Wordsology High Yield Notes - Gram Positive Cocci Flashcards
What two organisms are coagulase positive?
Staph aureus and Staph intermedius
What two types of Gram positive cocci are catalase positive, coagulase negative?
Coagulase negative Staph and Micrococcus
What are characteristics of Gram positive, coagulase positive Staphylococcus?
Staph aureus and Staph intermedius
- Salt tolerant
- Beta hemolytic
- Hyaluronidase
- Enterotoxins –> scalded skin syndrome
- Cause toxic shock syndrome (TSS)
- 50% people have as normal flora
What test(s) differentiate coagulase negative Staphylococcus from Micrococcus?
Oxidase/Microdase (modified oxidase test)
and
Bacitracin/Lysostaphin
Are coagulase-negative Staphylococcus oxidase/microdase positive or negative?
Oxidase/Microdase negative
Are coagulase-negative Staphylococcus bacitracin resistant or susceptible?
Resistant
What is susceptible to and shows a >16mm zone of inhibition to Novobiocin?
Staphylococcus epidermidis
What organism is an opportunistic pathogen and may cause endocarditis if allowed the opportunity to enter surgical wounds?
Staph epidermidis
What organism possesses glycocalyx (capsule/slime layer/biofilm)?
Staph epidermidis
What Gram-positive organism causes UTI in sexually active females?
Staph saprophyticus
Novobiocin is used to differentiate:
Staphylococcus epidermidis (susceptible) from Staphylococcus saprophyticus (resistant)
A gram positive organism is bacitracin susceptible and oxidase positive. What could it be?
Micrococcus
What test would you perform if you saw an alpha-hemolytic streptococcus colony?
Optochin disk to determine if it is Strep pneumo (susecptible).
What organism is lancet shaped in pairs?
Strep pneumoniae
What organism has glistening, wet, domed colonies?
Strep. pneumo
What organism has a quellung reaction (capsular swelling)?
Strep pneumoniae
What virulence factor does Strep pneumoniae have that protects it from phagocytosis?
Polysaccharide capsule
What organism causes otitis media in children?
Strep. pneumoniae
What is the optochin disk zone of inhibition for Strep pneumoniae?
> 14mm
What does Strep. pneumoniae need in order to grow?
CO2
Brain heart infusion agar
TSA
Chocolate agar
What type of organism can be found to be implicated in dental infections?
Strep. viridians
What type of organism can cause subacute endocarditis?
Strep viridians
What organism grows in low O2 and can be found in abscesses of the brain or abdomen?
Strep. anginosus, a type of viridians strep
What type of Strep is Strep. anginosus?
Viridians Strep
What environment can S. anginosus grow in and where is it usually found?
Low O2 environment
Found in abscesses of brain or abdomen
Enterococcus is PRY ____?
Enterococcus is PRY positive.
Group D Strep is PYR _____.
Group D Strep is PYR negative.
Which one can tolerate salt: Enterococcus or Group D Strep?
Enterococcus - can grow in 6.5% NaCl
What is the hemolytic pattern of enterococcus?
Enterococcus can be alpha or beta hemolytic.
What test(s) differentiates Enterococcus from Group D Strep?
PRY and 6.5% NaCl
What organism has Protein A as a virulence factor?
Staph aureus
What is the first test you would perform if you wanted to ID a beta hemolytic Streptococcus?
PRY and Bacitracin
Bacitracin and PYR result for Strep pyogenes:
Bacitracin susceptible, PYR positive
Bacitracin and PYR result for Strep. agalactiae:
Bacitracin resistant and PYR negative
What organism causes Scarlet Fever?
Strep. pyogenes (Group A Strep)
What organism causes Strep throat?
S. pyogenes
What Strep is the only one that is hippurate positive? What indicates a positive hippurate test?
Strep. agalactiae (Group B)
Purple color positive
Is Strep. agalactiae bile positive or negative?
Positive
What organism can cause neonatal sepsis-meningitis?
Group B Strep (can be transmitted to baby)
Group B strep capsule contains what?
Sialic acid
What organism’s capsule is anti-phagocytic and contains sialic acid?
S. agalactiae
