Details of a Researcher - YAMAMOTO Sou

Papers - YAMAMOTO Sou

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Rapid and Integrated Bacterial Evolution Analysis unveils gene mutations and clinical risk of Klebsiella pneumoniae.

Kojiro Uemura, Toyotaka Sato, Soh Yamamoto, Noriko Ogasawara, Jirachaya Toyting, Kotaro Aoki, Akira Takasawa, Masayuki Koyama, Atsushi Saito, Takayuki Wada, Kaho Okada, Yurie Yoshida, Koji Kuronuma, Chie Nakajima, Yasuhiko Suzuki, Motohiro Horiuchi, Kenichi Takano, Satoshi Takahashi, Hirofumi Chiba, Shin-Ichi Yokota

Nature communications 16 ( 1 ) 2917 - 2917 2025.03 [International journal]

Bacteria continually evolve. Previous studies have evaluated bacterial evolution in retrospect, but this approach is based on only speculation. Cohort studies are reliable but require a long duration. Additionally, identifying which genetic mutations that have emerged during bacterial evolution possess functions of interest to researchers is an exceptionally challenging task. Here, we establish a Rapid and Integrated Bacterial Evolution Analysis (RIBEA) based on serial passaging experiments using hypermutable strains, whole-genome and transposon-directed sequencing, and in vivo evaluations to monitor bacterial evolution in a cohort for one month. RIBEA reveals bacterial factors contributing to serum and antimicrobial resistance by identifying gene mutations that occurred during evolution in the major respiratory pathogen Klebsiella pneumoniae. RIBEA also enables the evaluation of the risk for the progression and the development of invasive ability from the lung to blood and antimicrobial resistance. Our results demonstrate that RIBEA enables the observation of bacterial evolution and the prediction and identification of clinically relevant high-risk bacterial strains, clarifying the associated pathogenicity and the development of antimicrobial resistance at genetic mutation level.

Bacillaceae serine proteases and Streptomyces epsilon-poly-l-lysine synergistically inactivate Caliciviridae by inhibiting RNA genome release

Soh Yamamoto, Noriko Ogasawara, Yuka Sudo-Yokoyama, Sachiko Sato, Nozomu Takata, Nana Yokota, Tomomi Nakano, Kyoko Hayashi, Akira Takasawa, Mayumi Endo, Masako Hinatsu, Keitaro Yoshida, Toyotaka Sato, Satoshi Takahashi, Kenichi Takano, Takashi Kojima, Jun Hiraki, Shin-ich Yokota

Scientific Reports ( Springer Science and Business Media LLC ) 14 ( 1 ) 2024.07 [Refereed]

Authorship： Lead author

Abstract Human norovirus (HuNoV) is an enteric infectious pathogen belonging to the Caliciviridae family that causes occasional epidemics. Circulating alcohol-tolerant viral particles that are readily transmitted via food-borne routes significantly contribute to the global burden of HuNoV-induced gastroenteritis. Moreover, contact with enzymes secreted by other microorganisms in the environment can impact the infectivity of viruses. Hence, understanding the circulation dynamics of Caliciviridae is critical to mitigating epidemics. Accordingly, in this study, we screened whether environmentally abundant secretase components, particularly proteases, affect Caliciviridae infectivity. Results showed that combining Bacillaceae serine proteases with epsilon-poly-l-lysine (EPL) produced by Streptomyces—a natural antimicrobial—elicited anti-Caliciviridae properties, including against the epidemic HuNoV GII.4_Sydney_2012 strain. In vitro and in vivo biochemical and virological analyses revealed that EPL has two unique synergistic viral inactivation functions. First, it maintains an optimal pH to promote viral surface conformational changes to the protease-sensitive structure. Subsequently, it inhibits viral RNA genome release via partial protease digestion at the P2 and S domains in the VP1 capsid. This study provides new insights regarding the high-dimensional environmental interactions between bacteria and Caliciviridae, while promoting the development of protease-based anti-viral disinfectants.

Multilayered proteomics reveals that JAM-A promotes breast cancer progression via regulation of amino acid transporter LAT1.

Kazufumi Magara, Akira Takasawa, Kumi Takasawa, Tomoyuki Aoyama, Misaki Ota, Daisuke Kyuno, Yusuke Ono, Taro Murakami, Soh Yamamoto, Yuna Nakamori, Naoya Nakahashi, Goro Kutomi, Ichiro Takemasa, Tadashi Hasegawa, Makoto Osanai

Cancer science 2024.06 [Refereed] [International journal]

Recent studies have shown that transmembrane-type tight junction proteins are upregulated in various cancers compared with their levels in normal tissues and are involved in cancer progression, suggesting that they are potential therapeutic targets. Here, we demonstrated the expression profile and a novel role of junctional adhesion molecule-A (JAM-A) in breast cancer. Immunohistochemistry of surgical specimens showed that JAM-A was highly expressed from carcinoma in situ lesions, as in other adenocarcinomas, with higher expression in invasive carcinomas. High expression of JAM-A contributed to malignant aspects such as lymph node metastasis and lymphatic involvement positivity. In breast cancer cells, JAM-A expression status affects malignant potentials including proliferation and migration. Multilayered proteomics revealed that JAM-A interacts with the amino acid transporter LAT1 in breast cancer cells. JAM-A regulates the expression of LAT1 and interacts with it on the whole cell membrane, leading to enhanced amino acid uptake to promote tumor growth. Double high expression of JAM-A and LAT1 predicts poor prognosis in patients with breast cancer. Of note, an antibody against an extracellular domain of JAM-A suppressed the proliferation of breast cancer cells. Our findings indicate the possibility of JAM-A-targeted therapy ideally combined with LAT1-targeted therapy as a new therapeutic strategy against breast cancer.

The clarithromycin-binding proteins NIPSNAP1 and 2 regulate cytokine production through mitochondrial quality control.

Soh Yamamoto, Noriko Ogasawara, Yukari Mitsuhashi, Kenichi Takano, Shin-Ichi Yokota

Scientific reports 14 ( 1 ) 2354 - 2354 2024.01 [Refereed] [International journal]

Authorship： Lead author

The mechanism underlying the anti-inflammatory effect of macrolide antibiotics, such as clarithromycin (CAM), remains to be clarified. The CAM-binding proteins 4-nitrophenylphosphatase domain and non-neuronal synaptosomal associated protein 25 (SNAP25)-like protein homolog (NIPSNAP) 1 and 2 are involved in the immune response and mitochondrial homeostasis. However, the axis between CAM-NIPSNAP-mitochondria and Toll-like receptor (TLR) and their molecular mechanisms remain unknown. In this study, we sought to elucidate the relationship between mitochondrial homeostasis mediated by NIPSNAP1 and 2 and the immunomodulatory effect of CAM. NIPSNAP1 or 2 knockdown (KD) by RNA interference impaired TLR4-mediated interleukin-8 (IL-8) production. Similar impairment was observed upon treatment with mitochondrial function inhibitors. However, IL-8 secretion was not impaired in NIPSNAP1 and 2 individual knockout (KO) and double KO (DKO) cells. Moreover, the oxygen consumption rate (OCR) in mitochondria measured using a flex analyzer was significantly reduced in NIPSNAP1 or 2 KD cells, but not in DKO cells. CAM also dose-dependently reduced the OCR. These results indicate that CAM suppresses the IL-8 production via the mitochondrial quality control regulated by temporary functional inhibition of NIPSNAP1 and 2. Our findings provide new insight into the mechanisms underlying cytokine production, including the TLR-mitochondria axis, and the immunomodulatory effects of macrolides.

Affinity of β-Lactam Antibiotics for Neisseria gonorrhoeae Penicillin-Binding Protein 2 Having Wild, Cefixime-Reduced-Susceptible, and Cephalosporin (Ceftriaxone)-Resistant penA Alleles.

Yoshiki Hiyama, Soh Yamamoto, Toyotaka Sato, Noriko Ogasawara, Naoya Masumori, Satoshi Takahashi, Shin-Ichi Yokota

Microbial drug resistance (Larchmont, N.Y.) 2024.01 [Refereed] [International journal]

Authorship： Lead author

Multidrug-resistant Neisseria gonorrhoeae is a serious concern worldwide. Resistance to β-lactam antibiotics occurs through mutations in penicillin-binding proteins (PBPs), acquisition of β-lactamases, and alteration of antibiotic penetration. Mosaic structures of penA, which encodes PBP2, play a major role in resistance to β-lactams, especially cephalosporins. Ceftriaxone (CRO) is recognized as the only satisfiable antibiotic for the treatment of gonococcal infections; however, CRO-resistant isolates have emerged in the community. Here, we examined the affinity of β-lactam antibiotics for recombinant PBP2 in a competition assay using fluorescence-labeled penicillin. We found no or little difference in the affinities of penicillins and meropenem (MEM) for PBP2 from cefixime (CFM)-reduced-susceptible strain and cephalosporin-resistant strain. However, the affinity of cephalosporins, including CRO, for PBP2 from the cephalosporin-resistant strain was markedly lower than that for PBP2 from the CFM-reduced-susceptible-resistant strain. Notably, piperacillin (PIP) showed almost the same affinity for PBP2 from penicillin-susceptible, CFM-reduced-susceptible, and cephalosporin (including CRO)-resistant strains. Thus, PIP/tazobactam and MEM are candidate antibiotics for the treatment of CRO-resistant/multidrug-resistant N. gonorrhoeae.

Serotype replacement and an increase in non-encapsulated isolates among community-acquired infections of Streptococcus pneumoniae during post-vaccine era in Japan.

Shin-Ichi Yokota, Naoyuki Tsukamoto, Toyotaka Sato, Yasuo Ohkoshi, Soh Yamamoto, Noriko Ogasawara

IJID regions 8 105 - 110 2023.09 [Refereed] [International journal]

OBJECTIVES: It is feared that the serotype replacement of Streptococcus pneumoniae occurred by the introduction of pneumococcal vaccines as periodical inoculation leads to reduced efficacy of the approved vaccines and altered antimicrobial susceptibility. METHODS: We determined serotypes of 351 S. pneumoniae isolates collected at a commercial clinical laboratory in Hokkaido prefecture, Japan, from December 2018 to February 2019 by using the polymerase chain reaction procedure of the US Centers for Disease Control and Prevention. Antimicrobial susceptibility and resistance gene profiles were also examined. RESULTS: Vaccine coverage rates were 7.9% for 13-valent conjugate vaccine, and 32.5% for 23-valent polysaccharide vaccine, respectively. Non-typable strains were 19.7%. cpsA-positive isolates (group I), and null capsule clade (NCC)1, NCC2 and NCC3 (group II) comprised 31.3%, 28.4%, 32.8%, and 7.5% of the 69 non-typable strains, respectively. No penicillin-resistant/intermediate isolates were found; however, serotypes 35B and 15A/F showed low susceptibility to β-lactams. Only five strains (1.4%) were levofloxacin-resistant, and all were from the older persons, and three strains were serotype 35B. CONCLUSION: The progression of serotype replacement in non-invasive pneumococcal infections has occurred during the post-vaccine era in Japan, and non-encapsulated isolates, such as NCC, have increased. Antimicrobial susceptibility is not worsened.

High prevalence of colistin heteroresistance in specific species and lineages of Enterobacter cloacae complex derived from human clinical specimens.

Shota Fukuzawa, Toyotaka Sato, Kotaro Aoki, Soh Yamamoto, Noriko Ogasawara, Chie Nakajima, Yasuhiko Suzuki, Motohiro Horiuchi, Satoshi Takahashi, Shin-Ichi Yokota

Annals of clinical microbiology and antimicrobials 22 ( 1 ) 60 - 60 2023.07 [Refereed] [International journal]

BACKGROUND: Colistin (CST) is a last-line drug for multidrug-resistant Gram-negative bacterial infections. CST-heteroresistant Enterobacter cloacae complex (ECC) has been isolated. However, integrated analysis of epidemiology and resistance mechanisms based on the complete ECC species identification has not been performed. METHODS: Clinical isolates identified as "E. cloacae complex" by MALDI-TOF MS Biotyper Compass in a university hospital in Japan were analyzed. Minimum inhibitory concentrations of CST were determined by the broth microdilution method. The population analysis profiling (PAP) was performed for detecting the heteroresistant phenotype. The heat shock protein 60 (hsp60) cluster was determined from its partial nucleotide sequence. From the data of whole-genome sequencing, average nucleotide identity (ANI) for determining ECC species, multilocus sequence type, core genome single-nucleotide-polymorphism-based phylogenetic analysis were performed. phoPQ-, eptA-, and arnT-deleted mutants were established to evaluate the mechanism underlying colistin heteroresistance. The arnT mRNA expression levels were determined by reverse transcription quantitative PCR. RESULTS: Thirty-eight CST-resistant isolates, all of which exhibited the heteroresistant phenotype by PAP, were found from 138 ECC clinical isolates (27.5%). The prevalence of CST-resistant isolates did not significantly differ among the origin of specimens (29.0%, 27.8%, and 20.2% for respiratory, urine, and blood specimens, respectively). hsp60 clusters, core genome phylogeny, and ANI revealed that the CST-heteroresistant isolates were found in all or most of Enterobacter roggenkampii (hsp60 cluster IV), Enterobacter kobei (cluster II), Enterobacter chuandaensis (clusters III and IX), and Enterobacter cloacae subspecies (clusters XI and XII). No heteroresistant isolates were found in Enterobacter hormaechei subspecies (clusters VIII, VI, and III) and Enterobacter ludwigii (cluster V). CST-induced mRNA upregulation of arnT, which encodes 4-amino-4-deoxy-L-arabinose transferase, was observed in the CST-heteroresistant isolates, and it is mediated by phoPQ pathway. Isolates possessing mcr-9 and mcr-10 (3.6% and 5.6% of total ECC isolates, respectively) exhibited similar CST susceptibility and PAP compared with mcr-negative isolates. CONCLUSIONS: Significant prevalence (approximately 28%) of CST heteroresistance is observed in ECC clinical isolates, and they are accumulated in specific species and lineages. Heteroresistance is occurred by upregulation of arnT mRNA induced by CST. Acquisition of mcr genes contributes less to CST resistance in ECC.

Colistin-resistant bacteria poses few risks under physiological conditions

Soh Yamamoto, Masaru Usui, Noriko Ogasawara, Wataru Hayashi, Masato Suzuki, Noriyuki Nagano, Chie Nakajima, Yasuhiko Suzuki, Motohiro Horiuchi, Satoshi Takahashi, Shin-ichi Yokota, Yutaka Tamura, Toyotaka Sato

Research Square ( Research Square Platform LLC ) 2023.06 [Refereed]

Abstract Globally, 5.0 million people die annually from infections associated with antimicrobial-resistant bacteria, most commonly Escherichia coli¹. As colistin is a last-resort antibiotic for multidrug-resistant bacterial infections, the global spread of plasmid-mediated colistin resistance genes (mcr) gene is considered a major public health risk^2-4. However, the actual health risks of colistin resistance in hazardous bacteria have never been evaluated under physiological conditions. Here, we show that the fitness/virulence and colistin resistance of the pandemic multidrug-resistant E. coli clone ST131⁵ very depending on the acquired colistin resistance determinants and differ between physiological and in vitro conditions. The fitness/virulence of ST131 was unaffected by chromosomal-gene (pmrB) mutations or the acquisition of mcr-5-harbouring plasmids in mouse models. However, the acquisition of mcr-1- or mcr-3-harbouring plasmids attenuated fitness/virulence and promoted colistin susceptibility in human serum. We identified two virulence attenuation factors (vafA and vafB) on the pIncI2_mcr-1 plasmid that hijacked the ST131 transcriptome and inhibited nucleotide synthesis, attenuating colistin resistance. Our results demonstrate that colistin resistance poses much less of a threat than believed^6,7. We suggest that “nonresistance genes,” rather than resistance genes, are important antimicrobial resistance determinants for human health because they determine fitness/virulence and ultimately antimicrobial susceptibility under physiological conditions.

Rapid, simple, and cost-effective plaque assay for murine norovirus using microcrystalline cellulose.

Soh Yamamoto, Yuka Sudo-Yokoyama, Noriko Ogasawara, Shin-Ichi Yokota

Journal of virological methods 316 114715 - 114715 2023.06 [Refereed] [International journal]

Authorship： Lead author

Murine norovirus (MNV) is used widely as a practical alternative to human norovirus (HuNoV). Plaque-forming assays for MNV are important for developing therapeutic agents against HuNoV infections. Although agarose-overlay MNV assays have been reported, recent improvements in cellulose derivatives suggest that they could be optimized further, particularly with respect to improving the overlay material. To determine which overlay material is optimal for the MNV plaque assay, we compared four typical cellulose derivatives [microcrystalline cellulose (MCC), hydroxyethyl cellulose (HEC), hydroxypropyl methylcellulose (HPMC), and carboxymethyl cellulose (CMC)] with conventional agarose. We found that 3.5% (w/v) MCC-containing medium provided clear round-shaped plaques on RAW 264.7 cells 1 day after inoculation; the visibility of plaques was comparable with that of the original agarose-overlay assay. Removing residual MCC powder from the MCC-overlay assay before fixing was important for obtaining distinct plaques that are clearly countable. Finally, after calculating the plaque diameter as a percentage of well diameter, we found that 12- and 24-well plates were better than other plates for accurate plaque counting. The MCC-based MNV plaque assay is cost-effective and rapid, and produces plaques that are easy to count. Accurate virus quantification using this optimized plaque assay will enable reliable estimation of norovirus titers.

Invasive pulmonary aspergillosis with candidiasis: usefulness of molecular and ultrastructural morphological analysis on FFPE tissue for invasive fungal infections.

Yusaku Kubota, Akira Takasawa, Yusuke Ono, Tomoyuki Aoyama, Kumi Takasawa, Akinori Tada, Kazufumi Magara, Taro Murakami, Fuminori Daimon, Soh Yamamoto, Shota Sato, Yutaro Hiratsuka, Daisuke Kyuno, Makoto Osanai

Medical molecular morphology 56 ( 2 ) 1 - 8 2023.02 [Refereed] [Domestic journal]

Invasive pulmonary aspergillosis (IPA) is one of the most frequent forms of invasive fungal infections (IFI); however, it is often difficult to identify the pathogenic fungal species and to select appropriate treatments for patients with IFI including IPA. Here, we describe the detailed pathophysiology of an autopsy case of severe respiratory failure due to IPA with candidiasis. The patient developed severe respiratory failure after influenza infection and died, and the autopsy revealed a mixed disease of IPA with candidiasis. In this study, in addition to the routine pathological examination, we further examined formalin-fixed paraffin-embedded (FFPE) tissues by scanning electron microscopy (SEM) and partial genomic DNA sequencing. Although optical microscopy alone was insufficient to identify the pathogenic organisms, SEM clearly depicted the characteristic morphology of Aspergillus sp. and Candida sp. as closely overlapping in a nested fashion, providing evidence of mixed infection of both fungal species in a focal site. The technique using FFPE tissue in combination with ultrastructural observation by SEM, elemental analysis by SEM-EDX, and DNA sequencing is promising for analyzing the pathophysiology of IFI.

抗菌性物質・薬剤耐性/生体防御大腸菌ST131におけるmcr-1保有プラスミドの獲得による病原性減弱機構(Antimicrobial agents and resistance/Host defense Virulent attenuation mechanism by acquisition of mcr-1-harboring plasmid into Escherichia coli ST131)

佐藤豊孝, 山本聡, 小笠原徳子, 臼井優, 長野則之, 土井洋平, 堀内基広, 高橋聡, 横田伸一, 田村豊

日本細菌学雑誌 ( 日本細菌学会 ) 78 ( 1 ) 48 - 48 2023.02

A Hydroxypropyl Methylcellulose Plaque Assay for Human Respiratory Syncytial Virus.

Yuka Takumi-Tanimukai, Soh Yamamoto, Noriko Ogasawara, Sayaka Nakabayashi, Katsumi Mizuta, Keisuke Yamamoto, Ryo Miyata, Takuya Kakuki, Sumito Jitsukawa, Toyotaka Sato, Hiroyuki Tsutsumi, Takashi Kojima, Kenichi Takano, Shin-Ichi Yokota

Journal of virological methods 304 114528 - 114528 2022.03 [Refereed] [International journal]

Quantifying proliferative virus particles is one of the most important experimental procedures in virology. Compared with classical overlay materials, newly developed cellulose derivatives enable a plaque-forming assay to produce countable clear plaques easily. HEp-2 cells are widely used in plaque assays for human respiratory syncytial virus (RSV). It is crucial to use an overlay material to keep HEp-2 cell proliferation and prevent RSV particles from spreading over the fluid. Among four cellulose derivatives, carboxymethyl cellulose sodium salt (CMC), hydroxypropyl methylcellulose (HPMC), microcrystalline cellulose (MCC), and hydroxyethyl cellulose (HEC), we found that HPMC was the optimal overlay material because HPMC maintained HEp-2 cell proliferation and RSV infectivity. Although MCC was unsuitable for RSV, it assisted the plaque-forming by human metapneumovirus in TMPRSS2-expressing cells. Therefore, depending on the cells and viruses, it is necessary to use different overlay materials at varying concentrations.

Reduction of susceptibility to azoles and 5-fluorocytosine and growth acceleration in Candida albicans in glucosuria.

Yoshiki Hiyama, Toyotaka Sato, Satoshi Takahashi, Soh Yamamoto, Noriko Ogasawara, Naoya Masumori, Shin-Ichi Yokota

Diagnostic microbiology and infectious disease 102 ( 1 ) 115556 - 115556 2021.09 [Refereed] [International journal]

Diabetes mellitus is a chronic metabolic disease characterized by hyperglycemia and glucosuria, and is a risk factor for Candida infections. To reveal the potential effects of glucosuria on Candida spp., we investigated their growth and antifungal susceptibilities in normal human urine to which glucose was added. The viable cell numbers of Candida spp. were more than 10 fold higher in the urine added 3000 mg/dL glucose than in plain urine. In antifungal susceptibility, more than 80% of Candida albicans clinical isolates increased minimum inhibitory concentrations of azoles and 5-fluorocytosine with the addition of glucose, and exceeded their breakpoints. In most of the C. albicans clinical isolates, the mRNA expression of the azole resistance genes ERG11, CDR1, CDR2, and MDR1 in the presence of glucose in urine. These observations provide valuable information about the clinical course and therapeutic effects of azoles against C. albicans infections in patients with diabetes mellitus and hyperglucosuria.

An autophagy-related protein Becn2 regulates cocaine reward behaviors in the dopaminergic system.

Yoon-Jin Kim, Qingyao Kong, Soh Yamamoto, Kenta Kuramoto, Mei Huang, Nan Wang, Jung Hwa Hong, Tong Xiao, Beth Levine, Xianxiu Qiu, Yanxiang Zhao, Richard J Miller, Hongxin Dong, Herbert Y Meltzer, Ming Xu, Congcong He

Science advances 7 ( 8 ) 2021.02 [Refereed] [International journal]

Drug abuse is a foremost public health problem. Cocaine is a widely abused drug worldwide that produces various reward-related behaviors. The mechanisms that underlie cocaine-induced disorders are unresolved, and effective treatments are lacking. Here, we found that an autophagy-related protein Becn2 is a previously unidentified regulator of cocaine reward behaviors. Becn2 deletion protects mice from cocaine-stimulated locomotion and reward behaviors, as well as cocaine-induced dopamine accumulation and signaling, by increasing presynaptic dopamine receptor 2 (D2R) autoreceptors in dopamine neurons. Becn2 regulates D2R endolysosomal trafficking, degradation, and cocaine-induced behaviors via interacting with a D2R-bound adaptor GASP1. Inactivating Becn2 by upstream autophagy inhibitors stabilizes striatal presynaptic D2R, reduces dopamine release and signaling, and prevents cocaine reward in normal mice. Thus, the autophagy protein Becn2 is essential for cocaine psychomotor stimulation and reward through regulating dopamine neurotransmission, and targeting Becn2 by autophagy inhibitors is a potential strategy to prevent cocaine-induced behaviors.

Aberrant expression of junctional adhesion molecule-A contributes to the malignancy of cervical adenocarcinoma by interaction with poliovirus receptor/CD155.

Taro Murakami, Akira Takasawa, Kumi Takasawa, Taishi Akimoto, Tomoyuki Aoyama, Kazufumi Magara, Yuki Saito, Misaki Ota, Daisuke Kyuno, Soh Yamamoto, Tadashi Hasegawa, Tsuyoshi Saito, Makoto Osanai

Cancer science 112 ( 2 ) 906 - 917 2021.02 [Refereed] [International journal]

Recent studies have shown that aberrant expression of tight junction proteins (TJP) contributes to malignant potential of various cancers. In the present study, we investigated the expression of junctional adhesion molecule-A (JAM-A), one of the transmembrane TJP, in uterine cervical adenocarcinoma and the significance of its expression for malignancy. Immunohistochemistry on human surgical specimens showed that JAM-A was aberrantly expressed in neoplastic regions including adenocarcinoma in situ (AIS). Knockout of JAM-A significantly suppressed cell proliferation and colony-forming and migration abilities. We also showed that an antibody specific to an extracellular region of JAM-A reduced cell proliferation ability and that loss of JAM-A increased drug sensitivity of cervical adenocarcinoma cells. Based on a comprehensive proteome analysis, we found that poliovirus receptor (PVR/CD155) was regulated by JAM-A and formed a physical interaction with JAM-A. In human surgical specimens, PVR/CD155 expression was significantly correlated with some clinicopathological features and prognosis of cervical adenocarcinoma. Interestingly, most of the PVR/CD155-positive cases expressed a high level of JAM-A, and patients with the expression pattern of PVR/CD155 positive/JAM-A high had significantly shorter periods of relapse-free survival (P = .00964) and overall survival (P = .0204) than those for the other patients. Our observations suggest that aberrant expression of JAM-A promotes malignancy of uterine cervical adenocarcinoma by regulation of PVR/CD155, and JAM-A is therefore a potential therapeutic target for this malignancy.

Sitafloxacin has a potent activity for eradication of extended spectrum β-lactamase-producing fluoroquinolone-resistant Escherichia coli forming intracellular bacterial communities in uroepithelial cells.

Yoshiki Hiyama, Toyotaka Sato, Satoshi Takahashi, Soh Yamamoto, Yukari Fukushima, Chie Nakajima, Yasuhiko Suzuki, Shin-Ichi Yokota, Naoya Masumori

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy 26 ( 12 ) 1272 - 1277 2020.12 [Refereed] [International journal]

INTRODUCTION: Eradication of asymptomatic bacteriuria (ASB) before urological procedures is important to reduce the risk for infectious complications after surgery. However, the appropriate regimen for antimicrobial treatment has not been fully determined. We experienced continuous (over 10 months) isolation of extended spectrum β-lactamase (ESBL)-producing fluoroquinolone-resistant Escherichia coli from urine of an asymptomatic patient. The four isolates obtained (SMESC1 to 4) were international high-risk clones of O25b:H4-ST131-H30R, and originated from one strain, as revealed by the whole genome sequences. Although the patient received meropenem (MEPM) and fosfomycin (FOM), to which the strains were susceptible before the urological procedures, they could not be eradicated. METHODS: To explore the reason for the continuous isolation even after MEPM and FOM administration, antimicrobial killing of adherent and/or intracellular bacterial communities (IBC) formed by coculture of the E. coli cells and T24 bladder epithelial cells were examined. RESULTS: FOM and levofloxacin did not decrease viable E. coli cells compared with gentamicin. MEPM partly decreased them, and sitafloxacin (STFX) decreased them most potently. These observations indicate that E. coli can survive in the urinary tract under antimicrobial administration, and some antimicrobials such as FOM and MEPM cannot eradicate E. coli in uroepithelial cells. Adhesion on urinary epithelial cells and/or IBC formation might result in continuous isolation from the urinary tract and recurrence of ASB and urinary tract infections. CONCLUSIONS: The present study suggests that STFX is a promising optional agent for the eradication of ESBL-producing fluoroquinolone-resistant E. coli in the urinary tract before urological procedures.

Structural analysis of the lipoteichoic acid anchor glycolipid: Comparison of methods for degradation of the glycerophosphate backbone polymer.

Tsukasa Shiraishi, Soh Yamamoto, Shin-Ichi Yokota

Journal of microbiological methods 166 105726 - 105726 2019.11 [Refereed] [International journal]

Comparison of measurements of anti-PLA2R antibodies in Japanese patients with membranous nephropathy using in-house and commercial ELISA.

Hajime Kaga, Atsushi Komatsuda, Soh Yamamoto, Tadashi Kikuchi, Mika Kamata, Akiko Sato, Masafumi Odaka, Shin-Ichi Yokota, Naoto Takahashi, Hideki Wakui

Clinical and experimental nephrology 23 ( 4 ) 465 - 473 2019.04 [Refereed] [Domestic journal]

BACKGROUND: The prevalence of antibodies against M-type anti-phospholipase A2 receptor (PLA2R) was reported to be ~ 70-80% in early studies on idiopathic membranous nephropathy (iMN) cohorts from Western countries, China, and Korea, and ~ 50% in recent studies on two Japanese iMN cohorts. METHODS: We developed an in-house enzyme-linked immunosorbent assay (ELISA) for the detection of anti-PLA2R antibodies, and examined sera from 217 patients with iMN, 22 patients with secondary MN (sMN), and 50 healthy individuals. All patients and healthy individuals were Japanese. The relationships between levels of anti-PLA2R antibodies and clinical parameters were analyzed. Serum samples were also tested using a standardized commercial ELISA (Euroimmun, Germany). RESULTS: In our ELISA, OD values greater than the mean + 3 standard deviation of healthy subjects were considered to be positive for anti-PLA2R antibodies. Of the patients with iMN, 33.6% (73/217) were positive, but all sMN patients were negative. Our ELISA and the Euroimmun ELISA had a high concordance (93.5%). The proportion of patients with nephrotic syndrome was significantly higher in anti-PLA2R antibody-positive patients than in antibody-negative patients (65.8 vs. 37.5%, P < 0.001). Levels of anti-PLA2R antibodies were significantly correlated with levels of urinary protein and serum albumin (P = 0.004 and P < 0.001, respectively). CONCLUSIONS: The prevalence of anti-PLA2R antibodies in our Japanese iMN cohort was lower than that in the previous studies from other countries and other Japanese institutes. The low prevalence of antibodies may be related with the characteristics of enrolled patients with mild proteinuria and undetectable antibody levels.

緑膿菌はリポ多糖の菌体外放出量が多く、高菌量下でコリスチンの抗菌活性が減弱する

横田伸一, 袴田浩, 山本聡, 佐藤豊孝, 白石宗

緑膿菌感染症研究会講演記録 ( 緑膿菌感染症研究会 ) 52回 52 - 54 2018.10

淋菌に対するpiperacillinとtazobactam/piperacillinの薬剤感受性の検討

桧山佳樹, 高橋聡, 佐藤豊孝, 山本聡, 品川雅明, 横田伸一, 舛森直哉

日本性感染症学会誌 ( (一社)日本性感染症学会 ) 29 ( 2 ) 236 - 236 2018.10

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