Chryseobacterium indologenes catheter-related meningitis in an elderly patient after intracranial aneurysm clipping surgery

A case of hospital-acquired pneumonia associated with Chryseobacterium indologenes infection in a patient with HIV infection and review of the literature

BACKGROUND

Chryseobacterium indologenes is an opportunistic, multidrug-resistant Gram-negative bacillus increasingly recognized as a cause of hospital-acquired infections, particularly in immunocompromised patients. Although rare, its intrinsic resistance to beta-lactams and its ability to colonize medical devices pose significant therapeutic challenges.

CASE PRESENTATION

We describe a case of C. indologenes hospital-acquired pneumonia in a 43-year-old HIV-positive patient with multiple comorbidities, including Kaposi sarcoma, diabetes mellitus, and chronic kidney disease requiring hemodialysis. The patient was initially admitted with fever and elevated inflammatory markers, and empirical broad-spectrum antibiotic therapy was initiated. Despite initial improvement, the patient developed respiratory failure, requiring oxygen therapy. A respiratory panel identified Rhinovirus, while sputum culture revealed C. indologenes, resistant to multiple antibiotics but susceptible to levofloxacin. Targeted therapy led to clinical improvement. However, the course was complicated by Clostridioides difficile-associated diarrhea, followed by fatal sepsis due to Klebsiella pneumoniae. Our review of the literature identified 71 reported cases, with bacteremia (51%) and pneumonia (29%) as the most common clinical presentations. Medical devices and prolonged antibiotic exposure were key risk factors. While C. indologenes is intrinsically resistant to beta-lactams and carbapenems, fluoroquinolones and trimethoprim-sulfamethoxazole demonstrated efficacy in most cases. Emerging therapies, such as cefiderocol, may provide additional options for multidrug-resistant strains. This case highlights the critical need for accurate microbial identification, targeted therapy, and vigilant antimicrobial stewardship to improve outcomes in vulnerable patient populations.

CONCLUSION

C. indologenes infections remain rare but clinically significant in hospitalized patients with immune dysfunction. The pathogen's multidrug resistance profile complicates treatment, necessitating early identification and targeted antimicrobial therapy. Fluoroquinolones, trimethoprim-sulfamethoxazole, and cefiderocol may serve as effective treatment options, emphasizing the importance of susceptibility-guided management.

Successful Treatment of Intracranial Infection Caused by Chryseobacterium Indologenes Following Aneurysm Clipping

Chryseobacteriumindologenes (C. indologenes) is a rare but emerging pathogen causing central nervous system (CNS) infections. It poses significant treatment challenges due to its antibiotic resistance. This case report describes the successful management of an intracranial infection caused by C. indologenes after aneurysm clipping, using a multidrug regimen. A retrospective analysis of the clinical course was performed, revealing that the patient responded well to intravenous Trimethoprim-Sulfamethoxazole (TMP/SMZ), oral Sulfamethoxazole (SMZ), and minocycline, resulting in complete resolution of the infection. The microbial characteristics of the infection and the subsequent treatment strategy were reviewed. Infections caused by C. indologenes present significant treatment challenges due to antibiotic resistance. A combination of intravenous TMP/SMZ, oral SMZ, and minocycline can be an effective therapeutic approach for managing such infections.

Description of Chryseobacterium timonianum sp. nov., isolated from a patient with pneumonia

Using a polyphasic taxonomic strategy, an aerobic, Gram-negative, non-motile, yellow pigmented rod isolated from a sputum sample of a patient with pneumonia was characterised. This bacterial strain, designated G972^T, could not be identified by our systematic MALDI-TOF screening on a MicroFlex. This led to the sequencing of the 16S rRNA gene, which shows 98.57% sequence identity with that of Chryseobacterium indologenes 16777^T, the phylogenetic closely related type strain of a species with standing in nomenclature, which putatively classifies it as a new species. The major cell fatty acids were identified as 13-methyl-tetradecanoic acid (61%), 3-hydroxy-heptadecanoic acid (16%) and 15-methyl-11-hexadecenoic acid (11%). D-glucose, D-mannose, aesculin, D-maltose, D-trehalose, and gentibiose are the main carbon source. Digital DNA-DNA hybridization (dDDH) estimation and average nucleotide identity values (ANI) of the strain G972^T against genomes of the type strains of related species ranged between 18.9 and 32.8% and between 71.46 and 83.61%, respectively, thus confirming again the new species status of the strain. Here, we describe the characteristics of this organism, complete genome sequence and annotation. The 5,390,132 bp size genome contains 4867 protein-coding genes, 89 RNAs (three genes are 5S rRNA, one gene is 16S rRNA, one gene is 23S rRNA and 84 tRNAs) with 35.51% GC content. Finally, on the basis of these polyphasic data, consisting of phenotypic and genomic analyses, we conclude that strain strain G972^T (= DSM 103388^T = CSUR P2233^T) represents a novel species for which we propose the name Chryseobacterium timonianum. The 16S rRNA and genome sequences are available in GenBank database under accession numbers LT161886 and FJVD00000000.

Chryseobacterium indologenes: an emerging infection in the USA

Nursing home-associated infections and antibiotic resistant pathogens constitute common and serious problems in the geriatric population.Chryseobacterium indologenes, a non-motile Gram-negative rod, though widely distributed in nature, is an uncommon human pathogen. Typically thought of as an organism of low virulence, it may cause serious infections, particularly among the immunocompromised. The majority of reported cases are nosocomial, often associated with immunosuppression or indwelling catheters. It has been reported as the causative agent in bacteraemia, peritonitis, pneumonia, empyema, pyelonephritis, cystitis, meningitis and central venous catheter-associated infections. We report a rare case of C. indologenesinfection affecting a nursing home resident in the USA and we provide a review of similar cases. This report emphasises the importance of individualised treatment and promotes awareness about this organism as one of several emerging pathogens in immunocompromised adults and in the frail elderly who are often nursing home residents, in the Western Hemisphere.

Transient bacteraemia due to Chryseobacterium indologenes in an immunocompetent patient: a case report and literature review

A 51-year-old woman was admitted to the emergency unit with diffuse headache, visus reduction, and paraesthesias of the trigeminal area and the left hand. Three days after admission she showed shaking chills, vomiting, and sudden onset of fever (39·4°C). Blood cultures were performed soon after fever onset. Fever persisted for the whole day, decreasing slowly after 12 hours. No empirical antibiotic treatment was started in order to better define the diagnosis. Fever completely disappeared the day after. Two blood cultures for aerobes were positive for Chryseobacterium indologenes. The patient was discharged with the diagnosis of transient bacteraemia and transferred to the neurology unit for further investigations. C. indologenes infections are described in 31 studies with a total of 171 cases (pneumonia and bacteraemia being the most frequent). Our case is the first report of transient bacteraemia caused by C. indologenes in an immunocompetent, non-elderly patient without needing medical devices.