What is infection?
The multiplication of a pathogen microbe on/in a susceptible host with associated dysfunction/damage
Outline the Henle-Koch’s Postulates
Proving the bacteria is the causation of the disease
1) Agent must be shown to be present in every case of the disease by isolation in pure culture
2) The agent must not be found in cases of other diseases
3) Once isolated, the agent must be capable of reproducing the disease in experimental animals, and must be recovered from the experimental disease produced
What colour do gram positive bacteria stain?
What colour do gram negative bacteria stain?
Explain the significance of genome composition when classifying and detecting viruses
RNA viruses are more likely to mutate as RNA is less stable
Explain the terms Pathogen and Non-Pathogen
A pathogen is a bacterium, virus, or other microorganism that can cause disease whereas a non-pathogen is a bacterium that doesn’t cause disease. Many non-pathogens perform essential ecological roles
Why is acid fast staining used?
- Allow us to detect the bacteria causes of tuberculosis and leprosy (mycobacteria)
- These bacteria cannot be identified by gram staining
Explain the significance of envelope presence when classifying and detecting viruses
If a virus has an envelope it's more easily sterilised as if holes are punched in the envelope the virus cannot survive
Explain the significance of Replication strategy when classifying and detecting viruses
RNA viruses can use reverse transcriptase (HIV), DNA viruses can use cell machinery (HPV), or a virus can carry its own replication enzymes
Name a DNA enveloped Virus
Any from: - Hepatitis B - Inflamed liver - Herpes - Oral/genital warts - Smallpox - smallpox
Name a DNA non-enveloped virus
HPV - Warts, cervical cancer
Name a RNA enveloped virus
Any from: - HIV - AIDS - Rubella - Rash, congenital rubella syndrome - Rotovirus - Diarrhoea - Coronavirus - SARS
Gram positive bacteria?
Staphylococcus, streptococcus and Clostridium
(Gram negative = everything else Acid fast - mycobacterium)
What is the target for the β -lactams class of antibiotics? Eg Amoxicillin, Penicillin
What is the target for the glycopeptide class of antibiotics? Eg Vancomycin
What is the target for the macrolide class of antibiotics? Eg Erythromycin
Define "carriage" in the context of infection
Passage taken by microorganism
Define "normal flora" in the context of infection
non-pathogenic bacteria naturally found in our bodies e.g. the gut
Define "Commensal" in the context of infection
Symbiotic relationship where one species derives benefit (microbe) and the other is unaffected (host). This is the time when the microbe may be replicating or waiting for the immune system to become compromised