Title : Right-sided infective endocarditis caused by lactococcus garvieae in a patient with a pacemaker: A rare but serious zoonotic threat
Abstract:
Background:
Lactococcus garvieae, a Gram-positive Lactococcus, is an emerging zoonotic pathogen primarily associated with fish infections but increasingly recognized in human disease. We present a rare case of infective endocarditis caused by L. garvieae with unusual pulmonic valve involvement and concomitant cardiac device infection.
Case Presentation:
An 80-year-old male with a complex cardiovascular history including mitral valve repair, dual-chamber pacemaker, atrial fibrillation on anticoagulation, hypertension, hyperlipidemia, chronic kidney disease, and suspected cryoglobulinemic vasculitis presented with acute hypoxic respiratory failure and atrial fibrillation with rapid ventricular response. Blood cultures were positive for both Lactococcus garvieae and Streptococcus mitis/oralis. Transesophageal echocardiography revealed a vegetation on the pulmonic valve, which grew to 2.2 × 0.8 cm despite appropriate antimicrobial therapy. The patient's pacemaker system required extraction due to suspected device infection. Epidemiological investigation suggested possible gastrointestinal translocation related to consumption of fish products months before presentation. The patient was successfully treated with a 6-week course of ceftriaxone following pacemaker extraction.
Discussion:
This case highlights several noteworthy features: (1) the rare involvement of the pulmonic valve in infective endocarditis, (2) polymicrobial infection with L. garvieae as the dominant pathogen, (3) cardiac device involvement necessitating extraction, and (4) delayed presentation several months after the presumed exposure. Additionally, initial positive ANCA serology mimicking vasculitis demonstrates how bacteremia can produce immunological phenomena that may confound diagnosis.
Conclusion:
This case expands our understanding of L. garvieae pathogenicity in humans and emphasizes the importance of considering atypical pathogens in infective endocarditis, particularly in patients with prosthetic cardiac devices. The case also underscores the need for comprehensive evaluation of cardiac structures beyond the commonly affected valves in suspected endocarditis cases.
Keywords:
Lactococcus garvieae, infective endocarditis, pulmonic valve, pacemaker infection, zoonotic infection.
