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Several staphylococcal species express a synergistic activity which potentiates hemolysis by beta-hemolysin. In Staphylococcus aureus, this activity is mediated by the delta-hemolysin, coded by the hld gene within the agr locus. In S. lugdunensis, the equivalent activity results from the production of 3 small peptides coded by an operon named slush, distinct from hld and located outside the agr region. We examined 15 clinically relevant staphylococcal species for the presence of hld, slush and agr by specific hybridisation. All species contained a recognizable agr-related locus. Three species never produced synergistic haemolysis and contained neither hld nor slush. Of the 12 producer strains, 5 contained hld, apparently within the agr region, 4 contained slush and one (S. caprae) contained both. Two other producer species (S. hominis and S. simulans) hybridised to neither probe.

A rapid polymerase chain reaction method was developed to differentiate Staphylococcus pasteuri from other staphylococcal species, especially the phenotypically similar S. warneri. The oligonucleotide probes used as primers were designed from the sequence of a S. pasteuri random amplified polymorphic DNA fragment.

Streptococci remain the bacterial group the most frequently associated with microbial endocarditis. This paper points out the ability of the different species to cause endocarditis. 128 streptococci are isolated from patients with microbial endocarditis (127 from blood cultures, 1 from a valve). Isolates are speciated by biochemical tests and the determination of their group antigen. The viridans streptococci most frequently isolated are S. sanguis I (27 p. cent), S. mitis (16,5 p. cent) and S. sanguis II (9,6 p cent). A comparative survey of the results is rather difficult due to the methodological and taxonomical divergences.

Staphylococcus aureus, strain Cowan I, is cultivated in the presence of povidone iodine (PVP.I) at the concentration of 0, 640, 960 micrograms/ml; growth curves points are platted (OD 640 mm) at 0, 1, 2.50, 3, 4.50, 7 and 24 hours. Growth curves in the presence of povidone alone as well as in the standard without antiseptic are similar and reproducible. A bacteriostatic effect is observed with 640 micrograms/ml PVP.I concentration compared to an incomplete bactericidal effect with 960 micrograms/ml concentration. Proteinee A detected by conditioned hemagglutination method is present in the centrifugation pellet of the standard and only in the supernatant of the test samples during the early phases of the growth. Production of alpha-ribitol-teichoic acid detected by counterimmunoelectrophoresis is not significantly different in the standard and in the presence of antiseptic. Biochemical characteristics studied by Api Staph gallery are identical for the control strain and the strain grown in the presence of PVP.I. Observed by scanning and transmission electronic microscope the bacterial cells do not present structural modification during growth with PVP.I.

Streptococci remain the bacterial group the most frequently associated with microbial endocarditis. This paper points out the ability of the different species to cause endocarditis. 128 streptococci are isolated from patients with microbial endocarditis (127 from blood cultures, 1 from a valve). Isolates are speciated by biochemical tests and the determination of their group antigen. The viridans streptococci most frequently isolated are S. sanguis I (27 p. cent), S. mitis (16.5 p. cent) and S. sanguis II (9.6 p cent). A comparative survey of the results is rather difficult due to the methodological and taxonomical divergences.