Papers - SHIBAYAMA Keigo

Corrigendum: Networking and Specificity-Changing DNA Methyltransferases in Helicobacter pylori. Reviewed International journal

Hirokazu Yano, Md Zobaidul Alam, Emiko Rimbara, Tomoko F Shibata, Masaki Fukuyo, Yoshikazu Furuta, Tomoaki Nishiyama, Shuji Shigenobu, Mitsuyasu Hasebe, Atsushi Toyoda, Yutaka Suzuki, Sumio Sugano, Keigo Shibayama, Ichizo Kobayashi

Frontiers in microbiology   Vol. 11   page： 596598 - 596598   2020

　More details

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

[This corrects the article DOI: 10.3389/fmicb.2020.01628.].

DOI： 10.3389/fmicb.2020.596598

Scopus

PubMed

researchmap

Comparison of de-duplication methods used by WHO Global Antimicrobial Resistance Surveillance System (GLASS) and Japan Nosocomial Infections Surveillance (JANIS) in the surveillance of antimicrobial resistance. Reviewed International journal

Toshiki Kajihara, Koji Yahara, John Stelling, Sergey Romualdovich Eremin, Barbara Tornimbene, Visanu Thamlikitkul, Aki Hirabayashi, Eiko Anzai, Satoyo Wakai, Nobuaki Matsunaga, Kayoko Hayakawa, Norio Ohmagari, Motoyuki Sugai, Keigo Shibayama

PloS one   Vol. 15 ( 6 ) page： e0228234   2020

　More details

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

A major issue in the surveillance of antimicrobial resistance (AMR) is "de-duplication" or removal of repeated isolates, for which there exist multiple methods. The World Health Organization (WHO) Global Antimicrobial Resistance Surveillance System (GLASS) requires de-duplication by selecting only the first isolate of a given bacterial species per patient per surveillance period per specimen type per age group, gender, and infection origin stratification. However, no study on the comparative application of this method has been reported. The objective of this study was to evaluate differences in data tabulation between the WHO GLASS and the Japan Nosocomial Infections Surveillance (JANIS) system, which counts both patients and isolates after removing repeated isolates of the same bacterial species isolated from a patient within 30 days, regardless of specimen type, but distinguishing isolates with change of antimicrobial resistance phenotype. All bacterial data, consisting of approximately 8 million samples from 1795 Japanese hospitals in 2017 were exported from the JANIS database, and were tabulated using either the de-duplication algorithm of GLASS, or JANIS. We compared the tabulated results of the total number of patients whose blood and urine cultures were taken and of the percentage of resistant isolates of Escherichia coli for each priority antibiotic. The number of patients per specimen type tabulated by the JANIS method was always smaller than that of GLASS. There was a small (< 3%) difference in the percentage of resistance of E. coli for any antibiotic between the two methods in both out- and inpatient settings and blood and urine isolates. The two tabulation methods did not show considerable differences in terms of the tabulated percentages of resistance for E. coli. We further discuss how the use of GLASS tabulations to create a public software and website that could help to facilitate the understanding of and treatment against AMR.

DOI： 10.1371/journal.pone.0228234

Scopus

PubMed

researchmap

Improved penicillin susceptibility of Streptococcus pneumoniae and increased penicillin consumption in Japan, 2013-18. Reviewed International journal

Shinya Tsuzuki, Takayuki Akiyama, Nobuaki Matsunaga, Koji Yahara, Keigo Shibayama, Motoyuki Sugai, Norio Ohmagari

PloS one   Vol. 15 ( 10 ) page： e0240655   2020

　More details

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

OBJECTIVES: To examine the association between penicillin susceptibility of Streptococcus pneumoniae and penicillin consumption in Japan. METHODS: We used Japan Nosocomial Infection Surveillance data on the susceptibility of S. pneumoniae and sales data obtained from IQVIA Services Japan K.K. for penicillin consumption. We analysed both sets of data by decomposing them into seasonality and chronological trend components. The cross-correlation function was checked using Spearman's rank correlation coefficient to examine the correlation between susceptibility and consumption. RESULTS: After adjusting for seasonality, the susceptibility of S. pneumoniae to penicillins gradually improved (55.7% in 2013 and 60.6% in 2018, respectively) and penicillin consumption increased during the same period (0.76 defined daily doses per 1,000 inhabitants per day [DID] in 2013, and 0.89 DID in 2018). The results showed positive cross-correlation (coefficient 0.801, p-value < 0.001). In contrast, cephalosporin consumption decreased (3.91 DID in 2013 and 3.19 DID in 2018) and showed negative cross-correlation with susceptibility of S. pneumoniae to penicillins (coefficient -0.981, p-value < 0.001). CONCLUSIONS: The rates of penicillin-susceptible S. pneumoniae isolates did not negatively correlate with penicillin consumption at the population level. Increased penicillin consumption might not impair the penicillin susceptibility of S. pneumoniae.

DOI： 10.1371/journal.pone.0240655

Scopus

PubMed

researchmap

Periodic Genotype Shifts in Clinically Prevalent Mycoplasma pneumoniae Strains in Japan. Reviewed International journal

Tsuyoshi Kenri, Masato Suzuki, Tsuyoshi Sekizuka, Hitomi Ohya, Yoichiro Oda, Tsutomu Yamazaki, Hiroyuki Fujii, Toru Hashimoto, Hiroshi Nakajima, Chihiro Katsukawa, Makoto Kuroda, Keigo Shibayama

Frontiers in cellular and infection microbiology   Vol. 10   page： 385 - 385   2020

　More details

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

Nationwide increases in Mycoplasma pneumoniae pneumonia cases in Japan were reported in 2011, 2012, 2015, and 2016. In this study, we isolated 554 M. pneumoniae strains in 4 areas in Japan (Kanagawa, Okayama, Osaka, and Saitama) between 2006 and 2019, and performed genotyping analysis. More than 80% of the strains isolated in 2011 and 2012 harbored type 1 p1 adhesin gene; however, strains harboring type 2 or its variant p1 gene increased in 2015 and 2016 and dominated after 2017. These findings suggested that a shift in the prevalent genotype of M. pneumoniae clinical strains occurred recently in Japan. More than 90% of the type 1 strains isolated after 2010 harbored macrolide-resistance mutations in their 23S rRNA gene, whereas most type 2 lineage strains had no such mutations. Consequently, the increase in type 2 lineage strains in Japan has reduced the macrolide resistance rate of clinical M. pneumoniae strains. During this analysis, we also identified M. pneumoniae strains carrying a novel variant type 1 p1 gene, and we classified it as type 1b. We then sequenced the genomes of 81 selected M. pneumoniae strains that we collected between 1976 and 2017 in Japan, and compared them with 156 M. pneumoniae genomes deposited in public databases to provide insights into the interpretation of M. pneumoniae genotyping methods, including p1 typing, multiple-locus variable-number tandem repeat analysis (MLVA), multi-locus sequence typing (MLST), and typing by 8 single-nucleotide polymorphism markers (SNP-8). As expected, p1 typing, MLST, and SNP-8 results exhibited good correlation with whole-genome SNP analysis results in terms of phylogenetic relationships; however, MLVA typing results were less comparable to those of the other methods. MLVA may be useful for the discrimination of strains derived from a single outbreak within a limited area; however, is not reliable for classification of strains collected from distantly separated areas at different time points. This study showed the usefulness of genome-based comparison of M. pneumoniae for molecular epidemiology. Genome sequencing of more strains will improve our understanding of global propagation routes of this pathogen and evolutionary aspects of M. pneumoniae strains.

DOI： 10.3389/fcimb.2020.00385

Scopus

PubMed

researchmap

Networking and Specificity-Changing DNA Methyltransferases in Helicobacter pylori. Reviewed International journal

Hirokazu Yano, Md Zobaidul Alam, Emiko Rimbara, Tomoko F Shibata, Masaki Fukuyo, Yoshikazu Furuta, Tomoaki Nishiyama, Shuji Shigenobu, Mitsuyasu Hasebe, Atsushi Toyoda, Yutaka Suzuki, Sumio Sugano, Keigo Shibayama, Ichizo Kobayashi

Frontiers in microbiology   Vol. 11   page： 1628 - 1628   2020

　More details

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

Epigenetic DNA base methylation plays important roles in gene expression regulation. We here describe a gene expression regulation network consisting of many DNA methyltransferases each frequently changing its target sequence-specificity. Our object Helicobacter pylori, a bacterium responsible for most incidence of stomach cancer, carries a large and variable repertoire of sequence-specific DNA methyltransferases. By creating a dozen of single-gene knockout strains for the methyltransferases, we revealed that they form a network controlling methylome, transcriptome and adaptive phenotype sets. The methyltransferases interact with each other in a hierarchical way, sometimes regulated positively by one methyltransferase but negatively with another. Motility, oxidative stress tolerance and DNA damage repair are likewise regulated by multiple methyltransferases. Their regulation sometimes involves translation start and stop codons suggesting coupling of methylation, transcription and translation. The methyltransferases frequently change their sequence-specificity through gene conversion of their target recognition domain and switch their target sets to remodel the network. The emerging picture of a metamorphosing gene regulation network, or firework, consisting of epigenetic systems ever-changing their specificity in search for adaptation, provides a new paradigm in understanding global gene regulation and adaptive evolution.

DOI： 10.3389/fmicb.2020.01628

Scopus

PubMed

researchmap

Genomic Diversity, Virulence, and Antimicrobial Resistance of <i>Helicobacter suis</i> Isolated from Human Stomachs Reviewed

Emiko Rimbara, Masato Suzuki, Hidenori Matsui, Masahiko Nakamura, Misako Morimoto, Chihiro Sasakawa, Takako Osaki, Noriyo Nagata, Keigo Shibayama, Kengo Tokunaga

SSRN Electronic Journal     2020

　More details

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

DOI： 10.2139/ssrn.3663972

researchmap

A novel multilocus variable-number tandem repeat analysis for Bordetella parapertussis. Reviewed International journal

Kazunari Kamachi, Nao Otsuka, Rei Fumimoto, Kensuke Ozawa, Shu-Man Yao, Chuen-Sheue Chiang, Laurence Don Wai Luu, Ruiting Lan, Keigo Shibayama, Mineo Watanabe

Journal of medical microbiology   Vol. 68 ( 11 ) page： 1671 - 1676   2019.11

　More details

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

Purpose. Human-adapted Bordetella parapertussis is one of the causative agents of whooping cough; however, there are currently no genotyping systems with high discriminatory power for this bacterial pathogen. We therefore aimed to develop a multilocus variable-number tandem repeat analysis (MLVA) for human-adapted B. parapertussis.Methodology. Four highly polymorphic variable number tandem repeat (VNTR) loci in the B. parapertussis genome were selected and amplified by multiplex PCR. MLVA was performed based on the number of tandem repeats at VNTR loci. The discriminatory power of MLVA was evaluated with three laboratory reference strains and 50 human isolates of B. parapertussis.Results. Multiplex PCR-based MLVA characterized 53 B. parapertussis reference strains and isolates into 25 MLVA types and the Simpson diversity index was 0.91 (95 % confidence interval, 0.86-0.97). The three reference strains exhibited different MLVA types. Thirty-one Japanese isolates, ten French isolates and three Taiwanese isolates belonged to fourteen, nine and three MLVA types, respectively. In contrast, all five Australian isolates belonged to the same type. Two Japanese isolates collected from patients with known epidemiological links had the same type.Conclusion. Our novel MLVA method has high discriminatory power for genotyping human B. parapertussis. Regarding this organism, this genotyping system is a promising tool for epidemiological surveillance and investigating outbreaks.

DOI： 10.1099/jmm.0.001095

Scopus

PubMed

CiNii Research

researchmap

Injectable Polypeptide Hydrogel Depot System for Assessment of the Immune Response-Inducing Efficacy of Sustained Antigen Release Alone. Reviewed International journal

Daisuke Asai, Tadashi Fukuda, Kazunori Morokuma, Daiki Funamoto, Yuko Yamaguchi, Takeshi Mori, Yoshiki Katayama, Keigo Shibayama, Hideki Nakashima

Macromolecular bioscience   Vol. 19 ( 10 ) page： e1900167   2019.10

　More details

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

Vaccines typically contain an antigen, delivery system (vehicle), and adjuvant, all of which contribute to inducing a potent immune response. Consequently, design of new vaccines is difficult, because the contributions and interactions of these components are difficult to distinguish. Here, it is aimed to develop an easy-to-use, non-immunogenic, injectable depot system for sustained antigen release that will be suitable for assessing the efficacy of prolonged antigen exposure per se for inducing an immune response. This should mimic real-life infections. Recombinant elastin-like polypeptides with periodic cysteine residues (cELPs) are selected, which reportedly show little or no immunogenicity, as carriers and tetanus toxoid (Ttd) as an antigen. After subcutaneous injection of the mixture, cELP rapidly forms a disulfide cross-linked hydrogel in situ, within which Ttd is physically incorporated, affording a biodegradable antigen depot. A series of Ttd-containing hydrogels is examined. A single injection induces high levels of tetanus antibody with high avidity for at least 20 weeks in mice. The chain length of cELP proves critical, whereas differences in hydrophobicity has little effect, although hydrophilic cELPs are more rapidly biodegraded. This system's ability to distinguish the contribution of sustained antigen release to antibody induction should be helpful for rational design of next-generation vaccines.

DOI： 10.1002/mabi.201900167

Scopus

PubMed

researchmap

DNA gyrase could be a crucial regulatory factor for growth and survival of Mycobacterium leprae. Reviewed International journal

Hyun Kim, Yasuo Fukutomi, Chie Nakajima, Youn Uck Kim, Shigetarou Mori, Keigo Shibayama, Noboru Nakata, Yasuhiko Suzuki

Scientific reports   Vol. 9 ( 1 ) page： 10815 - 10815   2019.7

　More details

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

Leprosy, an important infectious disease in humans caused by Mycobacterium leprae (Mle), remains endemic in many countries. Notably, the pathogen cannot be cultured in vitro, except in mouse footpads in vivo. The molecular basis of these characteristics and the mechanisms remain unknown. Consequently, analysis of Mle growth and survival is urgently needed to develop novel therapies against leprosy, including rapid, simple, and specific methods to detect infection. Here, we demonstrated the functional role and contribution of Mle-DNA gyrase, which regulates DNA topology, DNA replication, and chromosome segregation to promote bacterial growth and survival, in Mle growth and survival in vitro and in vivo. The optimum temperature for Mle-DNA gyrase activity was 30 °C. When the DNA gyrB-gyrA genes in Mycobacterium smegmatis were replaced with the Mle gyrase genes by allelic exchange, the recombinants could not grow at 37 °C. Moreover, using radiorespirometry analysis for viability of Mle bacilli, we found that Mle growth was more vigorous at 25-30 °C than at 37 °C, but was inhibited above 40 °C. These results propose that DNA gyrase is a crucial factor for Mle growth and survival and its sensitivity to temperature may be exploited in heat-based treatment of leprosy.

DOI： 10.1038/s41598-019-47364-5

Scopus

PubMed

researchmap

Genome-Based Epidemiological Analysis of 13 Acinetobacter Strains Isolated from Blood Cultures of Hospitalized Patients from a University Hospital in Japan. Reviewed

Ken-Ichi Oinuma, Masato Suzuki, Kiyotaka Nakaie, Kanako Sato, Kozo Saeki, Arata Sakiyama, Etsuko Takizawa, Makoto Niki, Mamiko Niki, Koichi Yamada, Keigo Shibayama, Hiroshi Kakeya, Yukihiro Kaneko

Japanese journal of infectious diseases   Vol. 72 ( 4 ) page： 274 - 280   2019.7

　More details

Language：English   Publishing type：Research paper (scientific journal)   Publisher：National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee  

The genus Acinetobacter comprises many species that can cause infectious diseases. Despite their importance as nosocomial pathogens, the clinical distributions of individual species or clones are not well understood. In this study, we aimed to characterize 13 Acinetobacter strains isolated from blood cultures from Osaka City University Hospital. We conducted whole-genome sequencing to reveal their genetic background. We also performed PCR-based open reading frame typing (POT) and compared the results with those of multilocus sequence typing (MLST) to confirm its reliability as a genotyping method. Although biochemical analysis suggested that most isolates were A. baumannii, genomic analysis revealed that the collection of Acinetobacter isolates comprised six different species, with non-baumannii Acinetobacter species representing the majority. All strains possessed an inherent ADC-type β-lactamase gene, whereas the distribution of OXA-type enzymes was limited to A. baumannii, A. pittii, and A. colistiniresistens. While MLST properly discriminated four A. baumannii strains as different clones, POT failed to distinguish three of the four A. baumannii strains from each other, highlighting a potential pitfall that may be encountered when applying POT to non-epidemiological A. baumannii strains.

DOI： 10.7883/yoken.JJID.2018.403

Scopus

PubMed

CiNii Research

researchmap

Novel Sequence Type in Bacillus cereus Strains Associated with Nosocomial Infections and Bacteremia, Japan. Reviewed International journal

Reiko Akamatsu, Masato Suzuki, Keiji Okinaka, Teppei Sasahara, Kunikazu Yamane, Satowa Suzuki, Daisuke Fujikura, Yoshikazu Furuta, Naomi Ohnishi, Minoru Esaki, Keigo Shibayama, Hideaki Higashi

Emerging infectious diseases   Vol. 25 ( 5 ) page： 883 - 890   2019.5

　More details

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

Bacillus cereus is associated with foodborne illnesses characterized by vomiting and diarrhea. Although some B. cereus strains that cause severe extraintestinal infections and nosocomial infections are recognized as serious public health threats in healthcare settings, the genetic backgrounds of B. cereus strains causing such infections remain unknown. By conducting pulsed-field gel electrophoresis and multilocus sequence typing, we found that a novel sequence type (ST), newly registered as ST1420, was the dominant ST isolated from the cases of nosocomial infections that occurred in 3 locations in Japan in 2006, 2013, and 2016. Phylogenetic analysis showed that ST1420 strains belonged to the Cereus III lineage, which is much closer to the Anthracis lineage than to other Cereus lineages. Our results suggest that ST1420 is a prevalent ST in B. cereus strains that have caused recent nosocomial infections in Japan.

DOI： 10.3201/eid2505.171890

Scopus

PubMed

researchmap

Detection of mcr-1-mediated colistin resistance in E. coli isolate from imported chicken meat from Brazil. Reviewed International journal

Naoko Chiba, Koichi Tanimoto, Junzo Hisatsune, Motoyuki Sugai, Keigo Shibayama, Haruo Watanabe, Haruyoshi Tomita

Journal of global antimicrobial resistance   Vol. 16   page： 249 - 250   2019.3

　More details

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

DOI： 10.1016/j.jgar.2019.02.004

Scopus

PubMed

researchmap

IncFII plasmid carrying antimicrobial resistance genes in Shigella flexneri: Vehicle for dissemination. Reviewed International journal

Dhiviya Prabaa Muthuirulandi Sethuvel, Shalini Anandan, Naveen Kumar Devanga Ragupathi, Revathi Gajendiran, Makoto Kuroda, Keigo Shibayama, Balaji Veeraraghavan

Journal of global antimicrobial resistance   Vol. 16   page： 215 - 219   2019.3

　More details

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

OBJECTIVES: Plasmids harbouring antimicrobial resistance determinants in clinical strains are a significant public-health concern worldwide. The present study investigated such plasmids in clinical isolates of Shigella flexneri. METHODS: A total of 162 Shigella isolates were obtained from stool specimens in the year 2015. Among the 70 multidrug-resistant (MDR) Shigella spp., 27 S. flexneri isolates were randomly selected for further characterisation. Antimicrobial resistance genes (ARGs) and plasmid incompatibility (Inc) types were analysed. RESULTS: IncFII plasmids were found in 63% (17/27) of the studied S. flexneri isolates. ARGs such as dhfr1a (81%), sulII (74%), blaOXA (74%), blaTEM (33%), blaAmpC (30%), qnrS (15%) and qnrB (4%) were identified by PCR, whereas blaCTX-M was not detected. Next-generation sequencing of a representative S. flexneri IncFII-type plasmid (pSF470) revealed the presence of blaTEM1-B, blaDHA-1, qnrB10, mphA, sulI, sulII, strA, strB and tetR ARGs along with the intI1 integrase gene. In addition, pMLST analysis showed that the replicon belonged to F2:A-:B- type. CONCLUSIONS: This study helps to know the prevalent plasmid types in MDR Shigella isolates and will improve our understanding of resistance dissemination among enteric bacteria. ARGs in plasmids further highlight the importance of such studies in enteric bacteria.

DOI： 10.1016/j.jgar.2018.10.014

Scopus

PubMed

researchmap

The recent trend of MRSA surveillance in Japanese health care facilities

Tsuzuki, S, Matsunaga, N, Hayakawa, K, Suzuki, Y, Noda, A, Yamagishi, K, Yahara, K, Tsutsui, A, Shibayama, K, Noda, H, Omagari, N, Nishiura, H

INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES   Vol. 79 ( 1 ) page： 49 - 49   2019.2

　More details

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELSEVIER SCI LTD  

DOI： 10.1016/j.ijid.2018.11.131

researchmap

Production and characterization of recombinant P1 adhesin essential for adhesion, gliding, and antigenic variation in the human pathogenic bacterium, Mycoplasma pneumoniae. Reviewed International journal

Tsuyoshi Kenri, Yoshito Kawakita, Hisashi Kudo, U Matsumoto, Shigetarou Mori, Yukio Furukawa, Yuhei O Tahara, Keigo Shibayama, Yuuki Hayashi, Munehito Arai, Makoto Miyata

Biochemical and biophysical research communications   Vol. 508 ( 4 ) page： 1050 - 1055   2019.1

　More details

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

Mycoplasma pneumoniae forms an attachment organelle at one cell pole, binds to the host cell surface, and glides via a unique mechanism. A 170-kDa protein, P1 adhesin, present on the organelle surface plays a critical role in the binding and gliding process. In this study, we obtained a recombinant P1 adhesin comprising 1476 amino acid residues, excluding the C-terminal domain of 109 amino acids that carried the transmembrane segment, that were fused to additional 17 amino acid residues carrying a hexa-histidine (6 × His) tag using an Escherichia coli expression system. The recombinant protein showed solubility, and chirality in circular dichroism (CD). The results of analytical gel filtration, ultracentrifugation, negative-staining electron microscopy, and small-angle X-ray scattering (SAXS) showed that the recombinant protein exists in a monomeric form with a uniformly folded structure. SAXS analysis suggested the presence of a compact and ellipsoidal structure rather than random or molten globule-like conformation. Structure model based on SAXS results fitted well with the corresponding structure obtained with cryo-electron tomography from a closely related species, M. genitalium. This recombinant protein may be useful for structural and functional studies as well as for the preparation of antibodies for medical applications.

DOI： 10.1016/j.bbrc.2018.11.132

Scopus

PubMed

researchmap

Genetic characterization of Mycoplasma pneumoniae isolated in Osaka between 2011 and 2017: Decreased detection rate of macrolide-resistance and increase of p1 gene type 2 lineage strains. Reviewed International journal

Chihiro Katsukawa, Tsuyoshi Kenri, Keigo Shibayama, Kazuo Takahashi

PloS one   Vol. 14 ( 1 ) page： e0209938   2019

　More details

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

We characterized 419 Mycoplasma pneumoniae isolates collected between 2011 and 2017 in Osaka prefecture of Japan. This analysis revealed high prevalence of macrolide-resistant M. pneumoniae (MRMP) in Osaka during 2011 and 2014 with annual detection rates of MRMP strains between 71.4% and 81.8%. However, in 2015 and after, the detection rate of MRMP decreased significantly and did not exceed 50%. Genotyping of the p1 gene of these isolates showed that most of MRMP strains harbored type 1 p1 gene. In contrast, strains expressing p1 gene type 2 or its variant were largely macrolide-susceptible M. pneumoniae (MSMP) strains. There was a strong correlation between p1 gene genotype and the presence of mutations conferring macrolide resistance in M. pneumoniae isolated in Osaka. These results indicate that lower incidence of MRMP strains in Osaka from 2015 was associated with the relative increase of p1 gene type 2 lineage strains. During these experiments, we also isolated three M. pneumoniae strains that showed irregular typing pattern in the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the p1 gene. Two of these strains harbored new variants of type 2 p1 gene and were designated as type 2f and 2g. The remaining strain with an irregular typing pattern had a large deletion in the p1 operon.

DOI： 10.1371/journal.pone.0209938

Scopus

PubMed

researchmap

Molecular epidemiological analysis and risk factors for acquisition of carbapenemase-producing Enterobacter cloacae complex in a Japanese university hospital. 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   page： 126 - 126   2019

　More details

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

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

Web of Science

Scopus

PubMed

researchmap

Seroprevalence of IgA and IgM antibodies to Bordetella pertussis in healthy Japanese donors: Assessment for the serological diagnosis of pertussis. Reviewed International journal

Rei Fumimoto, Nao Otsuka, Hajime Kamiya, Tomimasa Sunagawa, Keiko Tanaka-Taya, Kazunari Kamachi, Keigo Shibayama

PloS one   Vol. 14 ( 7 ) page： e0219255   2019

　More details

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

Pertussis is a human respiratory infection caused by the gram-negative bacterium, Bordetella pertussis. To evaluate the pertussis burden and vaccine efficacy, diagnosis and epidemiological surveillance should be based on accurate and valid diagnostic methods. Recently, the serodiagnostic tests Novagnost Bordetella pertussis IgA and IgM were approved in Japan for pertussis diagnostics. Although the anti-pertussis toxin (PT) IgG assay has been used for pertussis diagnosis worldwide, little is known about the anti-B. pertussis IgA and IgM assays. In this study, serum samples from 460 healthy donors were examined to determine the seroprevalence of anti-B. pertussis IgA and IgM in a Japanese population, and its correlation with donor age. Our data demonstrated that anti-B. pertussis IgA and IgM are positively and negatively correlated with age (r = 0.27, r = -0.37; P < 0.001, respectively). Age-specific analysis revealed high titers of anti-B. pertussis IgA in adults (46-50 years), while anti-B. pertussis IgM titers were high in schoolchildren (6-10, 11-15 years). When applying the arbitrary cut-off values for these ages, 17.6% and 39.5% of healthy donors were interpreted as pertussis-positive or indeterminate with anti-B. pertussis IgA (46-50 years) and IgM (11-15 years) titers, respectively. Overall, our findings indicated that the Novagnost Bordetella pertussis IgA and IgM testing could be greatly affected by subject age, limiting its value for pertussis diagnosis.

DOI： 10.1371/journal.pone.0219255

Scopus

PubMed

researchmap

Development of vaccine for Clostridium difficile infection using membrane fraction of nontoxigenic Clostridium difficile. Reviewed International journal

Mitsutoshi Senoh, Masaaki Iwaki, Akihiko Yamamoto, Haru Kato, Tadashi Fukuda, Keigo Shibayama

Microbial pathogenesis   Vol. 123   page： 42 - 46   2018.10

　More details

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

Although standard antibiotic therapy is performed for diarrhea and pseudomembranous colitis caused by Clostridium difficile, a high recurrence rate of C. difficile infection (CDI) remains a major problem. We previously showed that a membrane fraction of nontoxigenic C. difficile (ntCDMF) was effective as a vaccine antigen by in vitro experiments. In this study, we examined whether ntCDMF had an in vivo effect in animal challenge experiments. By intrarectal immunization with ntCDMF, the number of C. difficile cells in feces of mice was decreased approximately 99% compared to the control mice. In addition, survival rate of C. difficile-challenged hamsters was increased almost 30% by immunization with ntCDMF. These results showed that ntCDMF could be a practical vaccine candidate.

DOI： 10.1016/j.micpath.2018.06.039

Scopus

PubMed

researchmap

Effect of methicillin-resistant Staphylococcus aureus in Japan. Reviewed International journal

Hironori Uematsu, Kazuto Yamashita, Seiko Mizuno, Susumu Kunisawa, Keigo Shibayama, Yuichi Imanaka

American journal of infection control   Vol. 46 ( 10 ) page： 1142 - 1147   2018.10

　More details

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

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is the most common antimicrobial-resistant organism identified in Japanese health care facilities. This study analyzed the clinical and economic burdens attributable to methicillin resistance in S aureus in Japanese hospitals. METHODS: We retrospectively investigated data from 14,905 inpatients of 57 hospitals combined with data from nosocomial infection surveillance and administrative claim databases. The participants were inpatients with admission from April 1, 2014, to discharge on March 31, 2016. The outcomes were evaluated according to length of stay, hospital charges, and in-hospital mortality. We compared the disease burden of MRSA infections with methicillin-susceptible S aureus (MSSA) infections based on patients' characteristics and onset periods. RESULTS: We categorized 7,188 and 7,717 patients into MRSA and MSSA groups, respectively. The adjusted effects of the MRSA group were 1.03-fold (95% confidence interval [CI] 1.01-1.05) and 1.04-fold (95% CI, 1.01-1.06), respectively, with an odds ratio of 1.14 (95% CI, 1.02-1.27). CONCLUSIONS: The results of this study found that patient severity and onset delays were positively associated with both MRSA and burden and that the effect of methicillin resistance remained significant after adjustment.

DOI： 10.1016/j.ajic.2018.04.214

Scopus

PubMed

researchmap