What is the shape of Streptococcus Viridans?
Difference between S. pneumoniae and Viridans Streptococci
| S.N. | Characteristics | Viridans Streptococci |
|---|---|---|
| 1. | Morphology | Oval or round cells in chain |
| 2. | Capsule | Non-capsulated |
| 3. | Quellung Test | Negative |
| 4. | Bile solubility | Bile insoluble |
What are the properties of Streptococcus?
Streptococci are Gram-positive, nonmotile, nonsporeforming, catalase-negative cocci that occur in pairs or chains. Older cultures may lose their Gram-positive character. Most streptococci are facultative anaerobes, and some are obligate (strict) anaerobes. Most require enriched media (blood agar).
What are examples of viridans streptococci?
Streptococcus mitis
Streptococcus sanguinisStreptococcus oralisStreptococcus mutansStreptococcus sobrinus
Viridans streptococci/Representative species
How can you tell the difference between Streptococcus pneumoniae and Viridans?
A green, α-hemolytic, zone surrounds S. pneumoniae colonies on blood-agar plates. Pneumococci can be differentiated from other catalase-negative viridans streptococci by their susceptibility to Optochin and solubility in bile salts.
Is Streptococcus Viridans aerobic or anaerobic?
Microbiology. Viridans streptococci possess the general characteristics common to all streptococci (see Chapter 198). They are facultatively anaerobic, gram-positive cocci that do not produce catalase or coagulase.
What causes streptococcus Viridans?
Among the factors that predispose to development of viridans streptococcal sepsis are: profound neutropenia; mucositis, especially oral mucositis; cytarabine (Ara-C) therapy, which seems to have an effect beyond its association with mucositis; young age; and trimethoprim-sulphamethoxazole or quinolone administration.
Is strep Viridans normal flora?
Viridans streptococci are part of the normal microbial flora of humans [2]. In the past, the terminology applied to the viridans group of streptococci was confusing and inconsistent, and recovered species were often identified as “nonhemolytic” or “α-hemolytic,” rather than by a specific species designation.
What is the classification of streptococcus?
Streptococcus is a genus of gram-positive coccus (plural cocci) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Firmicutes.
Is strep viridans coagulase negative?
Is Streptococcus pneumoniae in the viridans group?
Streptococcus pneumoniae is a major cause of bacterial disease in humans, including pneumonia, otitis media, septicemia, and meningitis. Two naturally transformable viridans group streptococci, Streptococcus mitis and Streptococcus oralis, are closely related to S.
Is strep viridans group A strep?
In the medical setting, the most important groups are the alpha-hemolytic streptococci S. pneumoniae and Streptococcus viridans group, and the beta-hemolytic streptococci of Lancefield groups A and B (also known as “group A strep” and “group B strep”).