A clinical infection is characterised by which signs and symptoms? (7)
- inflammation
- pain
- pyrexia (fever)
- rigors
- increased WBC count
- increase C reactive protein
- tachycardia
what is an acute illness/symptoms? examples?
sudden and severe in onset such as asthma or a broken bone
what is a latent infection?
infection which is dormant (“sleeping”) and may reappear if activated
what is a sub-clinical infection?
asymptomatic infections with no signs or symptoms
what is definition of pathogen?
organism which can cause disease
what is definition of commensal? what is an example?
organism which is part of the normal flora (e.g. e.coli in the gut or s.aureus in the nose or axilla
which patients particularly make it difficult to distinguish between a pathogen and a commensal?
immunosuppressant patients
what is meant by Koch’s Postulates?
criteria established by Koch to identify the causative agent of a particular disease
what are the 3 Koch’s postulates? (criteria)
- organisms must be found in all cases of the disease
- able to be cultured outside the body for several generations
- should reproduce the disease on inoculation
what are the 4 things which should be known when identifying the causative agent of a particular disease?
Knowledge of…
- sterile/non-sterile sites
- normal flora of site
- organism’s pathogenicity
- clinical context
what does host-pathogen interaction depend on?
Patient’s immune system (e.g. pregnant, chronic condition or acute illness all have different immune systems)
what is meant by pathogenicity?
the capacity of a micro-organism to cause an infection
what are 2 requirements for pathogenicity?
- virulence
2. infectivity
what does virulence mean?
ability to cause harmful effects once pathogen is established
what does infectivity mean?
- ability for pathogen to become established
what are 2 examples of infectivity mechanisms?
- attachment (e.coli)
2. acid resistance (helicobacter pylori)
what are the 3 virulence factors which are microbial components?
- invasiveness
- toxin production
- evasion of the immune system
what is meant by invasiveness?
how fast the pathogen takes over the body
what are 3 types of toxins?
- exotoxin
- enterotoxin
- endotoxin
what is an exotoxin?
released extracellularly by the micro-organism
what is an enterotoxin?
they are exotoxins which act on the GI tract
what are endotoxins?
structurally part of the gram negative cell wall (intracellularly) , released from bacteria cell wall
what is an example of an exotoxin?
tetanus:
- infection of dirty wounds
- binds to nerve synapses and loss of inhibitory neurotransmitter
- death caused by respiratory paralysis
what is an example of an enterotoxin?
cholera;
- food and water contamination
- colonises small intestine
- increases cAMP, inhibits uptake of Na and CL, stimualtes secretion of Cl and HCO3 and outflow of H2O
- death by dehydration
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Introduction to medical microbiology18
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Introduction to bacteria24
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Gram Positive Bacteria53
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Gram negative bacteria26
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Tumours 122
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Parasites46
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Mendelian Inheritance11
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Drugs 1: Drug Absorption42
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Drugs 2: Drug Distribution and Excretion36
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Drugs 3: Drug Metabolism45
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Antimicrobial chemotherapy92
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Clinical Trials21
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Tumours 225
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Tumours 311
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Introduction to Viruses47
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Tumours 438
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Other types of bacteria (not gram positive and gram negative)14
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Introduction to fungi69
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Imaging in cancer63
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Tumours 558
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Drug Delivery48
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Therapeutic options40
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Pathogens and Host29
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Principles of Immunisation51
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Outline of disease process38
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Adverse Drug Reactions39
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Chemotherapy35
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Storing and Using Genetic Information46
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Viral Pathogenesis21
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Hypersensitivity +Immunity47
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Chromosomes and Cell Division50
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Mutations and Genetic Analysis48
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Genetic Basis of Complex Inheritance27
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Drug-Drug Interactions52
