Infection and antimicrobial chemotherapy Flashcards
Commensalism
One organism benefits and the other is unaffected
Mutualism
Both organisms benefit
How do microorganisms cause infection?
- Contact or enter host
- release toxins from distance
- Induce host cells to cause damage
APSAR
Viral replications steps
- Attachment
- penetration
- Synthesis
- Assemby
- Release
Spectrum of viral infection
Dont respond to antibiotocs
cold, covid, ebola, hiv
Fatigue can last 6 months
Some hibernate - shingles
7 Viral damage to cells
- Inhibit dna syntheses
- Damage membrane
- Lysis
- Manipulte apotosis mechanisms
- Cause an immue reposne
- Damage the imune response
- Cell roliferation - development of tumour cells
Bacteria
replicate by binary fission
How do bacteria damage cells
Invade cells and tissues
Using host cell nutrients.
Causing direct cellular damage.
Inducing hypersensitivity reactions.
Producing bacterial toxins.
Release endotoxins or exotoxins
Difference in an endotoxin and exotoxin
Endo- components of bacterial cell
Exo - secreation of bacterium
Check if more infoon viruses and bacteria are needed.
Infections
Invasion and multiplication of a pathogenic microorganism. Top 10 casues of death
50% are respiratory, mainly viral
What can Staphylococcal cause
Food poisoning
Toxi shock
Respiratory infection
Wound infection
Impetigo
Endocarditis
Focal skin infection
How do we defend against disease
Structural barriers
Inflammatoy response
Acquire immune sysyem
Hygiene
Improved nutrition and lifesyle
Antibiotics
Vaccination programmes
Chain of infection 6 steps
- way in- eyes, mouth,wound
- Host-
- Infectious agent - microorganism
- Reservoir - where germ lives & grows - person /h2o/fd
- Exit - sick, diarrhoea, sneeze
- Mode of transmission
Tapeworm example cycle
Sepsis
A lidf threatening organ dysfuction caused by dysregulated host response to infection
Most commn causes of sepsis
Staoh. aureus
e.coli
Pseudomonas
candida
Aspergillus
Common sites of infection for sepstis
respiratory tract
skin
urinary tract
blood stream
GI tract
6 signs of sepsis
- Shivering/ cold
- Extreme pain
- Clammy skin
- Confusion
- Short of breath
- High heart rate
What is the outcome of sepsis
Full recovery - early dagnosis key
partial recovery - post sepsis syndrome ( fatigue)
organ failure - Septic shock leads to low blood pressure and organ failure. Can be fatal.
How many deaths caused by Sepsis
1 in 5
treatment for sepsis
Antibiotics
Ventilators
Dialysis
Organ support
What is antimicrobial chemotherapy
How we treat micorbial infections - either kill or stop their growth.
Antimicrobials and antivirals.
Who and when discovered penicillin
Flemming 1928
How do anti viral drugs work?
Need host cell to replicate to actions are:
1) block attachment and entry
2) Block early protein syntheis
3) Block late protein synthesis
4) Block release
