What is the morphology of Streptococcus?
Morphology: Spherical, ovoid, or cocci shaped. Often occur in pairs or chains when grown in liquid media.
What does Streptococcus agalactiae look like?
Streptococcus agalactiae is a gram-positive coccus that, when cultured on sheep blood agar, forms glistening gray-white colonies with a narrow zone of β hemolysis. It is an invasive encapsulated organism capable of producing severe disease in immunocompromised hosts.
Is Streptococcus agalactiae Gram-positive or negative?
Gram-positive
Group B Streptococci (GBS), or Streptococcus agalactiae, is the most common cause of life-threatening bacterial infection in human newborns. These bacteria are Gram-positive, β-hemolytic, chain-forming cocci that are normal residents of the vaginal flora in 25% of healthy women [3].
What biochemical property is unique to Streptococcus agalactiae?
Biochemical Test and Identification of Streptococcus agalactiae
| Basic Characteristics | Properties (Streptococcus agalactiae) |
|---|---|
| Hemolysis | Beta Hemolysis |
| Motility | Non-motile |
| OF (Oxidative-Fermentative) | Facultative anaerobes |
| Oxidase | Negative (-ve) |
What is the colony morphology of Streptococcus pyogenes?
pyogenes colonies after 24 hours of incubation at 35-37°C is dome-shaped with a smooth or moist surface and clear margins. They display a white-greyish color and have a diameter of > 0.5 mm, and are surrounded by a zone of β-hemolysis that is often two to four times as large as the colony diameter.
What is the morphology of Streptococcus mutans?
Cell structure and metabolism Streptococcus mutans is a Gram-positive bacteria, has a thick cell wall, and retains a gentian violet. The cell wall is composed of peptidoglycan (murein) and teichoic acids that prevent osmotic lysis of cell protoplast and confer rigidity and shape on cell. S.
What is the morphology of Streptococcus pneumoniae?
Streptococcus pneumoniae cells are Gram-positive, lancet-shaped cocci (elongated cocci with a slightly pointed outer curvature). Usually, they are seen as pairs of cocci (diplococci), but they may also occur singly and in short chains.
How do you differentiate Streptococcus pyogenes and Streptococcus agalactiae?
This test is commonly used to distinguish between the b-hemolytic streptococci: Streptococcus agalactiae (bacitracin resistant) and Streptococcus pyogenes (bacitracin sensitive). The plate below was streaked with Streptococcus pyogenes; notice the large zone of inhibition surrounding the disk.
Which morphological property is characteristic of streptococci?
Morphology. Streptococci are coccoid bacterial cells microscopically, and stain purple (Gram-positive) when Gram staining technique is applied. They are nonmotile and non-spore forming.
How are Streptococcus mutans arranged?
mutans is characteristic of all Streptococci as the cells are arranged in pairs or as short- to medium-length chains. This arrangement is due to the presence of successive division planes that are parallel to one another as in rod-shaped bacteria.
How does Streptococcus look under a microscope?
With regards to shape, Streptococci may appear spherical or ovoid in shape. When viewed under the microscope, Streptococci occur in chains (resembling a string of beads) or in pairs. As is the case with other bacteria, the general shape of Streptococci is maintained by the manner in which they propagate.
Which of the following would best differentiate Streptococcus agalactiae from Streptococcus pyogenes?
118. Which of the following would best differentiate Streptococcus agalactiae from Streptococcus pyogenes? Hydrolysis of sodium hippurate, agalactiae is + and pyogenes -. 119.
What is the characteristic appearance of Streptococcus in culture?
CULTURAL CHARACTERISTICS OF STREPTOCOCCUS PYOGENES
| Cultural Characteristics | NAM (Nutrient Agar Medium |
|---|---|
| Elevation | Low Convex – convex |
| Surface | Matt (in Virulent strains) ; Glossy (In Non-Virulent Strains) ; mucoid (in case of Capsule production) |
| Color | Light yellow |
| Structure | Semi-Transparent – Opaque |
What is Streptococcus mutans shape?
The bacterium Streptococcus mutans is an example of a spherical (coccus) bacterium. This species of bacteria commonly aggregates into pairs and short chains.
What is the shape and arrangement of Streptococcus bacteria?
So far as the arrangement is concerned, it may Paired (diplo), Grape-like clusters (staphylo) or Chains (strepto). In shape they may principally be Rods (bacilli), Spheres (cocci), and Spirals (spirillum).
What shapes Streptococcus and Lactobacillus have?
Lactobacillus delbrueckii are rod with rounded ends shape, but Streptococcus thermophilus has a spherical to ovoid shape with an irregular segments (6). Both are Gram-positive, facultative anaerobic, non-motile and non-spore-forming bacteria (7).
What does Streptococcus look like under a microscope?
Under a microscope, streptococcus bacteria look like a twisted bunch of round berries. Illnesses caused by streptococcus include strep throat, strep pneumonia, scarlet fever, rheumatic fever (and rheumatic heart valve damage), glomerulonephritis, the skin disorder erysipelas, and PANDAS. Familiarly known as strep.