著者

Youta Takano Makiko Shibano Yuuya Takizawa Eriko Arai Shinobu Koyama Takahiro Shimizu Takehisa Matsumoto

出版者

National Institute of Infectious Diseases

雑誌

Japanese Journal of Infectious Diseases (ISSN:13446304)

巻号頁・発行日

vol.76, no.2, pp.159-161, 2023-03-31 (Released:2023-03-24)

参考文献数

11

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Klebsiella oxytoca is an opportunistic pathogen that causes nosocomial infections. Here, we describe an unusual clinical strain of indole-negative K. oxytoca, GU175, isolated from the urine of a patient with cystitis. The GU175 strain was identified as K. pneumoniae with a probability of 99.40%, negative for indole production, and resistant to third-generation cephalosporins by using the MicroScan Walkaway 40 SI system with the Negative combo EN1 J panel. Biochemical characterization of this strain using lysine-indole motility medium was negative for indole production. However, identification tests using the MALDI Biotyper system and 16S rRNA gene sequence analysis revealed that GU175 is K. oxytoca. DNA sequence analysis of the tryptophanase operon comparing the GU175 strain with the revertant GU176 strain, which tested positive for indole, revealed a point mutation in the Shine-Dalgarno sequence upstream of tnaC in the GU175 strain. This is the first report of indole-negative K. oxytoca, which was attributed to a mutation in the DNA sequence of the tryptophanase operon isolated from a patient with a urinary tract infection. As indole-negative K. oxytoca can be misidentified as K. pneumoniae by biochemical characterization, clinical microbiologists should be aware of such misidentifications.

著者

Eiji Soga Miki Akiyama Yusuke Ohsaki Wataru Hayashi Takehisa Matsumoto Kozue Oana Noriyuki Nagano Yoshiyuki Kawakami

出版者

National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee

雑誌

Japanese Journal of Infectious Diseases (ISSN:13446304)

巻号頁・発行日

vol.72, no.3, pp.193-195, 2019 (Released:2019-05-23)

参考文献数

11

被引用文献数

3

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A capnophilic Gram-negative rod-shaped bacterium was recovered from the urine of an octogenarian male patient with acute pyelonephritis. The isolate was found to produce CTX-M-2-type extended-spectrum β-lactamase. Interestingly, the isolate failed to grow on modified Drigalski (BTB) and MacConkey agar media, even under CO2-enriched atmosphere. Our analysis revealed that the pH-indicator dyes, bromothymol blue, and/or crystal violet that were incorporated into the agar media inhibited the growth of the isolate. Although routine identification methods using Vitek® 2 Compact systems were unsuccessful, the isolate was identified as Proteus mirabilis by 16S rRNA sequencing and MALDI-TOF MS analysis. The carbonic anhydrase (CA) region spanning approximately 2,000 bp upstream to 2,000 bp downstream, which is responsible for the CO2 requirement, was not amplified, which could be attributed to the large-scale deletion or mutation of the DNA sequences containing the CA gene region. In fact, revertants with the ability to grow without CO2 were not detected. However, a revertant that was capable of growing in both BTB and MacConkey agar was detected at frequencies less than 10-9. Therefore, the genes responsible for the highly sensitive reactions of the isolate to pH indicator dyes is not likely to be linked to the CA genes.

著者

Katsuhiko Sekimata Tomohiro Sato Naoki Sakai Hisami Watanabe Chiemi Mishima-Tsumagari Tomonori Taguri Takehisa Matsumoto Yoshifumi Fujii Noriko Handa Teruki Honma Akiko Tanaka Mikako Shirouzu Shigeyuki Yokoyama Kohei Miyazono Yoshinobu Hashizume Hiroo Koyama

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.67, no.3, pp.224-235, 2019-03-01 (Released:2019-03-01)

参考文献数

17

被引用文献数

11

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Mutant activin receptor-like kinase-2 (ALK2) was reported to be closely associated with the pathogenesis of fibrodysplasia ossificans progressiva (FOP) and diffuse intrinsic pontine glioma (DIPG), and therefore presents an attractive target for therapeutic intervention. Through in silico virtual screenings and structure–activity relationship studies assisted by X-ray crystallographic analyses, a novel series of bis-heteroaryl pyrazole was identified as potent inhibitors of ALK2 (R206H). Derived from in silico hit compound RK-59638 (6a), compound 18p was identified as a potent inhibitor of ALK2 (R206H) with good aqueous solubility, liver microsomal stability, and oral bioavailability.

著者

Miwa NISHIDA Ayako HINO Kazushige MORI Takehisa MATSUMOTO Takashi YOSHIKUBO Hideo ISHITSUKA

出版者

The Pharmaceutical Society of Japan

雑誌

Biological and Pharmaceutical Bulletin (ISSN:09186158)

巻号頁・発行日

vol.19, no.11, pp.1407-1411, 1996-11-15 (Released:2008-04-10)

参考文献数

20

被引用文献数

87 100

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The antitumor activity of cytostatic 5'-deoxy-5-fluorouridine (5'-dFUrd) depends on its being converted to 5-fluorouracil (5-FUra) by the enzyme thymidine phosphorylase (dThdPase, EC 2.4.2.4). We prepared mouse anti-human dThdPase monoclonal antibodies to serve as tools for clinical studies with this drug. Partially purified dThdPase obtained from HCT116 human colon cancer cells grown in athymic mice was used as an antigen for the immunization of mice. Six hydridomas were cloned which produced anti-human dThdPase antibodies, as detected by Western blot analysis with human dThdPase. With these antibodies, we developed an ELISA method sensitive enough to measure dThdPase levels, even in tumor tissue samples weighing as little as 10 mg. In addition, one monoclonal antibody was suitable for immunologically staining the enzyme in tumor tissues. Thus, these anti-human dThdPase monoclonal antibodies could be used to measure levels of the enzyme in tumor cells, which is essential for the activation of 5'-dFUrd.