A “fishy” situation, rare pathogen and presentation in prosthetic valve infective endocarditis

Lactococcus garviae (L. garviae) is a gram-positive coccus belonging to the Streptococcaceae family. While primarily a pathogen in fish farms causing hemorrhagic sepsis, it can act as a rare opportunistic pathogen in humans. A 2021 case report by Bravo et al. documented less than 30 cases of infective endocarditis caused by L. garviae worldwide at that time.1González-Bravo DH, Alegre-Boschetti S, Silva-Cantillo R, et al. Lactococcus garvieae: An Uncommon Human Pathogen Causing Infective Endocarditis in a Valve-in-Valve Transcatheter Aortic Valve Replacement. Liu T, ed. Case Reports in Cardiology. 2021;2021:1-6. doi:https://doi.org/10.1155/2021/5569533Google Scholar This case report describes the 27th documented case globally and 7th documented case in the USA of L. garviae causing infective endocarditis of a prosthetic valve.1González-Bravo DH, Alegre-Boschetti S, Silva-Cantillo R, et al. Lactococcus garvieae: An Uncommon Human Pathogen Causing Infective Endocarditis in a Valve-in-Valve Transcatheter Aortic Valve Replacement. Liu T, ed. Case Reports in Cardiology. 2021;2021:1-6. doi:https://doi.org/10.1155/2021/5569533Google ScholarLgarviae is found in unpasteurized dairy products, raw fish, and meat (pork, beef, and poultry), but the route of human transmission remains unclear.3Malek A. De la Hoz A. Gomez-Villegas S.I. Nowbakht C. Arias C.A. Lactococcus garvieae, an unusual pathogen in infective endocarditis: case report and review of the literature.BMC Infectious Diseases. 2019; 19https://doi.org/10.1186/s12879-019-3912-8Crossref PubMed Scopus (32) Google Scholar It seems to have a predilection for individuals with prosthetic valves, immunocompromised states, prior gastrointestinal surgery, gastrointestinal disorders (colon polyps and diverticulosis), and the use of acid-reducing medications.1González-Bravo DH, Alegre-Boschetti S, Silva-Cantillo R, et al. Lactococcus garvieae: An Uncommon Human Pathogen Causing Infective Endocarditis in a Valve-in-Valve Transcatheter Aortic Valve Replacement. Liu T, ed. Case Reports in Cardiology. 2021;2021:1-6. doi:https://doi.org/10.1155/2021/5569533Google Scholar, 2Rösch R.M. Buschmann K. Brendel L. Schwanz T. Vahl C.F. Lactococcus garvieae Endocarditis in a Prosthetic Aortic Valve: A Case Report and Literature Review.Journal of Investigative Medicine High Impact Case Reports. 2019; 7232470961983205https://doi.org/10.1177/2324709619832052Crossref PubMed Scopus (12) Google Scholar, 3Malek A. De la Hoz A. Gomez-Villegas S.I. Nowbakht C. Arias C.A. Lactococcus garvieae, an unusual pathogen in infective endocarditis: case report and review of the literature.BMC Infectious Diseases. 2019; 19https://doi.org/10.1186/s12879-019-3912-8Crossref PubMed Scopus (32) Google Scholar Infective endocarditis is the most common systemic disease caused by L. garviae 1González-Bravo DH, Alegre-Boschetti S, Silva-Cantillo R, et al. Lactococcus garvieae: An Uncommon Human Pathogen Causing Infective Endocarditis in a Valve-in-Valve Transcatheter Aortic Valve Replacement. Liu T, ed. Case Reports in Cardiology. 2021;2021:1-6. doi:https://doi.org/10.1155/2021/5569533Google Scholar, 2Rösch R.M. Buschmann K. Brendel L. Schwanz T. Vahl C.F. Lactococcus garvieae Endocarditis in a Prosthetic Aortic Valve: A Case Report and Literature Review.Journal of Investigative Medicine High Impact Case Reports. 2019; 7232470961983205https://doi.org/10.1177/2324709619832052Crossref PubMed Scopus (12) Google Scholar, 3Malek A. De la Hoz A. Gomez-Villegas S.I. Nowbakht C. Arias C.A. Lactococcus garvieae, an unusual pathogen in infective endocarditis: case report and review of the literature.BMC Infectious Diseases. 2019; 19https://doi.org/10.1186/s12879-019-3912-8Crossref PubMed Scopus (32) Google Scholar, 4Fefer J.J. Ratzan K.R. Sharp S.E. Saiz E. Lactococcus garvieae endocarditis: report of a case and review of the literature.Diagnostic Microbiology and Infectious Disease. 1998; 32: 127-130https://doi.org/10.1016/S0732-8893(98)00065-0Crossref PubMed Scopus (104) Google ScholarThis report details the case of a 75-year-old male, with multiple comorbidities and risk factors for L. garviae infection who was admitted for "symptomatic anemia". High clinical suspicion, coupled with an inadequate hemoglobin response to transfusion, a normal anemia workup, and blood cultures positive for L. garviae, promoted a transesophageal echocardiogram (TEE). However, the results were negative. Consequently, an 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan (18Østergaard Lauge Voldstedlund M. Bruun Niels Eske et al.Recurrence of bacteremia and infective endocarditis according to bacterial species of index endocarditis episode.Infection. 2023; 51: 1739-1747https://doi.org/10.1007/s15010-023-02068-xCrossref PubMed Scopus (4) Google Scholar FDG PET/CT) was performed. The scan revealed increased uptake in the aortic valve replacement consistent with prosthetic valve endocarditis in the setting of Lactococcus garviae bacteremia.