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Pile Management Card
Micro 201 Exam

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pathogen transport
-direct contact (sneezing, coughing)

-indirect contact
-vehicles (soil, water)
-living organisms (humans, insects)
-fomites (inanimate objects)
virulence
-degree of pathogenicity
-determines by:

-invasiveness (spread otu)
-infectivity (est. focal pt)
-pathogenic potential (how much damage?)
opportunistic pathogen
-normal until induced to produce disease
primary (frank_ pathogen
-cuases disease by direct interaction w/ host
-
T cells
-immune surveillence= destruciton of cancer cells
-production of cytokines (chemical activators of B cells, T cells, and other WBCs)
mononuclear cells
-macrophages
microbial flora
-tissues/internal organs free of microbes
-surface tissues extensively colonized
-different microbes occupy distinct parts of body
-normal mivorbes can prevent coonization by pathogens (outcompete)
preventing drug resistance
-high []
->2 drugs at same time
-use when necessary
-new drugs, baby
superinfeciton
-development and spread of drug-resistant pathogens
-caused by drug treatmetn
-pseudomonas membrane enterocolotoitis
-killed intestinal flora
-cloitridium diffiuclt to flourish and produce a toxin
origins of drug reistance
-spontaneous chromosomal mutation
-R plasmids (conjugation, transformation)
-transposons
mechanisms of antibiotic resistance
-inhibition of uptake or efflux from pathogen
-ex: tetracyclien pumped out by some gene)
-destruciton/inactivation (beta-lactomose): destroys pennecillin

-drug target modification
-resistance
drug effectiveness?
-microbe access (route, physical barriers like blood clots)
-suspectibility (appropriate drug)
-[] (igher than MIC)
-
antiviral drugs
-viral infectiosn depend on hosts' metabolic pathways
-want to disrupt specific phases of life cycle or inhibit virus-specific enzymes
-ex: amantidine (prevents flu)
antifungal drugs
-fungal cells similar to human cells (not effective)
-low TI
-easier to treat superficial than systemic infections
mechanisms of antibacterial drugs
-inhibits cell wall synthesis (pencillin)
-high TI b/c no cell wall in animals

-inhibits protein synthesis
-streptomycin, Tetracycline
-can dscriminates b/w bavterial and euk. robosomes

-nucleic acid inhibition
-quinolones
-inhibits bacterial DNA gyrase
Cipro used to treat anthrax

-antimetabolites
-competative inhibators of enzymes
-sulfonamides (inhibit microbial folic acid synthesis)
-high TI if drug targets essential microbial pathway not present in animals
disk diffusion tests
-disks w/ specific drugs on agar plates
-[] gradient of drug
-diameter of clear zones
Dilution susepticbility assay
-serial dilutions in broth
-add bacteria
-subculture broth w/o antibiotic
determinign MIC or MLC
-dilution assays/disk diffusion assays
MLC
-lowest [] of drug that will kill pathogen
MIC (min inhibatory [])
lowest [] of drug that inhibits pathogen growth (want low MIC)
Therapeutic Index (TI)
-ratio of toxic to therapeutic dose
-bigger TI the better
-(lots to kill you, only a little to kill the microbe)
toxic dose
-drug level at which drug becomes too toxic for patient (side effects)
therapeutic dose
-drug level required for clinical treatment
narrow spectrum drugs
-attacks only a few pathogens
broad spectrum drugs
-attacks many
static drugs
-complete elimination of pathogen requires activity of host defenses
-not effective on immunocompromised patients (need cidal over static)
antibiotic
-microbial product that kills/inhibits grwoth of microbes
-many are synthetic derivarives of natural compounds
Pennicillin
-Alexander Fleming
-1928
-Florey and Chain demonstrated usefulness in mice
Paul Ehrlich
-developed concept of selective toxicity
-magic bullet
-ID'd dyes to treat African sleeping sickness
1904

1910: ID's aresenic compounds to treat syphilis
selective toxicity
-chemical toxic to causative agent of disease and harmless to host
antimicrobial chemotherapy
-treats diseases w/ chemicals
-
chemical agetns
-denature proteins, disrupts cell membranes, oxidizes macromolecules

-phenolize (lysol)
-alcohols (ethanol)
-halogens (iodine, chlorine)
-sterilizing gases (ethylene oxide, kills spores)
ionizing
-very penetrating
-doesn't kill viruses
-but kills spores
-uses gamma rays
-poultry, fruit, meat, etc.
UV
-DNA damage
-not penetrating
-limited to surface
radiation
-UV and ionizing
filtration
-good for chemicals/drug
-gases (surgical masks)
antimicrobial agents
-cidal= kills (ampicillin)
-static= inhibits growth (baciliram)
dry heat
-oxidizes cellular components and denaturizes proteins
-less effective than moist heat (no H2O to hydrolyze rxns)
-not corrosive
pasteurization
-below b.p. for short time
eliminates pathogens
-reduces spoiling microbes
autoclaving
-ALL killed (even endospores)
-sterilizes
-15psi to get above boiling temps
boiling
-does not kill endospores
-does not sterilize, but disinfects
Decimal reduciton time (D valve)
-teim required to kill 90% pop at given temp
-influenced by local environment
heat
-degrades nucleic acids, proteins
-boiling, autoclaving, pasteurization
effectiveness of agent
-pop size
-pop composition (spores)
-antimicrobial agent []
-duration of exposure
-environment
microbial death
-exponential
-same fraction eliminated in each time interval
sanitization
-reduction of microbes to acceptable levels
disinfection
-eliminates most pathogens
-doesnt remove ALL cells, spores
-disinfect untensils
-antiseptics on tissues
sterilization
-eliminates ALL
role of microbes
-primary producers
-decomposers
-food source
-biogeochemical cycling
-changes soluble.gaseous
produce inhibatory compounds that limit survival of micorbes/plants
-ymbiotic interactions
consumers
-use organic matter as food
0humans (3 eat 2)
decomposers
-in ecosystem
-mineralization
primary produciton
-synthesize organic matter
-from CO2 and other inorganic compounds
-primary producers carry out
-plants, photosynthetic bacteria
ecosystems
-self-regulatory units
microbial mats
-thick biofilms
-macroscopic
-aquatic
-pond scum
-
biofilms
-can't be seen
-layers of microbial cells
-creates micro environment and niches
-plaque, etc.
metal
-organisms can modify metals to be more or less toxic
immobilization
-incorporation of simple soluble substances into body of organism
-
mineralization
-organic matter--> simple inorganic compounds
biogeochemical cycling of nutrients
-redox rxns to change characteristic of nutrients
-global level impacts
competition
-if 2 populations competing for resources, 1 pop dies
Ammenalism
negative effect of one organism on another
-unidirectional
-release of toxic compound (at a distance)
Parasitism
-parasites harms/lives at expense of host
-ex: bacteriophage
-host provides food, shelter, etc.
-ex: malaria, lichens
Predation
-predator attacks
=prey dies
Negative symbiosis
-predation
-parasitism
-ammensalism
commensalism
-commensal= organism that benefits
-not directly dependent on metabolism of host
-gets shelter/food from host
-host not hamred/benefits
-ex: mikl spoiling
-fermentation bacteria produce acids for acidophiles
-skin/surface bacteria releases organic compounds used by commensals
cooperation
-like mutualism, but not obligatory
-can survive alone, if needed
rumen
-one stomach of cow
-contains large, diverse opoulation of microbes
ruminants
-animal w/ 4 stomachs
Cows
-mutualism
-anaerobic micorbes in cow stomach that hydrolyze cellulose--> give glucose
-glucose fermented to organic acids used by cow
-produce methane/CO2
protozoa/termites
-mutualism
-protozoa have cellulose
-metabolize to acetate
-termites use acetate
Mustualism
-benefits both partners
-obligatory relationship
-dependent on each other
-ex: protozoa/termites
-ex: cows
Positive symbiosis
-mutualism
-cooperation
-commensalism
symbiosis
-relationship b/e 2 or moredissimilar organisms living in close association
-can be beneficial, harmful, or neutral
-most are beneficial or neutral b/w microbes and humans
micorbial ecology
micorbes and their environemnt
microbial interactions
microbes and other organisms
F plasmid
yeahhh
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