micro final

diplococci

cocci growing in pairs

streptococci

chains

staphylococci

grape-like clusters

tetrads

4 cocci in a square

sarcinae

cubic configuration of 8 cocci

coccobacilli

very short rods

vibrios

resemble rods, comma shaped

spirilla

rigid helices

spirochetes

flexible helices

Robert Hooke

described fruiting structures of molds, named "cell" after cork

Antony van Leeuwenhoek

first person to observe and describe microorganisms accurately

Franceso Redi

discredited spontaneous generation for large animals, demonstrated microbe fermentation, discoveries led to development of microbial control methods, discovered attenuation, developed vaccines for anthrax, chicken cholera, rabies, solidified germ theory of disease

Ignaz Sammelweis

Demonstrated that hand washing could drastically reduce the number of women dying during childbirth. "childbed fever"

Joseph Lister

developed a system of surgery designed to prevent microbes from entering wounds

Robert Koch

established relationship between bacteria and diseases

Edward Jenner

Discovered the small pox vaccine from cowpox pus

Ferdinand Cohn

Discovered and described bacterial endospores, classified bacteria by shape, botanist: though bacteria were plants

Alexander Flemming

discovered penicillin

Martinus Beijerinck

\-pioneered the use of enrichment cultures and selective media

\-isolated the first pure cultures of many soil and aquatic bacteria

\-described the first virus

Sergei Winogradsky

\-proposed concept of chemolithotrophy

\-isolated an anaerobic N2-fixing bacterium

Koch's Postulates

1. The suspected pathogen must be present in all cases of the disease and absent from healthy animals. (microscopy, staining)
2. The suspected pathogen must be grown in pure culture. (laboratory cultures)
3. Cells from a pure culture of the suspected pathogen must cause disease in a healthy animal. (experimental animals)
4. The suspected pathogen must be reisolated and shown to be the same as the original. (laboratory reisolation and culture)

general purpose media

to grow as broad a spectrum of microbes as possible

enriched media

general purpose media supplemented by blood or other special nutrients

minimal media

contains the minimal necessities for growth of the wild-type; only contains inorganic salts, a simple carbon source, and water

selective media

favor the growth of one organism over another

differential media

Allow distinguishing of colonies of different microbes on the same plate

Tuberculosis

a. Mycobacterium tuberculosis

b. Small, rod-shaped, strictly aerobic, acid-fast bacillus

c. Transmitted through the air

d. Cough with blood

Bubonic Plague

a. Yersinia pestis

b. Gram-negative, non-motile, coccobacillus

c. Transmitted through bite of infected flea

d. Large lymph nodes, bleeding into skin and organs

Tetanus

a. Clostridium tetani

b. Spore forming, gram-positive, bacillus

c. Transmitted from contaminated soil, dust, objects through cut

d. Locked muscles

Pertussis

a. Bordetella pertussis

b. Gram-negative, coccobacillus

c. Transmitted through air

d. Whooping cough

Rabies

a. Rabies lyssavirus

b. RNA, bullet-shaped

c. Transmitted from saliva (or nervous system tissue) of infected to open would or mucous membrane

d. Confusion, agitation, hydrophobia

Smallpox/Monkeypox

a. Orthopoxvirus, Variola virus

b. DNA, brick or oval shape

c. Transmitted through airborne saliva droplets

d. Progressive skin rash

basic stain

positive charged, salt of colored base, used to stain cell

acidic stain

negatively charged, salt of colored acid, used to stain background

microbial species

a collection of __strains__ that share many stable properties and differ significantly from other groups of strains

microbial strain

a strain consists of the descendants of a single, __pure__ microbial culture (a single cell)

subset of a microbial species

Koch’s Postulates

1. The suspected pathogen must be present in all cases of the disease and absent from healthy animals.
2. The suspected pathogen must be grown in pure culture.
3. Cells from a pure culture of the suspected pathogen must cause disease in a healthy animal.
4. The suspected pathogen must be reisolated and shown to be the same as the original.                  

refractive index

light is refracted when passing from one medium to another

total magnification =

mag. of ocular lens x mag. of objective lens

resolution (d) =

0\.5 λ/NA = 0.5 λ/(nsinθ)

ways to decrease d (better resolution)

shorter wavelength (λ), increase numerical aperture, increase θ (move objective closer), increase n (add oil)

gram stain

gram+ are purple, gram- are pink

defined media

exact composition is known, for growing a singular type of bacteria

complex media

contain some ingredients of unknown composition and/or concentration, general purpose to see what will grow

Common components

1\.     Peptones

2\.     Extracts

3\.     Agar

enriched media

general purpose media supplemented with highly nutritious substances such as blood, ex. Chocolate agar

minimal media

contains the minimal necessities for growth of the wild-type, only contains inorganic salts, a simple carbon source, and water

selective media

favor the growth of some microorganisms and inhibit the growth of others, ex. EMB agar selects for gram (-)

differential media

distinguish between different groups of microorganisms based on their biological characteristics, ex. Blood agar: hemolytic vs. nonhemolytic, MacConkey agar: lactose fermenters vs. nonfermenters

peptidoglycan functions

1\.     provides shape to cell

2\.     protects from __osmotic__ lysis

3\.     may contribute to pathogenicity

4\.     protects from __toxic__ substances

What makes up peptidoglycan?

two alternating sugars form backbone with Beta (1,4) linkages

*N*-acetylglucosamine __(NAG)__

*N*- acetylmuramic acid __(NAM)__

gram-positive cell wall

composed primarily of peptidoglycan (up to 90% of wall), may also contain teichoic acids (__negatively__ charged give bacteria negative charge)

1\.     bind Ca2+ and Mg2+

2\.     help maintain structure of cell wall

3\.     protect from harmful substances

4\.     role in __pathogenesis__

lipoteichoic acids - attached to membrane lipids

gram-negative cell wall

1. consist of a thin layer of peptidoglycan surrounded by an __outer membrane__
2. __outer membrane composed of lipids, lipoproteins, and lipopolysaccharide (LPS)__


1. __no teichoic acids__
2. peptidoglycan (up to 10% of cell wall)
3. periplasm (may constitute 20–40% of cell volume) (many enzymes present)
3. outer membrane - lies outside of the thin peptidoglycan layer


1. porins = channels through which small, hydrophilic molecules (like sugars) can pass
4. Braun’s lipoproteins - connect outer membrane to peptidoglycan
5. Lipopolysaccharide (LPS)

Lipopolysaccharide (LPS)

1\.     Three parts: lipid A, core polysaccharide, O-specific polysaccharide (O antigen – immune system reacts)

2\.     Lipid A embedded in outer membrane

3\.     Core polysaccharide (- charge gives cell – charge) and O side chain extend out

4\.     Importance:

a.     contributes to __negative__ charge on cell surface (core polysaccharide)

b.     helps stabilize outer membrane structure (lipid A)

c.     may contribute to attachment to surfaces and __biofilm__ formation

d.     creates a permeability barrier

e.     may mutate to protect from host defenses (O antigen)

f.      can act as an __endotoxin__ (lipid A)

what type of cells usually make endospores?

gram +

What makes endospores so resistant?

1. core


1. low water content


1. “frozen” state because of lack of water – dehydrated (1/4th)
2. calcium dipicolinate (Ca-DPA)


1. Ca-DPA important for dehydrating the core, gets between bases of DNA to protect
3. SASPs
4. small, acid-soluble, DNA-binding proteins


1. SASPs bind and compact DNA – to protect, can be used as a carbon source to start germinating
5. slightly lower pH


1. pH around 5.5 as opposed to normal 7


2. exosporium and spore coat 

formation of vegetative cell

1. activation


1. prepares spores for germination.
2. often results from treatments like heating.
3. not the point of no return – start to wake up a little
2. germination


1. environmental nutrients are detected.
2. spore swelling and rupture of spore coat.
3. loss of resistance
4. increased metabolic activity.
5. detectors on inner membrane – point of no return when water starts to come in – loses resistance, very vulnerable if conditions change.
3. outgrowth – emergence of vegetative cell, sloughs off layers – exosporium, spore coat, outer membrane, cortex

flagellum structure

1. Flagellin – one protein type stuck together – hollow tube.
2. Hook – single protein – attaches to motor (basal body) – hollow tube.
3. Motor –


1. L ring (in outer membrane – LPS layer), P ring (peptidoglycan ring): both don’t move and keep stability
2. MS ring (membrane supra = inner membrane, one on top), C ring (cytoplasm): both spin, like a revolving door (rotor) (interact with stator (Mot A and Mot B proteins)
4. Motor force – H protons to outside, charge separation, potential energy, H protons to inside (spin rings) transfer movement      

flagellum in gram+ vs gram-

counterclockwise rotation of flagella

forward motion - run

clockwise rotation of flagella

disrupts run causing cell to stop and tumble

monotrichous

one flagellum

polar flagellum

flagellum at one end of cell

amphitrichous

one flagellum at each end of cell

lophotrichous

cluster of flagella at one or both endsp

peritrichous

spread over entire surface of cell

chemotaxis

movement toward a chemical attractant or away from a chemical repellant

spirochete movement

flagella twisted around each other (axial fibril) and then would around spirochete (aka endoflagella)- gives twisting, flexing movement

twitching

social

short, intermittent, jerky motions

type IV pili at ends of cell

move together towards something like food or light

gliding

adventurous

smooth movements

helical track, gliding motors, and extracellular adhesion proteins

many times involves slime

phototrophs

use light as energy source

chemotrophs

obtain energy from oxidation of chemical compounds

lithotrophs

use reduced inorganic substances as electron source

organotrophs

obtain electrons from organic compounds

heterotrophs

use organic molecules as carbon sources

autotrophs

use carbon dioxide as their sole or principal carbon source

catabolism

fueling reactions

energy-conserving reactions

provide reducing power (electrons)

generate precursors for biosynthesis

anabolism

the synthesis of complex organic molecules from simpler ones

free energy (G)

the amount of energy that is available to do useful work

standard free energy change (DGo’)

the change in free energy during a chemical reaction for standard conditions (pH 7, temperature of 25°C, 1 atmosphere, reactants and products at 1 M concentration)

exergonic reactions

release energy

A + B → C + D + energy

DGo’ is negative (rxn proceeds spontaneously)

endergonic reactions

require energy

A + B + energy → C + D

DGo’ is positive (rxn will not proceed spontaneously)

oxidation

removal of an electron (or electrons) from a substance

reduction

addition of an electron (or electrons) to a substance

standard reduction potential (E’o)

equilibrium constant for an oxidation-reduction reaction

a measure of the tendency of the reducing agent to lose electrons.

more __negative__ E’o → better electron donor

more __positive__ E’o → better electron acceptor

the greater the difference between the E’o of the donor and the E’o of the acceptor → the more negative the DGo’

two classes of electron carriers

1. coenzymes


1. freely diffusible; can transfer electrons from one place to another in the cell (ex. NAD+)
2. prosthetic groups


1. firmly attached to enzymes in the plasma membrane (ex. cytochromes)

substrate-level phosphorylation

used in __fermentation__ and other pathways.

ATP is synthesized during steps in the catabolism of an organic compound.

The only way ATP can be made in fermentation.

oxidative phosphorylation

used in respiration

ATP is produced by proton motive force

Strep Throat (Streptococcal pharyngitis)

o   *Streptococcus pyogenes*

o   Gram +, cocci

o   Direct contact with discharges of infected

o   Red, sore throat; swollen tonsils

Cholera

o   *Vibrio cholerae*

o   Gram -, vibrios

o   Contaminated food/water

o   Severe diarrhea

Bacterial Meningitis (Meningococcal)

o   *Neisseria meningitidis*

o   Gram -, diplococci

o   Water droplets

o   Stiff neck, swelling of the head

Lyme Disease

o   *Borrelia burgdorferi*

o   Gram -, spirochete

o   Bite of infected tick

o   Rash

Infectious Mononucleosis

o   Epstein-Barr virus (EBV)

o   Double-stranded DNA virus, toroid-shaped protein core wrapped with DNA and nucleocapsid with 162 capsomers and external spikes

o   Saliva

o   Fatigue; swollen lymph nodes

Coronavirus (SARS-CoV-2)

o   SARS-CoV-2

o   Single-stranded RNA

o   Respiratory fluids

Influenza A (H1N1, Swine Flu)

\

1. RNA Virus 

Roughly Spherical envelope virus 

Has multiple proteins on the surface like spikes


3. Spreads through the air in droplets from an infected person’s sneezes or coughs

Can also spread after touching a contaminated surface and then touching your eyes, nose, or mouth  


4. Fever (not always)

Achy muscles

Chills and sweats

Cough, Sore throat, runny/stuffy nose,

Headache 

\
Other very basic symptoms that are common

Hepatitis A

1. Hepatitis A Virus (HAV)
2. RNA Virus

Spherical/icosahedral shape, has a protein shell


3. ingesting the virus through eating fecal/blood contaminated food or drink or close personal contact with an infected person
4. Yellowing of the skin and the whites of your eyes (**jaundice**)

Loss of appetite

Dark urine

Clay- or gray-colored stool

Sudden nausea, vomiting, and diarrhea

\
Pain near **liver** (upper right side below your ribs)

Polio

1. Poliovirus (Enterovirus C)
2. RNA Virus 

Non Enveloped icosahedral with a protein shell


3. Person-to-person contact

Contact with the **feces** of an infected person or droplets from an infected person


4. Paralysis

Meningitis 

Neck pain/stiffness

Tingling or pricking sensations

Muscle Spasms/Weakness

\
Less severe type only causes flu-like symptoms

Venereal Warts/Cervical Cancer

1. Human Papillomavirus
2. DNA Virus

Nonenveloped circular icosahedral symmetry


3. Sexually transmitted (vaginal, anal, or oral sex with an infected person)

Can also spread through close skin-to-skin contact 


4. Various Types of Warts (Genital, Common, Plantar, Flat)

\
Cervical cancer (takes a while to develop

West Nile Virus

\

1. RNA Virus

icosahedral symmetry with protein shell


3. the bite of an infected mosquito (most common)

Mother to baby during pregnancy

Blood transfusion


4. Most people have no symptoms 

Some get a fever, headache, body aches, rash, joint pains, fatigue, and weakness

Few people get a severe illness affecting the central nervous system

High fever

Neck stiffness

\
Disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis.

Zika Virus

\

1. RNA Virus

enveloped and icosahedral


3. through the bite of an infected *Aedes* species mosquito

Mother to baby during pregnancy

Sexually Transmitted


4. **Birth Defects for a fetus**

**Guillain-Barre Syndrome**

Mild to no symptoms

Fever 

Rash

Headache

\
Red Eyes 

Peptic Ulcer Disease

a.     *Helicobacter* *pylori*

b.     Gram-negative, spiral

c.     Close contact, exposure to fecal matter or vomit

d.     Stomach pain, uncomfortable fullness