Cardiobacterium hominis endocarditis presenting as acute embolic stroke: a case report and review of the literature

Cardiobacterium hominis infective endocarditis: A literature review

Background

Cardiobacterium hominis is a member of the HACEK group, which causes infective endocarditis (IE) but is rarely associated with other infections. It is difficult to biologically identify C. hominis because of its slow growth in culture. However, the clinical features of C. hominis IE remain unclear.

Method

We searched the PubMed database for all articles of C. hominis IE published between January 2000 and July 2022.

Results

The major clinical features of 44 previously reported cases of C. hominis IE were as follows: the median age was 59 years, of which 36 were men; the initial presenting symptoms were chest discomfort (30 %), followed by fever (27 %), night sweats (20 %), fatigability (18 %), weight loss (16 %), and dyspnea (16 %). Almost half of the patients were febrile upon admission. The major predisposing factors were postsurgical valve treatment (57 %), dental treatment or caries (20 %), and congenital valve abnormality (5 %). The median time to identify C. hominis in the blood culture was 4 days, but the longest time was 42 days. The most commonly infected valve was the aortic valve, and the most common complication was systemic embolism. Surgical treatment was performed in 23 (52 %) patients. The most frequent initial treatment regimen was cephem antibiotics, with a median treatment duration of 6 weeks. The overall mortality and recovery rates of C. hominis IE were 9 % and 91 %, respectively.

Conclusion

If C. hominis infection is confirmed, physicians should check for the presence of vegetations of the heart valves and understand these characteristics.

Neurology of inflammatory bowel disease

Inflammatory bowel diseases (IBD) are chronic inflammatory conditions affecting the digestive system, comprising two main distinctive entities, ulcerative colitis (UC) and Crohn's disease (CD). Besides gastrointestinal manifestations, IBD causes extraintestinal manifestations in the central and peripheral nervous system. The incidence of neurological complications in IBD ranges from 0.25% to 47.5%. The pathophysiology of neurological manifestations of IBD is mostly immune mediated, but dysfunction of the brain-gut axis, arterial and venous thromboembolism, infections, nutritional deficiencies and side-effects of medications (steroids, metronidazole, sulfasalazine, anti-TNF-α, anti-integrin antibodies) are other contributory mechanisms. Patients with IBD have an increased risk of arterial and venous stroke, mainly during periods of exacerbations. Vasculitis is extremely rare. There is a bidirectional association between multiple sclerosis and IBD, with a relative risk for comorbidity of 1.54, being 1.53 for the risk of multiple sclerosis in IBD and 1.55 for the risk of IBD in multiple sclerosis patients. Anti-TNF-α therapy is contraindicated in the treatment of patients who have both IBD and multiple sclerosis. Demyelinating disorders can also be a rare complication of anti-TNF-α therapy. Optic neuritis, transverse myelitis, progressive myelopathy, central nervous system infections, epilepsy and encephalopathy are among other uncommon neurological complications. Peripheral nervous system manifestations include peripheral neuropathy, either demyelination and axonal, myasthenia gravis and polymyositis/dermatomyositis and localized forms of myositis.

Intracranial Hemorrhaging Following Cardiobacterium hominis Endocarditis

Acute infectious endocarditis (IE) is a complex disease that presents as a serious clinical condition associated with a high mortality rate, especially due to intracranial hemorrhaging (ICH). The most common causative organism is Staphylococcus aureus. We herein report a patient with ICH following subacute IE with a positive blood culture for Cardiobacterium hominis. A review of the existing literature revealed that acute IE associated with Cardiobacterium has been reported to cause ICH in only seven previous cases. Prolonged culture-specific antibiotic therapy along with extended surveillance of blood culture is therefore essential for timely intervention.

Infective endocarditis caused by Cardiobacterium hominis endocarditis: A case report and review of the literature

BACKGROUND

While it has been increasing cases of C. hominis endocarditis in the past decades due to advances of diagnostic methods, the epidemiology and clinical manifestations of IE caused by C. hominis is still unknown.

CASE PRESENTATION

A 62-year old man was admitted to our institute with fever, anorexia and general fatigue for the preceding one month. He had a past medical history of both aortic and mitral valves replacement due to cardiac diseases. He was diagnosed as IE caused by C. hominis according to the modified duke criteria. The patient received 2 weeks of combination therapy of intravenous ceftriaxone (CTRX) 2g and gentamycin 180mg daily followed by 4 weeks CTRX 2g daily alone. Oral moxifloxacin 400mg once daily was given for an additional 4 weeks. After the antibiotic therapy was discontinued, disease recurrence was not observed. We reviewed previously reported C. hominis IE cases in 60 publications including ours. Of 73 patients enrolled, 53 were male, the mean age was 52 years. The most common risk factor of IE was past history of cardiac diseases in 44/73 (60%). As for antibiotics initially prescribed, third-generation cephalosporins was most frequently used in 28/69 (41%). While the cure rate was 67/73 (93%), 31/73 patients (43%) received a surgical intervention. Embolic lesions to the central nervous system and vertebrae were seen in 16/72 (22%) and 5/72 (7%).

CONCLUSION

IE caused by C. hominis has a favorable prognosis, showing the cure rate of 93%. Physicians should recognize the possible occurrence of emboli among IE patients.

Neurologic manifestations of gastrointestinal and liver diseases

Hepatic and gastrointestinal disorders can produce a wide spectrum of neurologic complications both affecting the central nervous system (CNS) and the peripheral nervous system. These manifestations range in severity from coma in acute liver failure and acute pancreatitis, to minor cognitive changes in chronic portosystemic encephalopathy and hepatitis C. Cerebrovascular diseases can complicate hepatitis C infection and inflammatory bowel disease. Demyelinating disorders may co-exist with inflammatory bowel disease. Anti-tumor necrosis factor alpha drugs may induce demyelination. Ataxia may occur in malabsorption syndromes and in gluten related disorders. Characteristic movement disorders are key features of acquired hepatocerebral degeneration and of Whipple disease. Multiple types of neuropathy can be found in association with hepatitis, inflammatory bowel disease and gluten related disorders.

Subacute bacterial endocarditis caused by Cardiobacterium hominis: A case report

Cardiobacterium hominis is a fastidious organism that can rarely cause subacute bacterial endocarditis. This report describes a case involving a 47-year-old man with subacute endocarditis due to C hominis; the isolate was initally found to be resistant to third-generation cephalosporins, but was later found to be susceptible using an alternative method. The authors discuss the likely cause of this error and emphasize the importance of adherence to fully validated methods for the determination of antibiotic susceptibilities.

Cardiobacterium hominis, a member of the HACEK group of organisms, is an uncommon but important cause of subacute bacterial endocarditis. First-line therapy is a third-generation cephalosporin due to rare beta-lactamase production. The authors report a case involving endovascular infection due to C hominis that initially tested resistant to third-generation cephalosporins using an antibiotic gradient strip susceptibility method (nitrocephin negative), but later proved to be susceptible using broth microdilution reference methods (a ‘major’ error). There are limited studies to guide susceptibility testing and interpretive breakpoints for C hominis in the medical literature, and the present case illustrates some of the issues that may arise when performing susceptibility testing for fastidious organisms in the clinical microbiology laboratory.

Cerebral arterial infarction in inflammatory bowel diseases

It has been estimated that up to 10% of hypercoagulable state manifestations in patients with inflammatory bowel disease (IBD) are ischemic strokes. The literature search through MEDLINE and EMBASE highlighted 33 case reports of IBD patients complicated with cerebral arterial infarction during the course of their disease. Most of these patients presented with either left or right sided hemiparesis on admission, while the most common site of arterial infarction was either the right or the left middle cerebral artery. Thrombocytosis and anemia were the most commonly observed potential risk factors for stroke in the laboratory analysis. Other coagulation abnormalities, hereditary thrombotic mutations, hyperhomocysteinemia, hyperlipidemia, structural cardiac abnormalities, endocarditis and cerebral artery vasculitis have also been reported in some of the cases that were reviewed. Even though many of these findings are commonly observed in IBD patients, literature data is still controversial about their causal relationship to ischemic stroke. Similarly, there is also lack of steady evidence and official guidelines for stroke management in both children and adults with IBD comorbidity. Finally, an algorithm based on both the American Heart Association and European Stroke Organization guidelines for stroke management and prevention in the general population, is presented as a reference point for the treatment of IBD patients who are complicated by an ischemic cerebral event.

Cardiobacterium hominis-induced acute dacryocystitis and lacrimal abscess

Cardiobacterium hominis is a member of the HACEK (Haemophilus sp., Actinobacillus actinomycetemcomitans, C. hominis, Eikenella corrodens, and Kingella kingae) group commonly associated with endocarditits and is normally present in the respiratory tract. We describe the first case of acute dacryocystitis with lacrimal abscess caused by C. hominis along with a brief review of the literature. The patient responded to oral and topical ciprofloxacin after incision and drainage and awaits dacryocystorhinostomy.

HACEK-induced endocarditis

A 61-year-old patient with diabetes had a bio-prosthetic aortic valve replacement 3 years before admission. He complained of lethargy, night sweats, decreased appetite and erratic blood glucose with no weight loss. He had splinter haemorrhage and a systolic ejection murmur at the aortic area. Chest and abdominal examination revealed no abnormality. The erythrocyte sedimentation rate and C reactive protein were raised. He had several sets of blood cultures and he was started on empirical vancomycin, rifampicin and gentamicin. Transthoracic echocardiography showed vegetation on the base of the anterior mitral leaflet, which was confirmed by a trans-oesophageal echocardiography. Blood culture was positive for Haemophilus aphrophilus, and he was started on ceftriaxone for 6 weeks instead of vancomycin and rifampicin and continued gentamicin for 2 weeks. Follow-up echocardiography showed no evidence of vegetations. The patient recovered completely and he was discharged home.

[A case of cerebral embolism caused by Cardiobacterium hominis endocarditis]

A 45-year-old woman was referred to our hospital by ambulance with left-sided palsy presented at dinner. Diffusion-weighted magnetic resonance imaging (DWI) showed a somewhat high intensity area in the right frontal lobe, and brain magnetic resonance angiography (MRA) revealed right middle cerebral artery (MCA) occlusion in the M1 distal segment. Although intravenous rt-PA treatment was initiated at 2 hours and 10 minutes after onset, recanalization was not achieved. The patient was diagnosed as infectious endocarditis, because highly echogenic vegetation was observed in the non-coronary cusp of the aortic valve; furthermore, Cardiobacterium hominis was incubated in blood culture, although fever was not so high and C-reactive protein (CRP) was not elevated at the time of hospitalization. It was thought that the bacteremia and infectious endocarditis had occurred due to tooth extraction about six months previously. The diagnosis of infectious endocarditis caused by the HACEK group containing C. hominis may become difficult because the fever was not so high and inflammation was not so severe.