How microbes cause disease Flashcards
what do microbes need to do to survive
adherance/colonisation
resist/avoid defence
persist and grow
exit&transmit to new host
what is the period with vague symptoms before illness called
prodromal
where do pathogens want to reach and how do they get there
sterile body sites, breach barriers eg BBB, skin, mucosal membrane
who competes with pathogens
natural flora
what chemicals do tears, saliva and mucus have in them which is antibacterial
lysozymes
what other ways do we get rid of toxins/pathogens
cilia/urinary flushing/antimicrobial FAs in skin, mucus and phagocytes in lungs
bacteria use more than one adherance mechanisms to stick to the host. give some examples
pili/fimbriae
outer membrane proteins eg adhesin&invasin
where does e coli keep its adhesin
tip of the pili
what are biofilms made of, what are they, give an example of a biofilm in action
slime layer, (Extracellular polymeric substances) polymer EPS, pseudonomas in CF - opportunistic infection
how else that pili and fimbriae can pathogens adhere to host cell
via host ECM
Internalins Listeria monocytogenes bind E-Cadherin and C-met
- M proteins Strep. pyogenes bind to receptor on respiratory mucosa
what are the two main problems with biofilms
avoiding host immunity
resistance to antibiotics
what do bacteria use to form lesions
degradative enxymes
what do degradativeenzymes do and not do
mess up tissue - hyaluronase and collagenase
do not kill cells
what are the two types of invasion into host cells
trigger zipper
who uses trigger and who uses zipper
T:salmonella, shigella
Z: listeria
what is the complement
part of innate immune system 30 circulatory proteins
what are the 3 things the complement does
opsonisation - tag path with IGG - cleared by pahogcytes
membrane attack complex - hole in bacterial membrane - lysis
enhancing inflammation - mast calls attract phagocytes to the area