human microbial disease

human microbial disease

1. Neisseria

   • Meningtitdis
     • sepsis
   • gonorrhoea
     • endotoxin Lipid A (LOS)

2. streptococci

   • gram +itve
   • pneumoniea
     • commenusal
     • fracticide: increase virulence
     • resistance to penicillin is spreading fast
   • GAS
     • IgG complexes: GN
     • super antigens
       • pyogenes: excessive cytokine production
     • penicillin sensitive

3. Bacterial toxins

   • Vibrio cholera
     • CTX: adp-ribo.
       • B bind to GM1 ganglioside
       • ADP ribsose to NAD
     • ChXA: inhibit EF2 so no translation
   • Diptheria
     • B part of AB toxin binds to heparin binding epidermal growth factor
   • pertussis
     • bacteria binds to the epithelial and release PTX
       • active subunit S1 is activated by calmodulin
   • RTX for E.coli: tss1
   • three types of toxins
     • AB
     • Membrane damaging
     • superantigens
   • shiga toxin: for e.coli uses Tss3
     • pyrotic cell death

4. Tss3

   • Vibrio species: Ysc
   • relationship to flagella
   • ATPase high conserved
   • salmonella
     • SPI-1: SipA for actin polyermisation to enter cell
     • Avra: dampen immune response
   • effectors of Tss3 can be exotoxins

5. Protozoa

   • Plasmodium
     • liver: sporozoites to merosoites
   • Toxoplasma
     • tissue cysts
     • transplacental transmission
   • cryptosporidum
     • Ingestion: diarrhoea
   • the apical complex is used for invasion

6. TB

   • uses Tss7
     • Protein secreted Esx A disrupt membrane
       • to escape the phagosome
   • LAM: avoid phagocytosis
     • Bacteria has to be alive for this to work
     • binds to TLR not CR3 and MHC class II receptors are not expressed
   • intracellular
   • latent infection is random organs

7. Pili for adherace

8. sharing of genes to increase virulence

   • Pneumoniae: fraticide
   • neisseria freely exchange genes