Pub Date : 2026-02-04DOI: 10.1016/j.jiac.2026.102922
Jun Taguchi , Hiroshi Morioka , Yoshiyuki Tokuda , Tomonari Uemura , Hiroshi Hamada , Ken-ichi Iwata , Kohei Kanda , Keisuke Oka , Tetsuya Yagi
Cutibacterium acnes is a low-virulence skin commensal that can cause late-onset prosthetic graft infections. We report the case of a 60-year-old man with diabetes who presented with fever and bilateral chest pain 10 months after an ascending aortic graft replacement. Computed tomography revealed right-sided pleural effusion and perigraft fluid collections; extended incubation of the pleural fluid and blood samples revealed C. acnes. Seven weeks after the intravenous antibiotic therapy, the patient underwent mediastinal irrigation, explantation of the infected graft, replacement with a rifampicin-soaked prosthesis, and omental flap coverage. Extended incubation of intraoperative specimens resulted in C. acnes in both samples. Following four additional weeks of intravenous antibiotic therapy, long-term oral amoxicillin suppression was initiated. At one-year follow-up, the patient remained clinically stable without evidence of recurrence. This case highlights the importance of extended incubation, vigilant diagnostic evaluation, and combined surgical and antimicrobial management in delayed C. acnes vascular graft infections. We also reviewed relevant literature on C. acnes prosthetic vascular infections to contextualize this case.
{"title":"Delayed Cutibacterium acnes infection of a thoracic aortic graft presenting as empyema: A case report and literature review","authors":"Jun Taguchi , Hiroshi Morioka , Yoshiyuki Tokuda , Tomonari Uemura , Hiroshi Hamada , Ken-ichi Iwata , Kohei Kanda , Keisuke Oka , Tetsuya Yagi","doi":"10.1016/j.jiac.2026.102922","DOIUrl":"10.1016/j.jiac.2026.102922","url":null,"abstract":"<div><div><em>Cutibacterium acnes</em> is a low-virulence skin commensal that can cause late-onset prosthetic graft infections. We report the case of a 60-year-old man with diabetes who presented with fever and bilateral chest pain 10 months after an ascending aortic graft replacement. Computed tomography revealed right-sided pleural effusion and perigraft fluid collections; extended incubation of the pleural fluid and blood samples revealed <em>C. acnes</em>. Seven weeks after the intravenous antibiotic therapy, the patient underwent mediastinal irrigation, explantation of the infected graft, replacement with a rifampicin-soaked prosthesis, and omental flap coverage. Extended incubation of intraoperative specimens resulted in <em>C. acnes</em> in both samples. Following four additional weeks of intravenous antibiotic therapy, long-term oral amoxicillin suppression was initiated. At one-year follow-up, the patient remained clinically stable without evidence of recurrence. This case highlights the importance of extended incubation, vigilant diagnostic evaluation, and combined surgical and antimicrobial management in delayed <em>C. acnes</em> vascular graft infections. We also reviewed relevant literature on <em>C. acne</em>s prosthetic vascular infections to contextualize this case.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 3","pages":"Article 102922"},"PeriodicalIF":1.5,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-04DOI: 10.1016/j.jiac.2026.102923
Takashi Shoji , Yuto Otsubo , Yuho Horikoshi
Background
In adults, cefepime is proposed as a treatment option for infections associated with a risk of AmpC β-lactamase overproduction; however, data in pediatric populations are limited. We aimed to compare clinical outcomes between cefepime versus carbapenem as definitive therapy for bacteremia caused by Enterobacterales with a relatively high risk of chromosomal AmpC production (AmpC-E) in children.
Methods
This retrospective cohort study was conducted at a tertiary children's hospital between 2010 and 2024. Eligible patients were <21 years old with blood cultures positive for AmpC-E. The primary outcome was 30-day mortality. Secondary outcomes included 30-day recurrence, time to negative blood culture and treatment-related toxicity.
Results
51 children met the inclusion criteria. The median age was 11 months (IQR: 3–63), with 54.9% male patients. Cefepime and meropenem were administered as definitive therapy in 38 (74.5%) and 13 (25.5%) cases. Baseline characteristics of the patients were comparable. Isolated organisms included Enterobacter cloacae complex (47.1%), Serratia marcescens (29.4%) and Klebsiella aerogenes (19.6%). The cefepime group had a higher prevalence of Klebsiella aerogenes (26.3%, p = 0.048) and Serratia marcescens (39.5%, p = 0.006). The 30-day mortality was 2.6% (1/38) in the cefepime group and 15.4% (2/13) in the meropenem group (p = 0.156). No recurrence of bacteremia or treatment-related toxicity were observed. The median time to negative blood cultures was 2 days (IQR: 1–3) in the cefepime group and 1 day (IQR: 1–5) in the meropenem group (p = 0.949).
Conclusion
Cefepime and meropenem as definitive therapy demonstrated comparable outcomes for AmpC-E bacteremia. Further prospective studies are warranted.
背景：在成人中，头孢吡肟被建议作为与AmpC β-内酰胺酶过量产生风险相关的感染的治疗选择；然而，儿科人群的数据是有限的。我们的目的是比较头孢吡肟和碳青霉烯作为儿童染色体AmpC产生（AmpC- e）风险相对较高的肠杆菌引起的菌血症的决定性治疗的临床结果。方法：回顾性队列研究于2010年至2024年在某三级儿童医院进行。结果：51例患儿符合纳入标准。中位年龄为11个月（IQR: 3-63），男性占54.9%。头孢吡肟和美罗培南分别为38例（74.5%）和13例（25.5%）。患者的基线特征具有可比性。分离出的细菌包括阴沟肠杆菌（47.1%）、粘质沙雷菌（29.4%）和产气克雷伯菌（19.6%）。头孢吡肟组产气克雷伯菌（26.3%,p=0.048）和粘质沙雷菌（39.5%,p=0.006）患病率较高。头孢吡肟组30天死亡率为2.6%(1/38)，美罗培南组30天死亡率为15.4% (2/13)（p=0.156）。未观察到菌血症复发或治疗相关毒性。头孢吡肟组中位血培养阴性时间为2 d (IQR: 1 ~ 3)，美罗培南组中位血培养阴性时间为1 d (IQR: 1 ~ 5) （p=0.949）。结论：头孢吡肟和美罗培南作为最终治疗AmpC-E菌血症的效果相当。进一步的前瞻性研究是必要的。
{"title":"Definitive cefepime versus carbapenems for bacteremia caused by Enterobacterales with a risk of chromosomal AmpC production in children","authors":"Takashi Shoji , Yuto Otsubo , Yuho Horikoshi","doi":"10.1016/j.jiac.2026.102923","DOIUrl":"10.1016/j.jiac.2026.102923","url":null,"abstract":"<div><h3>Background</h3><div>In adults, cefepime is proposed as a treatment option for infections associated with a risk of AmpC β-lactamase overproduction; however, data in pediatric populations are limited. We aimed to compare clinical outcomes between cefepime versus carbapenem as definitive therapy for bacteremia caused by Enterobacterales with a relatively high risk of chromosomal AmpC production (AmpC-E) in children.</div></div><div><h3>Methods</h3><div>This retrospective cohort study was conducted at a tertiary children's hospital between 2010 and 2024. Eligible patients were <21 years old with blood cultures positive for AmpC-E. The primary outcome was 30-day mortality. Secondary outcomes included 30-day recurrence, time to negative blood culture and treatment-related toxicity.</div></div><div><h3>Results</h3><div>51 children met the inclusion criteria. The median age was 11 months (IQR: 3–63), with 54.9% male patients. Cefepime and meropenem were administered as definitive therapy in 38 (74.5%) and 13 (25.5%) cases. Baseline characteristics of the patients were comparable. Isolated organisms included <em>Enterobacter cloacae</em> complex (47.1%), <em>Serratia marcescens</em> (29.4%) and <em>Klebsiella aerogenes</em> (19.6%). The cefepime group had a higher prevalence of <em>Klebsiella aerogenes</em> (26.3%, p = 0.048) and <em>Serratia marcescens</em> (39.5%, p = 0.006). The 30-day mortality was 2.6% (1/38) in the cefepime group and 15.4% (2/13) in the meropenem group (p = 0.156). No recurrence of bacteremia or treatment-related toxicity were observed. The median time to negative blood cultures was 2 days (IQR: 1–3) in the cefepime group and 1 day (IQR: 1–5) in the meropenem group (p = 0.949).</div></div><div><h3>Conclusion</h3><div>Cefepime and meropenem as definitive therapy demonstrated comparable outcomes for AmpC-E bacteremia. Further prospective studies are warranted.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 3","pages":"Article 102923"},"PeriodicalIF":1.5,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.jiac.2026.102915
Akihiro Nakamura , Tatsuya Nakamura , Makoto Niki , Tomokazu Kuchibiro , Katsutoshi Yamasaki , Masaru Komatsu , The Study of Bacterial Resistance in the Kinki region of Japan (SBRK) group
Introduction
The global dissemination of extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Escherichia coli sequence type 131 (ST131), particularly clade C, represents a major public health concern. However, the clade-specific genomic features underlying the long-term persistence and international spread of this lineage remain incompletely understood.
Methods
We performed whole-genome sequencing and comparative genomic analyses of 121 clinical E. coli isolates, including 83 ST131 and 38 non-ST131 strains, collected from 24 healthcare-associated facilities in Japan between 2001 and 2018. Plasmid replicon types, antimicrobial resistance genes, virulence factors, quinolone resistance–determining region (QRDR) mutations, and chromosomal structural variations were analyzed across ST131 clades.
Results
ST131 isolates, particularly clade C, showed a significantly higher prevalence of IncF plasmid replicons, QRDR mutations, and uropathogenic virulence genes such as iha, papA, kpsM, and usp compared with non-ST131 isolates. In contrast, dfrA family genes were less frequent in clade C, suggesting potential retained susceptibility to trimethoprim–sulfamethoxazole. Phylogenetic analysis demonstrated long-term persistence of clade C subclades (C1-nM27, C1-M27, and C2) in Japan. A clade-specific chromosomal region, M27PP1, encoding an ATP-binding protein with a conserved AAA + ATPase domain within a clade-specific genomic island, was identified exclusively in C1-M27 isolates.
Conclusions
Our findings highlight distinct clade-specific genomic characteristics of ST131 clade C in Japan, particularly in C1-M27. While the biological function of M27PP1 remains to be experimentally determined, its lineage-restricted distribution suggests a potential role in the long-term persistence and dissemination of this subclade. Continued genomic surveillance is essential for understanding and controlling high-risk E. coli lineages.
{"title":"Comprehensive genomic analysis of ESBL- and carbapenemase-producing Escherichia coli ST131 in Japan: Genetic characteristics of pandemic clade C","authors":"Akihiro Nakamura , Tatsuya Nakamura , Makoto Niki , Tomokazu Kuchibiro , Katsutoshi Yamasaki , Masaru Komatsu , The Study of Bacterial Resistance in the Kinki region of Japan (SBRK) group","doi":"10.1016/j.jiac.2026.102915","DOIUrl":"10.1016/j.jiac.2026.102915","url":null,"abstract":"<div><h3>Introduction</h3><div>The global dissemination of extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing <em>Escherichia coli</em> sequence type 131 (ST131), particularly clade C, represents a major public health concern. However, the clade-specific genomic features underlying the long-term persistence and international spread of this lineage remain incompletely understood.</div></div><div><h3>Methods</h3><div>We performed whole-genome sequencing and comparative genomic analyses of 121 clinical <em>E. coli</em> isolates, including 83 ST131 and 38 non-ST131 strains, collected from 24 healthcare-associated facilities in Japan between 2001 and 2018. Plasmid replicon types, antimicrobial resistance genes, virulence factors, quinolone resistance–determining region (QRDR) mutations, and chromosomal structural variations were analyzed across ST131 clades.</div></div><div><h3>Results</h3><div>ST131 isolates, particularly clade C, showed a significantly higher prevalence of IncF plasmid replicons, QRDR mutations, and uropathogenic virulence genes such as <em>iha</em>, <em>papA</em>, <em>kpsM</em>, and <em>usp</em> compared with non-ST131 isolates. In contrast, <em>dfrA</em> family genes were less frequent in clade C, suggesting potential retained susceptibility to trimethoprim–sulfamethoxazole. Phylogenetic analysis demonstrated long-term persistence of clade C subclades (C1-nM27, C1-M27, and C2) in Japan. A clade-specific chromosomal region, M27PP1, encoding an ATP-binding protein with a conserved AAA + ATPase domain within a clade-specific genomic island, was identified exclusively in C1-M27 isolates.</div></div><div><h3>Conclusions</h3><div>Our findings highlight distinct clade-specific genomic characteristics of ST131 clade C in Japan, particularly in C1-M27. While the biological function of M27PP1 remains to be experimentally determined, its lineage-restricted distribution suggests a potential role in the long-term persistence and dissemination of this subclade. Continued genomic surveillance is essential for understanding and controlling high-risk <em>E. coli</em> lineages.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 2","pages":"Article 102915"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146046859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Small-colony variants (SCVs) are a slow-growing subset of bacteria that exhibit unusual colony morphology and unique biochemical characteristics. They are associated with chronic and persistent infections. CO2-dependent SCVs of Staphylococcus aureus have been rarely isolated from clinical specimens. This study aimed to characterize the CO2-dependent phenotype of S. aureus SCV isolated from pacemaker leads and to determine the genetic basis underlying this trait.
Methods
CO2-dependent S. aureus SCV-5700 isolated from pacemaker leads of a patient with a pacemaker infection was used in this study. Phenotypic testing, antimicrobial susceptibility testing, and mecA polymerase chain reaction of the isolate were performed. Moreover, whole-genome sequencing was conducted for multilocus sequence typing and comparative genomic analysis.
Results
CO2-dependent S. aureus SCV-5700 grew poorly under ambient air conditions; however, tiny colonies formed after 48 h incubation. The isolate was sequence type 45 and did not harbor the mecA. The isolate was identified as S. aureus by biochemical characterization in a 5 % CO2 atmosphere. Comparative genomic analysis revealed that the isolate had a nonsense mutation (c.565C>T) in the mpsB; however, the revertant strain, Rev-5700, had no such mutation.
Conclusion
The CO2-dependent phenotype of clinical S. aureus isolates can be attributed, in part, to loss of MpsB function.
{"title":"Identification of the genetic basis of a CO2-dependent Staphylococcus aureus small-colony variant isolated from pacemaker leads","authors":"Tatsuya Negishi , Yuuki Higuma , Aika Takeda , Ayaka Hachiro , Tatsuya Natori , Kazuki Horiuchi , Nau Ishimine , Takeshi Uehara , Takehisa Matsumoto","doi":"10.1016/j.jiac.2026.102917","DOIUrl":"10.1016/j.jiac.2026.102917","url":null,"abstract":"<div><h3>Purpose</h3><div>Small-colony variants (SCVs) are a slow-growing subset of bacteria that exhibit unusual colony morphology and unique biochemical characteristics. They are associated with chronic and persistent infections. CO<sub>2</sub>-dependent SCVs of <em>Staphylococcus aureus</em> have been rarely isolated from clinical specimens. This study aimed to characterize the CO<sub>2</sub>-dependent phenotype of <em>S. aureus</em> SCV isolated from pacemaker leads and to determine the genetic basis underlying this trait.</div></div><div><h3>Methods</h3><div>CO<sub>2</sub>-dependent <em>S. aureus</em> SCV-5700 isolated from pacemaker leads of a patient with a pacemaker infection was used in this study. Phenotypic testing, antimicrobial susceptibility testing, and <em>mecA</em> polymerase chain reaction of the isolate were performed. Moreover, whole-genome sequencing was conducted for multilocus sequence typing and comparative genomic analysis.</div></div><div><h3>Results</h3><div>CO<sub>2</sub>-dependent <em>S. aureus</em> SCV-5700 grew poorly under ambient air conditions; however, tiny colonies formed after 48 h incubation. The isolate was sequence type 45 and did not harbor the <em>mecA</em>. The isolate was identified as <em>S. aureus</em> by biochemical characterization in a 5 % CO<sub>2</sub> atmosphere. Comparative genomic analysis revealed that the isolate had a nonsense mutation (c.565C>T) in the <em>mpsB</em>; however, the revertant strain, Rev-5700, had no such mutation.</div></div><div><h3>Conclusion</h3><div>The CO<sub>2</sub>-dependent phenotype of clinical <em>S. aureus</em> isolates can be attributed, in part, to loss of MpsB function.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 2","pages":"Article 102917"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146086020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although macrolide antibiotics are an effective first-line treatment for pertussis, the global emergence and spread of macrolide-resistant Bordetella pertussis (MRBP) presents a significant threat to antimicrobial treatment strategies. However, the current status of MRBP in Japan remains unclear due to the lack of a surveillance system. This study aimed to highlight the emergence and clinical impact of MRBP in Osaka, Japan.
Methods
We retrospectively reviewed cases of patients with pertussis whose B. pertussis strains were analyzed at the Osaka Institute of Public Health between August 2024 and January 2025. Information on the patients’ clinical characteristics, therapeutic interventions, antimicrobial susceptibility, and molecular analysis of B. pertussis strains was collected. During the study period, eight B. pertussis strains were analyzed.
Results
Seven of the eight (87.5 %) B. pertussis strains were macrolide resistant. All of the MRBP strains were highly resistant to macrolide antibiotics and carried the A2047G mutation in domain V of the 23S rRNA gene. Seven of the patients were pediatric; four of whom had not been fully vaccinated due to their young age. One unvaccinated 31-day-old infant experienced clinical and microbiological treatment failure following macrolide administration, resulting in severe hypoxia and lymphocytosis.
Conclusions
This descriptive analysis of recent pertussis cases in Osaka identified a high proportion of macrolide-resistant strains among the analyzed cases. Notably, one infant developed severe disease despite macrolide treatment. These findings support the urgent need for nationwide surveillance of macrolide resistance in Japan and the establishment of an appropriate initial antimicrobial strategy for suspected MRBP.
{"title":"Clinical and Microbiological Characteristics of macrolide-resistant Bordetella pertussis Infection: A case series in Osaka, Japan (2024–2025)","authors":"Kimihiro Taniguchi , Takahiro Yamaguchi , Kenichi Isoda , Masashi Shiomi , Yasuhiro Kawasaki , Kiyoko Amo , Yuki Wakabayashi , Ryuji Kawahara , Masatoshi Nozaki","doi":"10.1016/j.jiac.2026.102916","DOIUrl":"10.1016/j.jiac.2026.102916","url":null,"abstract":"<div><h3>Background</h3><div>Although macrolide antibiotics are an effective first-line treatment for pertussis, the global emergence and spread of macrolide-resistant <em>Bordetella pertussis</em> (MRBP) presents a significant threat to antimicrobial treatment strategies. However, the current status of MRBP in Japan remains unclear due to the lack of a surveillance system. This study aimed to highlight the emergence and clinical impact of MRBP in Osaka, Japan.</div></div><div><h3>Methods</h3><div>We retrospectively reviewed cases of patients with pertussis whose <em>B. pertussis</em> strains were analyzed at the Osaka Institute of Public Health between August 2024 and January 2025. Information on the patients’ clinical characteristics, therapeutic interventions, antimicrobial susceptibility, and molecular analysis of <em>B. pertussis</em> strains was collected. During the study period, eight <em>B. pertussis</em> strains were analyzed.</div></div><div><h3>Results</h3><div>Seven of the eight (87.5 %) <em>B. pertussis</em> strains were macrolide resistant. All of the MRBP strains were highly resistant to macrolide antibiotics and carried the A2047G mutation in domain V of the 23S rRNA gene. Seven of the patients were pediatric; four of whom had not been fully vaccinated due to their young age. One unvaccinated 31-day-old infant experienced clinical and microbiological treatment failure following macrolide administration, resulting in severe hypoxia and lymphocytosis.</div></div><div><h3>Conclusions</h3><div>This descriptive analysis of recent pertussis cases in Osaka identified a high proportion of macrolide-resistant strains among the analyzed cases. Notably, one infant developed severe disease despite macrolide treatment. These findings support the urgent need for nationwide surveillance of macrolide resistance in Japan and the establishment of an appropriate initial antimicrobial strategy for suspected MRBP.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 2","pages":"Article 102916"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the context of global population aging, pneumonia in older adults has become increasingly prevalent; frequently fatal; and remains challenging to diagnose, treat, and manage in alignment with patient goals. This narrative review synthesized contemporary evidence on pneumonia, particularly aspiration pneumonia, in older adults, integrating perspectives from diagnosis, antimicrobial management, prognosis, prevention, and end-of-life care. In this population, pneumonia often presents with atypical or nonspecific manifestations. Aspiration events are rarely directly observed, and current diagnostic definitions remain imprecise. Outcomes are predominantly driven by host-related factors, including frailty, dysphagia, multimorbidity, functional decline, and malnutrition, and conventional severity scores perform sub-optimally. Evidence from large observational studies indicated that early broad-spectrum or anaerobic-covering antibiotics provided limited survival benefit and may contribute to antimicrobial resistance, underscoring the importance of distinguishing colonization from true infection and adopting a stewardship-oriented approach. Preventive strategies include oral hygiene, postural and dietary modification, judicious medication review, and vaccination against major respiratory pathogens. In individuals with advanced frailty or recurrent pneumonia, multidisciplinary, ethically grounded, and shared decision-making on oral intake, eating and drinking with acknowledged risk, clinically assisted nutrition and hydration, and the role of antibiotics is required. Overall, pneumonia in older adults, particularly aspiration pneumonia, should be regarded as both an infectious disease and a clinical phenotype of age-associated vulnerability, which warrant a multidimensional approach that integrates geriatric assessment, antimicrobial stewardship, targeted prevention, and end-of-life care planning.
{"title":"Pneumonia in frail older adults: from diagnosis to optimized management","authors":"Kosaku Komiya , Yuki Yoshimatsu , Akihiko Hagiwara , Ryohei Kudoh , Hisayuki Shuto , Izumi Yamatani , Akihiko Goto","doi":"10.1016/j.jiac.2026.102914","DOIUrl":"10.1016/j.jiac.2026.102914","url":null,"abstract":"<div><div>In the context of global population aging, pneumonia in older adults has become increasingly prevalent; frequently fatal; and remains challenging to diagnose, treat, and manage in alignment with patient goals. This narrative review synthesized contemporary evidence on pneumonia, particularly aspiration pneumonia, in older adults, integrating perspectives from diagnosis, antimicrobial management, prognosis, prevention, and end-of-life care. In this population, pneumonia often presents with atypical or nonspecific manifestations. Aspiration events are rarely directly observed, and current diagnostic definitions remain imprecise. Outcomes are predominantly driven by host-related factors, including frailty, dysphagia, multimorbidity, functional decline, and malnutrition, and conventional severity scores perform sub-optimally. Evidence from large observational studies indicated that early broad-spectrum or anaerobic-covering antibiotics provided limited survival benefit and may contribute to antimicrobial resistance, underscoring the importance of distinguishing colonization from true infection and adopting a stewardship-oriented approach. Preventive strategies include oral hygiene, postural and dietary modification, judicious medication review, and vaccination against major respiratory pathogens. In individuals with advanced frailty or recurrent pneumonia, multidisciplinary, ethically grounded, and shared decision-making on oral intake, eating and drinking with acknowledged risk, clinically assisted nutrition and hydration, and the role of antibiotics is required. Overall, pneumonia in older adults, particularly aspiration pneumonia, should be regarded as both an infectious disease and a clinical phenotype of age-associated vulnerability, which warrant a multidimensional approach that integrates geriatric assessment, antimicrobial stewardship, targeted prevention, and end-of-life care planning.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 2","pages":"Article 102914"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbapenem-resistant Gram-negative bacteria (CRGNB) pose a major clinical threat. This study evaluated the in vitro activity of cefiderocol and other recently approved β-lactam/β-lactamase inhibitor combinations against major CRGNB.
Materials and methods
A total of 292 CRGNB clinical isolates were analyzed, comprising 146 Enterobacterales, 106 Pseudomonas aeruginosa, and 40 Stenotrophomonas maltophilia, all collected from hospitals across Japan. Antimicrobial susceptibility testing was performed by broth microdilution (BMD). Disk diffusion testing was also conducted for cefiderocol, and categorical agreement with BMD was assessed. Whole-genome sequencing (WGS) was used for species confirmation and characterization of resistance determinants.
Results
Carbapenemase producers accounted for 64.4 % of Enterobacterales (94/146) and 8.5 % of P. aeruginosa (9/106), with metallo-β-lactamase (MBL) producers comprising 92.6 % (87/94) and 77.8 % (7/9), respectively. Based on CLSI breakpoints, 94.5 % (276/292) of isolates were susceptible to cefiderocol, including 91.8 % of Enterobacterales, 99.1 % of P. aeruginosa, and 92.5 % of S. maltophilia. Ceftolozane-tazobactam, ceftazidime-avibactam, and imipenem-relebactam were active against 12.3 %, 44.5 % and 45.9 % of Enterobacterales, and 89.6 %, 86.8 % and 72.6 % of P. aeruginosa, respectively. Categorical agreement between cefiderocol disk diffusion and BMD exceeded 92 % across all groups, although very major errors occurred in Enterobacterales (n = 2) and S. maltophilia (n = 3). Cefiderocol-non-susceptible Enterobacterales isolates frequently harbored carbapenemase and extended-spectrum β-lactamase (ESBL) genes, together with mutations in ftsI (encoding PBP3), ompK35, or siderophore receptor genes (cirA, tonB).
Discussion
Cefiderocol showed potent in vitro activity against CRGNB in Japan, including MBL producers. Disk diffusion correlated well with BMD results; however, confirmatory BMD testing should be considered when resistance is clinically suspected.
{"title":"In vitro activity of cefiderocol against carbapenem-resistant Gram-negative pathogens in Japan","authors":"Kenjiro Matsui , Aki Sakurai , Yasufumi Matsumura , Takuya Hosoda , Masahiro Suzuki , Sho Saito , Ryota Hase , Hideaki Kato , Takehiro Hashimoto , Takashi Matono , Naoya Itoh , Momoko Mawatari , Kohei Uemura , Kayoko Hayakawa , Hiroyasu Ito , Yohei Doi","doi":"10.1016/j.jiac.2026.102905","DOIUrl":"10.1016/j.jiac.2026.102905","url":null,"abstract":"<div><h3>Introduction</h3><div>Carbapenem-resistant Gram-negative bacteria (CRGNB) pose a major clinical threat. This study evaluated the <em>in vitro</em> activity of cefiderocol and other recently approved β-lactam/β-lactamase inhibitor combinations against major CRGNB.</div></div><div><h3>Materials and methods</h3><div>A total of 292 CRGNB clinical isolates were analyzed, comprising 146 Enterobacterales, 106 <em>Pseudomonas aeruginosa</em>, and 40 <em>Stenotrophomonas maltophilia</em>, all collected from hospitals across Japan. Antimicrobial susceptibility testing was performed by broth microdilution (BMD). Disk diffusion testing was also conducted for cefiderocol, and categorical agreement with BMD was assessed. Whole-genome sequencing (WGS) was used for species confirmation and characterization of resistance determinants.</div></div><div><h3>Results</h3><div>Carbapenemase producers accounted for 64.4 % of Enterobacterales (94/146) and 8.5 % of <em>P. aeruginosa</em> (9/106), with metallo-β-lactamase (MBL) producers comprising 92.6 % (87/94) and 77.8 % (7/9), respectively. Based on CLSI breakpoints, 94.5 % (276/292) of isolates were susceptible to cefiderocol, including 91.8 % of Enterobacterales, 99.1 % of <em>P. aeruginosa</em>, and 92.5 % of <em>S. maltophilia</em>. Ceftolozane-tazobactam, ceftazidime-avibactam, and imipenem-relebactam were active against 12.3 %, 44.5 % and 45.9 % of Enterobacterales, and 89.6 %, 86.8 % and 72.6 % of <em>P. aeruginosa</em>, respectively. Categorical agreement between cefiderocol disk diffusion and BMD exceeded 92 % across all groups, although very major errors occurred in Enterobacterales (n = 2) and <em>S. maltophilia</em> (n = 3). Cefiderocol-non-susceptible Enterobacterales isolates frequently harbored carbapenemase and extended-spectrum β-lactamase (ESBL) genes, together with mutations in <em>ftsI</em> (encoding PBP3), <em>ompK35</em>, or siderophore receptor genes (<em>cirA, tonB</em>).</div></div><div><h3>Discussion</h3><div>Cefiderocol showed potent <em>in vitro</em> activity against CRGNB in Japan, including MBL producers. Disk diffusion correlated well with BMD results; however, confirmatory BMD testing should be considered when resistance is clinically suspected.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 2","pages":"Article 102905"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145933602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.jiac.2026.102913
Aya Tateishi , Takeru Kanazawa , Kazuhiko Matsuhashi , Ryo Karato , Yoshifusa Abe , Ayumi Tada , Yuho Horikoshi
Invasive group A streptococcal infection (iGAS) increases in Europe and it causes skin and soft-tissue infection, including orbital cellulitis. In this study, we report a case of a 7-year-old girl with orbital cellulitis and invasive emm1-type M1UK sublineage group A Streptococcus (GAS) detected in a blood culture. The patient was initially treated with a combination of cefotaxime (CTX) and clindamycin (CLDM). We changed antibiotics from CTX to ampicillin after susceptibility results were known. After discharge, oral clavulanic acid/amoxicillin was continued as an oral medication, and antibiotics were administered for a total of 21 days. The bacterium was isolated from a blood culture and identified as an emm1-type M1UK sublineage GAS. This case is unusual in that it involved bloodstream infection in a pediatric orbital cellulitis, and M1UK's highly toxin-producing and highly transmissible may have been implicated. In rapidly exacerbating orbital cellulitis, iGAS infection should be considered.
{"title":"Orbital cellulitis with emm1-type M1UK sublineage group A Streptococcus detected in a blood culture: a case report","authors":"Aya Tateishi , Takeru Kanazawa , Kazuhiko Matsuhashi , Ryo Karato , Yoshifusa Abe , Ayumi Tada , Yuho Horikoshi","doi":"10.1016/j.jiac.2026.102913","DOIUrl":"10.1016/j.jiac.2026.102913","url":null,"abstract":"<div><div>Invasive group A streptococcal infection (iGAS) increases in Europe and it causes skin and soft-tissue infection, including orbital cellulitis. In this study, we report a case of a 7-year-old girl with orbital cellulitis and invasive <em>emm</em>1-type M1<sub>UK</sub> sublineage group A <em>Streptococcus</em> (GAS) detected in a blood culture. The patient was initially treated with a combination of cefotaxime (CTX) and clindamycin (CLDM). We changed antibiotics from CTX to ampicillin after susceptibility results were known. After discharge, oral clavulanic acid/amoxicillin was continued as an oral medication, and antibiotics were administered for a total of 21 days. The bacterium was isolated from a blood culture and identified as an <em>emm</em>1-type M1<sub>UK</sub> sublineage GAS. This case is unusual in that it involved bloodstream infection in a pediatric orbital cellulitis, and M1<sub>UK</sub>'s highly toxin-producing and highly transmissible may have been implicated. In rapidly exacerbating orbital cellulitis, iGAS infection should be considered.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 2","pages":"Article 102913"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ureterorenoscopic lithotripsy (URSL) has become the first-line treatment for upper urinary tract calculi smaller than 20 mm in Japan. However, postoperative febrile urinary tract infection (f-UTI) sometimes leads to fatal outcomes. Few studies have evaluated the impact of bacterial strains and counts from preoperative urine cultures on f-UTI risk. This study investigated these associations and discussed potential preventive strategies.
Materials and methods
We retrospectively analyzed 1514 URSL cases performed between October 2018 and September 2023. Positive urine culture was defined as ≥104 CFU/mL. Cases were divided into a low-count group (<106 CFU/mL) and a high-count group (≥106 CFU/mL). F-UTI incidence was assessed according to demographics, bacterial strains, and counts. Statistical analyses included chi-square test, Student's t-test, and multivariate logistic regression.
Results
Postoperative f-UTI occurred in 127 cases (8.4%). Multivariate analysis identified preoperative f-UTI and positive urine culture as independent predictors. F-UTI incidence was 5.3% in culture-negative versus 12.1% in culture-positive cases. High-count cases showed a significantly higher f-UTI rate than low-count cases (17.9% vs. 11.2%, p < 0.01). Escherichia coli was associated with f-UTI even at low counts, while Enterococcus faecalis increased risk only at high counts. Multidrug-resistant strains such as Corynebacterium and Enterococcus faecium were also high-risk strains.
Discussion
Preoperative positive urine culture was an independent risk factor for f-UTI after URSL. Both bacterial strain and count influenced infection risk. When high-risk strains or high bacterial counts are present, careful antibiotic selection, shorter operative time, and intrarenal pressure control may help reduce postoperative f-UTI.
{"title":"Impact of preoperative urine culture on postoperative febrile urinary tract infection after ureterorenoscopic lithotripsy","authors":"Junya Hara , Katsuki Muramoto , Sumire Santo , Takuya Hagiwara , Kazuaki Yamaga , Hakaru Masumoto , Yuji Yata , Tomohiro Hongo , Tomoya Yamasaki , Rei Kato , Kei Fujio , Shinya Uehara , Mitsuru Oshiro , Hideo Otsuki","doi":"10.1016/j.jiac.2026.102918","DOIUrl":"10.1016/j.jiac.2026.102918","url":null,"abstract":"<div><h3>Introduction</h3><div>Ureterorenoscopic lithotripsy (URSL) has become the first-line treatment for upper urinary tract calculi smaller than 20 mm in Japan. However, postoperative febrile urinary tract infection (f-UTI) sometimes leads to fatal outcomes. Few studies have evaluated the impact of bacterial strains and counts from preoperative urine cultures on f-UTI risk. This study investigated these associations and discussed potential preventive strategies.</div></div><div><h3>Materials and methods</h3><div>We retrospectively analyzed 1514 URSL cases performed between October 2018 and September 2023. Positive urine culture was defined as ≥10<sup>4</sup> CFU/mL. Cases were divided into a low-count group (<10<sup>6</sup> CFU/mL) and a high-count group (≥10<sup>6</sup> CFU/mL). F-UTI incidence was assessed according to demographics, bacterial strains, and counts. Statistical analyses included chi-square test, Student's t-test, and multivariate logistic regression.</div></div><div><h3>Results</h3><div>Postoperative f-UTI occurred in 127 cases (8.4%). Multivariate analysis identified preoperative f-UTI and positive urine culture as independent predictors. F-UTI incidence was 5.3% in culture-negative versus 12.1% in culture-positive cases. High-count cases showed a significantly higher f-UTI rate than low-count cases (17.9% vs. 11.2%, p < 0.01). <em>Escherichia coli</em> was associated with f-UTI even at low counts, while <em>Enterococcus faecalis</em> increased risk only at high counts. Multidrug-resistant strains such as <em>Corynebacterium</em> and <em>Enterococcus faecium</em> were also high-risk strains.</div></div><div><h3>Discussion</h3><div>Preoperative positive urine culture was an independent risk factor for f-UTI after URSL. Both bacterial strain and count influenced infection risk. When high-risk strains or high bacterial counts are present, careful antibiotic selection, shorter operative time, and intrarenal pressure control may help reduce postoperative f-UTI.</div></div>","PeriodicalId":16103,"journal":{"name":"Journal of Infection and Chemotherapy","volume":"32 3","pages":"Article 102918"},"PeriodicalIF":1.5,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号