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Bacteria under Microscope
Enterococcus faecalis
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Gram-stain: |
Gram-positive cocci |
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Microscopic appearance: |
Cocci in clusters, short chains, diplococci and single cocci |
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Clinical significance: |
- Enterococcus faecalisis a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans and other mammals.
- E. faecalis can cause life-threatening infections in humans, especially in the nosocomial (hospital) environment.
- Urinary tract infections (UTI)
- Bacteremia
- Endocarditis
- Meningitis
- E. faecalis is resistant to many commonly used antimicrobial agents.
- VRE (Vancomycin-Resistant Enterococcus)
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Text: Wikipedia |
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Colony morphology: |
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| Enterococcus facalis identification |
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A |
Non-hemolytic (gamma-hemolytic) colonies of Enterococcus faecalis on sheep blood agar. Cultivation 24 hours, aerobic atmosphere, 37°C. |
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B |
Enterococcus faecalis on Bile Esculin Agar (BEA). Members of the genus Enterococcus are capable of growing in the presence of 4% bile and hydrolyzing esculin to glucose and esculetin.
Esculetin combines with ferric ions to produce a black complex visible as black zones around colonies.
Cultivation 24 hours in an aerobic atmosphere, 37°C. |
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C |
Colonies of Enterococcus faecalis cultivated on Columbia agar with 5% defibrinated sheep blood, 24 hours in an aerobic atmosphere, 37°C.
E.faecalis typically exhibits gamma-hemolysis on sheep's blood agar, but some strains are alfa-hemolytic or even beta-hemolytic (a plasmid-encoded hemolysin, called the cytolysin). |
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www.bacteriainphotos.com |
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