chapter 7 pt 2 Flashcards
human bacteria
symbiotic
-some can become opportunistic pathogens and cause infection
biofilm
surface microorgamisms enclosed in an extracellular matrix
-on most natural environments on earth
quorum sensing
bacterial communication with chemical messages than initiate a repsonse as a function of population density
-function as a group to accomplish tasks too big for one cell
-release toxin, digest food, flourescence
pseudomonas
-small gram negative rods with single polar flagellum
-free living in soil, sea, plants an d animals (biofilms)
-contaminate homes and hospitals
-decomposers
-aerobic respiration but dont ferment carbohydrates (non fermenters)
-produce oxidase and catalase, some make water soluble pigments
-true pathogens of plants
can some psuedomonas grow anaerobically?
yes but only if given growth factors
pseudomonas aeruginosa
soil and water
-intestinal resident in some people
-resist soap, dyes, quaternary ammonium disinfectant, drugs and drying
-contaminate ventilators, iv solutions, anesthesia equipment, contact lenses
-grape odor, green blue pigment (pyocyanin)
-multidrug resistance
-opportunistic nosocomial pathogen (attacks unhealthy) (burns, cancer, CF)
-pneumonia, uti, abscesses, corneal disease otitis externa (minor ear infection)
-meningitis, endocarditis, bronchopneumonia, bone and joint infection
-no tissue, cant infect
-eye drop outbreak
how do psuedomonas talk
autoinducer molecules
-inhibit them to shut down biofilm and toxin secretion
-can potentially put the inhibiting agent on clothing, medical supplies etc
microbial growth
-grows at cellular level which increases size
-grows at population level
binary fission
-how cell divides (splits in half)
-parent cell enlargers, duplicates chromosome, forms septum dividing the cell into 2 daughter cells
generation/ doubling time
time necessary for fission cycle
-each new cycle increases population by factor of 2 (exponential growth)
generation time
minutes or days
equation for population size
nf= (ni)2^n
nf
total number of cells in the population
ni
starting number of cells
exponent N
number of generations
2n
number of cells in that generation
growth curve
predictable pattern of growth over time
lag phase
stage in the growth cruve
-flat period of adjustment/ enlargement
-little growth here
exponential growth phase
period of maximum growth that will continue as long as cells have adequate nutrients and a favorable environment
stationary phase
cell growth rate= cell death rate
-caused by depleted nutrients and oxygen
-excretion of organic acids and pollutants
death phase
as limiting factors increase, cells die exponentially
how to analyze population growth
-turbidity (easiest): how cloudy does it look
-enumeration: viable colony count with cytometer
apicomplexan parasites
-sporozoans
-lack locomoter organelles in the trophozoite state
-sexual and asexual phases btwn different animal hosts
-special infective bodies that are transmitted by anthropod vectors, food, water etc
apicomplexia parasite types
plasmodium, toxoplasma, cryptosporidium
plasmodium is the agent of which illness
malaria
malaria
-dominant protozoan disease
-obligate intracellular sporozoan
-4 species
-anopheles/ girl mosquitos, blood transfusion and mother to fetus (mode of infection)
-300-500 million cases a year
-2 million dead yearly
4 species of malaria
-p. malariae, p vivax, p falciparum, p ovale
asexual malaria phase dormant
human host
-inject asexual sporozoite that localizes int he liver then undergoes schizogony generating many merozoites that enter circulation 5 to 16 days later
-exoerythrocytic development: symptomless developing in liver
asexual malaria entering circulation
-merozoites attach to and enter rbc where they convert to trophozoites and multiply
-rbc burst releasing trophozoites some become gametes some infect other rbc
-this is the erythrocytic phase
what happens if we get rid of all mosquitos
there will be no malaria
sexual phase
in mosquito host
-mosquito draws infected rbc, gametes will fertilize creating diploid cells that create sporozoites in mosquito stomach
-sporozoites lodge in the salivary glands to infect a human host
plasmodium symptoms
chills, fever, sweating, anemia, organ enlargement
-48-72 hrs as RBC ruptures
p faliparum
most malignant type of plasmodium
-highest death rate in kids
-causes cerebral malaria
-trophozoite presence in rbc diagnoses
-more resistant to drugs
p faliparum treatment
chloroquine, mefloquine
-can come back w out proper treatment and the next infection is likely to mild
sickle cell
resistant to malaria
-glu to val
-val is a hydrophobic amino acid that forms polymers/ chains which will change the shape of the RBC
sickle cell heterozygotes
have mostly normal rbc but have protection form malaria
-stress can trigger sickling
-stress includes plasmodium infection
sickle cell homozygotes
-not protected from malaria
-makes the disease worse
-macrophages in immune system will clear sickled RBC
