Microbial disease

Nota:

• pathology/damage resulting from an infection

1. Microbes
   1. bacteria
      1. salmonella enteritidis> food poisoning
      2. Mycobacterium tuberculosis > tuberculosis
   2. fungi
      1. Epidermophyton floccosum>ringworm
      2. Candida albicans> thrush
   3. viruses
      1. Rhinoviru>common cold
      2. HIV >AIDS
   4. parasites (protozoa & worms)
      1. Plasmodium falciparum> Malaria
      2. Giardia lamblia >diarrhoea
      3. Worm:Schistosoma mansoni> schistosomiasis
2. Microbe-host

   Nota:

   • successful parasites gets what it can without causing damage (disease is by product of multiplication)
   1. parasitic
      1. one benfits on the expense of other> measles, tuberculosis, typhoid
   2. Symbiotic/mutualistic
      1. both benefit> intestinal microbiota
   3. Commensalism
      1. one organism derives benefits without causing damage>skin microbiota
   4. Balanced pathogenicity
      1. Microbes and Host Organisms have evolved togethe
         1. over time pathogens become less virulent while host more immun
         2. its not beneficial for a microbe to kill its host before it has a chance to reproduce and disperse
3. Severity of microbial disease
   1. Host factors inlcuding genetic factors and host physilogy
      1. degree to which individuals respond to is highly variable
         1. 1926 Lubeck disaster: Mycobacterium tuberculosis given to babies: 76 died/173 survived
         2. Plasmodium falciparum> Sickle cell trait
         3. Hepatitis B virus > 1942 military personnel
         4. malbutrition> measles virus
         5. diabetesmellitus - high concentrations of blood sugar> infection by staphylcocci
   2. Viirulance of micro-organism