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Staphylococcus epidermidis is a Gram-positive bacterium, and one of over 40 species belonging to the genus Staphylococcus. [1] It is part of the normal human microbiota, typically the skin microbiota, and less commonly the mucosal microbiota and also found in marine sponges. [2] [3] It is a facultative anaerobic bacteria.
A fibrin clot formed in a test tube by the coagulase reaction. The tube test uses rabbit plasma that has been inoculated with a staphylococcal colony (i.e., Gram-positive cocci which are catalase positive). The tube is then incubated at 37 °C for 1.5 hours. If negative, then incubation is continued up to 18 hours.
Lancefield grouping is a system of classification that classifies catalase-negative Gram-positive cocci based on the carbohydrate composition of bacterial antigens found on their cell walls. [1]
S. aureus is catalase-positive (meaning that it can produce the enzyme catalase) and able to convert hydrogen peroxide (H 2 O 2) to water and oxygen, which makes the catalase test useful to distinguish staphylococci from enterococci and streptococci. S. pseudintermedius inhabits and sometimes infects the skin of domestic dogs and cats. This ...
SSSS is a clinical diagnosis. This is sometimes confirmed by isolation of S. aureus from blood, mucous membranes, or skin biopsy; however, these are often negative. Skin biopsy may show separation of the superficial layer of the epidermis (intraepidermal separation), differentiating SSSS from TEN, wherein the separation occurs at the dermo-epidermal junction (subepidermal separation).
S. epidermidis, a coagulase-negative staphylococcus species, is a commensal of the skin, but can cause severe infections in immune-suppressed patients and those with central venous catheters. S. saprophyticus , another coagulase -negative species that is part of the normal vaginal flora , is predominantly implicated in uncomplicated lower ...
For example, if a microbiologist observes colonies that resemble a Staphylococcus species, they may perform a catalase test to confirm that it belongs to the genus Staphylococcus, and a coagulase test to determine whether it is a coagulase-negative staphylococcus or a more pathogenic species, such as S. aureus. [3]: 101 [8]: 203
The main criterion for differentiation between Staphylococcus spp. and Streptococcus spp. is the catalase test. Staphylococci are catalase positive whereas streptococci are catalase-negative. [2] S. pyogenes can be cultured on fresh blood agar plates.