Term
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Definition
a symbiont that harms or lives at the expense of its host |
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Term
what are the two types of parasites |
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Definition
1. ectoparasite - lives on the host 2. endoparasite- lives within the host |
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Term
what are the four types of hosts |
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Definition
1. final host 2. intermediate host 3. transfer host 4. reservior host |
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Term
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Definition
host on ( or in) which parasite either gains sexual maturity or reproduces |
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Term
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Definition
serves as a temporary but essential enviroment for some stages of parasites development |
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Term
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Definition
is not necessary for development but serves as a vehicle to the final host |
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Term
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Definition
nonhuman organism infected with a parasite that can also infect humans |
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Term
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Definition
growth and multiplication of parasite on or within host |
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Term
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Definition
disease resulting from infection |
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Term
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Definition
a parasite organism that causes infectious disease |
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Term
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Definition
the ability for a pathogen to cause disease |
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Term
the outcome of a host-pathogen relationship depends on |
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Definition
the number of pathogen organisms present virulence of pathogen host's defense or degree or resistance |
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Term
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Definition
measures the degree or intensity of pathogenicity |
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Term
3 things virulence depends on |
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Definition
1. infectivity- the ability to establish a focal poitn of infection 2. invasivness- abuility to spread to adjecent cells or other tissue 3. pathogenic potential - the degree to which pathogens can cause damage to host the major aspect is toxgenicity ( the ability to prodeuce toxins) |
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Term
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Definition
the number of pathogens that will kill 50% of an experimental group of hosts |
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Term
infectious dose 50 (ID50) |
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Definition
number of pathogens that will infect 50% of an experimental group of host |
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Term
a successful basterial pathogen must be 7 things |
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Definition
1. maintain a reservior - place to live before and after infection 2. be transported to host 3. adhere to, coloinze, and or/ invade host 4. multiply or complete life cycle on or in hsot 5. initially evade host defenses 6. damage host 7. leave host ( return to reservior or enter new host |
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Term
all bacterial pathogens must have at least one reservior? |
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Definition
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Term
for human pathogens what are three reserviors |
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Definition
other humans animals enviroment |
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Term
what are two types of contact between hosts |
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Definition
direct contact- coughing, sneezing, body contact indirect contact- vehicles ( soil, air, water,food), vectors ( living organisms that transmit pathogens), fomites ( inanimate objects that harbor and tranmit pathogens) |
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Term
attachment of a parasite to a host is mediated by special molecules or structures called |
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Definition
adhesins or ligands which help bind to the receptors of the host cells |
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Term
common adhesins or ligands that help the parasite bind to the receptors of the host are |
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Definition
fimbriae or pili, glycocalyx or capsule, slime layer, M protein, techoic and liotechoic acids |
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Term
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Definition
establishment of a site of microbial reproduction on or within host |
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Term
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Definition
ability of the pathogen to compete |
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Term
is the result of colonization necessarily tissue invasion and or damage? |
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Definition
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Term
what can the invasion of the bacterial pathogen be |
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Definition
can be active penetration of hosts mucous membrane or epithelium via lytic substance that alter host tissue |
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Term
in what three steps does the invasion os a bacterial pathogen accomplish penetration |
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Definition
1. attack the ground substance and basement membranes of integuments and intestinial lining 2. degrade protein-carbohydrate complexes between cells 3. disrupt the cell surface |
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Term
passive penetration of invasion of the bacterial pathogen can be |
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Definition
skin or mucous lesions, insect bites, damage by other organism, wounds or abrasions, phagocytosis, endocytosis |
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Term
once below mucous membrane bacterium can spread into deeper tissue |
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Definition
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Term
when bacterium spreads into deeper tissue what might result |
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Definition
may involve production or specific products and or enzymes that promote spreading may enter small terminal lymphatic capillaries once the circulatory system is reached the pathogen has access throughout the host. |
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Term
when does the pathogen have access throughout the host? |
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Definition
once the pathogen has reached the circulatory system |
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Term
when does growth and multiplication of the pathogen occur |
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Definition
once the pathogen finds the appropriate enviroment within the host |
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Term
do some pathogens actively grow in the blood plasma? |
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Definition
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Term
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Definition
presences of viable bacteria in blood |
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Term
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Definition
presence of bacteria or of their toxins in the bloodstream |
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Term
the pathogen must leave the cell is it is going to be perpetuated |
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Definition
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Term
the pathogen leaves the hoat and either moves to -- or to -- |
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Definition
another host or into a reservior |
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Term
most pathogenic bacteria leave by passive mechanisms for example |
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Definition
feces, droplets, saliva,desquamated cells |
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Term
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Definition
products or structural components that contribute to virulence or pathogenicity |
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Term
example of virulence factors |
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Definition
adhesins, capsules, lytic subastances, products promoting spread |
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Term
often enviromental factors control expression of virulence factors |
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Definition
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Term
3 examples of regulation of virulence factors which are coontroled often by enviromental factors |
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Definition
1. gene for diptheria toxin regulated by iron 2. expression of virulence genes increased by body temperature 3. expression of cholera toxin regulated by PH, temperature osmolarity and available amino acids |
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Term
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Definition
disease that results from entry of a specific preformed toxin into host |
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Term
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Definition
a substance that alters the normal metabolism of host cells with negative effects on the host |
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Term
towins of bacteria are two types |
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Definition
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Term
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Definition
soluble, heat liable proteins that are usually released into the surrounding as the bacteria grow |
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Term
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Definition
the LPS of the gram negative bacteria |
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Term
exotoxins are specialized by specific bacteria ( often with plasmid or prophage containing toxic genes) |
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Definition
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Term
are exotixins heat liable proteins which are inactivated at 60-80 degrees celcius? |
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Definition
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Term
what are among the most lethal substances known |
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Definition
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Term
exotoxins are not associated with a specific disease and have no specific mechanism of action |
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Definition
false they are associated with a specific disease and have a specific mechanism of action |
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Term
highly immunogenic ( antitoxin antibodies are formed for endotoxins or exotoxins? |
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Definition
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Term
are endotoxons or exotoxins easily inactivated by chemicals? |
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Definition
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Term
formaldehyde and iodine form immunogenic toxiod are examples of chemicals which inactivate endo or exo toxins? |
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Definition
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Term
AB exotoxins are composed of two subunits |
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Definition
A subunit- responsible for toxic affect B subunit - binds to the target cell |
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Term
examples of AB exotoxins entry |
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Definition
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Term
can AB toxins be specific host site exotoxins? |
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Definition
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Term
spcific host site exotoxins may include |
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Definition
neurotoxins enterotoxins cytotoxins AB toxins |
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Term
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Definition
usually ingested as preformed toxins target nerve tissue |
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Term
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Definition
target intestinal mucosa elicit profuse fluid secretion |
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Term
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Definition
specific toxic action on cells/tissues of specific organs |
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Term
membrane disrupting exotoxins |
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Definition
lyses the cell by disrupting the integrity of the membrane they produce pore forming exotoxins which bind to the cholesterol portion of the membrane and insert itself in the membrane |
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Term
phospholipases are a type of --- that do what --- |
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Definition
are a type of membrane disrupting exotoxins that remove charged heads of phospholipids and destabilizes the membrane |
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Term
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Definition
a type of pore forming exotoxin that kills phagocytic leukocytes |
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Term
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Definition
are a type of pore-forming exotoxin that kills erythrocytes, leukocytes and many other cells |
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Term
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Definition
a type of hemolysin that is oxygen sensative |
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Term
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Definition
a type of hemolysin that is oxygen stable |
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Term
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Definition
nonspecifically stimulate T-cells, and cause a massive release of cytokines |
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Term
what do superantigens result in |
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Definition
systematic toxicity in host and supression of specific immune response |
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Term
what are two prime examples of superanitgens |
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Definition
1. staphylococcal enterotoxins that cause food poisioning and the toxin that causes toxic shock syndrome |
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Term
with endotoxins what is the toxic portion of the LPS |
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Definition
the lipid A, not a singel macromolecular structure seems to be a complex array of lipid residues |
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Term
is endotoxins heat stable |
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Definition
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Term
when are endotoxins toxic? |
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Definition
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Term
are endotoxins highlt immunogenic? |
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Definition
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Term
endotoxins are usually capable of producing general systematic effect like |
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Definition
fever shock blood coagulation weakness diarea inflamation intestinal hemmorage fibrinolysis |
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Term
endotoxins bring about effect indirectly by interacting with host molecules and cell activating host systems |
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Definition
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Term
when endotoxins interact with macrophages they release |
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Definition
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Term
when endotoxins bind to the LPS binding protein they release |
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Definition
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Term
exotoxins are ---- whereas endotoxins are |
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Definition
proteins.. lipopolysaccharides |
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Term
endotoxins are released when |
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Definition
gram-negative bacteria die and their cell walls undergoe lysis |
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Term
what three things on the envasion of a bacteria help the bacteria stay away from the comliment system |
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Definition
capsules, lengthened O-chanin, serum restance |
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Term
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Definition
modifies lipoolingosacharides interfere with formation of membrane attack system |
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Term
what is the compliment system |
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Definition
The complement system helps or “complements” the ability of antibodies and phagocytic cells to clear pathogens from an organism |
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Term
what helps bacteria resist phagosytosis of the host cell |
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Definition
1.capsules 2.specialized surface proteins -that block adherence of phagocyctes of bacterium 3.production of leukocidins 4. proteases production- that cleave compliment factor C5a (phagocyte chemoattractant) |
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Term
how do bacteria pathognes survive inside phagocytic cells? |
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Definition
escape from phagosome before fusion with lysosome prevents fusion of lysosome with phagosome resistance to toxic products of phagolysosome |
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Term
how do bacteria pathogens invade the immune responce |
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Definition
capsules, genetic variation of surface antigens production of IgA proteases production of proteins that interfere with antibody-mediated opsonization ( the process of targeting an antigen) |
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Term
exotoxins are ---- whereas endotoxins are |
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Definition
proteins.. lipopolysaccharides |
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