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The Brief Case: Bartonella quintana aortic and mitral valve endocarditis identified through 16S rRNA sequencing

Year: 2024

Type: article

Abstract: A 59-year-old male presented to the emergency department with left ankle pain, intermittent chest pain, and worsening exertional dyspnea.The patient was originally from Poland and was living undomiciled in Philadelphia, PA, USA.Through translation, he reported a 15-kg weight loss but denied recent fevers, chills, or intrave nous drug use.A review of the medical record showed a previous hospital admission for alcohol intoxication and withdrawal.Initial vital signs were normal, and the patient was afebrile.On physical examination, there was a purulent, superficial ulceration measuring 4 cm over the dorsal aspect of the left ankle surrounded by cellulitis of the lower left extremity.The cardiopulmonary examination was normal with no murmurs heard.The dental examination showed chronic periodontitis and multiple carious teeth.Bloodwork showed low white blood cell count (2.3/mm 3 ), anemia (hemoglobin, 8.0 g/dL), and thrombocytopenia (platelets, 114/mm 3 ).C-reactive protein was elevated at 11.2 mg/dL and serum B-type natriuretic peptide, a marker for congestive heart failure (CHF), was elevated at 918 pg/mL.Two sets of blood cultures were obtained before antibiotic administration and yielded no growth after 21 days of incubation.Chest x-ray showed a small pleural effusion and evidence of mild pulmonary vascular congestion and cardiomegaly suggestive of pulmonary edema resulting from CHF.Both transthoracic and transesophageal echocardiograms were obtained, revealing large, mobile aortic vegetations (the largest measuring 0.5 × 2.6 cm) with severe aortic regurgitation (Fig. 1A).Left and right ventricular functions were normal.CT scan showed diffuse cellulitis of the left lower extremity, no drainable fluid collection, subcutaneous gas, or osteomye litis.The patient was started on empiric vancomycin and cefepime, which were later changed to daptomycin and cefepime while the medical team searched for an infectious etiology of endocarditis.Six days after presentation, the patient underwent surgery.During the procedure, the surgeon confirmed the presence of multiple vegetations on the aortic and mitral valves.A Ross procedure was performed, in which the aortic valve was replaced using autologous pulmonary valve tissue.Vegetations on the mitral valve were debrided, and the mitral valve was irrigated (Fig. 1B).A surgical pathologist performed a histopathologic review of the resected aortic valve tissue and reported focal granulation tissue formation with focal acute and chronic inflammation.Gram stain, Ziehl Nielsen, and Gomori methenamine silver stains were all negative for organisms.Mitral valve tissue was submitted to the microbiology laboratory for aerobic, anaerobic, fungal, and mycobacterial cultures, which did not yield growth.Fresh tissue underwent 16S ribosomal RNA gene polymerase chain reaction and Sanger sequencing at a reference laboratory, in which Bartonella quintana DNA was detected.The patient was seropositive for Bartonella quintana with IgG IFA titer of >1:1,024 (IgM, <1:20), and Bartonella henselae IgG IFA titer of 1:64 (IgM, <1:20).HIV serology was non-reactive.Antimicrobial treatment was adjusted to doxycycline 100 mg twice daily for 6 weeks and gentamicin 3 mg/kg of

Source: Journal of Clinical Microbiology

DOI: 10.1128/jcm.00402-23

Authors: Andrew R. Motzer, Steven Mudroch, Sara Schultz, Kaede V. Sullivan, Eric Altneu

Institution: Temple University

Language: English

Topic: Bartonella species infections research

Subfield: Infectious Diseases

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

OpenAlex ID: W4390954800