Chapter 16

when microbe establishes itself and multiplies in a particular environment

colonization

microbes that show no known beneficial relationship to humans; benign

commensalism

cause histamine release leading to vasodilation and neutrophil chemotaxis and accumulation leading to inflammation

complement cascade

stage of infectious disease cycle of recovery and recuperation

convalescence

normal microbiota excludes pathogens by

covering binding sites for attachment, consuming nutrients, producing compounds toxic to other bacteria

exotoxins are synthesized in the

cytoplasm

toxins that interfere with essential cellular mechanisms/ lyse cells

cytotoxins

___ are able to penetrate body's first line of defenses and then multiply in host tissue

invasive pathogens

hyaluronidase enzyme viral pathway

invasive pathogens reach epithelial surface, pathogens produce hyaluronidase, pathogens invade deeper tissues

provided a foundation for establishing that a given microbe causes a specific disease

koch's postulates

general mechanism used by protozoa and helminths to avoid antibodies

live inside host cells

pathogens can hide within ___ and avoid antibodies, control part of immune response and be transported

macrophages

to avoid destruction by the complement system microbes must be able to inactivate or avoid formation of

membrane attack complex (MAC)

cytotoxins that disrupt eukaryotic cytoplasmic membranes, causing the cell to lyse

membrane-damaging toxins

when a pathogen disguises itself by coating its surface with molecules that are similar to those found in the host

molecular mimicry

methods viruses use to avoid antibodies

move from cell to cell, force fusion of cells (syncytium formation)

most invasive pathogens enter tissues via

mucous membranes

mutual benefit between microbes and human host

mutualism

toxins that affect the nervous system

neurotoxins

an ___ pathogen only causes disease when body's innate/adaptive responses are compromised

opportunistic

relationship benefits microbes but harms human host

parasitism

suites of genes encoding for virulence

pathogenicity islands

unlike other microbes, ___ have the ability to overcome host innate and adaptive immune response and cause damage

pathogens

coagulase enzyme viral pathway

pathogens produce coagulase, blood clot forms around pathogens, pathogens produce streptokinase dissolving clot and releasing bacteria

can cause symptoms similar to the release of an endotoxin; systemic response leads to septic shock

peptidoglycan

toxin that hydrolyzes phospholipids in the cytoplasmic membrane

phospholipases

exotoxin that destroys membrane integrity

phospholipid hydrolyzing phospholipase

damage membranes by inserting themselves into the phospholipid bilayer, forming channels that allow fluids to enter the cell

pore-forming toxins

microbe that causes disease in otherwise healthy individuals

primary pathogen

period of early vague symptoms

prodromal phase

when monocytes or macrophages interact with LPS molecule what can happen

production of cytokines which stimulate production of prostaglandins and leukotrienes, activation of complement cascade, activation of coagulation cascade to stimulate bradykinin release

microbiota that are only in body area for temporary amount of time

transient microbiota

life cycle of microbial pathogens

transmission, adherence to human host, invasion, reproduction/exit, survival, transmission

TTSS stands for

type three secretion system

presence of free viral particles in the blood

viremia

traits of a microbe that specifically allow it to cause disease

virulence factors

beta hemolysis produces a ___ color

yellow

3 parts of host defenses detect and eliminate viruses

interferon, apoptosis, antibodies

presence of toxins circulating the bloodstream

toxemia

koch's postulates

1. microorganism must be present in every case of disease but not in healthy hosts 2. microorganism must be grown in pure culture from diseased hosts 3. the same disease must be produced when a pure culture of the microorganism is introduced into susceptible host 4. same microorganism must be recovered from experimentally infected hosts

in AB toxins which part is toxic

A

stages of phagocytosis

chemotaxis, recognition/attachment, engulfment, fusion of phagosome with lysosomes

in AB toxins which part is a targeting piece that binds to specific receptors on target cell

B

lipopolysaccharides can affect which cells of the immune system?

B cells, macrophages, monocytes

degrades complement component C5a

C5a peptidase

first used to link Bacillus anthracis with disease anthrax

Koch's postulates

specialized cell of mucosa-associated lymphoid tissues (MALT) that samples materials from intestinal mucosa and can exploited by pathogens to cross membranes

M cells

when oral antibiotics inhibit normal intestinal microbiota what grows in response

clostridium difficile

lipopolysaccharide structure

O side chain, core polysaccharide, lipid A

after adherence, inject toxins that reorganize actin filaments causing loss of microvilli allowing toxin to enter cell

TTSS

allows certain toxins to be injected into host cell

TTSS

types of membrane disrupting exotoxins

channel forming (pore-forming) and phospholipid hydrolyzing phospholipase

exotoxin that inserts itself into normal host cell membranes

channel forming exotoxin

what effects the length of the incubation period?

age of individual, host's physical condition, growth rate of pathogen, number of infectious particles encountered

suspension of exotoxin-neutralizing antibodies used to treat exotoxin-induced diseases

antitoxin

presence of bacteria in the bloodstream

bacteremia

TTSS is similar to

bacterial flagella

function in coagulation, thrombosis and can lead to internal bleeding

bradykinin

produced by coagulation cascade

bradykinin

the toxic LPS molecule from gram-negative bacteria is a ____

endotoxin

unlike bacterial cells, a virus must ___ to cause disease

enter host cell

toxins that cause symptoms associated with intestinal disturbance

enterotoxins

type of toxin inactivated by heat

exotoxin

toxic secreted enzymes are ____

exotoxins

true or false: macrophages are the only way to kill shigella cells

false; they survive when engulfed by macrophages

bacterial source of exotoxins

gram + and gram - bacteria

bacterial source of endotoxins

gram - bacteria

alpha hemolysis produces a ___ color

green

molecules that lyse red blood cells

hemolysins

time between exposure to pathogen and onset of physical illness

incubation period

progression of infectious disease

incubation period, illness, convalescence

LPS net effect is to

induce inflammation, fever, intravascular coagulation, hemorrhage, and shock

a microbe establishing itself onto a body surface and into a parasitic relationship with its host

infection

when relationship between microbe and host is parasitic it is called an

infection

number of microbes necessary to establish an infection

infectious dose

by forming actin tails certain bacteria can __ themselves from the interior of one cell directly into the interior of an adjacent cell. This lets the bacteria __ extracellular immune response mechanisms

propel; avoid

powerful mediators of inflammation, fever, and septic shock

prostaglandins and leukotrienes

produced by cytokines

prostaglandins and leukotrienes

beneficial roles of normal microbiota

protecting against infection, promoting oral tolerance, aiding digestion, producing substances important for human health

exotoxins are what kind of molecule?

protein

used by staphylococcus aureus as a strategy to avoid antibody adhesion and phagocytosis

protein A

within an epithelial cell, ____ cells propel and force themselves into the next cell

shigella

if scarring from inflammatory response damages inner areas of fallopian tubes in female reproductive tract there is a higher likelihood of

sterility due to blocking of fertilization and ectopic pregnancy

virulence factors

structural features, exotoxins, endotoxins

when symptoms do not appear or are mild enough to go unnoticed

subclinical

exotoxins that activate too many effector helper T cells causing a massive release of cytokines that leads to fever, nausea, etc

superantigens

___ and subjective because only the patient can feel them and ___ are objective because the doctors can notice them

symptoms; signs