Catalase Positive GPCs (Parts I and II) Flashcards
What are the three genera of catalase positive GPCs?
Staphylococcus, Micrococcus and Rothia
What are the purposes of Mannitol salt and CNA agars?
CNA selects GP and used with normal flora, Salt selects Staphylococcus and turns yellow with S. Aureus used for outbreaks
What are small colony variants?
Resistant and relapsing infections (may be resistant to antimicrobials.
What organism turns yellow on mannitol salt?
Staphylococcus aureus
What organism is large, opaque, white and usually gamma?
Coagulase negative Staph
What organism is large opaque, golden and Beta?
Staphylococcus Aureus
What type of plate is a catalase preformed on? Why?
Trypticase Soy, Blood gives false pos.
What are two types of coagulase test? Their reagents? how are they preformed?
Slide then tube, both use rabbit/human plasma but Slide reacts with clumping and Tube looks for staphylocoagulase
What organism can give a false positive to slide coagulase?
S. Lugdunensis
How does S. Lugdunensis react on slide and tube coagulase tests?
False pos and Neg respectively
How does lysostaphin work?
Lyses Staphylococcus
What test identifies S. Aureus?
Tube coagulase is Pos
What test identifies S. Epidermis and S. Saprophyticus
Novo susceptible is S. Epidermis.; S. Saprophyticus is Novo Resistant.
What bacteria is Sticky yellow colonies and is a strict aerobe (not facultative)?
Micrococcus
How does micrococcus react with glucose in OF glucose test?
Oxidizer or non-oxidizer of glucose
What are the patient symptoms and conditions that define toxic shock syndrome?
Fever, rash, desquamation, shock, DIC
What virulent factor is the main factor for S. Aureus?
Protein A
What is the function on catalase?
Inactivates H2O2
What is the the prothrombin like clotting substance?
Coagulase
MRSA, MSSA, VISA, VRSA
Methicillin resistant, Penecillin susceptible, Vancomycin intermediate, Vancomycin resistant
Compare and contrast hospital acquired MRSA and community acquired MRSA.
Healthcare is highly resistant and requires isolation. Community is not typically as bad and is usually just skin infections of otherwise healthy people.
What is the process of screening patients for MRSA?
Oxacillin screening plate or PCR
What is the precess of screening colonies for MRSA?
Cefoxitin disk tests predicts Oxacillin resistance.
What is the best way to reduced infections?
Handwashing
What special result does HACO-MRSA have?
requires specialized testing parameters, Increased time and NaCl.
What is the term for an infection that looks like a spider bite?
Carbuncle
What bacteria is associated with dog bites?
Coagulates + in the tube, staphylococcus intermedius
What are coagulate negative staphylococcus?
S, Epidermidis and S. Saprophyticus
How do you tell the difference of S. Epidermidis and S. Saprophticus? What do they cause?
Saptophyticus is resistant to Novobiocin, and causes urinary tract infections in young females. Epidermidis has biofilm production, is slimy and is the leading cause of endocarditis.
How are lugdunensis and aurus confused? How do you differentiate?
They are both slide positive, however, only Lugdunensis is tube negative.
What bacteria is furazolidone resistant and lysotaphin resistant?
Micrococcus
What bacteria has beta hemolysis and is yellow?
Micrococcus
What bacteria causes toxic shock syndrome?
Aureus
What bacteria causes food poisoning?
Aureus
What toxin leads to scaled skin syndrome? What bacteria is it from?
Exfoliatin; Aureus
What catalase positive GPC will be oxidizers or non oxidizers when tested in OF glucose media?
Micrococcus
What disc prevents oxacillin resistance?
Cefoxitin
Review chart on GPC for test results to differentiate staph and micrococcus.
Review
