Aggregatibacter aphrophilus aortic valve infective endocarditis / Endocarditis infecciosa en válvula aórtica por Aggregatibacter aphrophilus

Nowadays, infective endocarditis remains a major cause of morbidity and mortality worldwide and there are concerns related to the increased number of infections associated with virulent agents and medical procedures. We present a case of a homeless man with unknown medical history, admitted for lumbar pain who became confused, hypotensive and tachy cardic, evolving to severe sepsis. His initial investigation was also suggestive of acute myocardial infarction but the transthoracic echocardiogram revealed massive aortic valve vegetation with perivalvular abscess leading to severe aortic regurgitation. The patient died with the final diagnosis of infective endocarditis. Later on the blood cultures was identified Aggregatibacter aphrophilus, an HACEK group agent. This case confirms that, albeit the general favorable outcomes, there are cases of serious infections, especially if the diagnosis and treatment were late.

Hoy día, la endocarditis infecciosa continúa siendo una causa importante de mor-bimortalidad en todo el mundo y es preocupante el aumento del número de infecciones asociadas con agentes virulentos y procedimientos médicos. Presentamos el caso de un indigente con antecedentes médicos desconocidos, ingresado por dolor lumbar, que comenzó a sentirse confuso, hipotenso y taquicárdico. Poco después de su ingreso su estado evolucionó a septicemia grave. Los resultados de las pruebas iniciales también eran indicativos de infarto agudo de miocardio, pero el ecocardiograma transtorácico reveló una vegetación masiva en la válvula aórtica con absceso perivalvular condicionando regurgitación aórtica grave. El paciente murió, con el diagnóstico definitivo de endocarditis infecciosa. Más tarde, en los hemocultivos se identificó Aggregatibacter aphrophilus, un microorganismo del grupo HACEK. Este caso confirma que, a pesar de los resultados favorables en general, hay casos de infecciones graves, sobre todo si el diagnóstico y el tratamiento fueron tardíos.

Prosthetic Valve Endocarditis caused by HACEK Organisms: a Case Report and Systematic Review of the Literature

HACEK is a rare cause of prosthetic valve endocarditis (PVE). We describe 42-year-old male patient who presented with Aggregatibacter aphrophilus PVE and cerebral infarct. A. aphrophilus was isolated from his blood cultures as the sole pathogen, which was confirmed by subsequent 16S rRNA sequencing. He was treated with valve replacement surgery and an 8 week course of pathogen-directed antibiotic therapy and followed for 20 months without recurrence.

A Case of Pyogenic Spondylitis Due to Aggregatibacter aphrophilus / 대한임상미생물학회지

Aggregatibacter aphrophilus, a normal component of oral cavity flora, mostly causes infective endocarditis and only rarely causes spondylitis; no spondylitis cases have been previously reported in Korea. We report a case of pyogenic spondylitis due to A. aphrophilus without endocarditis. A 64-year-old man was admitted for back pain lasting 3 weeks. There was severe tenderness on lumbar spines but no fever. Laboratory evaluation showed leukocytosis and elevated C-reactive protein. Blood cultures were negative. Magnetic resonance imaging showed psoas abscess and vertebral inflammation. Pus was obtained by computerized tomography-guided aspiration from the psoas abscess and inoculated into blood culture bottles. After 5 days of incubation, growth was detected: the isolate was a Gram-negative short rod bacteria identified as A. aphrophilus by the automated system; this was confirmed by 16S ribosomal RNA sequencing. There was no evidence of endocarditis in echocardiography and retinal examination. Back pain persisted despite 8 weeks of antibiotic treatment, so vertebral corpectomy was performed. A. aphrophilus, a rare cause of pyogenic spondylitis, can induce spondylitis without endocarditis. If a patient with pyogenic spondylitis shows negative routine bacterial cultures, fastidious organisms such as A. aphrophilus should be suspected and the blood culture bottles could be used.

A Case of Vertebral Osteomyelitis and Spinal Epidural Abscess Caused by Haemophilus aphrophilus / 대한내과학회지

Haemophilus aphrophilus is an aerobic, gram-negative oropharyngeal bacterium, commonly isolated from cases of HACEK endocarditis. In addition, H. aphrophilus has also been shown to cause invasive bone and joint infections. Although multiple cases of H. aphrophilus endocarditis have been described, no cases of invasive bone and joint infections caused by H. aphrophilus have been reported in Korea. Here we report the case of a 69-year old woman with a diagnosis of vertebral osteomyelitis and spinal epidural abscess with compressive myelopathy caused by H. aphrophilus, in which there was no objective evidence of infective endocarditis. She was successfully treated with intravenous administration of cefotaxime and drainage of the epidural abscess by laminectomy of the T3-7 vertebrae.

Identification of bacteria from the peri-implant sulcus of orthodontic mini-implants using 16S rDNA clone library / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to compare the bacterial flora at the peri-implant sulcus of the orthodontic mini-implant placed in the alveolar mucosa with the bacterial flora at the adjacent healthy gingival sulcus. METHODS: Two plaque samples from 7 patients were collected by inserting paper points into the sulcus between the mini-implant and ligature wire connected to the mini-implant head and inflamed alveolar mucosa, and from the gingival sulcus of a healthy tooth adjacent to the mini-implant. RESULTS: Using 16S rDNA clone library, the 24 kinds of bacteria including Haemophilus aphrophilus, Sphingomonas species, Capnocytophaga species, Prevotella melaninogenica, Lachnospiraceae species, Porphyromonas species, Neisseria flava were identified only from the sulcus around the mini-implant. These bacteria constituted only 9.2% of total clones, and the bacteria identified from both the sulcus around mini-implants and the gingival sulcus constituted 80.4% of total clones. Of these bacteria, clones of Prevotella species, Atopobium rimae, Veillonella species, Streptococcus intermedius/constellatus, Streptococcus salivarius were more frequently isolated from the peri-implant sulcus. CONCLUSION: This study suggests that a broad epidemiological study is needed to find causative bacteria which induce inflammation from the peri-implant sulcus.

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