Micro terms5 – Flashcards

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need this for successful infection. characteritics that allow the pathogen to thrive and survive in the host's environment
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virulence factors
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any point at which an organsim can enter the body is called a _________ and includes:
mucus membranes, skin, and parenteral routes
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portal of entry
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the most favorable portal for patheogens. colds, pneumonia, flu, measles and small pox use this portal of entry. productive portal of exiting pathogens
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thge respiratory tract
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located in areas adjacent to the outside world. respiratory, gastrointestinal and genitourinary tract. protect against the entry of microorganisms.
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mucus membranes
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open to the outside world. microorg can enter via the food and liquids we ingest. includes barriers (to pathogens) like stomach acid and bile..
use this as portal of entry:
polio, hepittis A, Giardia, Vibro cholera, typhoid fever and organisms that cause dysentery
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gastrointestinal tract
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the _______________ route of contamination has a major role in infections, especially w/ gram neg bacteria, viruses, protozoa,a dn other parasites
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facal-oral
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urinary and reproductive tracts opens to the outside. STDs use this as a portal of entry. once its mucus membrane barrier is broken pathogens gain entry
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genitourinary tract
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pathogens enter here through a breech in its surface, hair follicle, or perspiration duct. however each route is very well guarded
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skin
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a break in skin barrier portal of entry.
injections and insect bites is an example of this.
plasmodium use this as a way to enter the host
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parenteral route
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insect bite entry through the skin
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vector transmission
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some gram negative organsims (escherichia coli) uses structures called ____________ to attach to certain receptors on cells of the small intestine, colon and bladder
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fimbrae
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in many cases pathogens use molecules called _______, whcih are glycolipids or lipoproteins located on the pathogen surface, as means of adherring to tissue
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adhesins
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fluids produced by your oral tissue form a ____________ which is a protein film that coats the teeth
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pellicle
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the __________ is th e# of organisms required to kill 50% of the hosts
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lethal dose 50% (ID50)
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the ____________ is the # of organisms requirred for 50% of the population to show signs of infection
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infectious dose 50% (ID50)
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pathogens w/ the lowest ID 50 and LD50 are the most
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virulent
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one of the functions by filling the host cell w/ viral particles called virons until the host cell burst open and pours virions into the intracellular fluid. these viruns locate the new host and repeats this process until there are no more host cells available.
ex: HIV
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lytic virus
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pathogen has to deal w/ host defense for success.2 ways: structure of the cell built in ______ defense and the other involves attacking the jost defenses ______
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passive

active defense
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the main defenses od pathogenic bacteria are __________ and ______. this is what makes pathogens virulent
ex: S. pneumpniae, haemophilus influenzae, bacillus anthracis, and yersinia paestis can only cause w/ it
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capsules and cell wall components
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the 1st line of defense response _______ ingest pathofens then destroy them through adherence which causes the development of pseudopods to surround the organism . encapsulated pathogens arent affected by this
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phagocytosis
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the process in which antibody molecules bind to the capsule
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opsinization
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the process in which antibody molecules bind to the capsule
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opsinization
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when antibody molecules bind to the capsule they attract ____________ cells that use antibody molecules as bridges to adhere to the organism and _____ it
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phagocitic
phagocytose
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help increase the virulence of pathogems increasing adherence to host target cells and making the pathogen resistant to heat and acidic environments
inhibit phagocytosis and involved in toxic shock
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M proteins
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waxy substance infused to the bac cell wall that inhibitrs phagocytosis and protects the bacterium against antiseptics, disinfectants antibiotics
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mycolic acids
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capsules and cell wall components are ___________ measures used to defeat the host defenses
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passive
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enzymes that destroy WBCs.
are produced by staphylococoal and streptococcal pathogens
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leukocidins
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membrane damaging toxins that disrupts the plasma membrane of the host cells and cause the cells to lyse can damage the plasma membr in red and WBCs n produced by a variety of bacteria:
staphylococal and streptlococal species
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hemolysins
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hemolysin produced by streptoccal bacteria is referred to as _________ and can be divided into different groups such as group A and O
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streptolysin
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the different types of streptolysin differ from one another in the type of __________.
ex: streptolysin O is associated w/ B-hemolysis
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destruction they cause
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a pathogen produced enzyme that causes fibrin clots to form in the blood of the host. used by both host an dpathogen during infection
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coagulase
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enzymes that break down fibrin and dissolve clots. used by the pathogen to overcome attempts by the host to wall off infection, thereby ensuring spread
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kinases
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enzymes that break down connective tissue and collegen in host, thereby allowing infections to spread
ex: gas gangreene
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hyaluronidase and collagenase
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process in spreading important for increased virulence. enzymes inhibits the clotting machinery or to breakdown clots formed by the host, allowing the pathogen to spread.
ex: strep throat (minor) necrotizing facitis (major)
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group A streptocci
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able to survive in only one type of environment
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obligate
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salmonella produces a molecule called _______ that changes the structure of the actin filaments in the cytoskeleton. this changes moves the bac in the cell. the pathogen moves the actin filaments from place to place inside of the cell.
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invasin
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the host cell can also use a host cell molecule called ____ to move from one cell to another w/ out ever exposing itself to the immune defenses searching for it
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cadherin
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the major portals of entry are the
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mucus membranes, skin and parenteral routes
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_____ portals of entry are associated w/ the respitory, digestive and genitourinary tracts of the body
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mucus membrane
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can be accomplished using adhesion molecules, which are glyco lipids or lipoproteins.
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establishment (stayin in requirment)
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some pathogens take advantage of structures auch as ____ to adhere to tissue
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fimbrae
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most damage associated w/ infection can be divided up into 2 parts
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damage that occurs because the bacteria is present
damage that is a by product of the host's response
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obvious destruc of host cells and tissues
usual localized to site of infection
defense response is timely and potent, ususally limiting the damage done
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direct damage
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seen in most serious infections
dangerous to host due to cause systemic disease
results in production of bacterial toxins
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indirect damage
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are soluable in aqueous solution s and easily diffuse into and moove through the blood and lymph systems. causes pathogenic sites to be far from the inital infec site
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bacterial toxins
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produced by pathogen and enter host cells
most lethal
enzymatic protein soluable in the blood or lymph
diffuse in tissues and stop metabolic func of cell
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exotoxins
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many exotoxins are very dangerous and are usually produced by pathogens in ___________ form which inactive than activated after having left the pathogens cells
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proenzyme
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many genes that encode exotoxins are carried on _____ in the pathogens, which makes it possible to transfer genetic info from one bacterium to another
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plasmids
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there are 3 types of exotoxins
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cytotoxins, neurotoxins and enterotoxins
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kills cells in which they come in contact w/
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cytotoxins
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interfere w/ neurological signal transmission
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neurotoxins
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affect the lining of the digetive system
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entertoxins
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is a cytotoxin
produced by bacillus anthracis
increases vascular permebility
hemmorhage and pulmonary edema results
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anthrax (
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a cytotoxin
produced by the corynebacterium
inhibits protein synthesis
leads to heart damage, possible death weeks after apparent recovery
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diptheria toxin
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a neurotoxin
produced by clostridium botulinum
blobks the release of acetycholine
leads to respitory paralysis
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botulinum toxin
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a neurotoxin
produced by clostridium tetani
inhibits motor neuron antagonist
vauses violent skeletal muscle spasms (lock jaw)
and respiratory failure
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tetanus
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enterotoxin
produced by vibrio cholerae
causes excessive loss of water and electrolytes
severe diarherra; death can occur w/in hours
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vibrio
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bac staphylococcus aures produces an enterotoxin that affects the digestive system and cause this
loss lots of liquid from body which cause of death
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toxic shock
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after inactivation treatment, toxins are referred to as
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toxoids
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are bacterial toxins that are part of the cell wall of gram negative bacteria. active after a bacteria containing them has been killed. leave the dead cell wall and enter the blood stream of the infected host
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endotoxins
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endotoxins are a component of gram neg organisms
are part of the bacterial cell wall
symptoms: fever, chills, muscle weakness, and aches
lareg amounts can cause shock and diseminated intravascular cloting
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endotoxins
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are produced by gram positive organisms
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exotoxins
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have an outter layer made up of lipoproteins, phospholipids, and lipopolysacharides. while the organism is alive the outter layer stays in place but when it dies the layer falls apart. lipopolysaccharides of this layer contain a particular lipid called lipid A which have endotoxin properties
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gram negative bacteria
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condiotn in which minor clotting occurs throughout the body. this uses up clotting elements so they arent avail when needed
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disseminated intravascular clotting
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almost all gram positive
located extracellular, excreted by living organisms
is a polypeptide
among most powerful toxins
highly specific, several types
no fever production
very good as an antigen, long lasting immunity conferred
conversion to toxoid form by chemical treatment
lethal dose is small
unstable; @ high temp
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exotoxins
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diseases asociated:
botulism, gas gangreene, tetanus, diphtheria, cholera, plague, scarlet fever, staphylococcol food poisoning
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exotoxins
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almost all gram negative
location: part of pathogen cell wall, released when the cell dies
is made of a lipopolysaccharide complex
stable; can w/ stand high temp 4 hrs
nonspecific, local reactions such as fever, aches and possible shock
rapid rise to very high fever
weak usefulness as an antigen; no immunity conferred
lethal dose is large
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endtoxins
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ex:
salmonelosis, typhoid fever, tularemia, meningococal menigitis, endotoxic shock
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endtoxins
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a test to determine if theres an endotoxin contamination of supplies and equipment. takes advantage of the WBCs of the horse shoe crab
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limulus amebocyte lysate assay
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in the presence of endotoxin its WBCs clot into a gel like matrix that becomes cloudy (turbid). the degree of turbidity can be used as a measure of the amount of endotoxin contamination present
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limulus
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damage to the host can either be direct or indirect. direct damage is usually __________ and indirect damage is usually through the production of ______
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localized
toxins
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are extremely lethal substances produced by living cells (usually gram positive) and in most cases proteins
can cause the production of antibody
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exotoxins
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are contained inside the bacterial wall and released when the cell dies
are products of gram negative organisms, dont effectively generate antibody, less toxic
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endotoxins
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Lipid A which is part of the gram negative phospholipid outter layer of the bacterial cell wall has
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endotoxin properties
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virually caused cell death or damage is a
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cytopathic effect
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(cytopathic effect)
cytopathology associated w/ viral infections can occur in 3 ways
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viral overload
cytocidal effect
non-cytocidal effect
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(cytopathic effect)
causes the virus to explode out of the host cell and infect and lyse surrounding host cells
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virla overload
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(cytopathic effect)
when the host defense mech identify and kill virally infected cells
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cytocidal effect
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(cytopathic effect)
occurs when a virus shuts down the host DNA, RNA, and protein synthesis and thereby forces the host cell to devote all its efforts to virus production
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non- cytocidal effect
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inclusion bodies seen in rabies viral infections and can be diagnostic for this disease
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negri bodies
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gigantic cells formed as a # of infected host cells merge; can also be a visual identification of viral infection
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synctia
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use an array of virulence factors including capsules, M proteins, mycolic acids, leukocidins, hemolysin, coagulase, kinases, hyaluronidase, and collagenase
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to avoid being killed by the host defenses pathogens
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pathogens use ___________ such as __________ to establish themselves in the host
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virulence factors
adhesions
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a micro is infecting via the parenteral route. what does that mean
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it entered through a break in the skin
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using fimbrae to attach to a receptor, releasing several exotoxins to destroy the host cell. using adhesions to attach to tissues
creating a biofilm on the body's surface
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all have a role in establishment
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a bacterial enzyme that breaks down connective tissue
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hyaluronidase
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changes the structure of actin filaments in the host cell
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invasin
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you have a culture of cells that are producing exotoxins. the cells are probably
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gram positive bacteria
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toxins found on gram negative cell walls
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endotoxins
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a patient has disseminated intravascular clotting, the patients disease is caused by
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endotoxins
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