Staphylococcus spp. Flashcards
Lecture 5
What are the characteristic of the Staph species?
gram-positive cocci in “grape-like clusters”, normal microbiome of skin/mucous membranes/feces, facultative anaerobes, tolerate high salt concentrations, non-motile, non-spore forming, catalase positive
What does Staphylococcus aureus look like in a culture?
it is white at first but then the colony will turn yellow or golden
Where is Staphylococcus aureus found?
the skin, nose, axillae, and groin
What is the virulence of Staphylococcus aureus?
it is of high virulence; it has coagulase to prevent phagocytosis, leukocidins that kill neutrophils, enterotoxins that cause nausea/vomiting/abdominal cramps/diarrhea, lipases that allow it to spread, and HEMOLYSINS
What diseases does Staphylococcus aureus cause?
Skin infections (pimples, impetigo, furuncles, carbuncles, abscesses, cellulitis, and scalded-skin syndrome in infants), osteomyelitis, pneumonia, food poisoning, gastroenteritis, toxic shock syndrome
Osteomyelitis
inflammation of the bone
Toxic shock syndrome
associated with females typically at time of menstration, causes shock, vomiting, diarrhea, diffuse rash, and peeling on palms and can result in death
Where is Staphylococcus epidermidis found?
the skin of most people
What is the virulence level of Staphylococcus epidermidis?
it is of low virulence
What diseases can Staphylococcus epidermidis cause?
endocarditis, prosthetic infections, intravenous site infections
Endocarditis
heart valves become infected
Where do we commonly see Staphylococcus saprophyticus?
we see it in urinary tract infections in young, sexually active females
How can we identify Staphylococcus spp?
when we see gram-positive cocci in grape-like clusters
What are the test results for Staphylococcus aureus?
Gram-stain: +
Catalase: +
Latex agglutination test: +
What are the test results for Staphylococcus epidermidis?
Gram-stain: +
Catalase: -
Latex agglutination test: -
