A case of Haemophilus aphrophilus native valve endocarditis / 대한내과학회지

Haemophilus aphrophilus, a fastidious, gram-negative oropharyngeal species grouped as a HACEK organism, is a rare cause of infective endocarditis. Three cases of endocarditis with Haemophilus aphrophilus were reported in Korea, and all of them required valve replacement surgery. We describe a case of native valve infective endocarditis with cerebral embolism and infarction caused by Haemophilus aphrophilus in a 61-year-old woman who was successfully treated with antibiotic therapy for 6 weeks without valve replacement surgery.

Isolation of Haemophilus aphrophilus and Coagulase-Negative Staphylococci from the Blood of a Patient with Prosthetic Valve Endocarditis / 대한임상미생물학회지

Haemophilus aphrophilus is a facultative anaerobic, gram-negative coccobacillus or bacillus and its growth is stimulated by 5 to 10% CO2. Most Haemophilus species require either exogenous X or V factor or both to grow, but H. aphrophilus can grow without these factors. H. aphrophilus rarely causes invasive infections such as endocarditis, septicemia, pneumonia and peritonitis in human. Two cases of infective endocarditis by H. aphrophilus have been reported in Korea. However, there has been no report of polymicrobial endocarditis by H. aphrophilus and other bacteria. We isolated H. aphrophilus and coagulase-negative staphylococci (CNS) from the blood of a 38-year-old woman with prosthetic valve endocarditis. She underwent an emergent operation and a culture of the prosthetic valve grew H. aphrophilus. Brain abscess was developed at hospital day 11. H. aphrophilus was susceptible to all antibiotics tested such as ampicillin and cefotaxime, and CNS was susceptible to oxacillin and vancomycin. The patient responded well to therapy with ceftriaxone, teicoplanin, and gentamicin.

A Case of Haemophilus aphrophilus Endocarditis / 대한임상미생물학회지

Haemophilus aphrophilus is a facultatively anaerobic gram-negative bacillus and require 5 to 10 % CO2 to grow optimally. H. aphrophilus is differentiated from other members of Haemophilus species by no requirement of X or V factor. This organism is found as the normal flora in upper respiratory tract but a member of the HACEK group that cause native valve endocarditis. Since the first endocarditis of H. aphrophilus was reported at 1985 in Korea, we reported the second case. A 35-year-old male patient was admitted to Asan Medical Center because of fever for 15 days and altered mentality developed 2 days ago. His echocardiography revealed a mitral valve regurgitation with a hypermobile vegetation and multiple septic emboli were also found in the brain MRI. Three sets of blood cultures were taken on the day of admission, all of which grew pleomorphic, gram-negative bacilli at incubation day 1. Catalase and oxidase test was negative and Vitek NHI card (bioMerieux Vitek, Inc., Hazelwood Mo., USA) identified the organisms to H. aphrophilus 50%/H. paraphrophilus 49% (Bionumber 257310). It was finally identified to H. aphrophilus with requirement tests of X or V factors; it required neither X nor V factor. This H. aphrophilus strain was negative inlactamase and was susceptible to ampicillin, gentamicin, cefuroxime, imipenem, ciprofloxacin, aztreonam, azithromycin, rifampin, and trimethoprim/sulfamethoxazole. This patient was successfully treated with ampicillin and gentamicin after mitral valve replacement under diagnosis of H. aphrophilus endocarditis