Drugs Flashcards
what is Kochs Postulates
1) the microorganism must be found in abundance but not in healthy organisms
2) the microorganism must be isolated from a diseased organism and grown in pure culture
3) the organism must cause disease in a healthy organism
4) the microogaminsm must be preisolated from the inoculated, diseased experimental host and identified as the same as the original causative agent
what is modern kochs postulates
A nucleic acid sequence belonging to a putative pathogen should be present in most cases of an infectious disease. Microbial nucleic acids should be found preferentially in diseased organs known, and fewer/not in those organs that lack pathology.
With resolution of disease, the copy number of pathogen-associated nucleic acid sequences should decrease or become undetectable. With clinical relapse, the opposite should occur.
Where sequence detection predates disease, copy number correlates with severity of disease or pathology, there is more likely to be a causal relationship.
The nature of the microorganism should be consistent with the known biological characteristics of that group of organisms.
These sequence-based forms of evidence for microbial causation should be reproducible.
what is a primary pathogen
primary pathogen causes disease in non-immunocomprimised hosts
- intrinsics virulence
- toxin production
- induction of abnormal host response
example of immunocompromised patients
immnosupressed tissue damage catheter infection genetic disease host bacteria (deserted balance)
Transmission
droplet/sexual/blood/bites/faecal-oral/environmental/vector Bourne
attachment
- Adherence via adhesions interacting with host receptors
- Biofilms for attachment and intracellular adhesion
what is virulence
ability to replicate within the host
passive immune evasion
Latency e.g. herpes(hides in ganglia in the brain), Malaria
Can hide in sanctuary sites
Resistance to phagocytosis and destruction by lysosymes
active immune evasion
Production of immunomodulatory proteins-salmaollela comes in contact with white cell and come in with harpoon like protein that it inject in and destroys it)
Decoy- hep B produces a hep b like envelope so th eimmune system attacks this instead and it get worn out
Evolution
Leishmaniasis
parasite form sandfly and shuts down liver and organ
Bacteria
Huge Domain of single cell organisms
Ubiquitous in environment and within/without humans
Prokaryocytic- single cell simple organisms, organelles are non-membrane bound.
Asexual replication through binary fusion
what is gram +
purple coloured more likely to get this in the upper part of the body
viruses
Very small infectious agents that can only replicate within cells of host organisims.
The most abundant biological agent.
Contain DNA or RNA and important viral proteins
have mRNA
viral replication brief
RNA goes into cytoplasm / DNA goes into nucleus and cans it and you cell and hide
fungal infection
Eukaryocytic organisms-’-more complex organelles enclosed in cell walls
Yeasts (replicate through mitosis) and Moulds (replicate through Meiosis)
Cell walls contain Chitin-stromg
Septae divide cells and are relatively fluid