Haemophilus aphrophilus and Eikenella corrodens co-infection of brain : a unusual case from china

Abstract

Abstract Background: Haemophilus aphrophilus and Eikenella corrodens are both members of the HACEK group (Haemophilus spp., Aggregatibacter spp., Cardiobacterium hominis, Eikenella corrodens, and Kingella spp.) , are gram-negative acinetobacter that slow-growing and fastidious, these organisms are common causes of culture-negative endocarditis. however, brain abscesses caused by Haemophilus aphrophilus and Eikenella corrodens have been rarely reported. Case presentation: Herein, we report a case of brain abscess in a young male caused by Haemophilus aphrophilus and Eikenella corrodens. The patient was admitted to the hospital with sudden onset of vomiting, coma and fever. Magnetic Resonance Imaging(MRI) of the brain and cerebrospinal fluid (CSF) cell counts were suggestive of cerebral abscess, and the patient underwent drainage of the abscess and empirical antimicrobial therapy for more than 10 days without significant improvement. Metagenomicnext-generation sequencing(mNGS) and Matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF MS) of the drainage fluid suggested the presence of Haemophilus aphrophilus and Eikenella corrodens DNA sequences, which was supported by subsequent positive microbiological cultures. After 7 weeks antibiotic treatment of ceftriaxone in combination with meropenem intravenously, the patient was discharged with a normal temperature and the Computerized tomography(CT) of the brain showing improvement of the lesion. Conclusions: Related cases described in the previous literature are always associated with bacterial blood dissemination after dental surgery or myocarditis, what makes this case special is that the patient did not have any associated risk factors, and to the best of our knowledge, this is the first case of the central nervous system with Haemophilus aphrophilus and Eikenella corrodens co-infection that combined mNGS and MALDI-TOF in the diagnosis.