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

DOI： 10.1016/j.ijregi.2024.100511

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Publishing type：Research paper (scientific journal)   Publisher：American Society of Hematology  

The oral microbiota, second in abundance to the gut, is implicated in chronic systemic diseases, but its specific role in GVHD pathogenesis has been unclear. Our study finds that mucositis-induced oral dysbiosis in patients post-hematopoietic cell transplantation associated with increased chronic GVHD (cGVHD) even in patients receiving post-transplant cyclophosphamide. In murine HCT models, oral dysbiosis caused by bilateral molar ligatures exacerbated cGVHD and increased bacterial load in the oral cavity and gut with Enterococcaceae significantly increasing in both organs. In this model, the migration of Enterococcaceae to cervical lymph nodes (LNs) both pre- and post-transplantation activated antigen-presenting cells (APCs), thereby promoting the expansion of donor-derived inflammatory T cells. Based on these results, we hypothesize that pathogenic bacteria increased in the oral cavity might not only exacerbate local inflammation but also enhance systemic inflammation throughout the HCT course. Additionally, these bacteria translocated to the gut and formed ectopic colonies, further amplifying systemic inflammation. Furthermore, interventions targeting the oral microbiome mitigated murine cGVHD. Collectively, our findings highlight the importance of oral dysbiosis in cGVHD and suggest that modulation of the oral microbiome during transplantation may be an effective approach for preventing or treating cGVHD.

DOI： 10.1182/blood.2024024540

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

INTRODUCTION: Corynebacterium species potentially develop high-level daptomycin resistance (HLDR) shortly after daptomycin (DAP) administration. We aimed to investigate the clinical and microbiological characteristics of HLDR Corynebacterium infections. METHODS: We first presented a clinical case accompanied by the results of a comprehensive genetic analysis of the isolate, and then performed a systematic scoping review. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews, we searched for articles with related keywords, including "Corynebacterium", "Daptomycin", and "Resistance", in the MEDLINE and Web of Science databases from the database inception to October 25, 2024. Clinical case reports and research articles documenting the isolation of HLDR Corynebacterium species, defined by a minimum inhibitory concentration of DAP at ≥256 μg/mL, were deemed eligible for this review. RESULTS: Of 80 articles screened, seven case reports detailing eight cases of HLDR Corynebacterium infections, as well as five research articles, were included. C. striatum was the most common species (7/9 cases, 77.8%), and prosthetic device-associated infections accounted for 66.7% of the cases. Duration of DAP administration before the emergence of HLDR isolates ranged from 5 days to 3 months; three-quarters of the cases developed within 17 days. Three HLDR isolates were genetically confirmed to have an alteration in pgsA2. The majority of the patients were treated with either glycopeptides or linezolid, with favorable outcomes. In vitro experiments confirmed that C. striatum strains acquire the HLDR phenotype at higher rates (71% to 100%) within 24 hours of incubation, compared to other Corynebacterium strains CONCLUSION: DAP monotherapy, especially for prosthetic device-associated infections, can result in the development of HLDR Corynebacterium. Additional research is warranted to investigate the clinical implications of this potentially proliferating antimicrobial resistant pathogen.

DOI： 10.1016/j.jiac.2024.12.004

PubMed

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

Spread of carbapenemase-producing Enterobacterales (CPE) is an ongoing public health issue worldwide, including in Japan. In this study, we investigated the phenotypic and genetic characteristics of CPE isolates at Okayama University Hospital over the 5 years (2013-2018) prior to the outbreak of the 2019 coronavirus pandemic. Of 24 carbapenem-resistant Enterobacterales isolated during the study period, we identified 8 CPE isolates harboring blaIMP-1 (5 isolates) and blaIMP-6 genes (3 isolates). Bacterial species and carbapenem susceptibility patterns exhibited diversity. Minimum inhibitory concentrations (MICs) of meropenem were generally higher than those of imipenem and biapenem. Results of pulsed-field gel electrophoresis demonstrated that neither clonal nor plasmid-mediated outbreaks of blaIMP-harboring CPE isolates have developed at our hospital. One Klebsiella oxytoca isolate showed a high MIC (128 μg/mL) of meropenem, which could be explained by the high plasmid copy number. Subsequent analysis of this isolate may elucidate the intricacies of carbapenem resistance profiles among CPE isolates. Collectively, our findings underscore the necessity for ongoing genetic surveillance of CPE, complemented by tailored approaches for infection prevention and control.

DOI： 10.18926/AMO/67657

PubMed

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.diagmicrobio.2024.116399

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Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

We have isolated a blaNDM-1-harbouring ST147 Klebsiella pneumoniae strain from a Ukrainian immigrant hospitalized at a Japanese hospital, which was genetically corroborated to be highly identical to a Russian-derived isolate. This case highlights that the geopolitical risk potentially increases the global dissemination of antimicrobial resistance pathogens.

DOI： 10.1093/jtm/taae011

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