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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We isolated a hitherto undescribed microorganism from a patient with endocarditis. The microscopic appearance, a negative catalase reaction, and growth as satellite colonies next to Staphylococcus epidermidis suggested that this microorganism is a member of the genus Abiotrophia, formerly known as nutritionally variant streptococci. However, the clinical isolate described herein differed markedly from the known Abiotrophia spp., A. adiacens and A. defectiva, in terms of its (i) biochemical properties, (ii) restricted growth temperature range, (iii) whole-cell lysate polypeptide profile, and (iv) unique nutritional requirements. In contrast to the type strains of A. adiacens and A. defectiva, which used L-cysteine and pyridoxal hydrochloride as growth factors, the growth of the clinical isolate was only supported by L-cysteine hydrochloride and not by pyridoxal hydrochloride when the organism was tested in Todd-Hewitt or casein-soy peptone broth. Comparative 16S rRNA gene sequence analysis revealed that the microorganism was a member of the genus Abiotrophia and was most closely related to A. adiacens (96.9% homology). Phenotypic and phylogenetic data are consistent with the assumption of a new species within the genus Abiotrophia, for which we propose the name Abiotrophia elegans sp. nov. The unique nutritional requirements of this strain are of importance for diagnostic laboratories. The media of blood culture systems supplemented only with pyridoxal hydrochloride as a growth factor may fail to promote the growth of A. elegans sp. nov., and thus, these systems might not detect this microorganism as a possible cause of endocarditis.
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PMID:Abiotrophia elegans sp. nov., a possible pathogen in patients with culture-negative endocarditis. 943 29

OBJECTIVE: Infective endocarditis is frequently caused by oral streptococci, especially Streptococcus sanguis. In this group, many strains have recently been reclassified on the basis of new taxonomic schemes. The purpose of this study was to classify oral streptococci from patients with infective endocarditis and, further, to assess the importance of specific virulence factors for the development of streptococcal endocarditis. METHODS: Twenty-eight previously identified and 10 new streptococcal isolates from infective endocarditis were classified according to Kilian et al (1989) and compared to 30 streptococcal isolates from the oral cavities of periodontal patients without endocarditis. Subsequently, surface hydrophobicity was assessed by hydrophobic interaction chromatography, production of extracellular dextran was determined by precipitation, and non-specific proteolytic activity was evaluated by determination of hydrolysis of gelatin, and casein-precipitating activity. RESULTS: Eight streptococcal species were represented in the endocarditis isolates. Most strains were highly hydrophobic and none showed non-specific proteolytic activity. Dextran was produced with similar frequency in endocarditis and non-endocarditis isolates. CONCLUSIONS: The present study showed that infective endocarditis may be caused by a variety of oral streptococcal species. The possible virulence factors investigated were found in the same proportions in endocarditis and non-endocarditis isolates, and thus did not seem to be crucial for development of endocarditis.
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PMID:Current status of taxonomic groups of oral streptococci in endocarditis. Can virulence factors discriminate between endocarditis and non-endocarditis strains? 1185 21