Microbiology Final Exam Review

Susceptibility

100

Antibiotics that are destructive to both gram positive and negative bacteria

Broad Spectrum 

200

Antibiotics that are destructive to both gram positive and negative bacteria

Antagonism

300

Confirmatory Test of ESBL

Keyhole Formation Around Clavulanic Containing Disk and Cephalosporin Disk

400

Confirmation test for CRE

Modified Hodge with Carbapenem disk: imipenem, ertapenem or meropenem

500

Test for inducible resistance to clindamycin

D- zone: used for beta hemolytic streptococci and streptococci pneumoniae

Staphylococcus and Streptococcus

100

What differentiates Micrococcus from Staphylococcus?

Micrococcus: Gram stain in tetrads, yellow colony, Bacitracin susceptible, Oxidase positive

Staphylococcus: Gram stain clusters, beta hemolytic colony, Bacitracin resistant, Oxidase negative

200

What does tube coagulase detect?

free or unbound coagulase (Staphylococcus aureus)

300

Protein A

virulence factor in S. aureus: ability to bind the Fc portion of IgG which can block phagocytosis

400

What reagent/biochemical is needed to grow Nutritionally Variant Streptococcus species like Abiotrophia and Granulicatella invitro?

Pyridoxal hydrochloride

500

What screening test shows the most accurate expression of the MecA gene in MRSA?

Cefoxitin screen: better inducer for the MecA gene compared to Oxacillin

Introduction

100

Safranin

The counterstain in the Gram stain process

200

Mannitol salt agar and MacConkey agar are examples of what type of media?

Differential (Mac is both selective and differential)

300

What is the optimal temperature for Mesophiles?

 20-40⁰C

400

What is a example of a reason to reject patient samples?

Sputum sample reveals ≥10 epithelial cells per low power field

500

What is the appropriate collection of blood cultures?

•Aerobic and anaerobic bottle

•Adults – 20ml per set

•Children – 5-10 ml per set

Clinical symptoms/diseases

100

Boutonneuse Fever

Caused by R. canorii

200

Ophthalmia neonatorum

N. gonorrhoeae

300

Ritter’s disease

S. aureus

400

Brill-Zinsser disease

Caused by R. prowazekii

500

Endocarditis (Streptococcus pathogen)

Grp D: S. bovis group (gallolyticus)

Blood cultures

100

Occurs after procedural manipulation of a particular body site colonized by indigenous flora

Intermittent bacteremia

200

•Fever (> 38.3°C)

•Tachypnea (> 20 breaths/min)

•Tachycardia (>90 beats/min)

•At least one symptom of inadequate organ perfusion or dysfunction

Symptoms of septicemia

300

How many blood culture sets are drawn in a 24 hour period to rule out septicemia?

2-3, more than 3 does no good

400

What is the standard number of days for incubation of negative blood cultures with continuously monitored system?

5

500

What are some Gram-negative organisms responsible for sepsis?

Pseudomonas and Enterobacteriaceae