exam 1 (final review) Flashcards
the total destruction of all microbes including more resilient forms like spores, non-enveloped viruses, and fungi
sterilization
the physical procedures or chemical agents used to destroy microbes or render them inert
disinfection
level of disinfectant used for items involved in invasive procedures
high
level of disinfection used for items or surfaces that are not likely contaminated w/ spores or highly resilient microorganisms, used for noninvasive instruments
mid
level of disinfectant used to treat non critical items
low
Disinfection level of incineration
high, destroys living material
disinfection level of boiling (include times, temps)
med to high
100C for 10 min will kill veegtative bacteria, fungi, most viruses
30 min will sterilize
must be covered
disinfection level of autoclaving (include times, temps)
high
application of steam heat (121C) and pressure (15PSI), sterilizing in 15 min
filtration is useful for sterilizing:
liquids that could e damaged or destroyed by heat
crosslinks nucleic acids
UV radiation
creates strand breaks in nucleic acids
ionizing radiation
chemical agent that is used to kill microbes on living tissue
antiseptics
chemical agent that is used to kill microbes on non-living surface
disinfectant
ideal characteristics of a chemical disinfectant
kill or slow growth of microbes
non-toxic
soluble in wate/=r/alcohol
long shelf life
able to be used in a doluted form
fast-acting
nonstaining, noncorrosive
inexpensive
odorless
pc >1 means the disinfectant is _ than phenol
more effective
pc < 1 means the disinfectant is _ than phenol
less effective
ethylene oxide gas (level, mechanism, considerations)
high
akylates proteins, disrupting function
requires training, specialized chamber, explosive
formaldehyde gas (level, mechanism, considerations)
high
akylates proteins, disrupting function
requies training, specialized chamber, carcinogenic
oxidizing agents (level, mechanism, examples)
high
destroy proteins, DNA
hydrogen peroxide, peracetic acid, ozone
chlorine (level, mechanism, examples)
high
destroy proteins, membranes, nucleic acids
hypochlorous acid, sodium hypochlorite (10%)
alcohol (level, mechanism, examples)
med
disrupts membrane bilayers
isopropanol, ethanol (70%)
iodine (level, mechanism, examples)
med
precipitates proteins, oxidizes essential enzymes
tincture of iodine, povidone iodine
quaternary ammonium compounds (level, mechanism, examples)
low
disrupts membrane bilayers
four organic groups linked to nitrogen
benzalalkonium chloride, cetylpyridinium chloride
soap and water (level, mechanism, considerations)
disrupts membrane bilayers
cheap, easy
considerations when choosing a disinfectant
microbial susceptibility
temp, pH
concentration
environment
endospore formers
gram pos
9 amino acid crosslinks
LTA
can have capsule, S layer
periplasm is space between cell wall and membrane
gram neg
4 amino acid crosslinks
outer leaflet is LPS, inner leaflet is normal phospholipid
can have capsule
periplasm is space between inner and outer membrane
structures that enable organisms to stick to surfaces or each other
fimbriae
functions of pili
attachment
twitching motility
evade immune system
conjugal pilus
structures rotate to propel cell
flagella
single polar flagellum
monotrichous
a flagellum at each pole
amphitrichous
multiple flagella localized at the cell pole
lophotrichous
multiple flagella, inserted at many locations in the cell pole
lophotrichous
multiple flagella inserted at many location in the cell membrane
peritrichous
function of capsules and slime layers
assist in attachment to surfaces
protect against phagocytosis
resist desiccation
extrachromasomal molecule of DNA not required for cell survival in all conditions
plasmid
transfer of naked DNA
transformation
cell to cell transfer of plasmids, chromosomal material
conjugation
transfer of chromosomal DNA via bacteriphage
transduction
a unit of genetic material that functions ina coordinated manner by means of an operator, a promoter, and one or more structural genes
operon
a system of genes, formed by one or more operons, that have a common regulatory element
regulon
alpha subunit of RNA pol
2, interacts w/ regulator proteins
beta subunit of RNA pol
catalytic activity, holds onto RNA pol
beta’ subunit
involved in binding, staying bound to DNA
omega subunit of RNA pol
stabilizes complex
sigma factor
recognizes promoter region o fgene, released soon after the start of transcription
regulation that controls the activity of preexisting enzymes
post translational
regulation that controls the amount of an enzyme
regulation of gene expression
transcription of gene into mRNA followed by translation of mRNA into protein
gene expression
binds to environmental signal and auto phosphorylates
sensor kinase
activated via phosphorylation of sensor kinase, mediates response by altering gene transcription
response regulator
bind to regulatory sequences in the DN and prevent transcription of target genes usually block sigma factor from binding promoter
repressor/negative regulator
bind to regulatory sequences in the DNA and promote transcription of target genes, often act to recruit/stabilize sigma factor
activator/positive regulator
other functions of sigma factors
sporulation, stationary phase, heat shock and stress response, flagellar synthesis
prevent microorganisms from having access
physical barrier systems
recognize conserved microorganism elements, responds rapidly to remove microorganism
innate immune system
recognize traits particular to specific microorganisms and acts to remove them
adaptive immune response
at on non-self particules to inhibit growth/metabolism, lyse microorganism, promote immune response
antimicrobial molecules
innate protections are activated by:
PAMPs
a protein or carbohydrate that is recognized and sufficient to illicit an immune response, may contain one or more antigens
immunogen
a molecule that is recognized by a single specifici antibody or T cell receptor on T-cells
antigen
production of antibody proteins
humoral immunity
T cells that bind different antigens to control antibody production, kill intracellularly infected cells
cellular immunity
released by stroma in bone marrow, stimulate stem cell differentiation
colony stimulating factors
innate immune cells generally arise from:
myloid progenitor cells
adaptive immune cells generally arise from:
lmyphoid progenitor cells
natural killer cells arise from:
lymphoid progenitor cells
phagocytose and kill bacteria
neutrophils
phagocytose and kill bacteria and present antigens to T-cells via class II MHC proteins
APCs
APCs found in tissue, spleen, lymph nodes, other organs
initiate inflammatory response
macrophages
APCs found in lymph nodes and tissue, most potent APC, initiates and modulates T-cell response
dendritic cells
cells that produce antibodies and process and present antigens
B cells
type of B cells that are long lived and circulate until activated by a specific antigen
memory cells
type of B cells that are short lived and produce large amounts of antibody
plasma cells
control, suppress, and activate immune and inflammatory resposne by cell-cell interaction or release of cytokines
CD-4 T cells
role in recognizing virally infected cells, tissue transplant, and tumor cells
CD-8 T cells
kill antibody decorated cells, virus-infected cells, or tumor cells
natural killer cells
release histamine
basophils
phacogytic cells, role in response to parasitic pathogens
eosinophils
small polyptides that act as a chemical signal
cytokines
proteins that stimulate proliferation of fibroblasts
growth factors
network of organs, lymph nodes, lymph ducts, adn lymph vessels that make and move lymph from tissues to the bloodstream
lymphatic system
functions of the lymphatic system
maintain fluid balance
absorb fats, fat soluble vitamins
production, transport of immune cells
primary lymphoid organs (organs and function)
sites of initial lymphocyte differentiation
bone marrow, thymus
seocndary lymphoid organs (organs and function)
where B-cells, T-cells reside and respond to immune challenge
lymph nodes, spleen, Mucosa Associated Lymphoid Tissue (MALT)
PAMPs
pathogen associated molecular patterns
innate immune cells can be activated by:
direct interation w/ PAMPs mediated by PRRs
indirect activation w/ cytokines released by other cells
PRR
pathogen recognition receptors
majority of PRRs are part of protein family called:
Toll-like receptors (TLRs)
process by which a phagocyte engulfs and destroys microorganisms
phagocytosis
stimulates localized inflammation by promoting the activation of IL1B and IL18
inflammasome
cells that line hollow organs nad make up the outer surface of the body
epithelial cells
thin layer of cells that lines the interior surface of blood and lympathic vessels
endothilial cells
function of complement system
promote inflammation response
opsonize an invader
lyse invader by forming pore protein in membrane
to mark antigen for phagocytosis by complement or antibody binding
opsonize
destruction in phgolysosome is mediated by:
reactive oxygen species
acids, enzymes
proteases
MHC I (what kind of proteins does it present, where is it loaded, what cells)
presents proteins from cytoplasm, loaded in ER, all cells
MHC II (what kind of proteins does it present, where is it loaded, what cells)
exogenous proteins, loading in vesicle, only APCs
function of inflammatory response
allow immune cells to leave blood, enter site of infection, begin cellular immune response
extracellular enzyme that activates Bradykinin
Kallikrein
Bradykinin
binds to receptors on surface of capillary walls to open junctions, ninds to receptor on mast cells to stimulate release of histamine, leukotrienes, prostaglandins
increases blood flow to area (vasodilation)
histamine
attract local neutrophils
leukotrienes
promote dilaiton of blood vessles, recruit platelets, stimulate nerve cells to cause pain
prostaglandins
what key cytokines do phagocytes release that encourage selectin and ICAM/IVAM production
IL-1, TNFα
act to snag neutraphils, cause to roll along capillary wall
selectins
bind integrins on neutraphil surface initiating extravasation
ICAM/IVAM
movement of WBCs from capillaries to tissue
extravasation
fever is caused by:
pyrogens
chemicals originating from invading microorganism (LPS, LTA, etc), cause cells to release endogenous pyrogens
exogenous pyrogens
chemicals originating from host
endogenous pyrogens
advantages of fever
slow/inhibit bacterial growth to allow immune system time to respond, reduce iron availability for bacteria
a protein or carbohydrate that is recognized and sufficient to illicit an immune response
immunogen
piece of immunogen
a molecule that is recognized by a single antibody or TCR
antigen
the specific sequence or 3D structure of antigen that is recognized by the specific antibody or TCR
epitope
molecules too small to illicit an immune response
haptens
antigen is large repetitive structure sufficient to activate B cells directly to make antibody
T-independent antigens
what antibodies are produced by B cells when activated by T-independent antigens
IgM
antigen is generally protein and will generate all 5 different types of antibody
T-dependent antigens
specific receptors for antigens presented by MHCI or MHCII
T cell receptor
main T-cell responsible for antigen specific immune response
alpha/beta chain TCR
stimulate B cell antibody production in response to antigen
CD4 T helper cells
secrete chemical to kill a cell infected by an intracellular organism in response to antigen
CD8 Cytolytic T cells
CD 8 interact w/ what kind of MHC protein
I
protein that forms pores in membrane, released by CD8 T cells
perforin
proteases that stimulate apoptosis, released by CD8 T cells
granzymes
CD 4 interact w/ what kind of MHC protein
II
initial response, produce cytokines to promote expansion of the cellular immune response
TH0 cell
produce IFNγ to activate macrophages, dendritic cells, promote responses to intracelular infections
TH1 cell
stimulate antibody production, memory T cells
TH2 cell
activated cells are stimulated to grow and divide via mitosis, each successive division increases number of cells that recognize a specific antigen
clonal expansion
TH1 cells secrete _, which stimulates B cells to produce
IFNγ, IL-2
IgM, IgG
TH2 cells secrete _, which stimulates B cells to produce
IL-4, IL-5
IgG, IgA, IgM
part of antibody that is structural component - the same for every antibody of the same class
constant/class domain
region of antibody that is responsible for binding antigen
variable domain
fragment that is recognized by phagocytes for opsonization
fc
long term immunity, memory antibodies, neutralizes toxins, opsonizes, fixes complement
IgG
secretory antibody, on mucous membranes
IgA
defautl antibody, can serve as B cell receptors
IgM
receptor on B cells
IgD
antibody of allergy, worm infections
IgE
vdj linked to c
heavy chain
vj linked to c
light chain
rss
recombination signal sequence
ways antibodies remove antigens:
neutralization, agglutination of microbes, precipitation of dissolved antigens, activation of complement system
Nk cells, monocytes, macrophages, neutrophils bind Fc region, secrete enzymes and perforins to kill cell when bound to antibody
antibody-dependent cell-mediated cytotoxicity (ADCC)
the process by which a person or animal becomes protected against a disease
immunization
administration of a killed or weakened infectious microorganism or piece of infectious microorganism in order to prevent the disease
vaccination/inoculation
a product that produces immunity, therefore protecting the body from disease, administered by injection, mouth, or aerosol
vaccine
immunization of a population stops the spread of an infectious agent by reducing the number of infectious hosts
herd immunity
injection of purified or antibody-containing serum to provide rapid, temporary protection or treatment
passive immunization
when an immune response is triggered because of challenge with an immunogen, long lasting response
active immunization
vaccine that uses a microbe that is a natural pathogen but has lost virulence through extensive passaging
live, attenuated vaccine
advantages of live attenuated vaccine
create long-lasting and strong immune response, natural delivery = easy to administer
disadvantages of live attenuated vaccine
special storage, usually can’t be used for immunocompromised people, rare cases of vaccine related illness, long development
vaccines that use microorganisms that have been treated to destroy infectivity by heat or formaldehyde
inactivated, whole vaccines
advantages of inactivated whole vaccines
no risk of infection, more lenient storage, easier to produce
disadvantages of inactivated whole vaccines
not as robust response, some cannot be used in immunocompromised individuals, unimportant antigen may skew immune response
subunit vaccine
contain only antigenic parts of pathogen
advantages of subunit vaccine
no risk of infection, more lenient storage, strong and targeted immune response, can be used in immunocompromised individuals, can be combined
disadvantages of subunit vaccine
may require boosters, can make immune response unbalanced
mRNA vaccine w/ UTRs, cap, tail, coding sequence
non-replication mRNA vaccine (NRM)
mRNA vaccine w/ UTRs, cap, tail, coding sequence, replicase
self-amplifying mRNA vaccine (SAM)
advantages of RNA vaccine
no risk of infection, strong and targeted immune response, can be used in immunocompromised individuals, easy to tailor to new strains
disadvantages of RNA vaccines
may require multiple boosters, can make unbalanced immune response (new strains), special handling
possible outcomes of encounter w/ microorganism
- transient colonization
- permanent colonization
- produce disease
possible entry methods
inhalation, ingestion, injury, sexual contact
entry of pathogen or parasite
infection
damage or loss of tissue or organ function due to infection
disease
host provides benefit to microorganism, but microorganism does not provide benefit or harm host
commensalism
both microorganism and host benefit from colonization
mutualism
microorganism and host benefit from the colonization
mutualism
microorganism lives at expense of host
parasitism
microorganism causes disease in host
pathogenic
non-normal flora organism that are able to infect host and cause disease
primary pathogen
normal flora organisms that do not normally cause disease but can cause disease if the host is compromised
opportunistic pathogens
long infections where the pathogen in balance with the host, taking what it needs for existence and causing minimal harm to host
chronic infection
infections that arise suddenly and are characterized by rapid and dramatic disease onset
acute infection
measure of the ability of an organism to cause disease
pathogenicity
number of organisms to colonize 50% of hosts, measure of pathogenicity
id50
the measure of the severity of disease caused by an organism
virulence
number of organisms to kill 50% of hosts, measure of virulence
ld50
disease pathway
encounter, entry, spread, multiplication, damage, outcome
outcome is manipulated by _ and _
diagnosis, treatment
person to person dissemination of an organism
direct transmission
dissemination via an intermediate such as fomite or reservoir
indirect transmission
sites in which infectious agents remain viable and from which individuals can become infected; can be living or nonliving
reservoirs
allow pathogen to infect and cause disease in host
virulence factors
section of genome containing multiple virulence genes
pathenogenicity islands
decrease or loss of virulence
attenuation
surface proteins that bind host cell sugars or protein receptors
adhesins
proteins secreted by bacteria that damage the host cell
exotoxins
bacterial products or components that are released by bacteria, illicit an immune response
endotoxins
LPS and LTA are:
endotoxins
cholera toxin, tetanus toxin are:
exotoxins
B subunit of AB toxin
binds host cell, delivers A to cell
A subunit of AB toxin
toxic activity
types of exotoxins
cytolytic, proteases, block protein synthesis, block 2nd messenger pathways, superantigens
diagnostic characteristics of S. aureus
gram + cocci, non-motile, non-spore forming, catalase +, coag +, grow aerobic and anaerobically
entry of S. aureus:
skin to skin contact, injury from contaminated object, inhalation, ingestion
MSCRAMM
microbial surface components recognizing adhesive matrix molecules
S. aureus MSCRAMMs that facilitate adherence:
elastin, collagen, fibronectin binding proteins
binds to fibrin and converts to fibrinogen to clot blood/plasma and shield bacteria against attack by innate immune cells
coagulase
surface protein that binds the heavy chain in Fc region of antibody to block opsonization activity by IgG
protein A
cytolytic toxin of S. aureus that is a multisubunit pore forming proten
alpha toxin
toxin in S. aureus that damages membranes in erythrocytes, fibroblasts, leukocytes
beta toxin
multi subunit pore forming toxin that primarily effects leukocytes
leukocidin
high concentrations of leukocidin:
causes cell lysis
low concentrations of leukocidin:
stimulate apoptosis
responsible for virulence factor regulation in S. aureus
quorum sensing - AGR
outer layer of skin, composed of multiple layers of keratinocytes
epidermis
outer layer of dead keratinocytes
stratum corneum
complex layer beneath the epidermis that contains sweat glands, nerves, sebaceous glands, capillaries, and erector muscle
dermis
toxin that causes a sloughing off of top layer of epidermis by hydrolyzing cell junction proteins
exfoliative proteins
exfoliative dermatitis caused by presence of ET toxin
staphylococcal scalded skin syndrome
test for SSSS, slight pressure separates top layer of skin, creating blister w/ fluid that is free of bacteria and leukocytes
Niklosky sign
S. aureus food poisoning is a:
intoxication
superantigen that causes release of cytokines, leakage of endothelial cells at low concentrations, cytotoxic to T cells and APCs at high concentrations
Toxic Shock Syndrome toxin
infection primarily on face or arms, small red spot which develops in pus filled vesicle that when ruptured spreads organisms to secondary site
impetigo
infection of hair folliclles
folliculitis
pus filled boils, underlying pus contains necrotic tissue, bacteria
furuncles
grouping of furuncles that extend into deeper tissues
carbuncles
presence of bacteria in blood
bacteremia
growth of bacteria in the blood
septicemia
whole body inflammation response that is destructive to tissues
sepsis
organ failure due to sepsis
septic shock
inflammation of interior linings of heart valves and chambers
acute endocarditis
mecA:
encodes PBP-2a, does not bind B-lactams
