Infectious endocarditis secondary to Granulicatella adiacens
Ahish Chitneni, DO1 • Annina Giannuzzi, BS2 • Kaushik Manthani, DO1 •Sandeep A. Gandhi, MD1.2
1Peconic Bay Medical Center, Northwell Health, Riverhead, New York
2New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York
Chitneni A, Giannuzzi A, Manthani K, Gandhi SA. Infectious endocarditis secondary to Granulicatella adiacens. Consultant. Published online February 23, 2022. doi:10.25270/con.2022.02.00007
Received September 8, 2021. Accepted November 1, 2021.
The authors report no relevant financial relationships.
Sandeep A. Gandhi, MD, 200 Hawkins Avenue, #1362, Ronkonkoma, NY 11779 ([email protected])
A 73-year-old man presented to our emergency department with constipation. He reported that he was unable to have a bowel movement for 5 days before the presentation, despite using homemade enemas, suppositories and prune juice. His constipation was associated with chills, decreased oral intake, and decreased urine output.
Story. The patient had a history of hypertension, coronary artery disease and rheumatoid arthritis and was on disease-modifying antirheumatic therapy. He denied chest pain, fever, shortness of breath, nausea, vomiting or joint pain. He denied recent tick bites or international travel. He said he had never had a colonoscopy.
Physical examination. The patient had poor dentition. Her abdomen was soft with normal bowel sounds, and no murmurs were appreciated on chest examination. At initial presentation, the patient was afebrile and presented with tachycardia with a heart rate of 101 beats/min.
Diagnostic tests. Initial abdominal radiographs showed diffuse intestinal ileus versus distal large bowel obstruction. A CT scan of the abdomen and pelvis showed a slightly distended, fluid-filled stomach and small intestine, suggesting enterocolitis (Figure).
Figure. A CT scan of the abdomen and pelvis showed a slightly distended fluid-filled stomach and small intestine, suggesting enterocolitis.
The results of the laboratory study were significant for an elevated white blood cell count of 14.67 × 109/I. Initial blood cultures showed growth of gram-positive cocci in pairs and chains, but no growth was observed in urine culture. The patient was initially put on ceftriaxone and vancomycin. Three days after hospital admission, blood cultures increased Granulicatella adiacensand the patient underwent echocardiography, the results of which revealed bacterial endocarditis on the aortic valve.
The patient was informed of the need for outpatient colonoscopy and dental follow-up and discharged after 4 weeks of outpatient parenteral antibiotic therapy with intravenous ceftriaxone.
Discussion. Infectious endocarditis is an infection of the endothelium of the heart resulting from bacteria present in the blood. One of the main risk factors for infective endocarditis is heart valve disease, which allows bacteria in the blood to attach to damaged heart valves.1 Patients with infective endocarditis typically present with fever, fatigue, muscle aches, and a heart murmur on physical examination. In recent years, the epidemiology of infective endocarditis has evolved, with Staphylococcus aureus becoming the most common cause in approximately 26.6% of cases, Viridans Streptococci in 18.7% of cases, other strains of streptococci in 17.5% of cases and strains of enterococci in 10.5% of cases.2 Infectious endocarditis can be associated with bacterial species normally present in the oral flora. Since G adiacens can be found in the oral cavity, it is another organism potentially responsible for infective endocarditis.1
Nutritionally varying streptococci, named for their growth in satellite colonies surrounding other organisms and their unique nutritional requirements, were first discovered in 1961 by Frenkel and Hirsch.3 In 1995, Kawamura and colleagues found that nutritionally variant streptococci were phylogenetically distinct from other streptococcal species using 16S rRNA sequencing and reclassified the genus as abiotrophia.4 After further study, Collins and Lawson found the Abiotrophy genus was not monophyletic and reclassified some abiotrophic strains, including Abiotrophia adiacensin the new genus granulicatella.5
G adiacens is a nutritionally variant streptococcus. The growth of organisms requires sulfhydryl compounds such as cysteine and vitamin B6.6 Typically, G adiacens is part of the normal oral and gastrointestinal flora.7.8 One of the complications of infection includes infective endocarditis, in which nutritionally varying streptococcal organisms account for less than 5% of cases and G adiacens represent even fewer cases.9 In many cases, the organism can even cause negative blood cultures or delayed identification during the culture process, which can lead to untreated infections. In our case, the blood cultures developed G adiacens within 4 days of hospital admission, which facilitated early management; however, this is not always common according to our review of the literature.
Typically, the treatment of G adiacens includes administration of penicillin or ceftriaxone.ten Susceptibility profile studies conducted on G adiacens showed that 34% of isolates were susceptible to penicillin and 22% of isolates were susceptible to ceftriaxone.11 In our case, the patient was managed with 4 weeks of ceftriaxone. Additionally, research has shown that G adiacens often develop resistance to beta-lactams and macrolide antibiotics, indicating further evidence that cephalosporin is ideal for patients with G adiacens infections.12
Infective endocarditis is an infection caused by bacteria that enters the bloodstream and affects the heart. Although infective endocarditis is treatable in many cases, some studies have shown that 41% of cases result in treatment failure of the body.13 Overall, considering the rarity of the organism, the potential unique dental findings and gastrointestinal symptoms, the risk of treatment failure due to resistance, and the risk of G adiacens can cause infective endocarditis. The organism is an important consideration when evaluating patients with similar symptoms. Moreover, although many cases in the literature show G adiacens as a cause of endocarditis, no case in our literature search reported primary gastrointestinal problem as the primary symptom leading to aortic valve endocarditis.
As mentioned, echocardiography is the primary method to assess whether bacteremia has progressed to cause infective endocarditis. According to guidelines published by the European Society of Cardiology (ESC)ten and American College of Cardiology/American Heart Association14, transthoracic echocardiography (TTE) is recommended for patients suspected of having infective endocarditis to assess valve morphology and ventricular function. Suspicion of infective endocarditis is usually based on the Duke criteria (table) or clinical suspicion of organisms that can cause infective endocarditis.15 The Duke criteria consist of major and minor criteria. Primary criteria include positive blood cultures for endocarditis (eg, organisms generally consistent with infective endocarditis and evidence of endocardial involvement). Minor criteria include predisposing cardiac disease or injection drug use, fever, vascular phenomena (i.e. emboli, pulmonary infarcts, intracranial hemorrhage, Janeway lesions), immunologic phenomena (i.e. i.e. rheumatoid factor, Roth’s spots, Osler’s lymph nodes, glomerulonephritis) and microbiological evidence (i.e. positive blood culture that does not meet primary criteria). Typically, after antibiotic treatment, a repeat TTE is performed to assess resolution of valvular vegetation and infection. According to ESC guidelines, a baseline TTE should be performed after the patient has completed antibiotic treatment during the first year of follow-up to monitor the development of secondary heart failure. In our case, the patient met Duke’s criteria for major criteria in addition to meeting several minor criteria.
We conducted a literature review of cases of endocarditis caused by G adiacens. One case involved an older man who presented with fever and bilateral tingling and numbness in his lower limbs for 15 days.15 His physical exam showed a systolic murmur, an echocardiogram showed mitral valve vegetation, and blood cultures were increased. G adiacens. In this case, the patient had developed severe right lower extremity pain on the 6th day of admission. An ultrasound was performed, the results of which showed a thrombus in the right common femoral artery which was considered an embolic phenomenon. This case highlights the importance of potential complications of valvular adenoids, such as the risk of embolization, and further highlights the importance of immediate treatment with antibiotics and thrombosis prophylaxis and follow-up echocardiography for ensure good elimination of vegetation.
Another case featured a middle-aged man who presented with fever and mental status changes.16 In this case, the patient had positive blood cultures for G adiacens. A CT scan showed left internal jugular vein thrombosis, pulmonary embolism and abscesses in the gluteal muscles. In this case, the source of infection was suspected to be G adiacens in the oral flora, which had spread hematogenously to the internal jugular vein with septic metastases to the lungs and gluteal muscles. Given this patient’s unique symptoms and the spread of the disease, this case further demonstrates the potential complications of G adiacens infection.
Another article presented 2 cases of the organism causing subcutaneous abscesses in the elbow and a suprapatellar abscess.17 Similar to the previous case, hematogenous spread of infection from dental or gastrointestinal sources to various regions of the body is significant. Although many cases in the literature have shown that G adiacens caused infective endocarditis, abscesses and bacteremia, the gastrointestinal tract as a source of infection is very rare. In our case, our patient presented with constipation, an elevated white blood cell count, and a CT scan showing enterocolitis and stercoral colitis with perirectal edema and thickening of the rectal wall. G adiacens should be considered in the differential as a potential cause of infection in similar cases.