Liver and brain abscess caused by Aggregatibacter paraphrophilus in association with a large patent foramen ovale: a case report

Brain abscess due to Aggregatibacter aphrophilus in association with atrial septal defect：Case report and literature review

BACKGROUND

Aggregatibacter aphrophilus（A. aphrophilus）is one of the organisms of the HACEK group. Previously reported cases of brain abscesses caused by A. aphrophilus infection have occurred in children with a basis for congenital heart disease, or in adults with a basis for dental disease. Rare cases of brain abscess caused by A. aphrophilus have been reported in adults with congenital heart disease or in patients without dental disease history. Herein we present a rare case of brain abscess caused by A. aphrophilus, who was in association with atrial septal defect for more than 20 years, and had no dental disease and did not develop infective endocarditis.

CASE PRESENTATION

A 51-year-old female was admitted due to progressively worsening headache and left limb weakness for more than 10 days. She denied the history of chronic diseases such as hypertension and diabetes, and no periodontal disease. While she had a history of atrial septal defect, a form of congenital heart disease with severe pulmonary hypertension for more than 20 years. After admission, echocardiographic illustrated congenital heart disease with severe pulmonary hypertension. CT and MRI showed brain abscess. Cerebrospinal fluid (CSF) results also confirmed the presence of intracranial infection. Empirical therapy with vancomycin 1.0 g i.v q12h and meropenem 2.0 g i.v q8h was initiated from the day of admission. On the fourth day after admission, brain abscess resection and decompressive craniectomy were performed, and the pus drained on operation were cultured and Gram-negative bacilli grew, which was identified as A.aphrophilus. Vancomycin was discontinued and meropenem was continued（2.0 g i.v q8h）for 5 weeks, followed by oral levofloxacin 0.5 qd for 4 weeks of out-patient antibiotics. The patient recovered fully within 9 weeks of treatment.

CONCLUSIONS

This is the first case of A. aphrophilus to cause brain abscess in adult with a history of congenital heart disease for more than 20 years, who had no dental disease and did not develop infective endocarditis. We also highlight the value of bacterial 16 S rDNA PCR amplification and sequencing in identifying bacteria in abscesses which are culture-negative, and prompt surgical treatment，choosing effective antibiotics and appropriate course of treatment will get better clinical effect.

An unusual case of multiple hepatic and pulmonary abscesses caused by Aggregatibacter aphrophilus in a young man: a case report

Background

Aggregatibacter aphrophilus, formerly known as Haemophilus aphrophilus, belongs to the HACEK organisms, a group of pathogens classically associated with infectious endocarditis. A. aphrophilus is a rarely found pathogen, though abscess formation in various organs has been described, typically due to spread from an infected heart valve. Here we describe the unusual case of multiple hepatic abscesses caused by A. aphrophilus.

Case presentation

A 33-year-old Caucasian man presented at our hospital with fever and malaise, elevated inflammatory markers, and liver enzymes. Imaging was compatible with multiple liver and pulmonary abscesses, without evidence of endocarditis. Cultures of blood and liver abscess material remained without growth. Polymerase chain reaction finally revealed Aggregatibacter aphrophilus in the liver tissue. The patient recovered fully within 6 weeks of doxycycline treatment.

Conclusions

There are only a few case descriptions of liver abscesses caused by A. aphrophilus. As a ubiquitous organism in the gastrointestinal tract, A. aphrophilus may reach the liver via the portal venous system, as well as through hematogenous spread from the oropharynx. HACEK organisms are notoriously difficult to grow on culture, which highlights the diagnostic importance of eubacterial PCR.

An unusual case of aggregatibacter aphrophilus liver abscess

Liver abscess of oropharyngeal origin in an immunocompetent patient is a rare condition. Furthermore, microbiologic diagnosis of liver abscess can be challenging due to the tremendous diversity of the microorganisms implicated and culture difficulties under laboratory conditions. We report a case of a previously healthy 23-year-old male, who presented multiple liver abscesses, attributed to aggregatibacter aphrophilus, an obligatory oral gram-negative microorganism, that normally is a component of the commensal oral microbiota and non-virulent. The etiopathogenic microorganism was identified after needle aspiration of a liver abscess cavity. Treatment with broad-spectrum antimicrobials and percutaneous catheter drainage under computed tomography guidance of both abscesses, resulted in full recovery. A. aphrophilus represents a rare entity of liver abscess in healthy individuals and suggests that a pathogen of oropharyngeal origin should be suspected when an overt source of infection cannot be documented.

Brain abscess associated with patent foramen ovale

BACKGROUND

Brain abscesses can develop with Tetralogy of Fallot and pulmonary anterior venous fistula with large right-to-left shunt. However, some patients exhibit cryptogenic brain abscess (CBA) in the absence of any such congenital disease or other infections. Patent foramen ovale (PFO) is a very common disease that exhibits right-to-left shunt. This study reports the potential for concern between CBA and PFO.

METHODS

We enrolled patients with CBA in our hospital between January 2003 and January 2013. Patients underwent transesophageal echocardiography (TEE) with contrast medium to investigate the presence of PFO.

RESULTS

Seven patients were included. Four were females, and the mean age was 67.7 ± 9.2 years. In all patients, TEE failed to reveal any new findings, however, six patients had PFO, and another patient had pulmonary arteriovenous shunt. Four patients had odontopathy.

CONCLUSION

In this study, all CBA patients exhibited right-to-left shunt. CBA might be caused by paradoxical embolization of a bacterial mass via PFO. Thus, more patients with CBA need to undergo TEE to detect PFO.

Infective Endocarditis by Aggregatibacter paraphrophilus: Case Report and Literature Review

Aggregatibacter paraphrophilus (former name, Haemophilus paraphrophilus) is a normal inhabitant of the naso- and oropharynx and has been rarely reported as a cause of human infections. A case of infective endocarditis by this organism is being reported and literature of endocarditis cases caused by Aggregatibacter paraphrophilus is being reviewed.

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 51-year-old man with intramedullary spinal cord abscess having a patent foramen ovale

The authors report a case of a 51-year-old man with intramedullary spinal cord abscess (ISCA) having a patent foramen ovale (PFO). He developed fever and tetraplegia after a recent dental treatment. MRI showed ISCA with longitudinal swelling from the upper cervical to the lumbar spinal cord. Cerebrospinal fluid (CSF) analysis indicated bacterial meningitis, and the culture of CSF revealed Streptococcus viridans. Transoesophageal echocardiography revealed the existence of a PFO. We suspected another possibility other than systemic bacteraemia, that paradoxical bacteric embolisation through PFO after the dental treatment caused ISCA. While several reports of brain abscess with PFO are available, this is the first report of ISCA with PFO.