Diagnostic Microbiology Flashcards
What are the sterile body sites? (4)
- Blood
- CSF
- Vitreous fluid (Eye)
- Joint (Fluid/tissue)
How to do proper swab? (3)
- Clean away superficial debris
- Sample the most representative part
- Deep swab is better (Swab with firm pressure, press into wound to obtain fluid)
What are the types of non-invasive urine sample and which is the most common? (3)
- Mid stream urine (MSU - Most common)
- Clean catch urine
- Catheter specimen urine
Which 2 types of urine sample are sterile?
- kidney aspirate
- supra-pubic (bladder) aspirate
Principles of MSU/CCU? (2)
- Obtain as clean a specimen as possible
- Reduce contamination from urethra and perineal region
How to collect MSU?
- instruct pt to wash hand
- spread labia (female) or pull back foreskin (male)
- collect midstream
Principles of CSU? (2)
- Obtain as “fresh” a specimen as possible
- to reduce contamination from urine in drainage collection bag
How to collect CSU?
(DO NOT collect from the catheter bag as it contains lots of bacteria, collect from tube itself)
- clamp the tubing a few cm from the sampling port
- clean the sampling port
- aspirate required amount
- inject urine into specimen pot
Principles of sputum collection?
- Obtain a specimen from the lungs/Alveoli as far as possible
- Reduce contamination from mouth and throat
How to collect sputum?
- Collect in the morning before breakfast to avoid contamination with food particles
- Rinse with water
- Sit patient up
- Ask the patient to take several deep breaths, breath in through nose and exhale mouth to loosen secretions
- Ask patient to hold breath few seconds and cough into specimen container
What is contamination?
Growing organisms that are not from the intended site culture
What is colonization
Growing organisms that are unlikely to cause infection
What is the turn around time for non-culture test
- Blood test: 1-3 days
- Microscopy: 1-2 days
- PCR: 1-3 days
What is the turn around time for culture test
- Aerobic culture: 2-5 days
- Viral culture: 7-21 days
- TB culture: 10-42 days
What does mixed bacterial growth indicate in microscopy results?
Sample contamination from distal urethra or perineal flora
