of EPKP was 4.8% (144/2987 patients). MLST analysis revealed 62 distinct sequence types (STs). The distribution of STs was diverse, and only some EPKP strains had the same STs. ERIC-PCR showed discriminatory power similar to that of MLST. The major ESBL genotypes were CTX-M-15-, CTX-M-14-, and SHV-types, which were detected in 47, 30, and 27 strains, respectively. Ninety-one out of 118 strains had PMQR genes and 14 out of 65 strains which were not susceptible to CPFX had QRDR mutations, and the accumulation of PMQR genes and QRDR mutations tended to lead to higher minimum inhibitory concentrations (MICs) of LVFX. CONCLUSIONS: At three geographically separated university hospitals in Japan, the epidemiology of EPKP was quite diverse, and no epidemic strains were found, whereas CTX-M-14 and CTX-M-15 were predominant.

    DOI: 10.1016/j.jiac.2022.05.013

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  3. Mycobacterium Obuense Bacteremia: A Case Report and Literature Review Reviewed

    Oka Keisuke, Sahara Shoko, Kuramae Hitoshi, Osada Yukari

    International Journal of Mycobacteriology   Vol. 12 ( 3 ) page: 357 - 359   2023.7

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  4. Bursitis, Bacteremia, and Disseminated Infection of <i>Mycobacteroides</i> (<i>Mycobacterium</i>) <i>abscessus</i> subsp. <i>massiliense</i>

    Oka Keisuke, Morioka Hiroshi, Eguchi Motoki, Sato Yoshitaka, Tetsuka Nobuyuki, Iguchi Mitsutaka, Kanematsu Takeshi, Fukano Hanako, Hoshino Yoshihiko, Kiyoi Hitoshi, Yagi Tetsuya

    Internal Medicine   Vol. 60 ( 18 ) page: 3041 - 3045   2021.9

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:The Japanese Society of Internal Medicine  

    <p>We herein report a 59-year-old woman with a 2-year history of chronic bursitis of the hand who took 50 mg/day prednisolone for several autoimmune diseases. <i>Mycobacteroides</i> <i>abscessus</i> subsp. <i>massiliense</i> was isolated from the abscess and blood culture. Combination therapy (imipenem/cilastatin, amikacin, and clarithromycin) was administered for a month. Two months later, <i>M. massiliense</i> was detected from a blood culture again, and disseminated lesions were found. Clarithromycin and sitafloxacin were administered following eight weeks of the same regimen. Six months after the diagnosis, <i>M. massiliense</i> was isolated from a blood culture, and she expired due to multiple organ failure. </p>

    DOI: 10.2169/internalmedicine.6189-20

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  5. Case of monomicrobial necrotizing fasciitis caused by extended‐spectrum β‐lactamase–producing Citrobacter freundii

    Satoshi Kamiya, Tatsuro Sugai, Keisuke Oka, Eori Noda, Akira Miyazaki, Rika Hagiwara‐Fujishiro, Motohito Yamada, Tetsuya Yagi, Masashi Akiyama

    The Journal of Dermatology     2024.4

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    DOI: 10.1111/1346-8138.17246

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  6. Comparison of disease and economic burden between MRSA infection and MRSA colonization in a university hospital: a retrospective data integration study. Reviewed

    Hirabayashi A, Yahara K, Oka K, Kajihara T, Ohkura T, Hosaka Y, Shibayama K, Sugai M, Yagi T

    Antimicrobial resistance and infection control   Vol. 13 ( 1 ) page: 27   2024.2

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    Background: Although there is a growing concern and policy regarding infections or colonization caused by resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), the prognosis of MRSA infections compared to that of methicillin-susceptible Staphylococcus aureus (MSSA) infections remains controversial. Moreover, there have not been any studies comparing both the burden of disease and its impact on the healthcare economy between MRSA infection and colonization while adjusting for confounding factors. These comparisons are crucial for developing effective infection control measures and healthcare policies. We aimed to compare the disease and economic burden between MRSA and MSSA infections and between MRSA infection and colonization. Methods: We retrospectively investigated data of 496 in-patients with MRSA or MSSA infections and of 1178 in-patients with MRSA infections or MRSA colonization from a university hospital in Japan from 2016 to 2021. We compared in-hospital mortality, length of stay, and hospital charges between in-patients with MRSA and MSSA infections and those with MRSA infections and MRSA colonization using multiple regressions. We combined surveillance data, including all microbiological test results, data on patients with infections, treatment histories, and clinical outcomes, to create the datasets. Results: There was no statistically significant difference in in-hospital mortality rates between matched MRSA vs. MSSA infections and MRSA infection vs. colonization. On the contrary, the adjusted effects of the MRSA infection compared to those of MSSA infection on length of stay and hospital charges were 1.21-fold (95% confidence interval [CI] 1.03–1.42, P = 0.019) and 1.70-fold (95% CI 1.39–2.07, P < 0.00001), respectively. The adjusted effects of the MRSA infection compared to those of MRSA colonization on length of stay and hospital charges were 1.41-fold (95% CI 1.25–1.58, P < 0.00001) and 1.53-fold (95% CI 1.33–1.75, P < 0.00001), respectively. Regarding confounding factors, hemodialysis or hemofiltration was consistently identified and adjusted for in the multiple regression analyses comparing MRSA and MSSA infections, as well as MRSA infection and MRSA colonization. Conclusions: MRSA infection was associated with longer length of stay and higher hospital charges than both MSSA infection and MRSA colonization. Furthermore, hemodialysis or hemofiltration was identified as a common underlying factor contributing to increased length of stay and hospital charges.

    DOI: 10.1186/s13756-024-01383-8

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  7. How an Antimicrobial Stewardship Team Treated a Nocardia farcinica-Associated Brain Abscess: A Case Report Reviewed

    Tetsushi Amano, Tomohide Nishikawa, Keisuke Oka, Kosei Ota, Taro Shimizu

    Cureus   Vol. 16 ( 2 ) page: e54605   2024.2

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    DOI: 10.7759/cureus.54605

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  8. Catheter-related bloodstream infection caused by Lacticaseibacillus paracasei: A case report and literature review. Reviewed

    Fukuda Y, Morioka H, Yamamoto S, Iguchi M, Umeda S, Asahara T, Kanda K, Oka K, Nakayama G, Yagi T

    Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy     2024.1

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    Catheter-related bloodstream infections (CRBSIs) caused by Lactobacillus spp. and Lacticaseibacillus spp. are rare, and their clinical course and optimal treatment remain uncertain. In this report, we present a 46-year-old male patient who experienced clinically diagnosed Lacticaseibacillus paracasei CRBSI on four separate occasions, despite receiving systemic administration of antibiotics and antimicrobial lock therapy. The patient did not develop L. paracasei bacteremia after catheter removal. This case report furthers our knowledge of CRBSI caused by Lactobacillus and related genera and highlights the need for further research.

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  9. Surgical antimicrobial prophylaxis in Japanese hospitals: Real status and challenges Reviewed

    Hiroshi Morioka, Yusuke Koizumi, Toshitaka Watariguchi, Keisuke Oka, Yuka Tomita, Yumi Kojima, Masami Okudaira, Yuji Ito, Junichi Shimizu, Koichi Watamoto, Hiroki Kato, Masatoshi Nagaoka, Manabu Yokota, Chihiro Hasegawa, Takeshi Tsuji, Shinsuke Shimizu, Kenta Ito, Shohei Kawasaki, Kenji Akita, Yuichi Kitagawa, Yoshikazu Mutoh, Masamitsu Ishihara, Susumu Iwata, Yasuhiro Nozaki, Masanori Nozawa, Munehiro Kato, Masao Katayama, Tetsuya Yagi

    Journal of Infection and Chemotherapy     2024.1

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    DOI: 10.1016/j.jiac.2024.01.013

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  10. Methicillin-resistant Staphylococcus aureus-induced staphylococcal scalded skin syndrome in a preterm infant, and subsequent toxigenic analysis. Reviewed International journal

    Ryo Fukaura, Chiaki Terashima-Murase, Mai Ota, Haruka Noda, Keisuke Oka, Yuka Ishihara, Keigo Shibayama, Masashi Akiyama

    The Journal of dermatology   Vol. 50 ( 12 ) page: e422 - e423   2023.12

  11. First Case Report of Peritoneal Dialysis-associated Peritonitis Caused by <i>Lysinibacillus sphaericus</i> Reviewed

    Kinoshita Teruhisa, Sahara Shoko, Amano Tomomi, Ito Masashi, Sakakibara Takashi, Takimoto Norio, Osada Yukari, Oka Keisuke

    Internal Medicine   Vol. 62 ( 19 ) page: 2919 - 2922   2023.10

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    <p>We herein report a case of peritoneal dialysis-associated peritonitis caused <i>by Lysinibacillus sphaericus</i> in a 40s-year-old patient. Treatment was initiated with intermittent intraperitoneal cefazolin and ceftazidime. Later, both peritoneal dialysate and blood cultures detected <i>L. sphaericus</i>, so the antibiotic was changed to ampicillin (ABPC). The patient was treated with a combination of intraperitoneal intermittent and intravenous ABPC for 7 days, followed by 14 days of amoxicillin. The patient experienced no adverse events and no recurrence for 30 days. The patient had four dogs, and the infection was deemed likely to have been caused by environmental contamination and inadequate catheter replacement. </p>

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  12. Time course of skin rash, computed tomography findings, and viral load in a rheumatoid arthritis patient with severe varicella pneumonia. Reviewed International journal

    Hironori Kobayashi, Shunta Takeuchi, Yuka Torii, Tadasuke Ikenouchi, Jun-Ichi Kawada, Keisuke Oka, Sayaka Kato, Masahiro Ogawa

    IDCases   Vol. 33   page: e01866   2023.8

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    Varicella-zoster virus (VZV) infection in adults or immunocompromised patients has a more severe presentation compared to the mild disease in children. To the best of our knowledge, no reports have described the clinical course of VZV pneumonia focusing on time course of skin rash, chest computed tomography (CT) findings, and viral load. Furthermore, no reports have described the reactivation of human herpes virus 6 (HHV-6) in VZV pneumonia. Here, we report a case of severe VZV pneumonia that resulted in reactivation of HHV-6 in a patient with rheumatoid arthritis (RA). A 66-year-old female treated for RA was admitted to our hospital with papules. Her chest CT showed granular infiltrates, micronodules, and ground-glass opacities. The day after admission, because the typical skin rashes and chest CT findings were observed, she was diagnosed with VZV pneumonia and treated with acyclovir. Her skin rash then crusted over five days and entered the healing process, whereas it took approximately two weeks for her respiratory condition and chest CT findings to improve. In addition, VZV deoxyribonucleic acid (DNA) gradually decreased with treatment. On the 34th day of admission, VZV DNA was not found in the serum sample but remained in the sputum sample. Furthermore, although reactivation of HHV-6 was observed, viremia resolved without treatment. Clinicians should be able to recognize the differences in the improvement of skin rashes, respiratory status, and chest CT findings. In addition, treatment for HHV-6 reactivation should be carefully determined for each case.

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  13. Effectiveness of educating physicians on the appropriate use of oral antimicrobials for acute diarrhea among outpatients Reviewed

    Shoko Sahara, Teruhisa Kinoshita, Daichi Shibata, Ayumi Ishihara, Takato Kunito, Takeshi Masaki, Norio Takimoto, Keisuke Oka

    Japanese Journal of Chemotherapy   Vol. 70 ( 6 ) page: 460 - 465   2022.10

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  14. <Editors' Choice> Multicenter survey for carbapenemase-producing Enterobacterales in central Japan. Reviewed

    Yuki Hara, Mitsutaka Iguchi, Nobuyuki Tetsuka, Hiroshi Morioka, Aki Hirabayashi, Masato Suzuki, Yuka Tomita, Keisuke Oka, Tetsuya Yagi

    Nagoya journal of medical science   Vol. 84 ( 3 ) page: 630 - 639   2022.8

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    Carbapenemase-producing Enterobacterales (CPE) raise concerns about the treatment options for infectious diseases and infection control. We conducted a multicenter study to clarify the molecular epidemiology of CPE in the Aichi Prefecture during the first 3-month period from 2015 to 2019. Carbapenemase production was screened using a modified carbapenem inactivation method, and the genotypes of the carbapenemase genes were determined by polymerase chain reaction sequencing. Genetic relatedness was analyzed using multilocus sequence typing (MLST). Twenty-four hospitals participated in this study. Of the 56,494 Enterobacterales strains detected during the study period, 341 (0.6%) that met the susceptibility criteria were analyzed. Sixty-five of the 341 strains were determined to be CPE, with an incidence rate of 0.12% (65/56,494). The bacterial species responsible for CPE were Klebsiella pneumoniae (n = 24), Enterobacter cloacae complex (n = 23), Klebsiella oxytoca (n = 10), and Escherichia coli (n = 8). Most of the carbapenemase genotypes were IMP-1 (58/65), and only three were IMP-6 types. Three E. coli strains that produced NDM-5 were detected. MLST analysis showed that Sequence type (ST) 78 was predominant in E. cloacae complex CPE (14/23, 60.9%). Meanwhile, various STs were detected in carbapenemase-producing (CP) K. pneumoniae, of which ST37 and ST517 were the most common. The incidence rate of CPE in this region was comparable to national data. This 3-month surveillance revealed the spread of ST78 of CP E. cloacae complex and ST517 and ST592 of CP K. pneumoniae across hospitals, indicating the need to strengthen regional infection control programs.

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  15. A case of respiratory arrest due to epidural abscess of the cervical cord caused by <i>Mycobacteroides abscessus</i> complex Reviewed

    ANDO Maho, SHIMIZU Ayako, KISHIDA Honoka, SAKAKIBARA Chihiro, SOMEYA Yuki, KURAMAE Hitoshi, NAKAMURA Kiyotada, OKA Keisuke

    Japanese Journal of Medical Technology   Vol. 71 ( 3 ) page: 599 - 605   2022.7

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    Authorship:Last author   Language:Japanese   Publisher:Japanese Association of Medical Technologists  

    <p>The patient was a 67-year-old man who was on hemodialysis because of diabetic nephropathy and end-stage renal disease. There was a sign of infection in the subcutaneous arteriovenous fistula of the right forearm more than three weeks before he visited our hospital, and a culture test was performed three times in a nearby clinic, but all the tests showed negative results. He was urgently taken to our hospital because of neck pain during hemodialysis. After cervical computed tomography (CT) imaging in the emergency outpatient department, he suddenly experienced cardiopulmonary arrest and was resuscitated. It was determined that the epidural occupying the lesion found by cervical CT compressed the cervical spinal cord, leading to respiratory arrest. For this patient, surgery and antibiotic treatment were not possible owing to poor neurological prognosis. Blood cultures collected on the day of admission to determine the cause became positive for a bacterium on the 6th day of admission, which was identified as <i>Mycobacteroides abscessus</i> complex. Even rapidly growing mycobacteria require more time to grow than general bacteria, and it is difficult to detect them unless they are tested with the bacteria in mind and epidural abscesses may cause a rapid onset of irreversible symptoms. From these findings, it was considered that appropriate and prompt responses are important for such cases. If bacteria are not detected in cultures performed for the purpose of detecting general bacteria but the signs of infection persist, it is important to assume mycobacterium, perform appropriate tests, and provide information to the doctor in charge.</p>

    DOI: 10.14932/jamt.21-126

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  16. Difficulties in diagnosing Malassezia furfur bloodstream infection and possibility of spontaneous resolution in a patient undergoing chemotherapy for neuroblastoma: A case report. Reviewed International journal

    Nobuyuki Tetsuka, Hideki Muramatsu, Mitsutaka Iguchi, Keisuke Oka, Hiroshi Morioka, Yoshiyuki Takahashi, Tetsuya Yagi

    Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy   Vol. 28 ( 7 ) page: 987 - 990   2022.7

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    Malassezia furfur is a lipophilic, yeast-like fungus that forms part of the normal human skin microflora and is associated with a wide range of infections, such as pityriasis versicolor, folliculitis, and systemic infections in immunocompromised patients. Although matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has enabled rapid identification of Malassezia species, it is still a challenge to diagnose systemic infections because Malassezia fungemia can often be missed by automated blood culture systems. We report a case in which M. furfur in blood was detected by the presence of yeast-like fungi in blood smears. Yeast-like organisms were observed in the blood smears of a 3-year-old boy, taken over 2 weeks without any symptoms. He had undergone several courses of chemotherapy for neuroblastoma via an indwelling central venous catheter (CVC) that was placed in his right anterior chest for 11 months. Although the blood cultures obtained from an automated blood culture system were negative, M. furfur growth was detected in the subcultured blood taken from the CVC. The CVC was removed, and the scheduled chemotherapy was postponed. No systemic M. furfur bloodstream infection occurred; the infection resolved spontaneously without any specific treatment; only prophylactic fluconazole was administered. M. furfur fungemia may not be diagnosable by an automated blood culture system. Further, M. furfur may not cause infections in humans even when administered intravenously. This report may lead to the discovery of factors related to human infectivity of this disease in the future.

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  17. Epidemiology and molecular characterization of fecal carriage of third-generation cephalosporin-resistant enterobacterales among elderly residents in Japan. Reviewed International journal

    Miyuki Nakai, Keisuke Oka, Genichi Watanabe, Katsunori Kamei, Norio Tsukada, Ryota Mori, Masahiro Nagaya, Yasumitsu Ukai, Hiroshi Morioka, Nobuyuki Tetsuka, Mitsutaka Iguchi, Tetsuya Yagi

    Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy   Vol. 28 ( 4 ) page: 569 - 575   2022.4

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    INTRODUCTION: The spread of third-generation cephalosporin-resistant Gram-negative bacteria is a serious concern in acute and post-acute care settings. This study aimed to understand the epidemiology and molecular background of fecal colonization of resistant Enterobacterales in elderly people. METHODS: In December 2015-December 2017, stool or rectal swab samples were collected from 101 elderly patients receiving home care, using long-term care facilities (LTCF), and living in nursing homes repeatedly at 3-9-month intervals. Patient clinical background data were collected from medical records. After phenotypic screening for extended-spectrum β-lactamase (ESBL), AmpC-type β-lactamase or carbapenemase production, drug resistance genes of isolates were analyzed using polymerase chain reaction (PCR). ESBL-producing Escherichia coli isolates obtained from the same patients in repetitive screenings were analyzed using PCR-based ORF typing. Risk factors for persistent carriage of resistant Enterobacterales were analyzed using multivariate analysis. RESULTS: Resistant Enterobacterales isolates were detected in 37 of 101 (36.6%) and 29 of 80 (36.3%) residents in first and second screenings, respectively. ESBL-producing E. coli accounted for 80% isolates, the most common being CTX-M-9-group β-lactamase producers. Molecular epidemiological analysis revealed probable transmissions of ESBL-producing E. coli; 58% of ESBL-producing E. coli colonizers were persistent colonizers at least after 3 -month intervals. Age > 87 years and LTCF residence were independent risk factors for persistent carriage of ESBL-producing E. coli. CONCLUSIONS: We showed, for the first time, high persistent colonization rate of ESBL-producing E. coli among elderly people in post-acute care settings with probable horizontal transmission. We also identified significant risk factors for persistent colonization.

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  18. Lysinibacillus fusiformis bacteremia: Case report and literature review. Reviewed International journal

    Hiroshi Morioka, Keisuke Oka, Yosuke Yamada, Yoshimasa Nakane, Hitoshi Komiya, Chiaki Murase, Mitsutaka Iguchi, Tetsuya Yagi

    Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy   Vol. 28 ( 2 ) page: 315 - 318   2022.2

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    A 93-year-old woman was diagnosed with Lysinibacillus fusiformis bacteremia complicated with coma blisters. Initial gram staining for L. fusiformis indicated the presence of gram-negative rods; however, subsequent staining of colonies from Mueller-Hinton agar revealed the presence of gram-positive and gram-negative rods with spherical endospores, and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (VITEK ® MS and microflex® LT/SH) definitively identified the organism as L. fusiformis. The two-week administration of piperacillin/tazobactam and ampicillin resulted in an improvement of the patient's general condition, and the skin lesions gradually improved.

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  19. A case of acute focal bacterial nephritis caused by methicillin-resistant Staphylococcus saprophyticus in a 13-year-old adolescent girl treated with daptomycin Reviewed

    Teruhisa Kinoshita, Shoko Sahara, Yuka Mihara, Yumiko Asai, Hiroko Sato, Takashi Sakakibara, Norio Takimoto, Keisuke Oka

    IDCases   Vol. 29   page: e01594 - e01594   2022

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  20. Five-year point prevalence survey of healthcare-associated infections and antimicrobial use in a Japanese university hospital Reviewed

    H. Morioka, M. Iguchi, N. Tetsuka, F. Kinoshita, Y. Tomita, D. Kato, A. Hirabayashi, A. Matsumoto, K. Oka, H. Kato, T. Inagaki, Y. Kato, K. Kitagawa, K. Ichikawa, Y. Kouyama, N. Kawamura, Y. Toyodome, N. Adachi, Y. Ito, T. Yagi

    Infection Prevention in Practice   Vol. 3 ( 3 ) page: 100151 - 100151   2021.9

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  21. Weekly point-prevalence surveillanceを用いた医療関連感染対策の有効性評価

    豊留 有香, 西田 一貴, 井口 光孝, 森岡 悠, 手塚 宜行, 岡 圭輔, 矢田 吉城, 長田 ゆかり, 安立 なぎさ, 八木 哲也

    日本環境感染学会総会プログラム・抄録集   Vol. 36回   page: 274 - 274   2021.9

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    Language:Japanese   Publisher:(一社)日本環境感染学会  

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  22. 対症療法のみで軽快した新型コロナウイルス感染症(COVID-19)の1例 Reviewed

    武田 直也,加藤 早紀,岡 圭輔,浅野 元世,中島 国也,鈴木 嘉洋,吉田 憲生

    日本病院総合診療医学会雑誌   Vol. 16 ( 臨時増刊号2 ) page: 289 - 291   2020

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  23. Molecular epidemiological analysis and risk factors for acquisition of carbapenemase-producing Enterobacter cloacae complex in a Japanese university hospital Invited Reviewed International journal

    Nobuyuki Tetsuka, Aki Hirabayashi, Akane Matsumoto, Keisuke Oka, Yuki Hara, Hiroshi Morioka, Mitsutaka Iguchi, Yuka Tomita, Masato Suzuki, Keigo Shibayama, Tetsuya Yagi

    Antimicrobial resistance and infection control   Vol. 8 ( 8 ) page: 126 - 126   2019.7

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    Language:Japanese   Publishing type:Doctoral thesis  

    BACKGROUND: To clarify the molecular epidemiology of carbapenem-resistant Enterobacter cloacae complex (CREC) and the risk factors for acquisition of carbapenemase-producing E. cloacae complex (CPEC). METHODS: Using clinical CREC isolates detected in a Japanese university hospital over 4 years, carbapenemase production was screened with phenotypic methods. Carbapenemase genes were analysed by PCR and sequencing. Molecular epidemiological analyses were conducted with repetitive extragenic palindromic (REP)-PCR and multilocus sequence typing (MLST). CRECs were identified to the subspecies level by hsp60 sequencing. Whole-genome sequencing of plasmids was conducted. A case-control study was performed to identify risk factors for acquisition of CPEC among patients with CREC. RESULTS: Thirty-nine CRECs including 20 CPECs carrying blaIMP-1 were identified. Patients with CPEC had longer hospital stay before detection (26.5 days vs. 12 days, p = 0.008), a urinary catheter (odds ratio [OR], 5.36; 95% confidence interval [CI], 1.14-30.9; p = 0.023), or intubation (OR, 7.53; 95% CI, 1.47-53.8; p = 0.008) compared to patients without CPEC. Four genetically closely related CPEC clusters were observed, which showed that three of four CPEC clusters corresponded to E. asburiae (ST 53), E. hormaechei subsp. steigerwaltii (ST 113 and ST 1047) and E. cloacae subsp. cloacae (ST 513) by MLST and hsp60 sequencing. Seven representative plasmids shared structures with class I integron containing blaIMP-1 and IncHI2A replicon type. CONCLUSIONS: A longer hospital stay, presence of a urinary catheter, and intubation are risk factors for CPEC acquisition. In addition to horizontal transmission of genetically indistinguishable CPECs, IncHI2A plasmid carrying blaIMP-1 appeared to be transferred among genetically different ECs.

    DOI: 10.1186/s13756-019-0578-3

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  24. フライングディスク練習会の実施と運営 ―自施設内での新規立ち上げと他施設との交流― Reviewed

    加藤 聡之, 武田 直也, 岡 圭輔, 柴田 寛史, 酒井 元生, 河野 純子, 崎尾 百合子

    日本呼吸ケア・リハビリテーション学会誌   Vol. 16 ( 2 ) page: 313 - 317   2016.8

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  25. A Case of Contralateral Reexpansion Pulmonary Edema After Thoracoscopy Under Local Anesthesia Reviewed

    Yoshihiro Suzuki, Naoya Takeda, Hirofumi Shibata, Keisuke Oka, Hiroyoshi Kitagawa, Akira Matsui, Suguru Majima, Ayako Miyazawa, Norio Yoshida, Toshiyuki Katoh, Masaru Iwata

    The Journal of the Japan Society for Respiratory Endoscopy   Vol. 35 ( 2 ) page: 178 - 182   2015.3

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  26. A Case of Pulmonary Sclerosing Hemangioma in a Young Male Invited Reviewed

    The Journal of the Japanese Society of Internal Medicine   Vol. 104 ( 1 ) page: 103 - 106   2015.1

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MISC 1

  1. Mycobacterium abscessus subsp.abscessusによる播種性皮膚抗酸菌症の1例

    黒田 ケイ, 村瀬 千晶, 村瀬 友哉, 柴田 寛史, 阪本 考司, 岡 圭輔, 秋山 真志, 深野 華子, 星野 仁彦

    日本皮膚科学会雑誌   Vol. 130 ( 2 ) page: 255 - 255   2020.2

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Presentations 1

  1. Analysis of Enterobacter cloacae complex producing IMI-type carbapenemase International conference

    Keisuke OKA, Kazumitsu KAWAMURA, Tetsuya YAGI

    The 19th Asia Pacific Congress of Clinical Microbiology and Infectio  2023.7.7  Asia Pacific Society of Clinical Microbiology and Infection, Korean Society of Clinical Microbiology

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    Event date: 2023.7

    Language:English   Presentation type:Poster presentation  

    Venue:Seoul   Country:Korea, Republic of