title: Molecular analysis of viridans and nutritionally deficient (variant) streptococci causing sequential episodes of endocarditis in a patient.
abstract: Clinical blood isolates from sequential episodes of endocarditis occurring over a six-month period of time in an addict were investigated. The pathogens were Streptococcus sanguis II, Streptococcus mitis, and a nutritionally deficient (variant) streptococcus. The authors determined the DNA relatedness of these isolates by antibiograms, plasmid profiles, chromosomal endonuclease restriction digestions, and dot blot DNA-DNA hybridization analyses. The S. sanguis II and nutritionally deficient streptococcal strain had similar antibiograms being resistant to penicillin; neither produced beta-lactamase. No plasmids were found. The restriction endonuclease chromosomal digestion patterns of these isolates were unique and epidemiologically unrelated to each other. Dot blot DNA-DNA hybridizations, using the nutritionally deficient streptococcal DNA as the probe, showed homology to the preceding clinical isolates, S. sanguis II and S. mitis, at 15.4% and 45.1% hybridization levels, respectively. The nutritionally deficient streptococcus was only 4.2% homologous to a S. mitis ATCC strain and another nutritionally deficient streptococci isolate. Therefore, this patient had endocarditis with three distinct streptococcal strains.
authors.affiliation: Department of Medicine, Loyola University Stritch School of Medicine, Maywood, Illinois.
authors.forename: D S
authors.initials: DS
authors.lastname: Stein
authors.forename: C R
authors.initials: CR
authors.lastname: Libertin
mesh_terms: D000328:Adult; D004247:DNA / Q000032:analysis / Q000235:genetics; D004697:Endocarditis, Bacterial / Q000209:etiology* / Q000473:pathology; D005260:Female; D014644:Genetic Variation; D006801:Humans; D009693:Nucleic Acid Hybridization; D013290:Streptococcal Infections; D013291:Streptococcus / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004247:DNA