Search results
Results From The WOW.Com Content Network
A negative coagulase test would instead show the presence of coagulase-negative organisms such as S. epidermidis or S. saprophyticus. However, it is now known that not all S. aureus are coagulase-positive. [2] [3] Whereas coagulase-positive staphylococci are usually pathogenic, coagulase-negative staphylococci are more often associated with ...
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.
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 ...
The catalase test is done by placing a drop of hydrogen peroxide on a microscope slide. An applicator stick is touched to the colony, and the tip is then smeared onto the hydrogen peroxide drop. If the mixture produces bubbles or froth, the organism is said to be 'catalase-positive'. Staphylococci [47] and Micrococci [48] are
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
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 ...
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.
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]