Final exam Flashcards
6 groups of microbes
Bacteria
Archaea
Fungi
Protozoan
Algae
Small multicellular animals
Bacteria
Unicellular, prokaryote
Cell wall composed of peptidoglycans
- Requires sufficient moisture
- Obtains energy through organic molecules or photosynthesis or inorganic molecules (nitrogen/phosphorus)
Archaea
Unicellular, prokaryote
Cell wall
- Found in extreme conditions
- Not pathogenic to humans
Fungi
Unicellular/multicellular eukaryotes
Obtains energy by decomposing dead organisms
Can be pathogenic (ringworm)
ex: Mold (multicellular) and Yeast (unicellular)
Protozoa
Unicellular eukaryotes
Mobile
Found in water, some live in hosts
AKA: Parasites
Ex: Malaria
Algae
- Unicellular/Multicellular, eukarytotic
- Photosynthetic (chloroplasts)
- Important in ecology/enviornment
- Not usually pathogenic
Algae is not typically _____ but there’s 2 exceptions:
Pathogenic
- An immunosuppressed person
- Algae Bloom
Small Multicellular Organisms
- Multicellular eukaryotes
- Adult worms can be visible to the naked eye, but immature stages are microscopic
What are Koch’s Postulates?
- Suspected causative agent must be found in every case of the disease & absent in healthy hosts
- Agent must be isolated and grown outside of the host
- When agent is introduced to a healthy, susceptible host, the experimental host must get the disease
- Same agent must be found in the diseased experimental host
Pasteur
Disproved the idea of spontaneous generation/abiogenesis
Found what caused fermentation; discovered process now called “pasteurization”
Lister
Antiseptic technique
Jenner
Responsible for 1st vaccination (against smallpox)
He was aware that infection actually produced immunity
Ehrlich
Magic bullets (antibiotics)
Fleming
Discovered the 1st antibiotic to treat disease
Nightingale
Nursing and hygiene
Linneaus
Responsible for the binomial system of nomenclature (naming system)
DKPCOF
Genus
Species
Leeuwenhoek
“Father of Microbiology”
1st to observe live microorganisms (through his magnifying lenses)
Abiogenesis
Spontaneous generation theory that living things came from nonliving matter
Pasteurization
Process of heating it just enough to kill spoilage or pathogenic microorganisms.
Doesn’t alter the quality of food
What are the 4 common processes of all living things?
Growth
Reproduction
Responsiveness
Metabolism
The cell wall of a gram-positive bacteria forms a ____, rigid structure. It has many layers of ________, which refers to a chemical molecule that is part ___ and part _______.
The cell wall of a gram-positive bacteria forms a thick, rigid structure. It has many layers of peptidoglycan molecules, which refers to a chemical molecule that is part protein and part polysaccharide
Gram-positive bacteria:
The peptidoglycan layer also contains teichoic acid and (1) _____ _____. What does (1)______ ___ do?
Lipoteichoic acid
It attaches the cell wall to the cell membrane
Gram-positive bacteria:
The ______ part of peptidoglycan consists of long chains of repeating alternating molecules called ___ and ____. The layers are held together by ______ ________.
polysaccharide
NAG and NAM
tetrapeptide crossbridges
The cell walls of a gram-negative bacteria consist of a ____ ________ ___ surrounded by an outer membrane. Similar to gram-positive bacteria, they have alternating ___ and ____ structures, but they don’t have ______ _____.
The cell walls of a gram-negative bacteria consist of a thin peptidoglycan layer surrounded by an outer membrane. Similar to gram-positive bacteria, they have alternating NAG and NAM structures, but they don’t have lipoteichoic acid
The outer membrane of a gram-negative bacteria is a _______. Its inner layer is composed of _____ molecules and ____.
The outer membrane of a gram-negative bacteria is a bilayer Its inner layer is composed of phospholipid molecules & proteins
Gram-negative bacteria:
The outer layer of the outer _____ is composed of both phospholipid molecules and ________(___). The lipid portion of LPS is known as _____ __
The outer layer of the outer membrane is composed of both phospholipid molecules and lipopolysaccharide (LPS). The lipid portion of LPS is known as lipid A
Where is lipid A found?
The outer cell membrane of a gram-negative bacteria
Lipid A is also called an _______ (this is released when the cell ____ and can cause fever, vasodilation, inflammation, shock, and blood clotting)
Lipid A is also called an endotoxin (this is released when the cell dies and can cause fever, vasodilation, inflammation, shock, and blood clotting)
Tetrapeptide cross-bridges connect..
NAM to NAM
3 appendages can be found on the exterior of bacterial cell walls:
Flagella, Fimbriae, Pili
Flagella
- Used for movement
- Basal body attaches hook to a cell wall and cell membrane
Flagella arrangements
Monotrichous: one
Amphiritichous: two on opposite ends
Lophotrichous: 2+ on the same end
Peritrichous: all around/surrounding
Fimbriae and pili are both used for _____ and are made up of protein molecules called ____. What’s the difference between the two?
Fimbriae and pili are both used for ATTACHMENT and are made up of protein molecules called PILINS.
Pili attachment is for a specific purpose called conjugation.
Types of movement for flagella
Runs (propels foward): counterclockwise
Tumbles: Clockwise
How are ribosomes different in prokaryotes and eukaryotes
Bacteria/prokaryotes have 70S ribosomes while eukaryotes have 80S ribosomes (with 70S only being in mitochondria/chloroplasts)
Glycocalyx functions
Prevents desiccation (drying out), evade phagocytosis, attachment
Glycocalyx are found..
attached to the outermost layer of the cell wall
Glycocalyx:
If the sticky substance is ____ and ____ attached to the bacterial cell wall, the glycocalyx is described as a _____
v.s
If the sticky substance is ____ and ____ attached to the bacterial cell wall, the glycocalyx is described as a _____
Organized and firmly attached = capsule
Unorganized and loosely attached = slime layer
The outer cell membrane of bacteria is made up of a cholesterol-like molecule called a
Hoponoid
4 comparisons between bacterial (prokaryotic) and eukaryotic cells
Bacteria:
No nucleus
Flagella rotate
Cell walls (present in most) contain peptidoglycans
Endospores are present in some
Eukaryotes:
Nucleus
Flagella undulate
Cell walls- present in plants, algae, and fungi- NO peptidoglycans
No endospores
LPS is made up of
a lipid on one end and polysaccharide on the other
Endospores are considered the _________________________ to ______. Many endospores produce toxins that can cause fatal diseases such as ____ and ____.
most difficult biological structure to destroy
anthrax and tetanus
Found in the _______ of some bacteria are endospores, which are used as a ________ strategy against ______ _____, such as when nutrients (especially ___ and ___) are exhausted or if there isn’t sufficient _____.
Found in the CYTOPLASM of some bacteria are ENDOSPORES which are used as a DEFENSE strategy against UNFAVORABLE CONDITIONS, such as when nutrients (especially Carbon and Nitrogen) are exhausted or if there isn’t sufficient MOISTURE.
Where are endospores found?
Cytoplasm
Endospores are formed by a process called _____ which takes between 8-10 ____. Endospores can remain dormant for thousands of years and when conditions become ___ for growth, endospores ___ to produce new _____ ___ (cells that grow and reproduce).
Endospores are formed by a process called SPORULATION which takes between 8-10 HOURS. Endospores can remain dormant for thousands of years and when conditions become FAVORABLE for growth, endospores GERMINATE to produce new VEGETATIVE CELLS
If the color is in the positive ion, these stains are known as
basic dyes
If the color is in the negative ion, these stains are known as
acidic dyes
Bacterial cells are slightly negatively charged. Based on this information, what type of dye is best used to view bacteria?
basic dyes
Since acidic dyes carry negative electric charges, and bacteria cells are also negative, they are not ____ to bacterial cells. As a result, it can’t stain the bacterial cells and instead stains the ________
Since acidic dyes carry negative electric charges, and bacteria cells are also negative, they are not attracted to bacterial cells. As a result, it can’t stain the bacterial cells and instead stains the background
The procedure of a gram stain
1. _______(a basic dye w purple color) is applied and is referred to as a _____
2. Rinsed off the slide with water
3. Slide is then covered with ____, which is a ______ (purpose is to _______)
4. Next, the slide is washed with ____, a _____ ____. This breaks down the ____ of gram ______ cells.
5. It’s then rinsed off the slide with water, and the slide gets stained with ____ (a basic dye with red color). _______ is referred to as a _________ because it has a contrasting color to the primary stain.
- CRYSTAL VIOLET (a basic dye w purple color) is applied and is referred to as a PRIMARY STAIN
- Rinsed off the slide with water
- Slide is then covered with IODINE, which is a MORDANT (purpose is to INTENSIFY the color of the primary stain)
- Next, the slide is washed with ALCOHOL, a DECOLORIZING AGENT. This breaks down the cell wall of gram-NEGATIVE cells.
- It’s then rinsed off the slide with water, and the slide gets stained with SAFRANIN (a basic dye with red color). SAFRANIN is referred to as a COUNTERSTAIN because it has a contrasting color to the primary stain.
- The slide is rinsed with tap water, blotted dry, and observed under the microscope.
After the primary stain (_____) and the mordant (____) are used…
(crystal-violet)
(iodine)
all cells are stained purple
After the decolorizing agent (____) is used, it removes the _____ ___ from ONLY the ______ ____ _____, making the _____ ______ become ______
alcohol
purple color
gram-negative bacteria (2x)
become colorless
After staining with a counterstain (_____), it turns the ______ gram-____ bacteria ____. Since the gram-____ bacteria retained the original _____ color, they are ___ _______ by the counterstain
After staining with a counterstain (SAFRANIN), it turns the COLORLESS gram-NEGATIVE bacteria PINK. Since the gram-POSITIVE bacteria retained the original PURPLE color, they are NOT AFFECTED by the counterstain.
Acid-Fast Stain
Used for bacteria that have waxy cell walls
Ex: Mycobacterium and Nocardia
Metabolic reactions usually involve the movement of electrons (which are ________ of _____). The molecule that is oxidized is the one to _____ the electron and involves _____. The molecule that is reduced ______ the electron and involves _____.
Metabolic reactions usually involve the movement of electrons (which are carriers of energy). The molecule that is oxidized is the one to donate the electron and involves loss. The molecule that is reduced accepts the electron and involves gain
Phosphorylation is when
ATP is regenerated/recycled from ADP and Pi (inorganic phosphate)
3 ways phosphorylation can be accomplished:
(basically, who provides the energy for the third phosphorus? ADP + P —> ATP)
- Substrate-level phosphorylation
- Oxidative phosphorylation
- Photophosphorylation
transfers Pi from an organic molecule
(the bond gets broken)
Substrate-level phosphorylation
Using energy from the redox reaction to add Pi
(there’s no bond to be broken)
Oxidative phosphorylation
Using light energy to add Pi
(no bond broken)
Photophosphorylation
The overall process of cellular respiration can be summarized as
Glycolysis
Krebs Cycle
Electron Transport Chain
Glycolysis starting molecule:
ending molecule:
starting: Glucose
ending: Pyruvic Acid
What carrier molecule is used during Glycolysis and how many?
NADH, 2
How much ATP is used in Glycolysis? How much is produced? Net amount?
2 ATP is used
4 ATP is produced, 2 net
Summary of Metabolic Stages:
Glycolysis:_______—> ______
The Preparation stage: _____—> ______
The Krebs Cycle: _______—> ______
The Electron Transport Chain: once ______ _____ electrons, it is _____ to form ____
Glycolysis: 1 glucose molecule –> 2 pyruvate molecules
The Preparation stage: each pyruvate molecule—> acetyl CoA molecule
The Krebs Cycle: each acetyl CoA —> CO2
The Electron Transport Chain: once oxygen accepts electrons, it is reduced to form H20
Summary of Energy Yielded:
Glycolysis:
The Preparation Stage:
The Krebs Cycle:
The Electron Transport Chain:
Total:
Glycolysis: 2 ATP, 2 NADH
The Preparation Stage: 2 NADH
The Krebs Cycle: 2 ATP, 2 FADH2, 6 NADH
The Electron Transport Chain: 34 ATP
Total: 38 ATP molecules per glucose molecule
Each molecule of pyruvate coming from glycolysis must first be converted to another chemical called_______
acetyl coenzyme A (acetyl CoA)
Key concepts of the Krebs Cycle:
Starting molecule?
How many molecules of ATP?
What method of phosphorylation?
How many molecules of FADH2?
How many molecules of NADH?
How many molecules of CO2?
Starting molecule?
Acetyl-CoA
How many molecules of ATP? 2
What method of phosphorylation? Substrate level phosphorylation
How many molecules of FADH2? 2
How many molecules of NADH? 6
How many molecules of CO2? 4
What method of phosphorylation occurs in the Electron Transport Chain?
Oxidative phosphorylation
Electron Transport Chain:
Each NADH creates __ __
Each FADH creates __ __
In total, there are ___ ATP molecules that can be generated from one ____ ____
3 ATP
2 ATP
34 ATP
glucose molecule
Electron transport chain:
In aerobic respiration, ____ is the final electron acceptor. In anaerobic respiration, it’s an ______ _____ that acts as the final electron acceptor
Oxygen
Inorganic molecule
2 main pathways of energy production
cellular respiration
fermentation
Only ____ leads to fermentation, not ____
Only yeast leads to fermentation, not bacteria
End products of fermentation
Lactic acid and ethanol
How much ATP does fermentation produce?
2 atp
When does fermentation occur?
When there is an absence of final electron acceptors (no oxygen, no inorganic molecule)
What acts as a final electron acceptor in fermentation?
Pyruvic acid
Metabolism is divided into two types of chemical reactions:
What’s the difference between these two?
Catabolic: breaks down large molecules into smaller products, exergonic (releases energy), ex: proteins –> a.a
Anabolic: turns smaller products into large molecules, requires energy to make bonds (endergonic), ex: a.a—> protein or fatty acid –> lipid
To move the electrons around (for oxidation-reduction reactions), a carrier is often used. The important ones are:
The electron is usually associated with a _______ atom since it only has _____ ______. So the carriers pick up and drop off the _____
NAD+
NADP+
FAD
The electron is usually associated with a HYDROGEN atom since it only has ONE ELECTRON. So the carriers pick up and drop off the HYDROGENS.
Apoenzyme
The name of the protein portion when the enzyme is combined with other molecules
The apoenzyme is ____ if not bound to nonprotein ______
inactive
cofactors
Cofactors are ____ molecules, like ___ or ___. If the cofactor is an ______ molecule, it’s called a _____.
Cofactors are INORGANIC molecules, like Zn or Fe. If the cofactor is an ORGANIC molecule, it’s called a COENZYME
Important coenzymes:
NAD
FAD
CoA
Holoenzyme
Yields from when apoenzyme binds with its cofactors/coenzymes
3 basic requirements that all cells need for metabolism:
a carbon source, an energy source, and an electron source
Carbon sources and where they get their energy from
Autotrophs- CO2
Heterotrophs- organic
Energy sources and where they get their energy from
Chemotrophs- organic
Phototrophs- light
Electron (H) sources and where they get their energy from
Organotrophs- organic
Lithotrophs- inorganic
Plants and algae are considered
photoautotrophic (CO2 and light)
Humans, bacteria, animals, fungi, etc. are considered
chemoheterotrophs (both organic)
Obligate aerobes
Requires oxygen to live and grow
Oxygen is used as the final electron acceptor when making energy
Obligate anaerobes
Unable to use oxygen for growth because it lacks enzymes (like catalyse)
Oxygen can actually be toxic for them
Facultative anaerobes
Prefers oxygen, but can survive without it
Aerotolerant anaerobes
Has small levels of enzymes but doesn’t use oxygen
Prefers no oxygen but will tolerate it
Microaerophiles
able to survive with low levels of oxygen
Nitrogen Fixation- what is it and why is it important?
When microbes are able to convert the nitrogen in the air (N2) into NH3
This is essential since it’s providing a usable form of nitrogen for other organisms to use
Complex media
Most common, generalized (so most bacteria grow well in complex media)
Ex: Nutrient agar and tryptic soy agar (TSA)
Enriched media is also generalized, but with an added ingredient: blood. Enriched media is used to encourage the growth of a particular bacteria species of interest. It’s typically used to cultivate bacteria from samples such as:
blood, urine, and sputum
Examples of selective media
Sabouraud dextrose agar
MacConkey agar
EMB agar (Eosin-methylene blue agar)
HE agar (Hektoen enteric agar)
Examples of differential media:
MacConkey agar
HE agar
Blood agar
Sabouraud dextrose agar only selects for
the growth of fungi while inhibiting bacterial growth
- supplemented with antibiotics (added ingredient)
MacConkey agar only selects for
gram-negative bacteria while inhibiting the growth of gram-positive bacteria
What inhibits the growth of gram-positive bacteria for MacConkey agar?
Both bile salts and crystal violet
EMB agar only selects for
the growth of gram-negative bacteria while inhibiting the growth of gram-positive bacteria
What inhibits the growth of gram-positive bacteria for EMB agar?
Eosin and methylene blue
HE agar selects for
the growth of gram-negative bacteria ONLY while inhibiting the growth of gram-positive bacteria due to its chemical ingredients
What ingredient inhibits gram-positive bacteria for HE agar?
only bile salt
MacConkey agar differentiates whether the bacteria can _______ ______. What color change occurs?
ferment lactose = turns pink (G-)
do not ferment lactose = cream (G-)
HE agar differentiates based on
lactose fermentation and sulfur utilization
What color does lactose-fermenting gram-negative bacteria turn on HE agar?
What about non-lactose fermenting gram-negative bacteria?
- salmon-orange
- retains blue-green color
HE agar can differentiate bacteria based on their ability to utilize ____. When hydrogen sulfide reacts with iron, it forms ____ ____ on the HE agar.
sulfur
black precipitates
Eosin-Methylene blue is both a selective and differential media. It assesses for lactose fermentation: positive will look ____/____/metallic while negative will have ___ ____/media
positive will look purple/black/metallic while negative will have no color/media
What is a biofilm?
A complex relationship among numerous microbes
Binary fission steps:
Chromosome _____ (attaches to cell membrane)
Cell ______, ______chromosome
____ cell wall/cell membrane form ____
____ is completed, separating into___ _____ microbes.
Chromosome REPLICATES (attaches to cell membrane)
Cell ELONGATES, SEPARATING chromosome
NEW cell wall/cell membrane form SEPTUM
SEPTUM is completed, separating into 2 IDENTICAL microbes.
4 phases of bacterial growth
lag phase
log phase
stationary phase
death phase
Lag Phase
- Little change in # of microbes
- Adapting to environment
- Lasts hours to days
Log Phase
- Exponential growth (2^n)
- Cells most active
- Best time to gram stain
- Best time to assess effectiveness of antibiotics
Stationary Phase
- Growth slows
- Deaths = divisions- equilibrium
Death Phase
- Deaths > divisions
- Accumulation of wastes, depletion of nutrients, change in pH
3 groups based on the preferred temperature of a microbe
Which is most likely to be pathogenic and why?
Psychrophiles- likes cold
Mesophiles- in between
Thermophiles- likes heat
Mesophiles because they like human temperatures the best
Care must be taken when culturing a microorganism otherwise contamination may occur. The goal is to culture an Axenic culture. What does axenic mean?
Pure
Control plate and nothing grows on it
axenic and aseptic
Control plate has growth, but only one species of bacteria is growing:
axenic but not aseptic
Fastidious bacteria are
hard to grow
Quorum sensing in a biofilm is responsible for what 4 things?
- Communication between microbes
- Able to determine population and species of microbes
- Helps to control certain genes within each microbe
- Microbes assume specific functions to benefit community
Blood agar differentiates bacteria based on red blood cell _____, in other words, whether or not a bacteria can _____ (break down) red blood cells.
hemolysis
hemolyze
Alpha-hemolysis
partially hemolyze (green/gray media)
Beta-hemolysis
completely hemolyze
(clear)
Gamma-hemolysis
unable to hemolyze (no change)
Basically, with each division of binary fission, the population ____. This is represented as __ (indicates _____ growth)
n = generation
Basically, with each division of binary fission, the population doubles. This is represented as 2^n (indicates exponential growth)
n = generation
Generation Time
The time required for a bacterial cell to double (divide)
Most have a doubling time of 1-3 hours
What is a plasmid?
a small DNA molecule that replicates independently of the other chromosomes often carrying information required for replication.
4 different types of plasmids
Fertility
Resistance
Bacteriocin
Virulence
Fertility
instructions for conjugation
Resistance
antibiotic resistance
Bacteriocin
kills competitors
Virulence
enzymes/toxins that enable pathogenicty
Plasmids do not ________________
Plasmids do not control normal metabolism
Operons are composed of a
a Promoter, a series of genes, and an adjacent regulatory element called an operator.
The operator is important in determining when the operon is ______ ______ ______
actively producing proteins
To start making any gene, you need a
promoter
The regulatory gene controls the _____ and needs a _____ to start
operator, promoter
The operator controls the _____
operon
Lac Operon:
-______, turns __ when conditions are right
-Operon is normally ___ at all other times due to the production of a _______ ____
-Repressor protein blocks the _____
-When lactose is present, the bacteria can now ______ it
-Lactose is converted to ______
-________ _______ ___ ______ _____
-_______ of the lac operon can now occur
-Inducable, turns on when conditions are right
-Operon is normally off at all other times due to the production of a repressor protein
-Repressor protein blocks the operator
-When lactose is present, the bacteria can now catabolize it
-Lactose is converted to allolactose
-Allolactose inactivates the repressor protein
-Transcription of the lac operon can now occur
Tryptophan Operon:
-_______: turns __ when conditions are favorable
-Operon is normally __, allowing bacteria to make its own tryptophan
-Repressor protein is made continuously but is normally _____
-When _______ is in the environment the repressor is ______
-Turns ___ the _____
Repressible: turns off when conditions are favorable
-Operon is normally on, allowing bacteria to make its own tryptophan
-Repressor protein is made continuously but is normally inactive
-When tryptophan is in the environment the repressor is activated
-Turns off the operon
Transmission in which the bacteria acquire new genes from the same generation which it can then now pass on to the next generation vertically (gives to their ‘friends’)
Horizontal transmission
3 methods of horizontal transmission:
Transformation
Transduction
Conjugation
Transformation is …
The bacteria capable of this are called _____
Absorption of DNA from the environment
The bacteria capable of this are called competent
Transduction
A replicating virus, (called a Bacteriophage-the general term for a virus that attacks the prokaryote), transmits DNA from one cell that is picked up to another
Conjugation
-Uses ___ ___
-_____ ___ can be associated with __ ____ OR gene can be _______ ___ ___ ______ (called ___)
-Uses sex pilus
-Fertility gene can be associated with F plasmid OR gene can be integrated into the chromosome (called Hfr)
Operons that turn genes on in response to changes in the environment are categorized as:
Inducable
Operons that turn genes off in response to changes in the environment are categorized as:
Repressible
Physical Methods of Microbial control
Moist Heat
Dry Heat
Low Temperature
Desiccation
Filtration
Osmotic Pressure
Radiation
Chemical Methods of Microbial control
Phenolics
Halogens
Alcohols
Heavy Metals
Surfactants
Oxidizing Agents
Sanitation
Reducing the # of pathogens
Sterilization
The removal of all microorganisms, including endospores
Disinfection
A chemical treatment to kill/inhibit growth on inanimate objects
Degerming
The mechanical removal of most of the microorganisms in a limited area by scrubbing
Phenolics
- Denatures proteins and disrupts the cell membranes
- Triclosan: phenol and phenolics
- Found in garbage and diapers
Alcohols
- Kill bacteria and fungi but not endospores
- Denatures proteins and disrupts plasma membrane
Halogens
- Damages proteins with denaturation
- Iodine (oldest/most effective antispetic)
- Chlorine (disinfects water, present in bleach)
- Flouride (toothpaste)
- Bromine (hot tubs)
Surfactants-3 types
Soap
Acid-anionic detergents
Cationic detergents
Surfactants-mechanism of action
Disrupts cell membrane
Quats are considered a _____ ______. What do Quats do?
- Cationic detergent
- They disrupt the cell membrane and is bacteriocidal except for endospores
Other than endospores, what else can Quats not destroy and why?
Mycobacteria due to the waxy cell membrane
Static
inhibits growth but does not kill the microbe
Cidal
kills the microbe
Selective Toxicity (2 things about it)
- Drug will only affect microorganisms without damaging human
- Mechanism of action will affect cell structure or metabolism but not both
5 ways an antimicrobial drug can work:
- The inhibition of cell wall synthesis
- The inhibition of protein synthesis
- Disruption of the plasma membrane
- Inhibition of nucleic acid synthesis
- Inhibiting metabolic pathways
All penicillins have a _____ _____ structure containing a _____ _____ _____. So, _____ _____ are..
All penicillins have a common core structure containing a beta-lactam ring. So, beta lactams are inhibitors of cell wall synthesis
Examples of beta-lactams
Penicillin, Penicillin derivatives, and Cephalosporins.
Chloramphenicol side effect:
bone marrow suppression
Aminoglycoside side effects
- Ototoxic (deafness)
- Nephrotoxic (kidneys)
Tetracyclines side effect:
Teeth discoloration
Azole side effect
Hepatotoxic (liver)
Macrolides side effect:
Heart
Inhibiting metabolic pathways:
In order to produce DNA/RNA, bacteria need _____ _____. ____ disrupts DNA/RNA _______, but humans ______________
Bacteria need folic acid
- PABA
- Humans do not use PABA and therefore have minimal toxicity to these medications
Ergosterol: similar in composition to ________ which is found in _____-_____ bacteria
similar in composition to cholesterol which is found in gram negative bacteria
Multiple resistance is often referred to as a
Superbug
Resistance to many drugs simultaneously
Multiple resistance
Cross-resistance
resistance to drugs of similar action
The use of antibiotics has not _____ resistance but rather has ______ for it
The use of antibiotics has not produced resistance but rather has selected for it
Which spectrum of action may allow for secondary or superinfections
Broad
When a virus particle is located _______ (outside a cell) it is comprised of 2 basic components: a protein coat called a _____ which surrounds a ______ _____ core. There may be a third component, a phospholipid membrane called an ______, surrounding the capsid.
When a virus particle is located extracellularly (outside a cell) it is comprised of 2 basic components: a protein coat called a CAPSID which surrounds a nucleic acid core. There may be a third component, a phospholipid membrane called an ENVELOPE, surrounding the capsid.
The capsid is composed of protein subunits called ______. The capsomeres are arranged in different ways creating three basic viral shapes. These are:
The capsid is composed of protein subunits called CAPSOMERES. The capsomeres are arranged in different ways creating three basic viral shapes. These are:
- Helical
- Polyhedral
- Complex
General pattern of a typical virus life cycle:
- Attachment
- Entry of nucleic acids/enzymes
- Synthesis of new nucleic acids and capsids
- Assembly
- Release
The general pattern is called ____ _____
Lytic replication
Some viruses, once intracellular, go into a period of ____ where they remain ____ only to surface at a later date.
Some viruses, once intracellular, go into a period of LATENCY where they remain DORMANT only to surface at a later date.
Where does the life cycle get altered with latency?
A pause occurs between entry and synthesis
1. Attaches
2. Enters
3. Pauses
4. Synsthesis
5. Assembly
6. Release
Latency is often represented by the ______ _____
Lysogenic replication
Prions are a proteinaceous agent and are considered _____ ____ that cause neurologic lesions in ____ ____
Prions are a proteinaceous agent and are considered infectious proteins that cause neurologic lesions in multiple species
Prions:
- ___ _______
- Can only be destroyed by ______
- Cause for disease development:
- Any pattern to age?
- Any pattern to symptoms?
- No treatment
- Can only be destroyed by incineration
- Cause for disease development: inheritance or ingestion
- Any pattern to age? age-related, 50
- Any pattern to symptoms? amyloid plaques/ death
The prion converts normal ___ cellular PrP into __ (bad). Ultimately, prions ____ _____
The prion converts normal alpha cellular PrP into beta (bad). Ultimately, prions don’t replicate
T/F- Prions replicate very slowly
False, they don’t replicate!
Resident microbiota
- Been there since we were born
- Harmless under normal conditions (non-pathogenic)
Transient Microbiota are only _____ and do not persist in body due to 3 things:
temporary
1. Elimination by body’s defense cells
2. Hygiene
3. Competition from other microbe
Commensalism
Benefits microbe, no harm to host
Ex: mites on eyelashes
Mutualism
Benefits microbe, benefits the host
Ex: E.coli
Parasitism
Benefits microbe, harms the host
Ex: tapeworm
There’s an offset of parasitism called _____ in which there is..
Amensalism: no benefit to microbe, but the host is still harmed
If the pathogenic microorganism is not a normal microbiota the question is where is the pathogen normally found?
Reservoir
3 primary reservoirs:
Human reservoir
Animal reservoir
Nonliving/environmental reservoir
The majority of infections are from ____ ____ due to
Human reservoirs due to temp. and species specificity
There are three types of asymptomatic carriers:
- Incubation carriers: not yet showing signs
- Convalescent carriers: active stages of recovery
- Chronic carriers: recovered but still shedding
Types of contact transmission
Direct contact transmission
Indirect contact transmission
Droplet transmission
Vehicle Transmission-
Vehicle transmission is the spread of pathogen from its reservoir to the host by a _____, such as..
Vehicle transmission is the spread of pathogen from its reservoir to the host by a vehicle, such as water, food, or air.
Besides the vehicles that we mentioned above (water, food, or air), blood and other ___ ____ can also serve as a vehicle.
bodily fluids
Vector Transmission-
Vectors are referred to animals that carry pathogens from the _____ to the ___. The most important group of disease vectors are _____, such as flies, mosquitoes, fleas, ticks…etc. Some of these arthropods are ______vectors whereas others are ______vectors.
Vectors are referred to animals that carry pathogens from the reservoir to the host. The most important group of disease vectors are arthropods, such as flies, mosquitoes, fleas, ticks…etc. Some of these arthropods are mechanical vectors whereas others are biological vectors
Mechanical vectors pick up pathogens on their body parts, such as their feet, and carry them from one place to another. They ____ transmit pathogens present on their body to new hosts. Basically, the pathogens are ___ the bug, not __ it.
Mechanical vectors pick up pathogens on their body parts, such as their feet, and carrying them from one place to another. They passively transmit pathogens present on their body to new hosts. Basically, the pathogens are on the bug, not in it.
Biological vectors not only carry pathogens from reservoir to the host, but they themselves have also been _____ with the pathogens. Therefore, the pathogens are ___ the bug, not ___ it. Biological vectors usually transmit pathogens by ____
Biological vectors not only carry pathogens from reservoir to the host, but they themselves have also been infected with the pathogens. Therefore, the pathogens are in the bug, not on it. Biological vectors usually transmit pathogens by biting
If a person coughs and transmits a microbe through a ventilation system it’s ____. However, if they coughed within 3 ft of you, it’s _____
Vehicle
Contact
(droplet vs aerosol)
List the 5 stages of infectious disease
- Incubation period
- Prodromal period
- Illness
- Decline
- Convalescence
Describe the incubation period
no signs or symptoms (infected but not affected)
Describe the prodromal period
vague, general symptoms
Illness
most severe signs and symptoms
Decline
declining signs and symptoms
Convalescence
no signs or symptoms
Most of our Resident Microbiota can actually benefit us by a phenomenon called ______ ______(1)
_____ _____(1) is a way for the members of our Resident Microbiota to protect us from these intruders. Microbial antagonism involves _____ between our Resident Microbiota and the invading pathogens. One consequence of such competition is that our Resident Microbiota can protect the host by ______ any invading pathogens coming from outside the human body from establishing their ______
Microbial antagonism is a way for the members of our Resident Microbiota to protect us from these intruders. Microbial antagonism involves competition between our Resident Microbiota and the invading pathogens. One consequence of such competition is that our Resident Microbiota can protect the host by preventing any invading pathogens coming from outside the human body from establishing their residence
Resident Microbiota normally __ ___ cause disease.
But under certain conditions, some members of our Resident Microbiota can become harmful and cause disease when the proper “_______” arises. These microorganisms are known as _______ _____
Resident Microbiota normally do not cause disease.
But under certain conditions, some members of our Resident Microbiota can become harmful and cause disease when the proper “opportunity” arises. These microorganisms are known as opportunistic pathogens.
What conditions turn our Resident Microbiota to an opportunistic pathogen?
- Immune suppression
- Stressful conditions
- Introduction of resident microbiota into an unusual location
Every pathogen must have at least one reservoir. A reservoir is the ___ of a pathogen or the____ ____ of a pathogen. A reservoir is a place for the pathogen to survive, multiply (reproduce), and to stay before and after infecting a host. Some pathogens have more than one reservoir.
Every pathogen must have at least one reservoir. A reservoir is the source of a pathogen or the primary habitat of a pathogen. A reservoir is a place for the pathogen to survive, multiply (reproduce), and to stay before and after infecting a host. Some pathogens have more than one reservoir.
Zoonoses
Diseases that spread from another animal host to humans
Zoonoses is acquired through various routes:
- Direct contact with animals or their waste
- Eating affected animals
- Blood-sucking anthropods
Common portals of entry
Skin, Mucous Membranes, Placenta, and Parenteral (blood)
The portals of exit are the same as portal of entry (Skin, Mucous Membranes, Placental, and Parenteral) EXCEPT:
Placental
(Portal of entry)- Majority of infections come from
Mucous membranes
Signs are ____ manifestations of disease ____ or ____ by others
Signs are objective manifestations of disease observed or measured by others
Symptoms are ____ characteristics of disease that are ___ by the patient
Symptoms are subjective characteristics of disease that are felt by the patient
Examples of symptoms
pain, headache, fatigue, nausea
Examples of signs
fever, vomiting, a rash
Hereditary
Caused by genetics
Iatrogenic
Caused by a medical procedure
Nosocomial
Caused by the hospital (hospital aquired)
Idiopathic
Unknown cause
Congenital
Present at birth
Infectious
Caused by a pathogen, bacteria, etc.
The CDC (Center for Disease Control) provides weekly reports listing the ______and _________ for numerous diseases. Incidence is the _____ of ____ ____ whereas Prevalence is the _____ ____ of cases. One of the most important diseases in these reports is for ____- ______ _____ _____.
The CDC (Center for Disease Control) provides weekly reports listing the INCIDENCE and PREVALENCE for numerous diseases. Incidence is the number of new cases whereas Prevalence is the total number of cases. One of the most important diseases in these reports is for HAI’s- Healthcare Associated Infections.
Endemic disease
Disease is constantly present (stable)
Epidemic disease
Larger number of people affected in a short period of time
Epidemic disease
Larger number of people affected in a short period of time
Pandemic disease
Occurring in multiple countries within a short period of time
Structural barrier-
Microorganisms that form our normal microbiota only live on the surface of our body (it can be either external or internal surface), this body surface is made up of _____ ____. There are two main types of epithelial surfaces: the ____ and the ____
Microorganisms that form our normal microbiota only live on the surface of our body (it can be either external or internal surface), this body surface is made up of epithelial cells. There are two main types of epithelial surfaces: the skin and the mucous membrane.
(1) The first kind of mechanical barrier is due to the ______ ______ of the epithelial cells lining the surfaces of ____ and ____. These epithelial cells can produce mucus that entraps microorganisms. Cilia on epithelial cells constantly move this mucus toward the mouth, where the mucus along with the trapped microorganisms is swallowed and eliminated
The first kind of mechanical barrier is due to the mucociliary movement of the epithelial cells lining the surfaces of nose and throat. These epithelial cells can produce mucus that entraps microorganisms. Cilia on epithelial cells constantly move this mucus toward the mouth, where the mucus along with the trapped microorganisms is swallowed and eliminated
(2) The second kind of mechanical barrier is due to the movement of our body fluids (such as blood, urine, tears, semen…..etc). For example, in the ____, the rapid flow of urine washes away most microorganisms that happened to establish residence on the lining of urethra. Another example would be our ___ washing microorganisms off the conjunctiva
(2) The second kind of mechanical barrier is due to the movement of our body fluids (such as blood, urine, tears, semen…..etc). For example, in the urethra, the rapid flow of urine washes away most microorganisms that happened to establish residence on the lining of urethra. Another example would be our tears washing microorganisms off the conjunctiva
Biochemical barrier (or chemical barrier)-
Biochemical barriers are..
chemicals produced by cells on the surface of the human body against microorganisms
Examples of biochemical barriers
- Keratin
- Perspiration
- Lysozymes
- Sebum
- Acids (HCl)
Genetic barrier-
Some hosts are..
genetically immune to the diseases of other hosts
Genetic barrier, Species Specific Exs
- HIV (human) vs FIV (felines
- Ebola virus
- Heartworms
Innate immunity
- Present and functional at birth
- Nonspecific
- No memory
Adaptive immunity
- Present and nonfunctional at birth
- Specific
- Memory
Our body’s second line of defense against microbial invasion or infection has to do with our body’s natural, nonspecific immune responses. These immune responses include four components:
inflammation, phagocytosis, interferon, and complement
Inflammation can be identified by four classic symptoms: _______________. A fifth symptom, the loss of ____, is often added to these classic symptoms but can be attributed to the swelling and pain.
Inflammation can be identified by four classic symptoms: redness, heat, swelling, and pain. A fifth symptom, the loss of function, is often added to these classic symptoms but can be attributed to the swelling and pain.
Goals of inflammation:
- Remove the agent causing inflammation
- Keep damage localized
- Allow it to heal
- Alert adaptive immunity
3 sequential stages of inflammation (and local or systemic):
Vascular Changes (local)
Edema/Swelling (local)
Fever Development (systemic)
What does interferon do?
Inhibits the reproduction/synthesis of the viruses
Interferons are released by a cell once infected to
protect neighboring cells
Actions of complement / 3 different groups of protein:
- C3a/ C5a
- C3b
- C5 - C9
C3a/ C5a
chemotaxis
C3b
opsonization
C5-C9
Membrane Attack Complex (MAC)- actually kills the microbe by punching holes in it, causing lysis
5 sequential stages of phagocytosis:
- Chemotaxis
- Ingestion
- Fusion
- Killing
- Elimination
Recognition of invader due to signal molecules on the microbe surface
Chemotaxis
Ingestion- membrane extensions surround microbe forming a ____
membrane extensions surround microbe forming a phagosome
Fusion-______ fuses with phagosome creating a _______
lysosome fuses with phagosome creating a phagolysosome
In both types of immunity (humoral/cell-mediated), the attack of the pathogen occurs as a result of the ______ of an ______. The antigen is a molecule that triggers an immune response. The antigen is usually a surface protein however it could also be a carbohydrate or a lipid. There are 3 basic categories of antigens:
As a result of the recognition of an antigen
- Exogenous antigens
- Endogenous antigens
- Autoantigens
Exogenous antigens
found outside a body’s cells (including toxins and other components of microbial cell walls, membranes, flagella, pili)
Endogenous antigens
produced by microbes that reproduce inside a body’s cells
Autoantigens
self made antigens
2 types of lymphocytes and what they’re responsible for
T Lymphocytes (T cells)- responsible for cell-mediated immunity which is a response against intracellular pathogens
B Lymphocytes (B cells)- responsible for humoral immunity which is a response against extracellular pathogens
Important points- T Cell Activation:
- Infected cells are displaying _____ _ ______ antigens
- APC displays both _____ __ and ____ __
- Interleukin ____ produced by APC causes Th to become ___
- Interleukin ___ produced by both Th1 and T8- activates ___
- Infected cells are displaying MHC 1 endogenous antigens
- APC displays both MHC 1 and MHC 2
- Interleukin 12 produced by APC causes Th to become Th1
- Interleukin 2 produced by both Th1 and T8- activates T8
Components of T cell Activation
Cytotoxic T
Helper T
Memory T
Regulatory T
Types of lymphocytes used in B cell activation
B lymphocytes
Plasma cells
Helper T
Memory B
Key points of B cell Activation:
- _____ (both dendritic and B cell) displays _____
- Interleukin ___ causes Th to become ___
- Interleukin __ from Th also activates ______ to become _____ ____
- _______ made by plasma cells attack _______ antigens
- APC’s (both dendritic and B cell) displays MHC 2
- Interleukin 4 causes Th to become Th2
- Interleukin 4 from Th also activates B cell to become plasma cells
- Antibodies made by plasma cells attack exogenous antigens
Remember that B cells are responsible for humoral immunity, which is the
production of antibodies to attack extracellular epitopes (exogenous antigens)
5 types of antibodies
IgG
IgA
IgM
IgE
IgD
IgM
1st antibody produced; acute
IgG
most common and longest lasting; chronic
IgA
associated with body secretions; mucous membranes
IgE
involved in response to parasitic infections & allergies
A child has been infected with pinworms
IgG
Got the rabies vaccine a year ago
IgG
Just got coughed on from a person with the flu
IgM
4 functions/mechanisms of attack for antibodies
Phagocytosis
Lysis
Agglutination
Neutralization
The molecule that triggers an immune response
antigen
The antibodies that are produced by plasma cells come in a variety of different forms. The basic structure is a Y shaped molecule composed of __ heavy chains and ___ light chains. Each chain has a ______ region on it that creates an _______ ______ _____ that is ______ for each specific ______. The stem of the Y shaped antibody has some variation that is the premise for the difference between the types of antibody produced.
The antibodies that are produced by plasma cells come in a variety of different forms.The basic structure is a Y shaped molecule composed of 2 heavy chains and 2 light chains. Each chain has a variable region on it that creates an ANTIGEN BINDING SITE that is unique for each specific epitope.
On the antigens are variable regions called ______. The epitopes have variable shapes, sizes, and complexity. It is the epitope that the immune system recognizes when mounting an attack against the pathogen. Epitopes are only recognized by adaptive immunity cells when carried on _____
Epitopes
MHCs
Epitope definition
3-dimensional regions that recognize antigens
Epitopes are recognized by the lymphocytes when displayed as
Major Histocompatibility Complex (MHC) proteins
Function of MHCs: ______ and _____ ______ for presentation to _____ ____
Holds and positions epitopes for presentation to immune cells
Cells that presents the epitope to the lymphocyte is called an
Antigen Presenting Cell (APC)
MHC 1
- Present on all nucleated cells
- Fixed cells (stationary, not moving around)
MHC 2
- Wandering cells with a nucleus
- Only present on APCs
MHC 2s include
macrophages, dendritic cells, and B cells
Autoantigens are displayed as
self MHC’s
Endogenous and exogenous antigens are processed into ____ proteins to display _____ ______
Depending on the cell, these can be either ____ __ if a nucleated fixed cell, or ____ _ and ____ __ if an _____ ____ ____
are processed into MHC proteins to display foreign epitopes
Depending on the cell, these can be either MHC 1 if a nucleated fixed cell, or MHC 1 and MHC 2 if an antigen presenting cell
The interaction between leukocytes and dendritic cells and between different leukocytes requires ________ Costimulation is a result of the surface molecules on each of the cells as well as the release of important chemical molecules. These chemical molecules are referred to as _______
The interaction between leukocytes and dendritic cells and between different leukocytes requires COSTIMULATION. Costimulation is a result of the surface molecules on each of the cells as well as the release of important chemical molecules. These chemical molecules are referred to as CYTOKINES
Example of a cytokine and what it does
Interleukins (ILs): signal among leukocytes
Remember that T cells are responsible for cell-mediated immunity, which is the..
attack of infected cells
As a means of providing protection against pathogens not yet exposed a person can receive a _________, otherwise known as an immunization. The ________ that is administered is intended to be a ______ ______ of the pathogen so as to introduce the individual to specific foreign antigens/epitopes.
As a means of providing protection against pathogens not yet exposed a person can receive a VACCINATION, otherwise known as an immunization. The VACCINE that is administered is intended to be a harmless version of the pathogen so as to introduce the individual to specific foreign antigens/epitopes.
What’s the goal of vaccines?
To provide the individual with memory cells against that epitope
What can measure the effectiveness of a vaccine?
a titer
Titer:
- measures _______ ______in blood serum for a specific ______
- serum being tested is serially diluted and tested for _________ activity
- ______ dilution of serum gives a positive reaction to the titer
- measures antibody levels in blood serum for a specific antigen
- serum being tested is serially diluted and tested for agglutinating activity
- highest dilution of serum gives a positive reaction to the titer
Basically, the titer is a reflection of _______ The actual antibody level is generally not protective against infection but instead represents the presence of ______ ______
Basically, the titer is a reflection of protection. The actual antibody level is generally not protective against infection but instead represents the presence of memory cells.
Attenuated vaccine
- modified live
- uses pathogens with reduced virulence
- ex: measles, chicken pox
Inactivated vaccine
- killed
- often contains adjuvants (chemicals added to increase antigenicity)
- ex: rabies, polio
Toxoid vaccine
- chemically/thermally modded toxins to stimulate active immunity
- most useful for some bacterial diseases with exotoxins
- ex: tetanus
What do toxoids work against?
exotoxins (not attacking epitopes like others)
Subunit vaccine
- Only a portion of microbe is used in vaccine
- ex: whooping cough, HPV
mRNA vaccine
- Only a portion of mRNA is used in vaccine
ex: covid
T/F: Gram-negative bacteria have 2 cell walls
False
Flatworms and ringworms are
small multicellular organisms
Where is the electron transport chain located in microbes?
Cell membrane
What attaches a flagellum to the cell membrane?
Basal Body
Fermentation is considered to be
substrate level fermentation
The final electron acceptor for fermentation is ___ ___, but if it’s anaerobic it’s _____ ___
- Pyruvic acid
- Inorganic molecule
2 things selective toxicity mean
- No harm to host
- Only one mechanism of action
Blocking PABA disrupts metabolism of ___ ___
folic acid
What is quorum sensing?
Communication between microbes
Tick transmitted diseases are best treated with what group of antibiotics?
Tetracycline
T/F: Most illnesses in humans are caused by a single bacterial species
False
The R plasmid would most likely contain genes for:
Penicillinase
A microbe that is capable of making organic molecules from CO2 is an
autotroph
Teeth discoloration
Doxycline
Joint damage
Ciprofloxacin
How does using ozone work to sanitize water?
Creates free radicals that denature proteins
Which is true of an Hfr prokaryote?
Transfers entire chromosome to the recipient
Converts recipient into an Hfr cell
Has an F plasmid
None of the above
None of the above
May cause mild disease
Attenuated
Targets a flagella
Subunit
Inactivated
Adjuvant
Translation of proteins
mRNA
Tetanus is a
toxoid
In cell-mediated immunity, what will be used on APCs
Both MHC 1 and MHC 2
The surface of which of the following is normally axenic:
Intestines
Nose
Blood
Skin
Blood
An individual who is recovering from the flu should still stay home to prevent spread because they’re still considered a
convalescent carrier
Protein molecules that allow resident microbiota to attatch to epithelium surface
Adhesins
When a virus leaves a cell, taking a portion of the cell membrane with it:
Budding
An antiphagocytic factor that kills WBCs
Leukocidin
T/F Viruses synthesize and assemble envelopes prior to release from a cell
False (not envelopes)
Hepatitis C traveling in the blood to infect liver cells will have ____ ____ on the surface
exogenous antigens
T/F: Cytotoxic T cells attack infected cells displaying MHC 1 exogenous antigens
False- it should say endogenous antigens
What is responsible for conjugation?
Fertility gene (F factor)
What’s the difference between fertility in a plasmid vs in the chromosome?
If it’s F+, the recipient who was F- becomes F+ and no other chromosome gets transferred
If it’s Hfr, they stay F-, but the other chromosome does transfer
a small DNA molecule that replicates independently of the other chromosomes often carrying information required for replication.
plasmid
Failure to add iodine
All bacteria appear G-
Failure to apply decolorizer
All bacteria would appear G+
Failure to apply safranin
G- is colorless and G+ appears purple (unaffected)
Reversal of crystal violet and safranin stain
All bacteria would appear G+
