What are exogenous and endogenous micro-organisms?
Endogenous- Microorganisms found in our body.
Exogenous- Not found in normal flora.
What is a pathogen?
Harmful microorganism
What is an opportunistic pathogen?
Pathogen causing infection when opportunity arrives.
What is a commensal organism?
Part of normal flora. Mutualistic relationship with host. Endogenous.
What are the main types of infectious agents?
- Bacteria
- Viruses
- Fungi
- Protozoa
- Parasites
- Prions
Common fungal infections?
- Candida spp.
2. Aspergillus
Example of protozoan disease?
- Malaria
2. Taxoplasma
Common Gram -/+
Gram - E coli Salmonella Klebsiella Enterobacter
Gram +
Strep spp
Staph spp
Enterococcus spp
Give two examples of Gram - Cocci
- Neisseria Meningitidis
- Neisseria Gonorrhoea
What are coliforms?
Gram - bacilli that look like E coli on gram film when cultured on blood agar.
What antibiotic is given for a coliform infections?
Gentamicin
What are the steps involved in fever production?
- Antigen or LPS comes in contact with macrophage
- Macrophage releases cytokine
- Cytokine stimulate sepsis
- Cytokines stimulates hypothalamus in brain
- Prostaglandin E released, which increases body temp set point.
6 Body perceives normal temperature as cold. - Starts to shiver- Fever. Increased survival from infection
What temperature is termed as fever?
Above 38c
What is sepsis?
Host response to Severe infection
What happens in sepsis?
- Small vessels become leaky. Fluid move into tissues
- Blood volume reduced. HR goes up to maintain cardiac output.
- Poor O2 tissue perfusion so–>Blood supply to skin, liver, kidneys reduced to main cerebral blood flow.
- Blood clotting system activated= increased haemorrhage risk
Examples of Gram - Bacilli?
- Haemophilus influenzae
- Pseudomonas aeruginosa
- Legionella
- Vibrio Cholerae
What is streptococcal haemolysis?
Identify different strep species by growing on blood culture.
Types of Strep haemolysis?
- Partial- Alpha. Green discolouration
- Complete- Beta. colony clearance
- No- gamma. Red colour
Examples of Group A Streptococci diseases?
- Strep sore throat (Scarlet fever)
- puerperal sepsis
Important example of Non haemolytic strep?
Enterococci
Two important Staphylocci?
- Staph aureus
2. Staph epidermis
Example of anaerobic bacilli?
Clostridium- Gram+ Anaerobic bacilli
