Capnocytophaga sputigena bloodstream infection in hematopoietic stem cell transplantations: two cases report and review of the literature

Unique Presentation of a Ubiquitous Organism: Capnocytophaga canimorsus Meningitis With Pneumocephalus

Capnocytophaga canimorsus is a bacterium commonly found in the oral cavities of cats and dogs. Infections are particularly common in immunocompromised patients who have been exposed to bites or come in contact with saliva from these animals. The manifestations of infection include bacteremia, fever, and, rarely, meningitis. Diagnosis is challenging given the bacteria has slow growth on culture media. The organism is susceptible to beta-lactam antibiotics, with higher-generation cephalosporins recommended for treating meningitis. We present a case of a 74-year-old woman with altered mental status and no signs of immunosuppression. She was diagnosed with meningitis caused by Capnocytophaga, with an intriguing finding of pneumocephalus, which is a rare occurrence as per literature review.

Capnocytophaga sputigena Tonsillitis in a Patient With Acute Myeloid Leukemia

Capnocytophaga sputigena is a gram-negative facultatively anaerobic, capnophilic bacterium typically residing in the human oropharyngeal flora. This opportunistic pathogen can cause a wide range of infections, from bacteremia to septic abortion. However, it is exceedingly rare for a patient to present with tonsillitis due to C. sputigena. Herein, we discuss the presentation, hospital course, and clinical trajectory of a patient experiencing complications of tonsillitis related to C. sputigena in the context of acute myeloid leukemia. Additionally, we delve into the treatment approaches and challenges in managing this particular pathogen.

Meningitis caused by Capnocytophaga canimorsus in a COVID-19 patient: a rare complication of dog bites

Capnocytophaga canimorsus is a gram-negative rod that is part of the commensal microbiota of dogs' and cats' mouths. In this case, we report an 85-year-old man with COVID-19 who had his right arm bitten by a dog. His symptoms were impaired consciousness, agitation and aggressive behavior. Physical examination revealed neck stiffness and Brudzinski's sign. The cerebrospinal fluid culture was compatible with Capnocytophaga canimorsus. He required intensive care and received a 14-day prescription of meropenem. After 40 days of hospitalization, the patient was fully recovered and was discharged. This case highlights the importance of physician and microbiologist be awareness of this disease, mainly in patients with neurological symptoms after a dog or cat bite.

Catheter-related bloodstream infection due to biofilm-producing Capnocytophaga sputigena

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Capnocytophaga sputigena is a rare pathogen with diverse clinical presentations.

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We report a case of catheter-related C. sputigena bloodstream infection.

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C. sputigena clinical isolates can form biofilms in vitro.

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Biofilm development by Capnocytophaga species may potentiate disease pathogenesis.

Capnocytophaga sputigena is a facultatively-anaerobic bacterium that is part of the human oropharyngeal microflora. Although C. sputigena bacteremia is uncommon, systemic infections have been reported in both immunocompetent and immunocompromised patients. We report a case of catheter-related bloodstream infection by C. sputigena and highlight its enhanced biofilm-forming capacity in vitro.

Isolation and Characterization of Capnocytophaga bilenii sp. nov., a Novel Capnocytophaga Species Detected in a Gingivitis Subject

Capnocytophaga species are commensal gliding bacteria that are found in human and animal oral microbiota and are involved in several inflammatory diseases, both in immunocompromised and immunocompetent subjects. This study contributes to increased knowledge of this genus by characterizing a novel species isolated from a dental plaque sample in a male with gingivitis. We investigated morphological and chemotaxonomic characteristics using different growth conditions, temperature, and pH. Cellular fatty acid methyl ester (FAME) analysis was employed with gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI), and digital DNA–DNA hybridization (dDDH) relatedness were performed. The Marseille-Q4570^T strain was found to be a facultative aerobic, Gram-negative, elongated, round-tipped bacterium that grew at 25–56 °C and tolerated a pH of 5.5 to 8.5 and an NaCl content ranging from 5 to 15 g/L. The most abundant fatty acid was the branched structure 13-methyl-tetradecanoic acid (76%), followed by hexadecanoic acid (6%) and 3-hydroxy-15-methyl-hexadecanoic acid (4%). A 16S rDNA-based similarity analysis showed that the Marseille-Q4570^T strain was closely related to Capnocytophaga leadbetteri strain AHN8855^T (97.24% sequence identity). The OrthoANI and dDDH values between these two strains were, respectively, 76.81% and 25.6%. Therefore, we conclude that the Marseille-Q4570^T strain represents a novel species of the genus Capnocytophaga, for which the name Capnocytophaga bilenii sp. nov. is proposed (=CSUR Q4570).

The Characteristics of Capnocytophaga Infection: 10 Years of Experience

Background

Capnocytopha ga is a gram-negative, facultative anaerobe. Human infection is rare but can lead to devastating outcomes. Capnocytophaga canimorsus can cause sepsis following an animal bite, whereas human-oral-associated Capnocytophaga infections were reported in immunocompromised patients. Current data on these infections are not robust. Our goal is to provide a contemporary description of a unique characteristic of Capnocytophaga infections.

Methods

We performed a retrospective review of all patients with Capnocytophaga infection from January 2010 to August 2020 at 3 main hospitals of Mayo Clinic in Rochester, Minnesota; Scottsdale, Arizona; and Jacksonville, Florida. We collected baseline demographic data, clinical characteristics, microbiological data, and outcomes of C. canimorsus and human-oral-associated Capnocytophaga infection.

Results

Among 82 patients with Capnocytophaga infection, 46 patients (56.0%) had bacteremia. The most common species identified in this group was C. sputigena (57.9%), followed by C. canimorsus (34.8%). Patients with human-oral-associated Capnocytophaga bacteremia were often immunocompromised, presented with neutropenic fever, and had worse 6-month all-cause mortality compared to C. canimorsus bacteremia (36.4% vs 6.2%, P = .03). They also had a higher β-lactamase production rate (36.4% vs 0.0%, P = .02). Among patients without bacteremia, the main clinical syndrome was polymicrobial head and neck infections (47.2%).

Conclusions

Human-oral-associated Capnocytophaga bacteremia occurs primarily in immunocompromised patients, particularly those with hematologic malignancy. In contrast, C. canimorsus bacteremia is more likely to present with community-onset infection related to zoonotic exposure. Human-oral-associated Capnocytophaga infection without bacteremia is frequently isolated in polymicrobial infection; this phenomenon's significance is yet to be fully understood.