In vitro studies of haemolysis by some staphylococci grown in chemically defined media
Autor: | R. J. Stretton, W.G. Salt, S. Jassim |
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Rok vydání: | 1989 |
Předmět: |
Staphylococcus aureus
Hemolysin Biology medicine.disease_cause biology.organism_classification Haemolysis medicine.disease Applied Microbiology and Biotechnology Microbiology Hemolysis Culture Media Chemically defined medium chemistry.chemical_compound Hemolysin Proteins chemistry Staphylococcus epidermidis medicine Brain heart infusion Amino Acids Whole blood |
Zdroj: | The Journal of applied bacteriology. 67(5) |
ISSN: | 0021-8847 |
Popis: | Staphylococcus aureus (five strains) and Staph. epidermidis (one strain) have been evaluated for comparative growth and haemolysin titre in both brain heart infusion (BHI) and in developed, nutritionally adequate, chemically defined media (CDMs) varying only in amino acid composition. The ability to show a particular haemolytic profile was strain-dependent and the haemolytic titre (HU50/ml) was both strain- and medium-dependent. Highest titres of both alpha and beta type haemolysins were obtained in BHI. Maximum titres were in general detected in the late exponential phase in both CDMs and BHI. Titres declined during the stationary phase in CDMs. Staphylococcus epidermidis produced a delta-type haemolysis profile on BHI-based blood agars, but only rabbit blood was sensitive in agars based on a developed, chemically defined medium (CDM/A; 13 amino acids) in which all six staphylococci grew. The addition of yeast extract to CDM/A increased alpha haemolysin titre, but suppressed beta haemolysin formation; beta haemolysin was, however, detected in yeast extract/phosphate-buffered saline. Strain Wood 46 degraded haemoglobin, but only in (initially) whole blood; red blood cell-free haemoglobin-rich plates (BHI) were unaffected during growth. A novel haemolytic profile is described for Staph. aureus NCTC 8532 growing on blood agars based on CDM/A and may relate to the production of methaemoglobin during haemolysis. |
Databáze: | OpenAIRE |
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