eating habits - 12th set Flashcards
Inoculum
the starting culture. term used when microbes are introduced into a medium
(i.e. rich nutrient source ) to initiate growth
Culture (newport)
growth of microorganism in a culture medium.
Growth (divide)
refers to microbial multiplication; increase in number (or population) i.e. bacterial division not bacterial size
Culture medium (lab only)
defined as nutrient material prepared for growth of microorganism in lab. bacteria growing in nature are not growing in culture medium. culture only in lab.
Pure culture (adopt)
descendants of a single cell and separated from others
Bacterial growth may result either in…(US)
a colony or a biofilm
Colony (kenny)
aggregation of cells arising from a single parent cell
Biofilm (bugs on water - malaria)
collection (many different species of microbes) of surface microbes living in a complex community. it amplifies disease causing ability of bacteria if they’re in a biofilm community
pure colony
when all cells are of the same type, no contamination.
Criteria for culture medium - it must contain (cooking)
appropriate nutrients in proper proportion for the specific microorganism
growth requirements - physical factors (PLOOT)
temperature, ph, light (energy source), osmosis and osmotic pressure
nutrient uptake - passive process (diffusion) (ex)
= downhill movement
- substance movement is from a region of high concentration to low concentration
- NO expenditure of cellular energy - simple diffusion, facilitated diffusion, osmosis
nutrient uptake - active process (group bacteria - desert - bus tour) it includes…
= uphill process - functions when bacteria are in low nutrient environment there is expenditure of cellular energy. includes
active transport and group translocation
Simple diffusion and ex. (think small)
- small or lipid soluble substances easily moves down concentration gradient across plasma membrane. - movement continues until equilibrium is reached between inside and outside. Ex: oxygen, co2, water, short chain/small fatty acids
Facilitated diffusion and ex. (GUV)
used by molecules unable to diffuse or fails to dissolve across lipid bilayer - use channel proteins Ex: glycerol, urea, vitamins
Difference between simple and facilitated diffusion? (shuttle - rainy day)
- carrier requirement,
- facilitated diffusion is a saturable process unlike simple. saturable process is when all binding sites are used up, it will come to a standstill. (shuttle) channel proteins are like revolving doors.
Active transport (front door - jonathan - buf)
involves substance movement from outside to inside, i.e. against concentration gradient (uphill) - substance that cross membrane is not altered. no chemical alteration of molecule
group translocation (group mail thieves)
cells picks substance even though they are in lower concentration outside than inside- substance altered during transport; prevents from leaving the cell.
group translocation process (group photo of pony)
glucose utilization by the phosphotransferase system, purines, pyrimidines and long chain fatty acids transport
Minimum growth temperature (no more)
lowest temperature at which species will grow; slow metabolism - any lower and it’s too slow to support metabolic activities of the cell.
Optimum growth temperature
species grows best at this temperature; fastest growth because all metabolic reactions are supported well at this temperature.
Maximum growth temperature (lowest and highest - body temp)
highest temperature at which growth is possible, though slow growth. beyond this temperature, cell dies. below 4 degrees C, bacteria cell will die. at 37 degrees about will grow best.
temperature has an impact on both (protein bar)
proteins and lipids.
proteins: high and low temps (H - kitchen table - H - freezer)
h2 and covalent bonds of proteins are broken. irreversible damage. low temp - h2 bonds are formed, and it disrupts the 3 dimensional shape of the protein.
lipids: high temps (melt/freeze)
lipids become too fluid, and it is not able to support membrane function. at low temps - the lipid becomes rigid and fragile.
Majority of human pathogens belongs to (japan)
…mesophile - based on temp requirements
Mesophiles (meso-moderate) (and temp in degrees)
moderate temperature loving microbes optimum temperature variable ( between 20 - 40 C) - optimum temperature for growth of most pathogen is close to that of host - human internal body temp
Thermoduric mesophiles (travel mug - cow)
can survive brief high temp during inadequate pasteurization and canning. these are non pathogenic.
Mycobacterium leprae (cool)
hansen’s disease (leprosy). lesions are at cooler areas of the body. face, extremities, toes and fingers, ears, etc. It is found in foot pads of armadillos because of lower internal body temp.
Treponema sps - syphillis (lesions - rabbit)
lesions are at cooler areas of the body, genitals, lips, throat, etc. earlier times, one treatment option was to induce malaria. treponema is cultivated in rabbit testicles.
Cells maintains constant internal…(dove - swiss)
pH close to neutral. energy harvesting reactions demands neutral ph.
Neutrophiles - preferred pH range (think neutral)
from 6.5 – 7.5; internal cell pH is neutral, Ex: majority of pathogenic bacteria belong to the neutrophils (6.5 - 7.5 ph) internal and external ph is always neutral.
Acidophiles ex and #
optimum pH below 5.5; preferred by many fungi (prefer high salt and sugar for growth)
Alkalinophiles (# and ex)
optimum pH above 8.5 (alkaline range) Ex: Vibrio cholerae - found in alkaline soils and lakes
Stomach (h.pylori - breaks down)
colonized by acid tolerant microbes helicobacter pylori - secretes urease. breaks down urea to CO2 and ammonia. ammonia forms neutral envir. surrounding bacteria.
Urogenital area of adult female (garden w/ out O)
colonized by fermenting microbes includes,
i. Normal microbiota and
ii. Abnormal microbiota aka bacterial vaginosis - dominated by Gardnerella vaginalis and other anaerobic bacterial sps
bacterial vaginosis is clinically associated (lacto)
Poor pregnancy outcome
PID - chronic inflammation
Postoperative wound infection
Endometrosis following elective abortion
Vaginal discharge as well as increased risk of HIV and STD’s
vaginal muscle cells used by lactose bacillus
normal microflora - Lactobacillus acidophilus (in a healthy urogenital system) forms….
lactic acid.
Low pH (acidic ph) of vaginal epithelium prevents..
other bacteria yet allows yeast to establish - a classical example of protection by our normal microflora for our body. on long term antibiotics, it kills these microbes, and opens door for yeast overgrowth.
Osmosis (passive transport)
net movement of solvent molecules across a selectively permeable membrane- movement is from area of high solvent to an area of low solvent concentration
Remember : Living system solvent is always….(balance water)
water. During osmosis, water movement is to the ‘drier’ side of membrane - difference in water concentration is required on each side of membrane
Osmotic pressure (solute)
pressure exerted on membrane by solutes in solution
staphylococcus aureus ( salt tolerant ) (and %) (leg)
can tolerate up to 20% salt cause pimples, sties, boils etc - life threatening toxic shock syndrome - bc it secretes super antigen
Water is a…
reactant in several chemical reactions - enzymes and nutrients are dissolved in water. Dehydrated structures ( like spores and cysts) and can be inhaled and they are resistant structures.
Mycobacterium sps (waxy)
cell wall retains water; enables cells to survive dry condition for extended time bc they have mycolic acid in the cell wall, it gives a waxy nature - so it doesn’t lose water.
Trace elements for growth (trace co-eskimo)
required in small amount, acts as cofactor (contributes to disease) for enzymes
Sterile tap water is preferred over
distilled water or deionized water, it contains sufficient amount of ions and satisfies nutrient requirement.
Nitrogen required for… (CB2 - vitamins)
NH2 group of amino acids, nitrogenous bases of the nucleic acid contains the amine group
Phosphorous (kin - chyrno)
needed for proteins, nucleic acids (as phosphate backbone), phospholipids, ATP synthesis
Sulfur - chemical factors (sailor - cyst - di)
for synthesis of sulfur containing amino acids ( binds via S-S binds); includes cysteine, methiaonine. can make disulfide bonds. as well as for some vitamins ( like thiamine and biotin)
Other elements: such as Ca, Mg…(CMM FFLT the iron)
Mn, Fe, transferrin, ferritin and lactoferrin - They are all iron binding proteins. they limit the iron availability.
Growth factors ( aka organic growth factor) (anorex - corner)
are low molecular weight organic compounds that must be supplemented in medium since bacteria can’t make it; they are in addition to C and energy sources.
what are Transferrin and ferritin? (simple)
the iron binding proteins in humans.
Lactoferrin (drinking milk)
extremely high affinity for iron (II) present in saliva, mucus and milk. excess iron causes more bacterial infections. we only have limited storage for iron.
Siderophores (side of stomach)
bacterial secreted iron binding protein. it includes enterobacin.
siderophore complex - 2 fates (iron - on or off)
can enter as such, binds to receptor on cell surface, brought inside - iron stripped off. OR iron is made free first, subsequently enters cell by transport protein
most pathogens belong to the….(chemo - berkeley bowl)
chemoheterotrophs. most important one. they use carbon and energy source from breakdown of organic compounds
energy source used for (baby - BTM)
- building blocks
- transport processes
- motility
energy sources (2) (beach - sunlight) ALS
1) sunlight - uses radiant energy
2) Metabolism of chemical compounds - amino acids, lipids, or sugar
sunlight (camera)
Phototrophs - (photo - light, trophs - nourishment)
metabolism of chemical compounds (chemo__)
Chemotrophs -chemo - chemical
carbon sources (2) (org and not -AA)
inorganic carbon (co2) and Organic compounds - AA, sugars, lipids
inorganic carbon (auto)
autotrophs - auto - self
organic compounds (like different foods)
Heterotrophs - hetro - different
Toxic forms of oxygen (concert - proud)
toxic forms include singlet, superoxide radicals, hydrogen peroxide, and hydroxide radicals.
Superoxide radicals ( O2- ): (pour on proud)
are highly reactive, toxic, metabolic product found in cytoplasm- superoxide dismutase (SOD) neutralizes it to hydrogen peroxide.
Hydrogen peroxide and peroxide anion (anti)
active components of many antimicrobial agents
Role of vitamins E and C ? (skin cream gas mask)
Acts as antioxidants; provide electrons that reduces toxic forms of oxygen
Aerobic - (OMF - aerobic)
obligate aerobes, macroaerophiles, facultative anaerobes
Anaerobic / Fermentation - 02 requirements (less..) ex. (tolerate)
less ATP. Obligate anaerobes and Aerotolerant (also called obligate fermenters)
The level of enzymes that each bacteria possess determines (peroxidase or catalase, and SOD)..(think reaction)
how they fare in the presence of oxygen
Obligate aerobes ex. (nice one needs oxygen)
Pseudomonas. SOD and catalase abundant
Microaerophiles ex. (micro arrow in stomach - and % and sod amount)
H. pylorii (tolerant to 2-10 % oxygen). atmospheric oxygen is 20%. SOD and catalase limited amount; so have limited ability to detoxify
Facultative anaerobes ex. (you know this)
E.coli and yeast, flexible in O2 requirement SOD and catalase moderate level
Obligate anaerobes ex. (grave obligation)
Clostridium (in spores in soil) and Bacteroides sps SOD and catalase absent; intolerant to oxygen; it’s lethal
Aerotolerant aka obligate fermenters - ex. (snake need fermentation) don’t use….
Ex: Strep pyogenes, Lactobacillus sps
SOD and catalase little amount but don’t use O2 for energy harvesting process
shake tube method - to determine…
the 02 requirement of an unknown bacteria.
Dead tissue accumulating in ulcers can provide
an ideal growth environment forC. perfringens, causes gas gangrene.
bacteroids (thea bacteria)
Includes the B. fragilis and B. thetaiotamicron - main energy source is by fermentation of plant sugar derivatives
significance of bacteroids (bacteria in cows)
i. breaks down potential toxins in plant food ( their fermentation products yields 15% of the caloric value of food)
ii. they remove bile acid side chains ; returns bile to hepatic circulation
bacteroids escape from (thea escapes from denver)
colon, invade surrounding tissues forms abscess
add slide
28 here
Chemically defined medium (simple / synthetic) (exact chemicals)
is one whose exact chemical composition is known. has all required nutrients ( glucose, salts etc) for the target microbe(s) may contain vitamins / amino acids in known quantity
Complex medium (mystery)
is one whose exact composition is unknown
exact composition of complex medium is unknown because…. (different milk)
of batch to batch variation (different milk from different grocery stores, ex), ex. exact peptones unknown
complex medium - nutrients are derived from…(complex palate)
soy, yeast or beef extract / partial digests
complex medium - peptones are hydrolyzed…(peanuts - AAE - drop elka vitamins). Hydrolysis can be done through…
protein (aka - protein hydrolysis). it can be done by acid hydrolysis, alkaline hydrolysis, or enzyme hydrolysis
Advantage of complex medium (wide range)
it supports growth of a wide range of bacteria whose nutrient requirement is a challenge.
Both complex or chemical media can be either…
in liquid (nutrient broth) or solidified form (nutrient agar)
Buffers are more critical in a___medium…
defined medium but not for complex medium
agar (poly swimming)
complex polysaccharide, derived from marine algae
agar has no (can’t…)
nutritive value; few microbes can degrade it
agar is used at…(% - soaks up water)
1.5 - 1.55% final concentration. high concentration is toxic because it creates hypertonic environment
agar dissolves at what temp..(half)
100°C and solidifies at 45°C (heat labile (like glucose, like vitamins, these are added add later)
agar is…(trans)
translucent and makes easier to visualize colonies
Fastidious organism (picky - ex)
picky organisms, ex neisseria gonorrhea - demands all vitamins, amino acids and additional components.
e.coli is really….(skin cream)
versatile. e.coli can grow in the presence or absence of vitamin e. doesn’t mean e.coli doesn’t need the vitamin E. it means e.coli can make vitamin e from the carbon and hydrogen sources.
function types/special media (GAan- SSED)
general purpose, selective, differential, anaerobic growth, specimen transport and enrichment medias.
Selective media (select steve)
have components that inhibit growth of unwanted bacteria and encourage the growth of desired microorganism.
Ex : Thayer Martin media (TM )
Differential media (willow is different)
designed for easier detection and isolation of microorganism of interest from others growing on the same plate - often a particular trait of the microbe is exploited.
Ex: Blood agar (and hemolysin)
blood agar - Alpha hemolysis (green pneom. is the alpha)
hemolysin (cytotoxin) - incomplete destruction of RBCs greenish color. s. pneuomonia
Beta hemolysis (apocolypse)
complete deconstruction
Anaerobic growth media: (aka reducing medium) (gas pak)
A. Sodium thioglycollate - crystals added to medium. absorbs dissolved 02 and makes it unavailable.
Transport media (bedside), and it ensures that..
are usually used in clinical settings
Ensures
i. individuals are not infected
ii. specimen not contaminated and cells are kept alive
transport media contains…(transport buf)
buffer and absorbents. Buffers are critical to keep cell’s healthy and to maintain ratios of different microbes in specimen
transport media absorbents…(transport waste)
“soaks up” wastes generated so that it’s not toxic to cells
Enrichment media (if it needs to be enriched..)
have components that favor the isolation of specific bacteria from low level to detectable (respectable) levels.
no medium formulated…
that would support syphlis pathogenic growth unlike e.coli (syphlis observed at patient bedside, it’s fragile)
Animal cell cultures (the 2 mentioned earlier)
M. leprae (armadillo foot pads) and Treponema sps (rabbit testicles) in animals
Chlamydia and Rickettsias (rocky mountain spotted fever - trunk area) special culture techniques (bird mountain)
(Rickettsias can’t make atp)- birds eggs and cell culture are used to cultivate these. chlamydia causes sexual and non sexual diseases. blindness.
Low oxygen culture (neonatal - candle)
use of CO2 incubators and candle jars
siderophore role in gonorrhoeae pathogen (what all bacteria want..)
greater affinity for iron
iron is stored in liver complexed to…(perry, that’s it)
ferritin
iron transferred from liver to…(perry - bone - kitchen - BBL)
bone marrow, it is complexed with transferrin. in blood, body fluids and in liver - limits iron availability ( by sequestering )
toxic peroxide is neturalized by…(what breaks down peroxide)
Catalase - breaks down hydrogen peroxide to water and Oxygen
perfringens treatment options (foot on slide)
Spore forming and killed by penicillin. treatment option is to use oxygen under high pressure. anaerobic bacteria.
Why do bacteria stop growing below minimum growth temperatures? (snow sled)
transport process becomes too slow to support metabolic activities for sustaining growth
Lipids and low temperature
membrane becoming rigid and fragile
High temperature
lipids becomes too fluid; membrane fails to hold back cellular contents
Proteins and low temperature (pb - fridge)
supports new hydrogen bonds
High temperature (pb in kitchen table)
H2 bonds tends to break; high order structures are lost, and subsequently proteins looses it’s function
Neisseria gonorrhoeae - low oxygen (bran - canope - mountain)
is a capnophile (capno - means smokey) and corn starch. grows better at low oxygen and higher co2. Corn starch binds free fatty acids in the medium.
acidiophiles ex. (theo on ferry)
Thiobacillus ferroxidans, grows between 0 - 2 pH
optimal temp for humans
37 degrees C in humans.- clinical incubators and human pathogens - set at 37 degrees C to mimic our internal body temp
3 groups based on the pH factor (ph…Naa)
Neutrophiles, Acidophiles, Alkalinophiles.
criteria for cultured medium - it should contain sufficient moisture and…(dove)
properly adjusted pH which should be maintained ( by buffer)
criteria for cultured medium - it must contain a suitable level of (chemo newport - lights and clean 02)
oxygen and energy source (chemotrophs)
criteria for cultured medium - it must be sterile to….(warm temp in newport)
begin with; not contaminated from start
temperature should be maintained constant for growing cultures
substances altered during group translocation (cups of sugar - kitchen counter)
glucose 6 phosphate can’t be bound again. it gets chemically altered, it comes inside, and the same transport will not allow it to bind. now glucose 6 is trapped.
growth factors - yeast or…(impossible)
beef extract is the source for the growth factor.
growth factors include some…(VAPP)
amino acids, vitamins ( such as thiamine, riboflavin etc) purines, pyrimidines
c. perfringes
Vegetative cells secrete 11 toxins. lt lyses RBC/WBC increases vascular permeability reduces blood pressure, kills cells. large rectangular cells. they have a rapid generation time 11-12 minutes, about 100 - 200 bacteria.
shake tube method steps (boil water)
heat. dissolved oxygen escapes. cool. form a gradient of 02. inoculate and incubate. if they are aerotolerant (no o2 needed) there will be uniform growth throughout medium. macroaerophiles up to 10% growth.
enrichment media ex. Vibrio cholerae and cold enrichment
enrichment media is selective for the vibrio cholera - still grows at the 4 degrees celcius.
complex medium - vitamins and organic growth factors are provided by..(think lab)
the extract - variation due to peptones and extract.
Thiobacillus ferroxidans (obligate acidiophiles) - action (theo - hot tub)
oxidizes S compounds for energy - it makes sulfuric acid, separates to make hydrogen and sulfur ions.
aerotolerant
can survive without oxygen
macroaerophiles (macro not quite aerophiles)
needs oxygen but requires environments containing lower levels of oxygen than that are present in the atmosphere. Many microaerophiles are also capnophiles, requiring an elevated concentration of carbon dioxide
hypertonic (mattias - plastic toy)
more solute outside than inside. if that happens, plasmolysis sets in (hypertonic solution).
plasmolysis in a hypertonic solution (peeling skin)
when the plasma membrane pulls itself away from the cell wall.
s. aureus is a…
neutrophile
cholesterol- is needed for…
mycoplasma
heme - needed for
cytochromes. PABA
PABA- is needed for
folic acid.
SOD (radicals)
is an enzyme that catalyzes a superoxide radical into oxygen and hydrogen peroxide.
Peroxidase does not form…
oxygen - it uses a reducing agent
Catalase (think catalyst)
breaks down hydrogen peroxide to water and Oxygen.
Importance of using slants in microbiological labs ?
provides greater surface area and tube can be stored in small ( limited space) areas unlike Petri plates
Gamma hemolysis is a (little one)
lack of hemolysis in the area around a bacterial colony.
hypotonic
solute outside is less than inside the cell. cells bursts.
ex. of trace elements (stove)
aka Micronutrient - Cu (copper), Zn (Zinc), Co (Colbalt), Mb (Molybdenum), Se (selenium)
