What is the shape and morphology of a Staphylococcus bacteria?
S. aureus cells are Gram-positive and appear in spherical shape. They are often in clusters resembling bunch of grapes when observed under light microscope after Gram staining. The name ‘Staphylococcus’ was derived from Greek, meaning bunch of grapes ( staphyle ) and berry ( kokkos ) [1].
What are the cellular morphology of Staphylococcus?
Structure. Staphylococci are Gram-positive cocci about 0.5 – 1.0 μm in diameter. They grow in clusters, pairs and occasionally in short chains. The clusters arise because staphylococci divide in two planes.
Is Staphylococcus epidermidis Gram-positive or Gram negative?
Staphylococcus epidermidis which is known as a coagulase-negative and Gram-positive Staphylococcus, is one of the five significant microorganisms that are located on human skin and mucosal surfaces with the ability of causing nosocomial infections due to the wide usage of medical implants and devices, hence until 1980 …
What is the Gram reaction and shape of Staphylococcus?
Staphylococcus aureus bacteria are pathogens to both man and other mammals. They are gram positive bacteria that are small round in shape (cocci) and occur as clusters appearing like a bunch of grapes on electron microscopy.
What is the morphology of Staphylococcus epidermidis?
Cellular morphology and biochemistry S. epidermidis is a very hardy microorganism, consisting of nonmotile, Gram-positive cocci, arranged in grape-like clusters. It forms white, raised, cohesive colonies about 1–2 mm in diameter after overnight incubation, and is not hemolytic on blood agar.
What is the colony morphology of Staphylococcus?
S. aureus – individual colonies on agar are round, convex, and 1-4 mm in diameter with a sharp border. On blood agar plates, colonies of Staphylococcus aureus are frequently surrounded by zones of clear beta-hemolysis.
What color is gram-positive?
The staining method uses crystal violet dye, which is retained by the thick peptidoglycan cell wall found in gram-positive organisms. This reaction gives gram-positive organisms a blue color when viewed under a microscope.
What Gram stain is Staphylococcus epidermidis?
5.1 Staphylococcus epidermidis. S. epidermidis is a gram-positive bacterium. Its cell wall teichoic acid is formed by polymerized glycerol, glucose, and N-acetyl glucosamine.
What is the gram reaction of Staphylococcus aureus?
Staphylococci are gram-positive aerobic organisms. Staphylococcus aureus is the most pathogenic; it typically causes skin infections and sometimes pneumonia, endocarditis, and osteomyelitis. It commonly leads to abscess formation.
What color should be seen when viewing a gram stain of Staphylococcus epidermidis?
purple
epidermidis stained purple and were classified as Gram-positive. It was determined that E. coli likely stained pink due to having it’s cell walls composed of less peptidoglycan than B. subtilis and S.
What is difference between gram-positive and negative?
Difference in structure of Gram positive vs Gram negative bacteria. Gram positive bacteria have a thick peptidoglycan layer and no outer lipid membrane whilst Gram negative bacteria have a thin peptidoglycan layer and have an outer lipid membrane.
What is the morphology of the Staphylococcus epidermidis?
Coccus is the morphological description used to describe the spherical shape of Staphylococcus epidermidis, explains the National Center for Biotechnology Information. Bacterial morphology is used to designate the shape of bacteria, according to the American Society for Microbiology.
Why are Gram stain reactions different for different bacteria?
One factor that may have influenced the Gram Stain is the time a bacterial cell needs for the stain to bind. First, because cell wall structures and components are variable from bacteria to bacteria, the amount of time needed for a staining solution to bind to the cell wall may be different.
What is the Gram positive reaction color of E coli?
The E. coli had a Gram Stain reaction color of pink and classified as Gram-negative. Both the S. epidermidis and B. subtilis had a Gram Stain reaction color of purple and then classified as Gram-positive (Table 1).
Can a Staphylococcus epidermidis infection cause meningitis?
As a post-surgical complication, Staphylococcus epidermidis can also spread through the blood stream and cause meningitis. This type of infection can also occur in patients with infections of heart valves, a previous history of meningitis, trauma and past brain infections, according to MedlinePlus.