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Uracil and pyruvate requirements of anaerobic growth of staphylococci
Abstract:
Sixty-six strains of staphylococci recently isolated from human skin and identified as members of the three recognized species of staphylococci, and 21 stock strains representing most of the Baird-Parker subgroups of staphylococci and micrococci were studied. All 16 skin strains of Staphylococcus aureus demonstrated weak to moderate anaerobic growth in the basal medium, growth stimulation by either uracil or pyruvate, and best growth when both were added. The 20 skin strains of S. epidermidis responded similarly to S. aureus but with a tendency toward heavier growth. The 28 isolates of S. saprophyticus generally gave little or no growth in the basal medium, no increase due to pyruvate alone, a weak response to uracil alone, and, with three exceptions, gave moderate to good growth when both supplements were present. The Baird-Parker strains from subgroups S-II and S-III responded like S. epidermidis; those from subgroups S-V, S-VI, M-1, M-2, M-3, and M-6 generally responded like S. saprophyticus; and those from subgroups M-4 and M-5 failed to grow anaerobically in all media.
Insights
Staphylococcus aureus, S. epidermidis, and S. saprophyticus exhibit distinct anaerobic growth patterns influenced by uracil and pyruvate. Supplementation with both nutrients enhances growth, particularly in S. saprophyticus.
Area of Science:
- Microbiology
- Bacteriology
Background:
- Staphylococci are common skin bacteria with diverse metabolic capabilities.
- Understanding their anaerobic growth requirements is crucial for identification and clinical relevance.
Purpose of the Study:
- To investigate the anaerobic growth characteristics of human skin-isolated staphylococci and stock strains.
- To determine the differential effects of uracil and pyruvate supplementation on staphylococcal anaerobic growth.
Main Methods:
- Culturing of 66 human skin-isolated staphylococci (Staphylococcus aureus, S. epidermidis, S. saprophyticus) and 21 stock strains under anaerobic conditions.
- Assessing growth in basal medium with and without uracil and/or pyruvate supplementation.
Main Results:
- Staphylococcus aureus strains showed weak to moderate anaerobic growth, stimulated by uracil and pyruvate.
- S. epidermidis strains exhibited similar but heavier growth responses.
- S. saprophyticus strains generally required both uracil and pyruvate for moderate to good anaerobic growth, with some exceptions.
Conclusions:
- Anaerobic growth requirements, specifically the need for uracil and pyruvate, can differentiate staphylococcal species.
- These metabolic insights aid in the characterization and identification of staphylococci from clinical samples.