Chryseobacterium Indologenes Sepsis and Acute Renal Failure Secondary to Abdominal Compartment Syndrome in a Confirmed COVID-19 Patient

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.

A rare urinary tract infection of multidrug-resistant Chryseobacterium urinae sp. nov. isolated from a diabetic, non-catheterized patient

Chryseobacterium demonstrates a diverse environmental presence and a significant pathogenic potential across various ecosystems. This clinical case showcases a rare instance of bacterial infection in a 75-year-old male with untreated diabetes and recurrent urinary tract infections (UTIs). The patient presented symptoms of abdominal pain, burning urination, fever, and an elevated eosinophil count. A subsequent urine culture identified a Chryseobacterium-related bacterium as the causative agent, exhibiting sensitivity to piperacillin/tazobactam, trimethoprim/sulfamethoxazole, and nitrofurantoin, which led to successful treatment using oral nitrofurantoin. Analysis of the 16S rRNA gene sequence of APV-1T revealed a close relationship of 98.2% similarity to Chryseobacterium gambrini strain 5-1St1aT (AM232810). Furthermore, comparative genome analysis, incorporating Average Nucleotide Identity (ANI), Digital DNA-DNA Hybridization (dDDH) values, and comprehensive phylogenetic assessments utilizing 16S rRNA gene sequences, core genes, and amino acid sequences of core proteins, highlighted the unique phylogenetic positioning of APV-1T within the Chryseobacterium genus. Distinct carbon utilization and assimilation patterns, along with major fatty acid content, set APV-1T apart from C. gambrini strain 5-1St1aT. These findings, encompassing phenotypic, genotypic, and chemotaxonomic characteristics, strongly support the proposal of a novel species named Chryseobacterium urinae sp. nov., with APV-1T designated as the type strain (= MCC 50690 = JCM 36476). Despite its successful treatment, the strain displayed resistance to multiple antibiotics. Genomic analysis further unveiled core-conserved genes, strain-specific clusters, and genes associated with antibiotic resistance and virulence. This report underscores the vital importance of elucidating susceptibility patterns of rare pathogens like Chryseobacterium, particularly in immunocompromised individuals. It advocates for further analyses to understand the functional significance of identified genes and their implications in treatment and pathogenesis.