Lactococcus lactis endocarditis and liver abscess in an immunocompetent patient: a case report and review of the literature

Abstract

Background Over the last two decades, several cases of infections caused by Lactococcus lactis have been reported. This Gram-positive coccus is considered non-pathogenic for humans. However, in some rare cases, it can cause serious infections such as endocarditis, peritonitis, and intra-abdominal infections. Case presentation A 56-year-old Moroccan patient was admitted to the hospital because of diffuse abdominal pain and fever. The patient had no past medical history. Five days before his admission, he developed abdominal pain in the right lower quadrant along with chills and feverish sensations. Investigations showed a liver abscess, which was drained, and the microbiological study of the pus revealed Lactococcus lactis subsp. cremoris. Three days after admission, control computed tomography objectified splenic infarctions. Cardiac explorations were performed and showed a floating vegetation on the ventricle side of the aortic valve. We retained the diagnosis of infectious endocarditis according to the modified Duke criteria. The patient was declared afebrile on day 5 and the evolution was clinically and biologically favorable. Lactococcus lactis subsp. cremoris, formerly known as Streptococcuscremoris, is a rare cause of human infections. The first case of Lactococcus lactiscremoris endocarditis was reported in 1955. This organism includes three subspecies: lactis, cremoris, and hordniae. A MEDLINE and Scopus search showed only 13 cases of infectious endocarditis due to Lactococcus lactis, with subsp. cremoris identified in four of the cases. Conclusions To our knowledge, this is the first case report of the co-occurrence of Lactococcus lactis endocarditis and liver abscess. Despite its reported low virulence and good response to antibiotic treatment, Lactococcus lactis endocarditis must be considered a serious disease. It is imperative for a clinician to suspect this microorganism of causing endocarditis when they notice signs of infectious endocarditis in a patient with a history of consumption of unpasteurized dairy products or contact with farm animals. The finding of a liver abscess should lead to an investigation of endocarditis, even in previously healthy patients without obvious clinical signs of endocarditis.

Left‐sided infective endocarditis presenting with pulmonary involvement and liver abscess: A case report

“…reported a case of bacteriemia with Streptococcus constellatus which caused endocarditis and hepatic abscess in a patient with gastric adenocarcinoma, which expired shortly after diagnosis. In a case report by Wahib Lahlou et al 23 . a 56‐year‐old previously healthy male presented with liver abscess, pneumonia, and pleural effusion.…”

Update of the list of qualified presumption of safety (QPS) recommended microbiological agents intentionally added to food or feed as notified to EFSA 19: Suitability of taxonomic units notified to EFSA until September 2023

“…Title and abstract screenings reduced their numbers to four. One of them did not deal with safety concerns leaving three relevant articles for the QPS exercise: in one , no indication on how the identification of the organism isolated from an urinary tract infection was provided; in the second report (Lahlou et al, 2023), only cultivation was used for identification, which is not reliable for L. lactis. Finally, the report by Giuliano et al (2023) described a fatal L. lactis infection in an 82 year-old man who suffered from thrombocytopenia and had to receive blood and platelet transfusions weekly, in addition to further underlying diseases.…”

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

“…Dual therapy with gentamycin is also used. Notably, this patient's L. garviae strain exhibited resistance to penicillin and clindamycin [ [1] , [2] , [3] , [7] , [8] , [9] , [10] ].…”

“…When clinical suspicion is high and ultrasound is inconclusive, 18 F-FDG PET/CT can be a valuable tool to aid in the diagnosis of infective endocarditis. Early identification, diagnosis, and treatment can significantly improve patient outcomes [ [6] , [7] , [8] , [9] , [10] , [11] , [14] , [15] , [17] , [18] ].…”