Acta microbiologica et immunologica Hungarica最新文献

{"title":"Hidden reservoirs in clinical settings: Clonal dissemination and virulence profile of multidrug-resistant Staphylococcus aureus from healthcare workers' mobile phones.","authors":"Mehdi Goudarzi, Mohammad Javad Nasiri, Masoud Dadashi, Hossein Goudarzi","doi":"10.1556/030.2026.03012","DOIUrl":"10.1556/030.2026.03012","url":null,"abstract":"<p><p>Mobile phones used in healthcare environments may serve as overlooked reservoirs facilitating the transmission of clinically significant pathogens. This study investigated antimicrobial resistance patterns, virulence-associated determinants, and genetic diversity among Staphylococcus aureus isolates recovered from healthcare workers' mobile phones. Phenotypic antimicrobial susceptibility testing, staphylococcal cassette chromosome mec (SCCmec) typing, multilocus sequence typing (MLST), and polymerase chain reaction assays were employed to detect antimicrobial resistance, biofilm-associated, and toxin-encoding genes. Among 349 mobile phones screened, 42 (12%) were positive for S. aureus. Among the isolates, 76.2% were identified as methicillin-resistant S. aureus (MRSA), while 23.8% were methicillin-susceptible S. aureus (MSSA). High-level mupirocin resistance (HLMUPR) and inducible macrolide-lincosamide-streptogramin B (iMLSB) phenotypes were observed in 26.2 and 35.7% of isolates, respectively. Biofilm formation analysis demonstrated that 49.2% of isolates were strong biofilm producers, followed by intermediate (30.8%) and weak producers (15.4%). Of the 42 isolates examined, 12 (28.6%) harbored the pvl gene, and 10 (23.8%) harbored the tst gene. The most frequently detected resistance gene was erm(B) (33.3%), followed by msrA (19%) and erm(C) (16.7%). All isolates harbored the adhesion genes fnbA and fnbB. Additional biofilm- and adhesion-associated genes included clfA and clfB (85.7%), cna and fib (38.1%), icaA (35.7%), icaD (33.3%), sdrD (28.6%), sdrC, sdrE, eno, and bap (21.4% each), while ebpS was detected in 4.8% of isolates. MLST analysis revealed distribution across six clonal complexes, predominantly CC8 (42.9%), followed by CC5 (21.4%), CC59 (11.9%), CC22 (11.9%), CC1 (7.1%), and CC398 (4.8%). Panton-Valentine leukocidin (PVL)-positive isolates were mainly associated with ST8-SCCmec IV/t008 and ST22/t1869 lineages, whereas toxic shock syndrome toxin (TSST-1)-positive strains belonged primarily to ST239-SCCmec III/t037 and ST59-SCCmec IV/t437. High-level mupirocin-resistant isolates carrying mupA were distributed among several epidemic clones, including ST5-SCCmec IV/t002 (36.4%), ST8-SCCmec IV/t008 (27.2%), ST239-SCCmec III/t037 (18.2%), and ST22/t1869 (18.2%). Overall, the findings demonstrate substantial circulation of multidrug-resistant and virulence-associated S. aureus lineages on healthcare workers' mobile phones, underscoring their potential role in pathogen dissemination and emphasizing the necessity for targeted infection prevention and mobile device decontamination strategies in healthcare settings.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"317-329"},"PeriodicalIF":1.5,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148786861","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}

{"title":"Correction to: Candida auris: An opportunistic fungal pathogen and a priority emergent threat.","authors":"Shila Kumari Singh, Anantabotla Vamsimohan","doi":"10.1556/030.2026.12993","DOIUrl":"10.1556/030.2026.12993","url":null,"abstract":"","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"298"},"PeriodicalIF":1.5,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148760564","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}

{"title":"From Dysbiosis to systemic health: Microbiome modulation as a unified therapeutic framework.","authors":"Neena Kumar Dhiman, S Rehan Ahmad","doi":"10.1556/030.2026.03015","DOIUrl":"https://doi.org/10.1556/030.2026.03015","url":null,"abstract":"<p><p>The gut microbiome is a dynamic microbial ecosystem regulating gastrointestinal, metabolic, immune, and neurobehavioral physiology. Dysbiosis has been linked to irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and systemic disorders including metabolic syndrome, autoimmune conditions, and neurodegenerative diseases. This narrative review synthesizes mechanistic, clinical, and translational evidence to delineate molecular pathways of microbiome-targeted interventions, evaluates clinical outcomes in IBS and IBD, and proposes a unified framework linking gastrointestinal modulation to systemic health. A structured literature search across PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar (2012-2024) identified approximately 68 eligible sources, appraised using Cochrane Risk of Bias 2.0 and AMSTAR-2. Five principal molecular pathways were identified: competitive pathogen exclusion, epithelial barrier reinforcement, immune modulation, short-chain fatty acid (SCFA) production, and neurotransmitter signaling. Clinically, dietary strategies, biological agents (probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation [FMT]), advanced modalities (rifaximin, psychobiotics, bacteriophage therapy), and lifestyle interventions collectively engage these pathways. The same mechanisms underpin emerging applications in metabolic, autoimmune, neurological, and cardiovascular disease. We propose a three-tier model progressing from molecular mechanisms through gastrointestinal outcomes to systemic benefits, with precision medicine and standardized trial designs as prerequisites for therapeutic translation.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148688342","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}

{"title":"Clonal diversity of multidrug-resistant Klebsiella pneumoniae from ICU patients in central Türkiye.","authors":"Altan Akineden, Fatih Mehmet Akilli, Selçuk Türkel, Christina Rehagel, Ömer Akineden","doi":"10.1556/030.2026.03061","DOIUrl":"10.1556/030.2026.03061","url":null,"abstract":"<p><p>The increasing prevalence of multidrug-resistant (MDR) Klebsiella pneumoniae, particularly carbapenem-resistant strains, represents a major clinical challenge worldwide. Data on the molecular characteristics of MDR K. pneumoniae in central Türkiye remain limited. This study aimed to characterize the antimicrobial resistance profiles and molecular features of MDR-K. pneumoniae isolates recovered from hospitalized patients in a tertiary care hospital in central Türkiye.A total of 1,560 clinical specimens collected from intensive care unit (ICU) patients between November 2024 and June 2025 were analyzed. Thirty-three non-duplicate MDR-K. pneumoniae isolates obtained from 26 patients were included. Identification and antimicrobial susceptibility testing were performed using the VITEK®2 system. ESBL genes (blaTEM, blaSHV, blaCTX-M groups), carbapenemase genes (blaKPC, blaOXA-48, blaNDM-1), virulence-associated genes (iucA, rmpA2), and efflux pump genes (acrAB, tolC) were investigated by PCR. Clonal relatedness was assessed by pulsed-field gel electrophoresis (PFGE).All isolates were resistant to multiple β-lactams and ciprofloxacin. Resistance to meropenem and amikacin was observed in 97.0% of isolates, while 94.0% were resistant to gentamicin. Colistin and ceftazidime-avibactam resistance rates were 27.3 and 18.2%, respectively. The most prevalent genes were blaSHV (90.9%), blaCTX-M-1 (81.8%), and blaOXA-48 (66.7%), whereas blaTEM, blaKPC and blaNDM-1 were detected in 36.4, 21.2 and 3.0% of isolates, respectively. None of the isolates carried iucA or rmpA2. PFGE revealed substantial genetic diversity with multiple pulsotypes and no dominant epidemic clone.These findings demonstrate the dissemination of genetically diverse MDR K. pneumoniae lineages carrying ESBL and OXA-48 carbapenemase genes in an ICU setting in central Türkiye. Despite occasional hypermucoviscosity, no molecular evidence of hypervirulence was detected, highlighting the need for continuous molecular surveillance and effective infection-control measures.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"307-316"},"PeriodicalIF":1.5,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148683062","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}

{"title":"Prosthetic valve endocarditis due to non-toxigenic Corynebacterium diphtheriae: A case report.","authors":"Ahmed Fakhfakh, Sana Ferjani, Lamia Kanzari, Amel Rehaiem, Zaineb Hamzaoui, Olfa Smaoui, Rim Abdelmalek, Hana Hedhli, Dhekra Hosni, Aymen Zoubli, Lamia Ammari, Sarra Jouini, Ilhem Boutiba Ben Boubaker","doi":"10.1556/030.2026.03046","DOIUrl":"10.1556/030.2026.03046","url":null,"abstract":"<p><p>Prosthetic valve endocarditis (PVE) caused by Corynebacterium diphtheriae is rare and may be associated with severe embolic complications and high mortality. In March 2026, a 61-year-old woman with a mechanical mitral valve receiving chronic acenocoumarol therapy was admitted with fever, malaise, and abdominal pain. Thoracoabdominal computed tomography revealed multiple splenic infarctions suggestive of systemic embolization. Transthoracic echocardiography demonstrated vegetations on the prosthetic mitral valve. Blood cultures yielded C. diphtheriae, identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Whole-genome sequencing confirmed a non-toxigenic C. diphtheriae sequence type 542 lacking the tox gene. Antimicrobial susceptibility testing showed resistance to penicillin G and trimethoprim-sulfamethoxazole, with susceptibility to meropenem, erythromycin, clindamycin, tetracycline, linezolid, vancomycin and rifampicin, and susceptibility with increased exposure to cefotaxime and ciprofloxacin. Cerebral computed tomography angiography demonstrated complete occlusion of the right internal carotid artery without initial parenchymal lesions. Intravenous vancomycin and bisoprolol were initiated. Acenocoumarol was initially continued and subsequently switched to intravenous unfractionated heparin. On hospital day 3, the patient developed sudden neurological deterioration with coma, hemodynamic collapse, and respiratory failure. Brain imaging revealed massive intracerebral hemorrhage with intraventricular extension and cerebral herniation. Despite intensive supportive management, the patient died. This case highlights the severe invasive potential of non-toxigenic C. diphtheriae in PVE and the risk of devastating thromboembolic and hemorrhagic neurological complications. It also emphasizes the necessity of rapid microbiological identification, integration of genomic data, and multidisciplinary management, particularly regarding anticoagulation strategies in patients with mechanical prosthetic valves.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"330-335"},"PeriodicalIF":1.5,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148700477","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}

{"title":"Candida auris: An opportunistic fungal pathogen and a priority emergent threat.","authors":"Shila Kumari Singh, Anantabotla Vamsimohan","doi":"10.1556/030.2026.02993","DOIUrl":"10.1556/030.2026.02993","url":null,"abstract":"<p><p>Candida auris is an opportunistic yeast causing infections in vulnerable patients leading to high mortality ratio. The Centers for Disease Control and Prevention (CDC) has designated it as a pathogen of concern. The World Health Organization (WHO) has listed it in priority list of fungal pathogens. C. auris has the ability to spread very fast inside the hospital environment and cause outbreaks worldwide. It has a very high affinity toward skin colonization, especially in the areas like axilla and groin. Based on whole genome sequencing it is classified into five clades. Each clade has different geographical distribution. Often C. auris gets misidentified as other species due to its phylogenetic similarity with C. heamulonii. This can only be resolved by establishing diagnosis at molecular levels. Whole genome sequencing and polymerase chain reaction are some of the important molecular diagnostic methods for detection of C. auris. MALDI-TOF-MS is a culture based highly efficient method that is widely being used for C. auris identification. Treatment of C. auris infection depends on effective antifungal therapy, as multidrug resistance is quite common, the drug regime is decided after antifungal sensitivity testing. It is commonly treated with echinocandins and polyenes. Apart from the antifungal therapy it is also important to monitor the fungemia by performing blood cultures. A strict surveillance system can help prevent the disease. Timely screening of hospital personnel carrying the yeast can contain the spread of this organism. Newer antifungal agents are also required as the organism develops resistance very fast.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"288-297"},"PeriodicalIF":1.5,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148668091","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}

{"title":"Gut microbiome profiles as predictors of response to chemoradiotherapy in locally advanced rectal cancer.","authors":"Jiya You, Rashid Mahmood Khan, Nidhi Reji","doi":"10.1556/030.2026.02874","DOIUrl":"10.1556/030.2026.02874","url":null,"abstract":"<p><p>This prospective cohort study investigates the predictive role of gut microbiota composition in determining the therapeutic response to neoadjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer (LARC) at Qiqihar Jianhua Hospital. A total of 178 patients underwent standardized CRT protocols and were stratified into responders and non-responders based on pathological tumor regression grades. Gut microbiome profiling was conducted via 16S rRNA amplicon sequencing and shotgun metagenomics at three treatment stages (pre-, mid-, and post-CRT). Responders exhibited significantly higher alpha diversity (Shannon, Chao1) at baseline and maintained greater microbial richness throughout treatment. Taxonomic analysis identified Faecalibacterium, Akkermansia, and Bifidobacterium as enriched in responders, while non-responders showed elevated Clostridium, Escherichia, and Streptococcus. Multivariate regression confirmed Faecalibacterium (OR = 1.16, P = 0.0002) and Akkermansia (OR = 1.27, P = 0.0146) as independent predictors of CRT response. Functional profiling revealed enrichment of anti-inflammatory pathways (butyrate synthesis, tryptophan metabolism) in responders and pro-inflammatory, stress-related functions (lipopolysaccharide biosynthesis, oxidative stress) in non-responders. Exploratory microbiome modulation using probiotics or fecal microbiota transplantation (FMT) targeting Faecalibacterium and Akkermansia demonstrated increased responder rates by 12.5 and 18.2%, respectively. These findings highlight the potential of gut microbiome signatures as non-invasive biomarkers for CRT response prediction and as targets for adjunctive therapeutic strategies. Personalized microbiome-informed treatment may enhance CRT efficacy and reduce unnecessary exposure in non-responders, paving the way for precision oncology in rectal cancer.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"396-404"},"PeriodicalIF":1.5,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148547488","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}

{"title":"Genome-resolved analysis of multidrug-resistant ESKAPE pathogens reveals Klebsiella pneumoniae diversity and plasmid-mediated resistance in a patient in intensive care.","authors":"Aarti Pustam, Rajeev P Nagassar, Jayaraj Jayaraman, Adesh Ramsubhag","doi":"10.1556/030.2026.03025","DOIUrl":"10.1556/030.2026.03025","url":null,"abstract":"<p><p>Multidrug-resistant (MDR) Gram-negative pathogens continue to threaten patient outcomes in intensive care units (ICUs) worldwide, particularly in regions where genomic surveillance is limited. Understanding intra-host genomic diversity and mobility of resistance determinants remain essential for mitigating global antimicrobial resistance (AMR) threats. Whole genome sequencing and molecular analysis were performed on three selected isolates to identify resistance and virulence determinants. The isolates exhibited complex and heterogenous resistomes shaped by extensive antimicrobial exposure during prolonged ICU care. Two genetically distinct Klebsiella pneumoniae strains (ST11 and ST15) demonstrating intra-patient strain diversity, an emerging trend in high-risk clinical settings globally, along with an Acinetobacter baumannii strain (ST944) were recovered from the same patient. Key resistance genes linked to mobile genetic elements (MGEs) were identified, including blaCTX-M-15 and blaNDM-5 in K. pneumoniae ST11 and blaADC-152 in A. baumannii. A plasmid-associated contig harbouring blaDHA-1 and qnr resistance genes represented a 'high-risk' mobile platform with international similarity in K. pneumoniae, highlighting the global circulation of resistance plasmids. Virulence profiling revealed conserved and unique determinants, including biofilm, siderophore, and secretion loci, with one isolate carrying a complete Yersiniabactin locus associated with MGEs. This study provides the first genome-resolved case from the Caribbean demonstrating intra-host co-existence of globally important MDR lineages and plasmid-mediated dissemination of key resistance genes. Within the global AMR challenge, this analysis offers novel insight into the convergence of resistance and virulence traits and highlights the value of localized genomic surveillance in understanding pathogen adaptation, mobility, and persistence under high antimicrobial pressure. These findings emphasize the importance of incorporating genomic data from diverse geographic regions into global AMR networks to better manage MDR ESKAPE pathogens in ICU environments.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"299-306"},"PeriodicalIF":1.5,"publicationDate":"2026-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148306639","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}

{"title":"Longitudinal effects of antiretroviral therapy on the oral microbiota in people living with HIV: A systematic review.","authors":"Handayani Ali, Irene Edith Rieuwpassa, Nurlindah Hamrun, Erni Marlina, Risfah Yulianty, Fuad Husain Akbar, Dewi Ayu Siti Hartina Dewang","doi":"10.1556/030.2026.02910","DOIUrl":"10.1556/030.2026.02910","url":null,"abstract":"<p><p>People living with HIV frequently experience oral microbial dysbiosis, contributing to oral disease burden and reduced quality of life. Although antiretroviral therapy (ART) effectively suppresses viral replication and promotes immune recovery, its longitudinal effects on the oral microbiota remain incompletely understood. This systematic review aimed to evaluate longitudinal changes in oral microbiota composition and diversity in people living with HIV before and after ART initiation. A systematic review was conducted in accordance with PRISMA guidelines and registered in PROSPERO (CRD420251164326). Electronic searches were performed in PubMed, ScienceDirect, Wiley Online Library, DOAJ, and Google Scholar for studies published between 2015 and 2024. Eligible studies included longitudinal human studies reporting pre- and post-ART oral microbiota data using 16S rRNA gene sequencing or metagenomic approaches. Methodological quality was assessed using Joanna Briggs Institute critical appraisal tools. Due to substantial heterogeneity, findings were synthesized narratively. Six longitudinal studies met the inclusion criteria. ART was associated with partial and non-uniform modulation of the oral microbiota. Changes in beta diversity and selective taxonomic shifts were commonly reported, whereas changes in alpha diversity were inconsistent. Taxonomic alterations were more evident at the genus level, while several dominant oral genera remained stable before and after ART. Evidence linking oral microbiota changes with immune recovery was limited. Longitudinal evidence indicates that ART induces selective and heterogeneous changes in the oral microbiota without consistent normalization toward a non-HIV microbial profile, underscoring the importance of integrating oral health into long-term HIV care.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"279-287"},"PeriodicalIF":1.5,"publicationDate":"2026-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148282943","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}

{"title":"Rare case of bacteremia, liver abscess and possible infective endocarditis caused by Fusobacterium nucleatum.","authors":"Despoina Spentzouri, Petros Ioannou, Andria Papazachariou, Georgios Vougiouklakis, Vasiliki Theodorakopoulou, George Vrentzos, Maria Vakonaki, Kyriaki Tryfinopoulou, Diamantis Kofteridis","doi":"10.1556/030.2026.03014","DOIUrl":"10.1556/030.2026.03014","url":null,"abstract":"<p><p>Fusobacterium nucleatum is a Gram-negative obligate anaerobic bacterium typically found as a commensal in the human oral cavity, gastrointestinal and female genital tract. While it is a common cause of endodontic infections, it is a rare cause of infective endocarditis (IE), which can lead to high morbidity if diagnosis is delayed due to the challenges of culturing anaerobic bacteria. The case of a 75-year-old male patient with a history of type 2 diabetes who presented with high fever, rigors, and hemodynamic instability is presented herein. Physical examination revealed a new systolic murmur. Initial investigations identified inflammatory syndrome and elevated liver enzymes. Further imaging via contrast-enhanced ultrasound and computed tomography confirmed two abscesses in the left lobe of the liver. Blood cultures grew F. nucleatum, and a transesophageal echocardiogram demonstrated vegetation on the aortic valve. The patient met the Modified Duke criteria for a diagnosis of infective endocarditis. It was later elicited that the patient had undergone dental interventions one month prior to admission. The patient was successfully treated with a six-week course of targeted antimicrobial therapy consisting of ceftriaxone and metronidazole, resulting in favorable clinical recovery. Fusobacterium species are rare but significant causes of invasive infections such as liver abscesses and IE. This case emphasizes that anaerobic pathogens should be suspected in patients presenting with unexplained sepsis, concomitant deep-seated abscesses, or a history of recent dental procedures. Early use of echocardiography and anaerobic blood cultures are essential for the timely diagnosis of these rare clinical entities.</p>","PeriodicalId":7119,"journal":{"name":"Acta microbiologica et immunologica Hungarica","volume":" ","pages":"336-339"},"PeriodicalIF":1.5,"publicationDate":"2026-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148275663","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}