Intro to Microbiology Flashcards
List infecting agents
- Bacteria
- Viruses
- Fungi
- Parasites
- Prions
List sterile sites
- Blood
- CSF
- Lung
- Bladder
List non-sterile sites
- Skin
- Nasophaynx
- Urethra
- Gut
What makes a site sterile?
Internal sites which has no organisms associated with it
Any organisms found in sterile sites indicates that there is a problem
What makes a site non-sterile?
An external site with a variety of organism associated with it
What specimen would be required for a chest infection?
Sputum
What specimen would be required for a UTI?
Mid-stream urine (MSU)
What specimen would be required for tonsillitis/pharyngitis?
Throat swab
What specimen would be required for a wound or site of infection?
Swan or pus
What specimen would be required for bacteraemia?
Blood culture
What specimen would be required for meningitis?
CSF
What types of microscopy if there?
- Light
- Unstained (for pus and parasites)
- Stained (bacteria and fungi)
- ZN stain or auramine stain - mycobacteria
- Virus not visible
Describe gram stain
- Rapid
- Not sensitive
- Can’t identify particular species
Describe bacterial culture
- Slow
- Sensitive
- Culture conditions must be suitable for expected species - type of media, atmosphere, temp, duration of incubation
What are the different types of media?
- Non-selective: blood, chocolates - Specialised - for mycobacteria
- Selective - MacConkey
How to ID species
- Use observable characters; morphological, physiological, biochemical
- DNA based tests
- Typing distinguishes strains within a species
How to diagnose viral infections
- PCR
- Antigen detection
- Serology to determine immunity
Diagnostic principle in parasitology
- Microscopy of different stages
- Parasites, cyst, ova in faeces
- Blood films for malaria
- Culture rarely possible
- Serology
List healthcare acquired infections
- Methicillin resistant staph aureus (MRSA)
- Clostridium difficile
- Organisms with B-lactamases (ESBLs)
- Noroviruses
List way to carry out infection control
-Wash hands before touching patients and between patients
Swab stethoscope between patients
-Patients isolated in single room or have extra precautions
