Microbiology: Final Exam

Hooke

**1660** =**Before the Golden Age** of Microbiology

\-**Discovered the microscope**

\-**1st person** who created name **cell**= individual living unit

Van Leeuwenhoek

**1670= Before the Golden Age of Microbiology**

**-1st person to look at living cells.**

\-Developed a more **sophisticated microscope**

* Looked at living cells, fecal material, pond water, and samples of own teeth.

Jenner

**1800= Before the Golden Age of Microbiology**

**-1st vaccination= for smallpox**

\-English physician

Semmelweis

1840= Before the Golden Age of Microbiology

-1st person to start doing hand hygiene(washing hands)

• So microbes will not be passed on between patients.

• A Hungarian doctor= worked maternity hospital

Pasteur

**1860= During Golden Age of Microbiology**

\-**Proved Biogenesis and disproved spontaneous generation**

* Hypothesized that the cells were already present in the air
* **Louis Pasteur Swan Neck Experiment**

Proving Biogenesis

Living things only come from pre-existing living things= Pasteur proved by Swan Neck Experiment

* Disproved Spontaneous generation= you take non-living material and it can generate living things
* ex: leaving meat out and maggots would appear on meat

Lister

**1870= During the Golden Age of Microbiology**

**-1st apply antiseptic antimicrobial compounds to surgical wounds to reduce infection**

* Wanted to **prevent infection after surgery**, applied substance to surgical wounds

Koch

**1870= During the Golden Age of Microbiology**

\-**Proved the Germ Theory of Disease**= microbes cause disease

Germ Theory of Disease Koch’s Postulates

Idea that microbes can cause disease.

\-Sequence of experiments steps can go through to prove that particular microbe causes a specific disease.

* Back then they thought that disease was caused because God was unhappy, witch cursed you, or breathing some bad air.

Fleming

**1928 = After the Golden Age of Microbiology**

\-In 1928 discovered a **fungus called= Penicillium.** **Not useable** yet.

* Penicillin secreted a substance that killed bacteria

Chain and Florey

**1942= After the Golden Age of Microbiology**

\-Converted **penicillin into a useable form**, used it to treat bacterial infections,

* Became **1st antibiotic**= during WWII

Watson and Crick

**1953=** **After the Golden Age of Microbiology**

\-Discovered structure of **DNA, has double helix**

Prusiner

**1997=** **After the Golden Age of Microbiology**

\-Discovered Prions= infectious proteins that can cause Mad Cow Disease

* Newest type of microbe, got Nobel prize

Benefits of Microbes

• Cycling of Elements

• Flow of Energy

• Food Chains

• Microbiota

• Biotechnology

• Genetic Engineering

• Bioremediation

• Gene therapy

Cycling of Elements

Referring to atoms that make up all living things

\-How microbes affect life on earth

* The most common cycling of elements is the carbon cycle

Flow of Energy

How energy moves through ecosystems, One direction

\-All energy originally comes from the sun

Food chains

Food chain in soil

Microbiota

Microbes that live on and in your body

\-Microbes help with your immune system and help fight infection and digestive system

Ecological benefits of microbes in….

Helping with:

• Cycling of elements

• Flow energy

• Food chain

-Are important for life on earth by not very personalized.

Biotechnology

where you live, use living things to create something you want

* Ex: If you take yeast and give it the right conditions it can generate bread or beer.

Genetic Engineering

\-Type of biotechnology, Engineer the DNA where we can change the microbes DNA or organisms DNA to get a result we want.

* Proved that you can swap out genes from any species put it into another species, recipient will produce product.

Bioremediation

where we use microbes to clean up pollution

* Ex: Oil spill= spraying bacteria that has been engineered to use the oil as food.= The bacteria will metabolize the oil and when oil is gone the bacteria will die off.

Gene Therapy

is used to treat a genetic disease where an individual has been born with a mutation in one of their genes that causes disease

Pathogens

harm us and cause disease

\-2 tyes= Opportunistic and obligate

Opportunistic Pathogens

\-Under normal circumstances is harmless or beneficial.

\-But if it gets to a part of your body where it shouldn’t be or overgrows then takes the opportunity to take nutrients from your body to replicate. will cause disease

* Most common

Obligate pathogens

-Microbes that must infect host, so they must infect the host because that is the only way they get nutrients and can replicate

• No other option they need to infect host to get nutrients to replicate=parasites

• ex= HIV

Personal benefits of microbes…

1. Normal development of the digestive and immune system

2. Provide vitamins= E. coli produces vitamin K

3. Protection from Infectious disease

Biotechnology benefits of microbes….

1. Food

2. Genetic Engineering(DNA)

3. Bioremediation

4. Gene Therapy

Archaea

• very small

• No organelles

• Unicellular

• Heterotrophic and some autotropic

• Some produce asexually

Do Not have peptidoglycan in their cell wall

* Most are Extremeophiles **

Cocci (coccous)

-5 different arrangements that bacteria can be arrangement has to do with how the bacteria alls divide.

1. diplococci =1 (oo)

2. streptococci= long chain (oooooooo)

3. tetrad= 4 (oooo)

4. sardine = 8(oooooooo)

5. staphylococci = irregular clusters

Bacilli (bacillus) = Rods

1. single bacillus =1

2. diplobacilli=2

3. streptobacilli=long chain

4. coccobacillus= rounded rods

Spiral

1. Vibrio= curved rods

2. spirillum= several curves, very rigid

3. spirochete= several turns, flexible, not as regular with curves

Unusual shapes

1. Star-shaped bacteria

2. rectangular bacteria

• Very unusual bacteria usually do not cause disease

Appendages= Prokaryotic

\-Flagella

\-Fimbriae

\-Pillis

Flagella

\-Appendages that extend out from the cell, are relatively long and thin.

\-Only Bacillus and Spiral types of cells, Coccus cells do not have it.

\*Composed of protein H antigens(identification). Much more simple in structure compared to eukaryotic

Prokaryotic flagella

\-Main function= Locomotion for both prokaryotic and Eukaryotic flagella.

\-Prokaryotes move in a run and tumble type of way

Eukaryotic flagella

Move more directed they have chemotaxis or phototaxis

-Chemotaxis=response to chemical(molecule)

• (+)= cell moves toward the molecule

• (-)= cells move away from the molecule

-Phototaxis= movement in terms of light or relation to light.

• (+)= cell moving into the light

• (-)= cell moving away from light

Peritrichous

Flagella are evenly distributed all over bacteria.

Momotrichous

Bacterial cells has 1 flagella at 1 end

Lophotrichous

more than 1 flagella at 1 end

Amphitrichous

1 flagella at both ends, each end

Endoflagella

only found on flexible spiral bacteria

\-Wrapped around cell, held by the outer sheath.

Fimbriae

\-Usually found on Gram-negative bacteria mainly

\-Evenly distributed over the surface of cell. More ridged.

\**Main purpose= attachment*\*

* Better able to adhere to tissue, makes bacteria much more likely to cause disease.

Pili

\-Bacteria only going to have 1 to 2, usually longer than Fimbriae.

\-Usually found on Gram-negative bacteria

\*-*Main purpose= Conjugation= sexual reproduction in bacteria*\*

Conjugation

referred to as sexual reproduction of bacteria(not with gametes)

\-Process= Involved DNA transferring from 1 bacteria to another, starts with F+ cell and has F factor. F+ will form a pills to F- cell, copy of plasmid going to cross pills, go into recipient cell. Converting cell into F+ cell.

* Pillus used to transfer copy of plasmid form one cell to another.

Plasmid

The DNA that is transferred via a pills to another bacterium. Smaller circular pieces of DNA, often find genes for toxins and antibiotic resistance.

Glycocalyx

The cells outermost layer of prokaryotic cell

• Mainly composed of carbohydrates, glycoproteins, glycolipids

• Main Purpose: Adherence is sticky, helps cell to stick to surface and protective, can protect cell.

  • 2 Types; Slime layer and Capsule

Slime layer

Usually found in bacteria, found out in the environment; soil, water, rocks.

\-Very unorganized, very loosely held to cell, thin

\- Purpose= attachment, protect against dehydration

Capsule

usually found in pathogens

* More highly organized, very tightly held in cell, thick
* Purpose= attachment, increase pathogenity, protect from phagocytosis(cell tries to eat bacteria-white blood cells).

Cell walls

Main purpose= to protect the bacterium from osmotic lysis, helps hold shape

* 2 types help identify them= Gram-Negative, Gram-Positive.

Gram-Positive

Many layers of peptidoglycan, very thick and ridged

Gram-Negative

Have outer membrane, tend to be more resistant to different chemical disinfections, more pathogentic

* Imbeded in outer membrane= Lipopolysaccharide
* One layer of peptidoglycan

Chromosome

Contain= essential genes that determine which proteins- determine characteristics of particular cell

-Nucleotide= area you find chromosome

• Prokaryotic= Must have 1 chromosome per cell, circular composed of DNA only cells does NOT have organelles

• Eukaryotic= Several there, many linear, composed of DNA, complex with protein called histone.

-Eukaryotic ___= Multiple ___ that are linear, complex DNA and Histones.

-Prokaryotes____=__ Single circular double-stranded ___ composed of only DNA

Cytoplasm

everything found inside the cell

Everything in cell, between the cell membrane and nucleus, Includes liquid, organelles inside cell

\**Everything inside cell except nucleus*\*

Cytosol

liquid part inside cell

• Prokaryotic= 80% water

• Eukaryotic= 90% water

Refers to liquid inside cell, Just referring to liquid

-Mainly water, dissolved; nutrients, waste, sugars, salts, ions

Cell membrane

• Prokaryotic cell= there are mainly enzymes, proteins that are bound in cell wall membrane. No cholesterol

• Eukaryotic cell= Not very many enzymes, have cholesterol embedded in membrane

Endospores

Highly resistant to disinfection, heat, chemicals, and antibiotics

\-Specialized resting cells that produced by 2 types of bacteria= Bacillus and Clostridium.

Inclusions

storage area, within cell

\-Dark staining areas that are not found in normal cells and these are sites where viruses is replicating, copies of genome, capsid

\-Cells can’t function normally and have impact on the host.

Types

• Fungi= Mold(multicellular), Yeast(Unicellular)

• Algae= Photosynthetic, unicellular or multicellular

  • Multicellular algae= seaweed

• Protozoa= Unicellular, found in water and soil

• Helmets= multicellular, worms

Appendages= Eukaryotic cell

\-Flagellum

\-Cilia

Flagellum= Eukaryotic

Locomotion= one place to another

• Eukaryotic _____= Much more complex in structure

• Both Eukaryotic and Prokaryotic ______ have the same function but different structure

Cilia

Movement, move fluids, locomotion

\-Much shorter than Flagella, very numerous

\-Respiratory Epithelium= ____ involved in the movement, moving fluid, Mucus layer traps any particles, and microbes when a person inhales.

Fungal cell wall

Have chitin(a type of carbohydrate that is indigestible)= digestive system unable to break down

• Yeast has= Mannan, B-glucan, chitin

• Mold only has chitin

Algal cell wall

Main molecule= Cellulose

* Fungi cell walls have chitin, ___ have Cellulose

Pellicle

Thick outer protective covering Protozoa

• Composed of protein, others are composed of carbohydrates

• Do Not have true cell walls instead have ____

Glycocalyx= Eukaryotes

Outer surface of outer layer of animal cell

\-Purpose= Important for attachment, for cells to attach to surface and each other. Help strength cell, involved for cells to cell recognition

\-Animal cells Do Not have cell wall. Instead have ____. Only type of Eukaryotic organism

* Lots of glycoproteins and glycolipids

Endosymbiosis theory

Is to describe how eukaryotes evolved from prokaryotic cells.

Yeast

\-Unicellular

\-To identify _____ need Biochemical reactions(tests) to determine enzyme profile, biochemical reaction they catalyze.

Mold

\-Multicellular

\-Macroscopic, different morphologies

\-Under microscope look different

\-Can identify different ____ physically don’t need microscope.

\-Make Hyphae

Mycosis

Disease caused by fungus

• Opportunistic pathogens= majority

• Obligate pathogens= few

• Chronic= last long time

• Dimorphic= found in yeast and mold

Lichens

\-Symbiotic **relationship between Algae and Fungi**

\-Algae performs photosynthesis, and produce glucose is used by fungus

\-Not parasite on tree, just grow on top of tree

Protozoa

• Water and soil

• Heterotrophic and Autotrophic

• Unicellular

• Asexual and sexual reproduction

  • Trophozoites= active form, moving around, reproducing

  • Cysts= protective form forms cysts when it wants to protect itself

Excavata/Archaezoa

\-Have flagella

\-No mitochondria, No cyst form= can’t survive outside host

Euglenozoa

\-Use flagella, have mitochondria, have chloroplast, have autotrophs, performs photosynthesis

\-Obligatie pathogens

\-Hemoflagellates

Hemoflagellates

\-Parasitic obligate pathogens, infect mammals, get nutrients from red blood cells, Euglenozoa

* Transmitted to host by an insect bite
* Ex: Trypanosoma brucei=aftrian sleeping sickness
* Ex: Trypanosoma cruzi= Chagas disease

Amebae

Amoebas

\-Have Pseudopods= for locomotion

* Ex= Entamoeba histolytica= amoebic dysentery

Apicomplexa

-Pointed end, No mode of Locomotion, 2 types;

• Plasmodium= causes malaria, requires mosquito and human(intermediate host)

• Toxoplasma gondii= causes toxoplasmids in feces

Cilliates

Use cilia as locomotion

\-non-pathogenic

Helminths

• Water

• Multicellular= Body systems

• Heterotrophic

• Sexual reproduction

  • Monoecious and Dioecious

• Trematodes, Cestodes, and Nematodes

Trematodes

Flukes, All Monoecious

* Ex: Schistosoma= blood fluke

Cestodes

\-Monoicious, can have proglottids

\-Scolex(head)= attaches to intestines

\-Sucker, Scolex, and Hooks

\-Ex: Tapeworm, Taenia saginata= beef tapeworm, don’t have proglottids

* Released with feces

Nematodes

Round worms, Dioecious

• Ex: Enterobius vermicularis= pinworm, usually infects children, lays eggs on anus

• Ex: Necator americanus= Hookworm, burrow through skin, enter circulatory and respiratory system, poor sanitation

Predisposing Factors

• Gender

• Genetics

• Climate/weather

• Age

• Nutrition

• Smoking and Drinking

Portals of entry

Each microbe has a specific way it prefers to enter the body

1. Mucous Membrane(Respiratory, gastrointestinal, urogenetial, and Conjunctive)

2. Skin

3. Parenteral Route= injections or insects

Penetrate Host Defenses

Microbe enters person’s body, 3 parts of immune system, need to worry about.

1. Phagocytosis= WBC➤ ingest any microbes that enter the body.

2. Fever

3. Antibodies= serum proteins, found in your body

Bacteria have structures to protect from initial defenses:

1. Capsule= helps bacterium avoid being phagocytose by WBC

2. M Proteins= heat resistant, acid resistant, and help bacterium avoid being phagocytose

3. Mycolic acid= Very resistant to phagocytosis➤ Waxes and mycolic acid.

Toxins

microbes can release toxins and damage hosts, 2 types

1. Endotoxins= part of bacteria cell wall, are released at death.

2. Exotoxins= made inside the cell, secreted out, need a living cell that can create exotoxins, and secrete them out.

Endotoxins

• Gram (-) cells

• Gene on the Chromosome

• Released at death

• Released at death

• Lipids= nonpolar, hydrophobic, don’t interact with water.

• Highly concentrations

• General Symptoms= fever, shock

• No inactivation

• No antibody stimulation

• No Vaccine

  • 1 type= Lipid A

Portal of Exit

microbes leave the individual to infect others

1. Mucous membranes

2. Skin

3. Parenteral Route

Exotoxins

• Gram(-) or Gram(+)

• Genes on plasmid= antibiotic resistance and toxins

• Released by living cells

• Proteins= 3D structure, highly specific

• Low concentration= interact with water

• Specific symptoms= heat can denature

• Antibody stimulation= can make antibodies

• Vaccines

• 3 types= A-B toxins, membrane disrupting and superantigens

Membrane Disrupting Exotoxins

Rupture membranes, often target WBC and kill WBC.

\-Benefit= microbes➤ lower WBC, fewer WBC attacking the microbe

Superantigens

over stimulate the immune system

* Ex= Toxic shock syndrome

A-B Exotoxin has 2 components..

A➤ active component, negative effect on target cell.

B➤ binding component, used to recognize specific target cell.

Overreaction/ Hypersensitivities- Overreaction to antigen

-Overreaction= immune system is responding to something that is not pathogenic. Sometimes referred as Hypersensitive, overly stimulate.

4 types= Anaphylaxis, Cytotoxic reactions, and Immune complex(Involve B-cells, antibodies triggering hypersensitive), Cell-mediated(Involves T-cells).

1. Anaphylaxis= hay fever, immediate, Involves B-cells

2. Cytotoxic reactions= Blood types incompatibilities, Involves B-cells

3. Immune complex= Rheumatoid arthritis, serum sickness, Involves B-cells.

4. Cell-mediated= Contact dermatitis, graft rejection, involves T-cells only.

Anaphylactic

-Involves IgE antibodies= found on surface of mast cells and Basophils, purpose to activate Basophils and Mast cells.

• When IgE binds to allergen that its specific for, it will stimulate mast cells or B-cells to release Histamine and other mediators= lead to inflammatory reaction in individual

• Often for these reactions person has sensitized to allergen

  • Already come in contact with allergen, formed primary response and now have memory cells, so far second response will have very strong reaction.

• 2 types= Localized and Systemic

Localized Anaphylaxis

Inflammatory response remains localized to 1 part of the body of 1 body system.

• Inhalants= Antigens, allergens that enter through respiratory system. There going to stimulate inflammatory reactions.

  • Effecting upper respiratory system= considered hay fever.

  • Effecting Lower respiratory system= Often leading to asthma. Response to inhaled allergens. Cause inflammation in lower respiratory system can be life threatening.

• Ingestants= Food allergies, when individual ingest the food it will stimulate an inflammatory reaction. Often involves: swelling of: lips, eyelids, and formation Hives.

Systemic Anaphylaxis

Response to allergens that are injected.

* Injectants= Bee sting, injected medication.
* IgE on mast cells and basophils all over the body are triggered to release Histamine= causes vasodilation and become more permeable.
* Epinephrine= counteracts Histamine, which causes vasodilation to maintain blood pressure.
* Allergy Testing= can be used to identify different allergens an individual may be sensitive to. Inject small amounts of different types of allergens into skin, wait for inflammatory response.

Desensitization

Way to reduce a persons allergic response to an allergen, can use ELISA to test if they have allergen.

\-Expose individual to small amounts of allergen, hoping it will stimulate B-cells to produce IgG. IgG produce if individual is exposed to actual allergen, it will agglutinate the allergen and Neutralize the allergen. Allergen will be unable to interact with the IgE molecules:

\-If not able to interact with IgE molecules there will be no degranulating, no secretion of histamine, no allergic symptoms.

Cytotoxic

Involves IgG and IgM binding to molecules on blood cells and results in death of red blood cells.

* 3 types= Transfusion reactions, Hemolytic Disease of Newborn, and Drug-Induced.

Immune Complex

Involve IgG binding to soluble antigens and Antigen has entered the body.

-Some targets for immune complex, hypersensitivite’s are forming complexes in blood vessels, hearts, joints, skin, and kidneys= causing inflammation.

-Steps:

1. Antibody combines with excess soluble antigen, forming large quantities of Ag-Ab complexes.

2. Circulating immune complexes become lodged in basement membrane of epithelia in sites, like Kidneys, lungs, joints, skin.

3. Fragments of complement causes release of histamine and other mediator substances.

4. Neutrophils migrate to site of immune complex deposition and release enzymes that cause severe damage in tissues and organs involved.