What are the characteristics of Staphylococcus and streptococcus?
Staphylococci and Streptococci are grouped as Gram-positive cocci. Staphylococci form clumps, whereas Streptococci grow in chains. They can be discriminated by catalase test because Staphylococci have the capability to produce catalase .
What are the distinctive characteristics of Staphylococcus aureus?
S. aureus is an aerobic and facultative anaerobic organism that forms fairly large yellow or white colonies on nutrient rich agar media. The yellow colour of the colonies is imparted by carotenoids produced by the organism.
How do you identify staphylococci?
Coagulase testing is the single most reliable method for identifying Staphylococcus aureus . Coagulase production can be detected using either the slide coagulase test (SCT) or the tube coagulase test (TCT).
What are the characteristics of Staphylococcus epidermidis?
Staphylococcus 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 one feature that differentiates Staphylococcus aureus from other species of staphylococci?
S. aureus is differentiated from other staphylococci by the coagulase test. However it is now known that not all S. aureus are coagulase positive and not all coagulase positive staphylococci are S.
What is the shape of staphylococci?
Staphylococci are spherical organisms that divide sequentially in three orthogonal planes over three consecutive division cycles1,2. This mode of division is less common in bacterial cells than equatorial division, observed in many genera.
What are the 5 characteristics of pathogenic S. aureus?
aureus expresses many potential virulence factors: (1) surface proteins that promote colonization of host tissues; (2) invasins that promote bacterial spread in tissues (leukocidin, kinases, hyaluronidase); (3) surface factors that inhibit phagocytic engulfment (capsule, Protein A); (4) biochemical properties that …
What are the three major species of Staphylococcus?
There are five species of staphylococci commonly associated with clinical infections: Staphylococcus aureus, S. epidermidis, S. haemolyticus, S. hominis and S.
What characteristics distinguish Staphylococcus species from most other species?
Biochemical identification Staphylococcus species can be differentiated from other aerobic and facultative anaerobic, Gram-positive cocci by several simple tests. Staphylococcus species are facultative anaerobes (capable of growth both aerobically and anaerobically). All species grow in the presence of bile salts.
What is the texture of Staphylococcus epidermidis?
S. epidermidis is a very hardy microorganism, consisting of non-motile, 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 haemolytic on blood agar.
Which of the following characteristics distinguish the Archaea from the bacteria?
Cell walls: virtually all bacteria contain peptidoglycan in their cell walls; however, archaea and eukaryotes lack peptidoglycan. Various types of cell walls exist in the archaea. Therefore, the absence or presence of peptidoglycan is a distinguishing feature between the archaea and bacteria.
Why is catalase useful for the differentiation of staphylococci from streptococci?
The catalase test is a particularly important test used to determine whether the Gram + cocci is a staphylococci or a streptococci. Catalase is an enzyme that converts hydrogen peroxide to water and oxygen gas.