Faculty Profiles - SHIBAYAMA Keigo

Papers - SHIBAYAMA Keigo

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Screening for Group B Streptococci with Reduced Penicillin Susceptibility in Clinical Isolates Obtained between 1977 and 2005 Reviewed

Kouji Kimura, Yasunobu Nishiyama, Seiichi Shimizu, Jun-ichi Wachino, Mari Matsui, Satowa Suzuki, Kunikazu Yamane, Keigo Shibayama, Yoshichika Arakawa

JAPANESE JOURNAL OF INFECTIOUS DISEASES Vol. 66 ( 3 ) page： 222 - 225 2013.5

Language：English Publishing type：Research paper (scientific journal) Publisher：NATL INST INFECTIOUS DISEASES

Group B streptococcus (GBS; Streptococcus agalactiae) is a leading cause of neonatal invasive infections, and until recently, it was thought to be completely susceptible to penicillin. However, we recently identified several clinical GBS isolates with reduced penicillin susceptibility (PRGBS) whose minimum inhibitory concentrations of penicillin were >0.12 mu g/ml, which is above the susceptibility breakpoint set by the Clinical and Laboratory Standards Institute. These PRGBS were isolated between 1995 and 2005 in Japan; whether these PRGBS existed in Japan before 1995 is unknown. In the study described here, we screened for PRGBS among 349 clinical GBS isolates obtained in Japan between 1977 and 2005 using the previously developed disk diffusion method for the detection of PRGBS. With this method, we selected 6 PRGBS candidates and confirmed that 1 isolate was PRGBS, using agar dilution method, including oxacillin, ceftizoxime, and penicillin-binding protein 2X (PBP2X) gene sequencing analysis. This isolate was obtained from sputum in 2005, and we could not detect PRGBS isolates before 1995 in this investigation.

DOI： 10.7883/yoken.66.222

Hemin-binding proteins as potent markers for serological diagnosis of infections with bartonella quintana Reviewed

Mayumi Matsuoka, Toshinori Sasaki, Naomi Seki, Mutsuo Kobayashi, Kyoko Sawabe, Yuko Sasaki, Keigo Shibayama, Tsuguo Sasaki, Yoshichika Arakawa

Clinical and Vaccine Immunology Vol. 20 ( 4 ) page： 620 - 626 2013.4

Language：English Publishing type：Research paper (scientific journal) Publisher：4

It is difficult to distinguish infections with different Bartonella species using commercially available immunofluorescence (indirect immunofluorescent antibody [IFA]) assay kits. To identify appropriate proteins for serodiagnosis of Bartonella quintana infections, we investigated the antigenicity of B. quintana proteins using sera from homeless people with high B. quintana IgG titers in IFA assay. These sera reacted strongly to an outer membrane protein, hemin-binding protein D (HbpD). Further, serum from an endocarditis patient infected with B. quintana reacted to HbpB and HbpD. To locate the antigenic sites within the proteins, we generated deletion mutants of HbpB and HbpD. Amino acid residues 89 to 220 of HbpB and 151 to 200 of HbpD were identified as the minimum regions required for recognition by these sera. Several oligopeptides comprising parts of the minimum regions of HbpB and HbpD were synthesized, and their immunoreactivity with the above-mentioned sera was tested by enzyme-linked immunosorbent assay (ELISA). Serum from the endocarditis patient reacted similarly to synthetic peptides HbpB2 (amino acid residues 144 to 173 of HbpB) and HbpD3 (151 to 200 residues of HbpD), while sera from the other subjects reacted to HbpD3. These results indicate that synthetic peptides HbpB2 and HbpD3 might be suitable for developing serological tools for differential diagnosis of B. quintana infections from other Bartonella infections. © 2013, American Society for Microbiology. All Rights Reserved.

DOI： 10.1128/CVI.00717-12

Active Screening of Group B Streptococci with Reduced Penicillin Susceptibility and Altered Serotype Distribution Isolated from Pregnant Women in Kobe, Japan Reviewed

Kimura Kouji, Matsubara Kousaku, Yamamoto Go, Shibayama Keigo, Arakawa Yoshichika

JAPANESE JOURNAL OF INFECTIOUS DISEASES Vol. 66 ( 2 ) page： 158 - 160 2013.3

Active Screening of Group B Streptococci with Reduced Penicillin Susceptibility and Altered Serotype Distribution Isolated from Pregnant Women in Kobe, Japan Reviewed

Kouji Kimura, Kousaku Matsubara, Go Yamamoto, Keigo Shibayama, Yoshichika Arakawa

JAPANESE JOURNAL OF INFECTIOUS DISEASES Vol. 66 ( 2 ) page： 158 - 160 2013.3

Language：English Publishing type：Research paper (scientific journal) Publisher：NATL INST INFECTIOUS DISEASES

Group B streptococcus (GBS; Streptococcus agalactiae) is a leading cause of neonatal invasive infections and was believed to be fully susceptible to penicillin. However, we recently identified several clinical GBS isolates with reduced penicillin susceptibility (PRGBS), which were mainly isolated from respiratory specimens of elderly people. An investigation of both the isolation rate of PRGBS and the serotype distribution among pregnant women is crucial to decisions regarding optimal prevention and strategies for GBS treatment in neonates. We collected 141 GBS isolates from vaginal specimens of 122 pregnant women in a hospital in Kobe, Japan, from 2007 to 2008. Of the 141 GBS isolates, 139 were subjected to antimicrobial susceptibility testing based on the results of screening for PRGBS by the disk diffusion method. All 139 isolates were susceptible to penicillin G, ampicillin, cefotaxime, cefepime, and meropenem; no PRGBS isolates were detected. However, the rates of erythromycin and clindamycin resistance in the isolates were 10.1% and 5.0%, respectively, which are much higher than the values previously reported in Japan. Serotypes VI and VIII accounted for 26% of GBS; a markedly decreased percentage from the rates observed around the year 2000. These findings suggested that penicillin remains an effective means of intrapartum antibiotic prophylaxis in Japan.

DOI： 10.7883/yoken.66.158

High frequency of fluoroquinolone- and macrolide-resistant streptococci among clinically isolated group B streptococci with reduced penicillin susceptibility Reviewed

Kouji Kimura, Noriyuki Nagano, Yukiko Nagano, Satowa Suzuki, Jun-ichi Wachino, Keigo Shibayama, Yoshichika Arakawa

JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY Vol. 68 ( 3 ) page： 539 - 542 2013.3

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS

Recently several clinical isolates of Streptococcus agalactiae [also known as group B Streptococcus (GBS)] that have acquired reduced penicillin susceptibility (PRGBS) by amino acid substitutions in the penicillin-binding protein 2X have emerged. The frequency of fluoroquinolone (FQ)- and macrolide-resistant streptococci among PRGBS is not yet known.
Fifty-seven GBS [19 PRGBS and 38 penicillin-susceptible GBS (PSGBS)], isolated from different medical institutions in Japan, were studied. For GBS, the MICs of penicillin G, levofloxacin and erythromycin were determined using the agar dilution method. Nineteen PRGBS were previously confirmed as genetically diverse streptococci by PFGE. Further, the mechanisms underlying penicillin, FQ and macrolide non-susceptibility/resistance were analysed.
The frequency of non-susceptibility to FQs among PSGBS was 18.4 (7/38), whereas that among PRGBS was 100 (19/19). The frequency of resistance to erythromycin among PSGBS was 7.9 (3/38), while that among PRGBS was 47.4 (9/19). Statistical significance was determined using Fishers exact test between reduced penicillin susceptibility and FQ non-susceptibility (P0.0001) and macrolide resistance (P0.0012). The resistance/non-susceptibility mechanisms among PRGBS were diverse, suggesting that the PRGBS examined were not clonal.
PRGBS isolates tend to show resistance to FQs and/or macrolides. Because the drug choice for treating these multidrug-resistant GBS is more limited than that for usual GBS, these strains may present future public health challenges.

DOI： 10.1093/jac/dks423

Carbapenem-resistant Escherichia coli and Klebsiella pneumoniae strains containing new delhi metallo-beta-lactamase isolated from two patients in Vietnam Reviewed

Tran Huy Hoang, Heiman Wertheim, Nguyen Binh Minh, Tran Nhu Duong, Dang Duc Anh, Tran Thi Lan Phuong, Trinh Hong Son, Hidemasa Izumiya, Makoto Ohnishi, Keigo Shibayama, Nguyen Tran Hien

Journal of Clinical Microbiology Vol. 51 ( 1 ) page： 373 - 374 2013.1

Effects of Simultaneous Immunization of Haemophilus influenzae Type b Conjugate Vaccine and Diphtheria-Tetanus-Acellular Pertussis Vaccine on Anti-Tetanus Potencies in Mice, Guinea Pigs, and Rats Reviewed

Tadashi Fukuda, Masaaki Iwaki, Takako Komiya, Keigo Shibayama, Motohide Takahashi, Hideki Nakashima

JAPANESE JOURNAL OF INFECTIOUS DISEASES Vol. 66 ( 1 ) page： 41 - 45 2013.1

Language：English Publishing type：Research paper (scientific journal) Publisher：NATL INST INFECTIOUS DISEASES

Haemophilus influenzae type b vaccine conjugated with tetanus toxoid (HibT) was licensed for use in childhood immunization in Japan in 2007. As adsorbed diphtheria-tetanus-acellular pertussis (DTaP) combined with HibT vaccine has not been introduced in Japan, DTaP and HibT vaccines are injected at separate sites with a similar immunization schedule. There are various interfering or stimulatory effects between components of combined vaccines contained in DTaP and HibT vaccines. In this study, we investigated the effect of HibT containing combination vaccines on anti-tetanus potencies by using animal models (mouse, guinea pig, and rat). HibT vaccine and HibT components of imported DTaP-HibT vaccine alone showed comparable or higher anti-tetanus potency than DTaP vaccine and DTaP-containing components of combination vaccines. Mixing these components before injection resulted in potencies greater than the sum of individual potencies. Injecting individual components at separate sites in animals resulted in potency roughly equivalent to the sum of the individual potencies. These results provide useful information regarding the use of HibT-containing multivalent vaccines in childhood immunization.

DOI： 10.7883/yoken.66.41

First Report of OXA-48 Carbapenemase-Producing Klebsiella pneumoniae and Escherichia coli in Japan from a Patient Returned from Southeast Asia Reviewed

Nagano Noriyuki, Endoh Yasunobu, Nagano Yukiko, Toyama Masami, Matsui Mari, Shibayama Keigo, Arakawa Yoshichika

JAPANESE JOURNAL OF INFECTIOUS DISEASES Vol. 66 ( 1 ) page： 79 - 81 2013.1

First Report of OXA-48 Carbapenemase-Producing Klebsiella pneumoniae and Escherichia coli in Japan from a Patient Returned from Southeast Asia Reviewed

Noriyuki Nagano, Yasunobu Endoh, Yukiko Nagano, Masami Toyama, Mari Matsui, Keigo Shibayama, Yoshichika Arakawa

JAPANESE JOURNAL OF INFECTIOUS DISEASES Vol. 66 ( 1 ) page： 79 - 81 2013.1

Structural Insights into the Subclass B3 Metallo-beta-Lactamase SMB-1 and the Mode of Inhibition by the Common Metallo-beta-Lactamase Inhibitor Mercaptoacetate Reviewed

Jun-ichi Wachino, Yoshihiro Yamaguchi, Shigetarou Mori, Hiromasa Kurosaki, Yoshichika Arakawa, Keigo Shibayama

ANTIMICROBIAL AGENTS AND CHEMOTHERAPY Vol. 57 ( 1 ) page： 101 - 109 2013.1

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER SOC MICROBIOLOGY

A novel subclass B3 metallo-beta-lactamase (MBL), SMB-1, recently identified from a Serratia marcescens clinical isolate, showed a higher hydrolytic activity against a wide range of beta-lactams than did the other subclass B3 MBLs, i.e., BJP-1 and FEZ-1, from environmental bacteria. To identify the mechanism underlying the differences in substrate specificity among the subclass B3 MBLs, we determined the structure of SMB-1, using 1.6-angstrom diffraction data. Consequently, we found that SMB-1 reserves a space in the active site to accommodate beta-lactam, even with a bulky R1 side chain, due to a loss of amino acid residues corresponding to F31 and L226 of BJP-1, which protrude into the active site to prevent beta-lactam from binding. The protein also possesses a unique amino acid residue, Q157, which probably plays a role in recognition of beta-lactams via the hydrogen bond interaction, which is missing in BJP-1 and FEZ-1, whose K-m values for beta-lactams are particularly high. In addition, we determined the mercaptoacetate (MCR)-complexed SMB-1 structure and revealed the mode of its inhibition by MCR: the thiolate group bridges to two zinc ions (Zn1 and Zn2). One of the carboxylate oxygen atoms of MCR makes contact with Zn2 and Ser221, and the other makes contact with T223 and a water molecule. Our results demonstrate the possibility that MCR could be a potent inhibitor for subclass B3 MBLs and that the screening technique using MCR as an inhibitor would be effective for detecting subclass B3 MBL producers.

DOI： 10.1128/AAC.01264-12

Identification of VanN-Type Vancomycin Resistance in an Enterococcus faecium Isolate from Chicken Meat in Japan Reviewed

Takahiro Nomura, Koichi Tanimoto, Keigo Shibayama, Yoshichika Arakawa, Shuhei Fujimoto, Yasuyoshi Ike, Haruyoshi Tomita

ANTIMICROBIAL AGENTS AND CHEMOTHERAPY Vol. 56 ( 12 ) page： 6389 - 6392 2012.12

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER SOC MICROBIOLOGY

Five VanN-type vancomycin-resistant Enterococcus faecium strains were isolated from a sample of domestic chicken meat in Japan. All isolates showed low-level resistance to vancomycin (MIC, 12 mg/liter) and had the same pulsed-field gel electrophoresis profile. The vancomycin resistance was encoded on a large plasmid (160 kbp) and was expressed constitutively. The VanN-type resistance operon was identical to the first resistance operon to be reported, with the exception of a 1-bp deletion in vanT(N) and a 1-bp substitution in vanS(N).

DOI： 10.1128/AAC.00747-12

Identification of Mycoplasma pneumoniae type 2b variant strains in Japan Reviewed

Tsuyoshi Kenri, Hitomi Ohya, Atsuko Horino, Keigo Shibayama

JOURNAL OF MEDICAL MICROBIOLOGY Vol. 61 ( 11 ) page： 1633 - 1635 2012.11

Molecular epidemiologic analysis and antimicrobial resistance of Helicobacter cinaedi isolated from seven hospitals in Japan. Reviewed International journal

Emiko Rimbara, Shigetarou Mori, Mari Matsui, Satowa Suzuki, Jun-Ichi Wachino, Yoshiaki Kawamura, Zeli Shen, James G Fox, Keigo Shibayama

Journal of clinical microbiology Vol. 50 ( 8 ) page： 2553 - 60 2012.8

Language：English Publishing type：Research paper (scientific journal) Publisher：8

Helicobacter cinaedi colonizes the colons of human and animals and can cause colitis, cellulitis, and sepsis in humans, with infections in immunocompromised patients being increasingly recognized. However, methods for analyzing the molecular epidemiology of H. cinaedi are not yet established. A genotyping method involving multilocus sequence typing (MLST) was developed and used to analyze 50 H. cinaedi isolates from Japanese hospitals in addition to 6 reference strains. Pulsed-field gel electrophoresis (PFGE) results were also compared with the MLST results. Based on the genomic information from strain CCUG18818, 21 housekeeping genes were selected as candidates for MLST and were observed to have high homology (96.5 to 100%) between isolates. Following a comparison of the 21 housekeeping genes from 8 H. cinaedi isolates, 7 genes were chosen for MLST, revealing 14 sequence types (STs). The isolates from 3 hospitals belonged to the same STs, but the isolates from the other 4 hospitals belonged to different STs. Isolates belonging to ST6 were analyzed by PFGE and showed similar, but not identical, patterns between isolates. Isolates belonging to ST9, ST10, and ST11, which belonged to the same clonal complex, had the same pattern. All isolates were found to contain mutations in GyrA and the 23S rRNA gene that confer ciprofloxacin and clarithromycin resistance, respectively, in H. cinaedi. These results raise concerns about the increase in H. cinaedi isolates resistant to clarithromycin and ciprofloxacin in Japan.

DOI： 10.1128/JCM.06810-11

Simple and specific detection of Bordetella holmesii by using a loop-mediated isothermal amplification assay Reviewed

Nao Otsuka, Shuji Yoshino, Kimiko Kawano, Hiromi Toyoizumi-Ajisaka, Keigo Shibayama, Kazunari Kamachi

MICROBIOLOGY AND IMMUNOLOGY Vol. 56 ( 7 ) page： 486 - 489 2012.7

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

A loop-mediated isothermal amplification (LAMP) assay for simple detection of Bordetella holmesii was developed. This assay discriminates between B. holmesii and other Bordetella species and successfully detect B. holmesii DNA in nasopharyngeal swab samples from subjects with suspected pertussis. The LAMP assay results were in complete agreement with the results of previously published real-time PCR assay, indicating that the former is a powerful tool for the accurate diagnosis and surveillance of B. holmesii.

DOI： 10.1111/j.1348-0421.2012.00465.x

Transmission of Bordetella holmesii during Pertussis Outbreak, Japan Reviewed

Hajime Kamiya, Nao Otsuka, Yuka Ando, Fumito Odaira, Shuji Yoshino, Kimiko Kawano, Hirokazu Takahashi, Toshihide Nishida, Yoshio Hidaka, Hiromi Toyoizumi-Ajisaka, Keigo Shibayama, Kazunari Kamachi, Tomimasa Sunagawa, Kiyosu Taniguchi, Nobuhiko Okabe

EMERGING INFECTIOUS DISEASES Vol. 18 ( 7 ) page： 1166 - 1169 2012.7

Language：English Publishing type：Research paper (scientific journal) Publisher：CENTERS DISEASE CONTROL

We describe the epidemiology of a pertussis outbreak in Japan in 2010-2011 and Bordetella holmesii transmission. Six patients were infected; 4 patients were students and a teacher at the same junior high school. Epidemiologic links were found between 5 patients. B. holmesii may have been transmitted from person to person.

DOI： 10.3201/eid1807.120130

Reply to Letter to the Editor regarding Shibayama etal.: Biochemical and pathophysiological characterization of Helicobacter pylori asparaginase Reviewed

Shibayama K.

Microbiology and Immunology Vol. 56 ( 6 ) page： 422 - 422 2012.6

Corynebacterium ulcerans 0102 carries the gene encoding diphtheria toxin on a prophage different from the C-diphtheriae NCTC 13129 prophage Reviewed

Tsuyoshi Sekizuka, Akihiko Yamamoto, Takako Komiya, Tsuyoshi Kenri, Fumihiko Takeuchi, Keigo Shibayama, Motohide Takahashi, Makoto Kuroda, Masaaki Iwaki

BMC MICROBIOLOGY Vol. 12 page： 72 2012.5

Language：English Publishing type：Research paper (scientific journal) Publisher：BIOMED CENTRAL LTD

Background: Corynebacterium ulcerans can cause a diphtheria-like illness, especially when the bacterium is lysogenized with a tox gene-carrying bacteriophage that produces diphtheria toxin. Acquisition of toxigenicity upon phage lysogenization is a common feature of C. ulcerans and C. diphtheriae. However, because of a lack of C. ulcerans genome information, a detailed comparison of prophages has not been possible between these two clinically important and closely related bacterial species.
Results: We determined the whole genome sequence of the toxigenic C. ulcerans 0102 isolated in Japan. The genomic sequence showed a striking similarity with that of Corynebacterium pseudotuberculosis and, to a lesser extent, with that of C. diphtheriae. The 0102 genome contained three distinct prophages. One of these, (sic)CULC0102-I, was a tox-positive prophage containing genes in the same structural order as for tox-positive C. diphtheriae prophages. However, the primary structures of the individual genes involved in the phage machinery showed little homology between the two counterparts.
Conclusion: Taken together, these results suggest that the tox-positive prophage in this strain of C. ulcerans has a distinct origin from that of C. diphtheriae NCTC 13129.

DOI： 10.1186/1471-2180-12-72

Nosocomial spread of multidrug-resistant group B streptococci with reduced penicillin susceptibility belonging to clonal complex 1 Reviewed

Noriyuki Nagano, Yukiko Nagano, Masami Toyama, Kouji Kimura, Takashi Tamura, Keigo Shibayama, Yoshichika Arakawa

Journal of Antimicrobial Chemotherapy Vol. 67 ( 4 ) page： 849 - 856 2012.4

Language：English Publishing type：Research paper (scientific journal) Publisher：4

Background: Multiple group B Streptococcus (GBS) isolates with reduced penicillin susceptibility (PRGBS) were recovered from several patients, hence a probable nosocomial transmission of PRGBS in a hospital setting was suspected. Methods: Ten PRGBS recovered from eight patients in a general hospital were characterized. Sequence analysis of genes for penicillin-binding proteins (PBPs) and quinolone resistance-determining regions (QRDRs) of gyrA, gyrB and parC was performed, and the macrolide resistance genes were detected by PCR. Genetic relatedness among the isolates was examined by PFGE and multilocus sequence typing. Results: All the PRGBS had the key amino acid substitution V405A, together with F395L, R433H, H438Y and G648A in PBP 2X and T567I in PBP 2B. A 23S rRNA methylase gene, erm(B), was also found in all 10 PRGBS strains. PFGE analysis revealed considerable genetic relatedness among the isolates. Isolates of pulsotype I were obtained from four patients in ward A and one patient in ward B, while isolates of pulsotypes II and III were obtained from two patients in ward B and one patient in ward C, respectively. Isolates of pulsotype I were resistant to levofloxacin (MIC >8 mg/L) and had the following amino acid substitutions in the QRDRs: S81L in GyrA, E476K in GyrB and S79Y in ParC. However, pulsotype II strains resistant to levofloxacin (MIC 8 mg/L) had no change in GyrA, but changes in GyrB (E476K) and ParC (S79Y). All 10 PRGBS strains belonged to serotype VI and ST458 (where ST stands for sequence type). Conclusions: This is the first description of the nosocomial spread of multidrug-resistant PRGBS strains belonging to the genetic lineage ST458. © The Author 2011. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

DOI： 10.1093/jac/dkr546

Complete genome sequence of Mycoplasma pneumoniae type 2a strain 309, isolated in Japan Reviewed

Tsuyoshi Kenri, Atsuko Horino, Mari Matsui, Yuko Sasaki, Satowa Suzuki, Mitsuo Narita, Hitomi Ohya, Norio Okazaki, Keigo Shibayama

Journal of Bacteriology Vol. 194 ( 5 ) page： 1253 - 1254 2012.3

Language：English Publishing type：Research paper (scientific journal) Publisher：5

Mycoplasma pneumoniae strain 309, a type 2a (subtype 2 variant) strain of this bacterium, has variations in the P1 protein, which is responsible for attachment of the bacterium to host cells. Here, we report the complete genome sequence of M. pneumoniae strain 309 isolated from a pneumonia patient in Japan. © 2012, American Society for Microbiology.

DOI： 10.1128/JB.06553-11

Crystallization and preliminary X-ray analysis of the subclass B3 metallo-β-lactamase SMB-1 that confers carbapenem resistance Reviewed

Jun Ichi Wachino, Yoshihiro Yamaguchi, Shigetarou Mori, Yuriko Yamagata, Yoshichika Arakawa, Keigo Shibayama

Acta Crystallographica Section F: Structural Biology and Crystallization Communications Vol. 68 ( 3 ) page： 343 - 346 2012.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Pt 3

The carbapenem-hydrolyzing subclass B3 metallo-β-lactamase SMB-1 was expressed in Escherichia coli and purified. Diffraction data were collected from two types of SMB-1 crystals that were obtained under different conditions. One crystal (SMB-1a) belonged to the trigonal space group P31 with unit-cell parameters a = b = 67.83, c = 48.67 Å, while the other crystal (SMB-1b) also belonged to space group P3 1 but with unit-cell parameters a = b = 67.25, c = 46.83 Å. Both crystals contained one molecule per asymmetric unit. Initial phases were determined by molecular replacement; further refinement and model building are in progress. © 2012 International Union of Crystallography All rights reserved.

DOI： 10.1107/S1744309112004691

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Papers - SHIBAYAMA Keigo