Gemella haemolysans prosthetic valve endocarditis

An Emerging Threat: A Systematic Review of Endocarditis Caused by Gemella Species

Infective endocarditis caused by Gemella species is increasingly recognized as an emerging clinical entity. Gemella species are fastidious gram-positive cocci that are typically commensal organisms but can become opportunistic pathogens. This systematic review aimed to provide a comprehensive overview of endocarditis due to Gemella species by synthesizing existing evidence. A total of 52 case reports were identified through a rigorous search and selection process. The most prevalent causative species were G. morbillorum (46.3%) and G. haemolysans (25.9%), with a striking male predominance (79.6%). The clinical presentation was largely nonspecific, mirroring typical infective endocarditis. However, the indolent nature of the illness and fastidious growth requirements of Gemella species often led to diagnostic delays. Echocardiography, particularly transesophageal echocardiography, played a crucial role in the diagnosis, enabling the detection of valvular vegetation and the assessment of complications. Management posed significant challenges, including the need for broad-spectrum empirical antibiotic therapy and increasing antimicrobial resistance among Gemella isolates. Surgical intervention was frequently required for severe valvular dysfunction, persistent infection, or embolic complications. Despite advances in diagnosis and treatment, endocarditis due to Gemella species remains associated with significant morbidity and mortality, underscoring the importance of early recognition and multidisciplinary management. This review highlights the emerging clinical significance of Gemella species as causative agents of infective endocarditis and identifies areas for further research.

Infective endocarditis caused by Gemella haemolysans in a patient with bicuspid aortic valve: A case report

Gemella haemolysans is a gram-positive coccus, and commensal of the upper respiratory tract and oral mucosa. In rare cases, it has been identified as an opportunistic pathogen in the development of endocarditis. Here, we describe a case of Gemella haemolysans endocarditis in a patient with bicuspid aortic valve. A 14-year-old male presented to our hospital with a 1-month history of intermittent fever. Gemella haemolysans was isolated from the patient's blood cultures. Transesophageal echocardiography revealed severe aortic stenosis and a pseudoaneurysm of the mitral-aortic intervalvular fibrosa. The patient underwent aortic valve replacement with pseudoaneurysm of the mitral-aortic intervalvular fibrosa repair and remained symptom-free during follow-up. This case highlights the importance of considering atypical pathogens as causative agents of infective endocarditis.

<i>Gemella hemolysans</i> endocarditis and septicemia: case report and literature review

A suggestive report of Gemella hemolysans endocarditis and sepsis is described and commented on the ground of an updated literature review.

Risk Factors and Patient Profile of Infective Endocarditis due to Gemella spp

BACKGROUND

The diagnosis of infective endocarditis is difficult, especially when it involves atypical organisms. Therefore, our study identified risk factors of infective endocarditis caused by rare pathogen, Gemella spp.

METHODS

A systematic review was conducted to investigate characteristics of endocarditis patients infected with Gemella spp. using the search term "Gemella" and "endocarditis." Case reports were gathered by searching Medline/Pubmed, Google Scholar, CINAHL, Cochrane CENTRAL, and Web of Science databases. 83 articles were selected for review.

RESULTS

Five species of Gemella were identified. Typical patients were males between 31 and 45 years of age. On admission, patients had fever, tachycardia, and normal blood pressure. Common clinical manifestation other than fever included fatigue and weakness, chills and sweating, and nausea, vomiting, diarrhea, and weight changes. One in four reported a history of congenital heart disease, and a recent oral cavity infection. Laboratory tests reveal anemia, leukocytosis, and elevated erythrocyte sedimentation in all age groups, elevated C-reactive protein is observed among adult and geriatric populations only. Mitral and aortic valves were most commonly infected by Gemella spp.. The most common Gemella spp.-susceptible antibiotics were penicillin, vancomycin, cephalosporin, macrolide, and aminoglycosides. However, antibiotic resistance was observed against penicillin, aminoglycoside, and fluoroquinolone. Antibiotic course of at least six weeks resulted in superior clinical improvements than durations under six weeks. Finally, one in two patients underwent valve replacement or repair, with common complications affecting the cardiovascular, neurological, and renal systems. Finally, death occurred in 1 in 8 patients, half of which occurred post-surgical procedure, and the majority occurring equal to or greater than 1 week from admission.

CONCLUSION

Our systematic review highlights the importance of considering rare pathogens, particularly in the presence of predisposing risk factors.

Benefits of a Pre-Treatment Comprehensive Geriatric Assessment in a Rare Case of Gemella Haemolysans Endocarditis in an 86-Year-Old Patient and a Review of the Literature

Infective endocarditis is a serious condition, which is associated with high mortality in elderly patients. Gemella haemolysans (GH) is a microorganism from the Streptococcus family, rarely involved in infective endocarditis. Here, we present a case of Gemella haemolysans endocarditis in an 86-year-old patient, successfully treated by antibiotics and surgery following a pre-treatment comprehensive geriatric assessment (CGA). This case is discussed in the context of a review of all published cases of Gemella haemolysans endocarditis. We illustrate the benefit of a systematic pre-treatment comprehensive geriatric assessment in elderly patients with infective endocarditis.

Cerebrospinal fluid shunt infection due to Gemella haemolysans

Gemella haemolysans has long been considered a commensal in the human upper respiratory tract. Commensals are natural inhabitants on or within another organism, deriving benefit without harming or benefiting the host. Opportunistic infection of the CNS by the species is exceedingly rare. In the present case, a 16-year-old boy was admitted with a ventriculoperitoneal shunt infection, which was confirmed to be due to G. haemolysans. Following antibiotic treatment, removal of the old shunt, and delayed insertion of a new shunt, the patient made a full neurological recovery. To the authors' knowledge, this is the eighth case of CNS infection with G. haemolysans. Although prosthesis-related infections have been reported in other systems, this is the first case of CNS infection by the bacterium associated with an implant. Previous reported cases of CNS infection by G. haemolysans are reviewed. Due to the variable Gram staining property of the organism, the difficulty in diagnosing G. haemolysans infection is emphasized.

Molecular identification of Gemella species from three patients with endocarditis

Gemella morbillorum and Gemella haemolysans are opportunistic pathogens which cause endocarditis and other severe infections. We report on three patients with endocarditis, one with endocarditis caused by G. haemolysans and two with endocarditis caused by G. morbillorum. The paucity of reports concerning these bacteria is probably related to the difficulties associated with their identification. For example, one of the strains reported in this study was originally sent to our laboratory with a preliminary characterization as a short "gram-negative" coccobacillus, highlighting the specific problem associated with Gram staining of these bacteria. The usefulness of 16S rRNA gene amplification, partial sequencing, and comparison of the nucleotide sequence to those in databases when standard phenotypic identification schemes are not helpful is emphasized. We also suggest that the use of simple tests, such as testing susceptibility to vancomycin for gram-negative bacteria and colistin for gram-positive bacteria, could prevent misinterpretation of Gram staining in gram-variable bacteria such as Gemella spp.