Microbiology Flashcards
How do we name bacteria using genus and species?
-Genus:
>Start with capital letter, in italics
-Species:
> No capital letter , in italics
Why do we use Rapid urine analysis?
-Differentiate which urine samples ARE from urinary tract infections
- Sample contains 1x10(5) cfg/ml of bacteria = we perform microscopy/ further culture
-Less we chuck away
What is the common bacterial cause for:
1. Soft tissue infections
2. Urinary tract infections
- *Staphylococcus.aureus
-Group A streptococci
-Pseudomonas aeruginosa
2.
*Uropathogenic Escherichia Coli
-Proteus mirabilis
-Klebsiella pneumoniae
-Enterococcus faecalis
-Staphylococcus saprophyticus
Why do we use gram staining?
-How is the test done?
-First test we get back, helps us choose what antimicrobial to use/change for patient.
Why do we use selective and differential media?
-Selective: Prevent certain organisms growing in the first place
-Differential: Colour changes in colonies to tell us about organisms biology
Why we use nutrient agar to culture bacteria?
Why do we use CLED to culture bacteria?
Why do we use Mannitol-salt agar to culture bacteria?
Analyse what these medium results mean?
Why do we use motility testing?
-How do we use it to differentiate between E.coli + Klebsiella
-E.coli is motile
-Klebsiella is non-motile
Why do we use oxidase test?
- All Enterobacterales are
(ox -)
-E.coli
-Klebsiella
-Proteus
Why do we use Catalase test?
Patient 1 : 36 Yr old male
- Cellulitis
-Take aspirate sample
-Staphylococcus aureus
-Flucloxacillin
Patient 2 : 17 Yr old female
-Uncomplicated, community acquired, lower tract urinary infection
-Mid-stream urine sample
-Uropathogenic Escherichia Coli
-Drink water, Oral trimethoprim x3 day course
Patient 3: 22 yr old female
- Urine and blood sample sent to Microbiology
- Pyelonephritis
- Not staphylococcus aureus , maybe saprophyticus
-Send to E.D
Patient 4: 69 yr old man
-Health care acquired complicated upper renal urinary tract infection
-Remove catheter , take sample from first lot of urine from new catheter
-Uropathogenic Escherichia Coli - Staphylococcus aureus?
-Prescribe gentomicin
What is MRSA?
-a type of bacteria that’s resistant to several widely used antibiotics > harder to treat
What bacteria would be found on a sample of healthy skin?
-CONS (Gram positive)
-Enterobacterales
Test yourself with this table
Why do we use blood agar?
-Differentiate bacteria based on their hemolytic properties
-Beta-hemolysin breaks down the red blood cells and hemoglobin completely. This leaves a clear zone around the bacterial growth.
-Alpha-hemolysin partially breaks down the red blood cells and leaves a greenish color behind.
