Review of MicroBiology Flashcards
How many prokaryotic cells in body per 1 eukaryotic cell?
5
Cause disease
Pathogenic Organisms
normal human flora or transient bacteria when intact immunologic or anatomical defenses are compromised they attack.
Opportunists organism
Organisms that work better in an environment with a a lot of other organisms.
Synergist
Study of microorganisms, huge amount of different kinds that exist as single cells or cell cultures. (includes viruses)
Microbiology
What is the main difference between a eukaryote and a prokaryote?
Compartmentalization of DNA in a nucleus + controlled cell divisions (vertical gene transfer)
Main elements that distinguish a prokaryote from eukaryotes:
-No membrane
-Quantity> quality, rapid cell division (horizontally)
-Infinite diversity
-Soup of organelles
Why is it important to kill all the bacteria not just ~some~
Left over bacteria can become super bacteria!
What does great diversity of of prokaryotes lead to?
Drug resistance!
Over time what happens to certain genes in a bacteria that have not been activated for a while?
Gene gets shed.
Ex. Shedding of drug-resistant gene against ex. penicillin
methods by which bacteria divide
Binary fission
What is the Doubling time of most bacteria via binary fission? What kind of mathematical growth does it display?
20 MINTUES. Exponential growth
If you start with 200 bacterial colonies how many will you have after 40 min?
800!
What element of bacteria emphasizes the stress of maintaining a sterile environment?
their insane doubling time!
How many chromosomes does a prokaryotic cell have?
1
What is the size of a prokaryotic ribosome?
70S
What do prokaryotic cell walls have that is very distinguishing from eukaryotic?
Peptidoglycan
Bacteria can survive a good range of what 4 things?
-Temp
-pH
-Osmolarity
-Salinity
Proteins that act like viruses, ex. mad cows diseases
Prions
Nucleic acids within a protein capsid & lipoprotein envelope , non-living, very tiny can’t be seen under microscope
Viruses
Contain both RNA/DNA, eukaryotic, 80S ribosome, contain mitochondria, chitin cell wall budding (yeast) /mitosis (mold).
Fungus
Contain both RNA/DNA, eukaryotic, 80S ribosome, contain mitochondria, flexible membrane, motile, mitosis
Protozoa & Helminiths
What is a main characteristic that makes something be able to target and affect a specific kind of cell?
Receptors!!!
Explain how the Avian flu became the Human flu
A virus that only affected avians, mutated and change it receptor from a bird cell receptor to a human cell receptor. Virus entered Patient 1 via (ingestion?) and replicated then spread among humans!
Each coordinated effort of ____ departments results in a steep decline in death rates due to infection.
Public health department efforts.
What are 3 body sites that should be completely sterile?
-Cerebral Spinal Fluid (CSF)
-Blood
-Urine (theoretically)
Staphylococcus aureus =
Corynebacterium, propionibacterium=
Staphylococcus aureus = Potential pathogen of SKIN
Corynebacterium, propionibacterium= low virulence resident
Candida albicans=
Neisseria spp.=
Candida albicans = Potential pathogen of MOUTH
Neisseria spp.= low virulence resident
Strep. Pneumonia=
Neisseria spp. Virdans streptococci=
Potential pathogen of NASOPHARYNX
Neisseria spp. Virdans streptococci= low virulence resident
none, strep, other from mouth
No potential pathogens ins stomach, but some low virulence residence from mouth.
No pathogenic bacteria in the ____
Small intestine
What part of body contains LOTs of pathogenic bacteria?
Ex.E.coli, pseudomonas, candida, clostridium, etc
COLON
What stage of life may the vagina has potential pathogens like C. Albicans
or low virulence residents like Staph, Enterobacteria, Deptheroids, etc?
Pre-pubertal & post-menopausal
What stage of life may the vagina have potential pathogens like Group B streptococci & C. Albican
or low virulence residents like strep. or lactobacillus
Childbearing
What does this depict?
Gram positive cell wall (it has the lipotechoic acid cell wall)
What does this depict?
Gram negative cell wall ( outer & inner membrane with periplasmic space)
What color does gram + stain and why?
Purple! It has at thick layer that traps the crystal violet stain and
What color does gram - stain and why?
Red, following decolorization all crystal violet will drain out but Safran red will stain!
What are 3 major ways to differentiate between cells?
Cell size, shape, reaction to gram stain
What do Gram + membrane contain?
Thick peptidoglycan layer with fibers of techoic acids which protrude outside peptidoglycan
What do Gram - membrane contain?
Thin single layer of peptidoglycan, no techoic acids BUT have:
Complex outer layer of lippolysachrrides, lipoproteins & phospholipid.
In pepriplasmic space, some bacteria contain enzymes that help degrade target cells.
Lipopolysachrrides act as a ____ on gram __ cells.
Endotoxins! on Gram - cells.
Enzymes within the periplasmic space of gram- cell that can degrade penicillin and other drugs
Beta-Lactamases
Only vital within cells so stain will not show it
Intracellular
What doe this picture depict?
How streamlined DNA replication is within bacterial cells.
FAST, no separation, all at once!
Toxic chemical in outer membrane of Gram - cells, that is released following cell destruction.
Lipid A
Giver rigid support against osmotic pressure, action of penicillins & cephalosporins, and is degraded by lysozymes
Peptidoglycan
Major surface antigen on Gram - used frequently in lab diagnosis
Polysaccharide
Major surface antigen on Gram + used rarley used in lab diagnosis
Techonic Acid
Made of polysacrrides, protects agains phagocytosis
Capsule
Made of glycoprotein (1) mediates attachment to cell surfaces (2) sex plus. *main reason for why one cell affects
Pilus or Fimbria
What does saliva & tooth brushing do?
Helps remove & detach fimbria bacteria and break its attachment to the surface of tooth.
made of protein, helps with motility
Flagellum
Made of kertain like coat & dipcolinic acid, *provides resistance to dehydration, heat, chemical.
Hibernation mode of bacteria
Spore
What type of bacteria are most common to become spores?
Gram + rods
Major location of spores?
Soil
Made of DNA, contained a variety of genes for antibiotic resistance and toxins
Plasmid
Made of glycogen, lipids, polyphosphates.
Site of nutrients in cytoplasm
Granuales
Made of polysaccharides, mediate adherence to surface. Sticky substance, Segway to biofilm formation
Glycocalyx
Why is it import to sterilize medical supplies to 121 for at least 15 minutes?
To kill spores!
-Can survive for years in soil ex. tetnus,
-no metabolic activity= unaffected by antibiotics
-Only form when nutrients lack= not found at sites of infection b.c nutrients are present
Characteristics of spores and medical implication
Bacillus or Clostridium are the only two genus that produce ____
Spores
As long as a niche has all the requirements, populations of microorganism will remain constant.
Rate of ___ = Rate of ____
rate of growth= rate of death
The survival of a microorganism is dependent on its what?
Ability to succeed in competing for nutrients + maintain healthy # of cells
Physiology (growth) of organism is influenced by mainly what?
Nutritional stress
If an organism is removed from an niche what happens?
The space will be filled by another!
When one parent cell divides into 2 progeny cells, exp. growth
Binary fission
The increased in the total sum of ALL components if a given organism.
Growth
increase in cell size is growth? t/f
FALSE! not true growth!
Removing an organism ability to replicate is a major concept in the _____ of disease
Treatment!
UV light in dental practice overnight, mutate bacterial cells does what?
affect cell ability to replicate= kill all bacteria
2 ways to measure concentration of a living organism:
- concentration= #viable cells/unit of volume
- Mass= dry weigh of cells/ unit of volume
Studies of microbial genetics & inactivation of microbes uses what method of measuring?
Concentration of cells!
Studies of microbial biochemistry or nutrition uses what method of measuring?
Mass!
Pt. with v/infected tooth take a swab of fluid and observe # of bacterial colonies grown. LOTS of coloinies (ex.500) =
Pt. has bad infection
typical measure of cell concentration
Viable cell count
measuring the turbidity of a culture, measured by spectrophotometry.
Indirect way to measure viable cell count
The relationship between viable cell count and turbidity measurement is related in the form of a
Standard curve
How foggy or clear the fluid is
Turbidity
A barley _____ suspension of Escherichia coli contains about 10^7 cells per milliliter,
A fairly _____suspension contains about 10^8 cells per milliliter.
Turbid! More cells= more turbid
What is the main drawback of connecting turbidity & viable cell count?
There may be a lot of cells (very turbid) BUT cells may be dead (non-viable)
the time required for a population or mass (of bacteria) to double, since they grow by binary fission
(Biomass vs Td)
Generation time or Doubling time (td)
How does undertaking doubling time and growth rate help you treat disease?
Study growth and death to know HOW to treat them and HOW LONG to treat them for.
Wha does a big td mean in terms of symptoms and effects?
More effect on patients, MORE SYMPTOMS
What is this?
Bacterial growth curve
replication rate= death rate, its is the adjustment time of the bacteria, adapting.
Lag Phase
How can the lag phase be used to your advantage?
Used to limit resources in oral cavity
ex. Mouth wash, prevents bacterial growth because limited resources for bacteria to use*
replication rate> death rate. Bacteria has found niche and they’re READY to go.
Log phase
How can you combat the log phase?
prescribe antibiotics, limit resources, increase waste, all to trigger the plateau as early as possible
zero growth, no more possible. Limited resources & WASTE products accumulating which is toxic to bacterial cells. More waste> resources.
Maximum stationary phase
Death rate> growth. Stay winning.
Decline Logarithmic
How to trigger decline?
Prescribe things that are Toxic to bacteria not pt. cells. Ex. Attack cell wall b/c our eukaryotic cells don’t have cell walls; therefore, our cells will not be affected*
bacterial resistance to all antimicrobial mechanisms
Pan resistance
A device used to gather steady state data about an organism in order to generate a mathematical model relating to its metabolic processes
Chemostat
Bacterial growth in an intimate and complex communities communicating among themselves
single bacterium nucleating a surface followed by replicating themselves or recruiting other bacteria into a forming colony
LAYERS
Biofilm
What is the purpose of debriding our teeth every day to remove the film of bacteria that grow up while we sleep (Gum, tooth disease-heart disease!).
To remove Biofilms
___ cannot be treated with antimicrobials because all layers cannot be penetrated
Biofilms
what are the 2 benefits of biofilm growth patterns?
- deep layers are less susceptible to immune clearance
- Antibiotics can’t penetrate deep laters
Losing ability to reproduce means what?
CELL DEATH
A microbial cell that is not physically disrupted is thus “dead” only in terms of the conditions used to test viability. So death here is a ____ term!
relavent!
In terms of sterility, can you ever kill every single organism?
No.
6 Properties that apply to microorganism growth?
1.Oxygen levels
2. Temp
3. pH
4. Salinity
5. Presence of essential minerals for catalyst
6. Carbon source, nitrogen source
Acetone, alcohol, lactic acid, cheese, pickles, are all what
Example of what we use bacteria for.
Requres O2 canot ferment
M. tuberculosis, P. aeruginosa
Aerobe
Killed by O2, ferments in absence
C. Botulinum, B. Melaniogenicus
Anerobe
Respires with O2 but cant also ferment without O2
E.Coli, S. Aureus
Faculatative aerobes
Three methods of genetic material transfer among bactierial cells?
- Conjugation (plasmid transfer)
- Transduction (any gene, bacteriophages)
- Transformation (DNA taken up by cell)
- Virus can only replicate ___ cells
- Bacteria can either spread through ___ or inject protien into cell
Viruses= replicate inside cell
Bacteria spread through blood, or inject into cell
Protein like virus, enconded by cellular genes.
Prion
Explain viral growth curve:
Viron enter, eclipse period (no infectious virous detected) then rise period (EXTREME increase in number of irons in the span of 10 hrs)
need oxygen because they cannot ferment or respire anaerobically. However, they are poisoned by high concentrations of oxygen. They gather in the upper part of the test tube but not the very top.
Microaerophiles
do not require oxygenas they metabolise energy anaerobically. Unlike obligate anaerobes however, they are **not poisoned by oxygen. **They can be found evenly spread throughout the test tube.
Aerotolerant organisms
