Session 1 Flashcards
How is chickenpox spread?
Airborne transmission
Exotoxin vs endotoxin
Exotoxins are proteins produced inside the bacterium (usually gram positive) which are secreted into the external environment. E.g. enzymes, AB toxins, diphtheria toxin
Endotoxins are the lipopolysaccharides in the outer membrane of gram negative bacteria. They’re released when the bacterium dies
Information needed from the patient with a potential infection? (Patient history)
- Potential exposures
- Symptoms; duration, severity, local/systemic
EXAMINATIONS for potential infections?
Examine for organ dysfunction
- Jaundice > liver dysfunction
INVESTIGATIONS for potential infections?
1) Supportive
- CRP
- FBC
- LFT’s
- Kidney function tests (U & E’s)
- Imaging
- Histopathology
2) Specific
- Bacteriology
- Virology
Disease determinants in patient
Co-morbidities
Site of infection
Disease determinants for pathogen?
Virulence factors
Antibiotic resistance
Inoculum size
Bacteriology?
Take specimen and look for bacteria. - Specimen; tissue, fluids, swabs - MCS microscopy + gram stain culture (bacterial and patient cells) antibiotic sensitivity - Rapid antigen test - Nucleic acid test
Virology?
- Immunohistochemistry for patient antibodies
- look for viral DNA/ RNA
- pathogen antigen
What’s a WBC differential?
- percentages of each type of WBC
- included in a full blood count
Reduction in white blood cells?
Splenomegaly (stores platelets and WBC’s)
Autoimmune conditions
Liver disease (produce monocytes)
Bone marrow failure
3 categories of WBC?
Monocytes- macrophages
Lymphocytes
Granulocytes
Where are the monocytes produced?
The reticuloendothelial system /
The mononuclear phagocytic system
Gram stain microscopy
Distinguishes between gram positive and gram negative bacteria.
- Gram positive stain purple because the thick peptidoglycan layer retains crystal violet dye
- Gram negative stains red due to a thinner peptidoglycan layer
Enriched agar plates
Red because it contains blood and proteins which provide nutrients for bacterial growth. Standard plate.
Note; some bacteria are inhibited by blood and won’t grow