Microbiology 2314

• Metabolism
• Growth
• Reproduction

• Responsiveness or
Irritability
• Conductivity
• Growth
• Respiration
• Digestion
• Metabolism
• Absorption
• Secretion
• Excretion
• Circulation
• Reproduction

• Cells are the fundamental units of life
• Cells are the simplest unit capable of independent existence
• All living things are made of cells
Note: Credit for developing Cell Theory is usually given to two scientists, Theodor Schwann, a zoologist and Matthias Jakob Schleiden, a botanist. In 1839 these two scientists suggested that cells were the basic unit of life. In 1858, Rudolf Virchow concluded that all cells come from pre-existing cells thus completing the theory.

• Cells contains hereditary information which is passed from cell to cell during cell division.
• Cells have similar chemical composition, metabolic activities, and physiological functions.
• Cell activity depends on the activities of organelles.

• Biology is hierarchial with each level building on the level below it.
• In order to understand how something is built and how something works, you must look at all of its components and analyze them both individually and together.

• Atom / Element
• Molecule / Compound
• Organelle
• Cell
• Tissue
• Organ
• Organ System
• Organism
• Population
• Community
• Ecosystem
• Biosphere

• Atoms form all matter.
• Atoms are the basic building blocks of matter that make up everyday objects. A desk, the air, even you are made up of atoms!
• There are 90 naturally occurring kinds of atoms. Scientists in labs have been able to make about 25 more.
Atom

• Groups of atoms form molecules .
• Molecules come together to form compounds and compounds come together to form organelles
• Organelles can include the nucleus, endoplasmic reticulum, golgi apparatus, mitochondria, etc.
Atom
Organelle
Mitochondria are the 'power plants' of cells that convert organic materials into energy. Mitochondria have their own DNA and may be descended from free-living prokaryotes that were related to Rickettsia bacteria

• The basic unit of life is the cell.
• All living things are composed of one or more cells
• The human body contains about 100 trillion cells.
• There are about 200 different types of cells in the human body.
Atom
Organelle
Cell

•
Tissue is a collection of interconnected cells that perform a similar function within an organism.
• The study of tissue is known as histology , or in connection with disease, histopathology
• There are four basic types of tissue in the body of all animals, including the human body and lower multicellular organisms such as insects.
Atom
Organelle
Cell
Tissue

• Organs are the next level of organization in the body.
• An organ is a structure that contains at least two different types of tissue functioning together for a common purpose.
• There are many different organs in the body: the liver, kidneys, heart, even your skin is an organ.
Atom
Organelle
Cell
Tissue
Organ

•
Organ Systems are composed of two or more different organs that work together to provide a common function.
• There are 10 major organ systems in the human body.
Atom
Organelle
Cell
Tissue
Organ
Organ System

• In biology and ecology, an organism is an individual living system (such as animal, plant, fungus or micro-organism).
• In at least some form, all organisms are capable of reacting to stimuli, reproduction, growth and maintenance as a stable whole.
Atom
Organelle
Cell
Tissue
Organ
Organ System
Organism
Albino Peacock

• An organism may be unicellular or made up, like humans, of many billions of cells
( multicelluar ) divided into specialized tissues and organs.
• Based on cell type, organisms may be divided into the prokaryotic and eukaryotic groups.

• In biology a population is the collection of organisms or individuals of a particular species located in a specific area.
Atom
Organelle
Cell
Tissue
Organ
Organ System
Organism
Population

• A community includes all the biotic (living) organisms sharing an environment, normally with shared interests.
Atom
Organelle
Cell
Tissue
Organ
Organ System
Organism
Population
Community

• An ecosystem is a natural unit consisting of all the biotic and abiotic elements that composes it.
Atom
Organelle
Cell
Tissue
Organ
Organ System
Organism
Population
Community
Ecosystem

• The biosphere is the part of the earth, including air (atmosphere), land (lithosphere), and water
(hydrosphere), within which life occurs, and which biotic processes in turn alter or transform.
• From the broadest point of view, the biosphere is the global ecological system integrating all living beings and their relationships.
Atom
Organelle
Cell
Tissue
Organ
Organ System
Organism
Population
Community
Ecosystem
Biosphere

Cells are 90% water. A mere 2% drop in body water can trigger fuzzy short-term memory, trouble with basic math, and difficulty focusing on the computer screen.

Cells are 90% water. Of the remaining molecules present, the dry weight is approximately:
• 50%
Protein
• 15%
Carbohydrate
• 15%
Nucleic Acid
• 10%
Lipid
• 10%
Miscellaneous

• Proteins are found literally everywhere in your system. From your muscle tissues, to the enzymes that digest your food, to your skin cells, and even within your blood.
• When we take protein in our body through the foods we eat, it gets broken down into smaller compounds called amino acids . Of the 20 amino acids found in the foods we eat, 9 of these are essential.

• All carbs end up as sugar.
Starches, or complex carbohydrates, are just longer strings of sugar.

• Lipids are among the fundamental categories of nutrients that are required by our bodies for healthy functioning.

“We are a generation that is computer literate but food illiterate.”

• 4.5 Billion Years Ago
Earth Formed
• 3.5 Billion Years Ago
First Life (Prokaryotic)
• 1.5 Billion Years Ago
Eukaryotic Cells Arise
• 0.5 Billion Years Ago
Multicellular Eukaryotes

• Chemical Composition
• Chemical Reactions
• DNA
• Membrane Bound
• Ribosomes
• Basic Metabolism
• Occur in Diverse Forms

• Procaryotic cells lack membrane-bound organelles
(Including a Nucleus)
• Procaryotic cell walls contain peptidoglycan

Life
/ \
Prokaryotes Eukaryotes
/ \ |
Archeabacteria Eubacteria
(Ancient Bacteria)
Eukarya
(True Bacteria) (Everything Else)

• Archaebacteria
1. Methanogens
2. Halophiles
3. Hyperthermophiles
4. Thermoplasma
• Eubacteria
1. Cyanobacteria
2. Soil Bacteria
3. Nitrogen-Fixing
4. Pathogens

• More Well Known
• Can be Pathogenic

• Ancient
• Non-Pathogenic
• Extreme
Environments
• Unusual Metabolizing
Abilities
• No Peptidoglycan
• Resistant to Lysozyme

The hot springs of Yellowstone National Park, USA, were among the first place Archaea were discovered

Anaerobic Methane
Producers
•
Common in wetlands
•
Responsible for marsh gas
•
Found buried under km of ice in greenland and under dry deserts.
•
They are known to be the most common archaebacteria in deep subteranean habitats.

Salt-Dependent Organisms
Anywhere with a concentration of salt 5 times greater than the salt concentration of the ocean
•The Great Salt Lake, Utah
•Owens Lake, California
•The Dead Sea

Heat-Dependent
Organisms
Hyperthermophiles were first discovered in the 1960s in hot springs in Yellowstone National
Park, Wyoming.
The most hardy hyperthermophiles thus known live on the superheated walls of deep-sea hydrothermal vents, requiring temperatures of at least 90 °C for survival.

Hyperthermophiles produce some of the bright colors of Grand Prismatic Springs

Heat and Acid
Resistant
Example: Thermoplasma Volcanium

• Diplo
• Strepto
• Staphylo
• Vibrio
• Tetrad
• Pleomorphic – can assume more than 1 shape
• Monomorphic – can assume only one shape

Spirillum

•
Slime Capsule is a distinct Defined Layer with a Distinct Outer Edge
•
Slime Layer is a Poorly Defined
Concentration of Slime. It Lessens with
Distance.
•
Glycocalyx Refers to a Gelatinous
Polysaccharide and/or Polypeptide Covering.

1. Protects Pathogens from Phagocytosis
2. Enable Adherence to Surfaces
3. Protects Against Desiccation
4. Stores Food Reserves

• The patient was a 22-year-old female with a history of mitral valve prolapse (a defect of the valve between the left atrium and ventricle caused by a weakening of the tough, connective tissue of the valve leaflets, which allows the valve to project back into the left atrium). She was admitted with complaints of intermittent fevers for 1 month and headaches for 3 weeks. Two weeks before symptoms developed she had undergone a dental procedure.
• Four blood cultures were performed on admission. All four blood cultures demonstrated Gram-positive cocci in chains.

The diagnosis is bacterial endocarditis (a bacterial infection of the tissue lining the inside of the heart; usually involves the heart valves).
The patient had recently had her 6 month dental appointment to have her teeth cleaned.

• During dental procedures, transient bacteremia occurs in up to 80% of individuals.
• Transient bacteremia is defined as the presence of bacteria in the bloodstream for short periods.
• The organisms that cause this are generally of low virulence and are usually easily removed by the reticuloendothelial [filtering and phagocytic] system.

• This 47-year-old man had a history of sickle cell disease that resulted in many previous hospitalizations for the management of painful crisis.
• The patient had been admitted 9 days prior to the current admission for management of such a crisis, and a right port-a-cath (a central venous catheter that is designed to remain in place for a prolonged period) was placed in his right subclavian vein.
• He was discharged (with port-a-cath remaining) after a
4-day hospitalization.

• O n the day of readmission, the patient had right arm discomfort and swelling, a temperature of
38.1C (normal is 37C), and chills. He presented to the hospital emergency room, where he was afebrile. Physical examination was remarkable for right extremity swelling.
• Two blood cultures were obtained (one set through the port-a-cath and one set via a peripheral vein). The two sets of blood cultures grew identical Gram-positive cocci that were catalase positive. The diagnosis is in-line sepsis.

Any indwelling device introduced through the skin places an individual at risk for infection.
Bacteria can produce a slime layer that can enhance their adherence to a wide variety of plastic surfaces.
Slime-producing strains of staphylococci may also be more difficult to eradicate by antimicrobial therapy than nonslime-producing ones due to antibiotic resistance.

Hook is similar to a universal joint
Basal Body penetrates the cell and causes the flagellum to rotate. It serves as a “motor”.
Filament is actually an extension of the plasma membrane.

Examples of bacterial flagella arrangement schemes.
A-Monotrichous
(one flagella)
B-Lophotrichous (a tuft of flagella)
C- Bipolar
Monotrichous (one flagella at both ends)
D-Peritrichous (a hair ball)

• Monopolar
Lophotrichous
• Bipolar
Lophotrichous
• Peritrichous

• Positive Taxis
• Negative Taxis
• Phototaxis
• Chemotaxis
• Magnetotaxis
Plankton

• Bacteria Flagella is composed of protein which acts as an antigen when introduced into the human body.
• What happens then?
• Why is this beneficial for vaccines?

• Spirochetes are long and slender bacteria that are tightly coiled, and so look like miniature springs or telephone cords.

Short, Rigid, Hollow,
Thin, Protein Appendages
They are NOT involved in motility.

Fimbriae Help Cells Adhere To Surfaces
Pili Join Cells for the Transfer of DNA From
One Cell to Another

Have Thicker Layer of Peptidoglycan and Have Teichoic Acids

Thinner Layer of Peptidoglycan

• More susceptible to breakage
• Thinner layer of peptidoglycan

Outer membrane is strongly negative aiding is resisting phagocytosis and providing a barrier to antibiotics and digestive enzymes
Periplasmic space containing specialized proteins and enzymes involved in nutrient acquisition
It has Porins and
Specific Channel
Proteins

Water Moves Freely Across Membranes to Try and
Equalize Concentration

Lysozyme and Penicillin

• Permeability Barrier or Selective Barrier
• Prevents cell contents from leaking away
• Impermeable to polar and charged molecules
• Contains specific proteins to carry out selective transport
• 50% lipid and 50% protein

Very delicate and easily ruptured

50% Lipid
50% Protein

Fluid Mosaic Model of Membrane Structure

Ribosomes Utilize 25% Cell’s Volume – 90% Cell’s
Energy

• Composed of RNA and Protein
• Function to Make Protein (Mainly Enzymes)
• Size is Measured in Svedberg (S) units
• Bacterial Ribosomes are ~70S

Plasmids are small circular DNA elements found in virtually all bacterial cells.
They carry extra genes and are important in
Genetic Engineering.

Prokaryotic bacteria exist in very competitive environments where nutrients are usually in short supply, so they tend to store up extra nutrients when possible.
• Fats
• Sugars
• Phosphates
• Sulfur
• Metachromatic
Granules

Survival Mechanism for Extended Periods in the
Absence of Food, Water, of Proper Growth Conditions

• Can resist Sterilization
• Can resist Boiling
• Can resist UV Light
• Can resist Dessication
• Can resist Harmful Chemicals
• Abundant in
Bacillus and Clostridia
• Germination in Minutes
• Create a Problem with Canned Foods

Oval Terminal
Rectangular Terminal
Rectangular Subterminal
Rectangular Central
Circular Terminal
Circular Central
Club Shaped Terminal

Bacteria
Endospores

Schaeffer Fulton
Method of
Staining

Dorner
Method of
Staining

• Spores taken from prehistoric mosquitoes suspended in Amber
• Roman Fort Vindolanda
- 1976 Fort dating AD 90-95 was drained and excavated
- Found viable endospores of Thermoactinomyces vulgaris
- Thermophilic Aerobic Bacterium (Warmth and Moisture)
- Had been sealed in a cold anaerobic environment (flooded)
- Would date this particular endospore to being 2000 years old

Endosymbiotic Theory of Cellular
Evolution
• Proposed by Lynn Margulis in 1981
• Studied Mitochondria
• Saw association between Mitochondria and
Gram-negative Bacteria

• Endoplasmic
Reticulum
• Golgi Apparatus
• Various Vesicles
• Lysosomes
• Microbodies
• Nuclear Membrane
Rough E.R.

• Compartmentalization
• Chemical Homeostasis
• Communication
• Transport
Golgi Apparatus

Membrane Transport
| |
Small Molecules Large Molecules
| | | |
Passive Transport Active Transport Endocytosis Exocytosis
| |
Diffusion Phagocytosis
Osmosis Pinocytosis
Facilitated Diffusion

• The endosymbiotic theory concerns the mitochondria, chloroplasts, and possibly other organelles of eukaryotic cells.
• According to this theory, certain organelles originated as free-living bacteria that were taken inside another cell as endosymbionts.
• Mitochondria developed from proteobacteria such as Rickettsiales, and chloroplasts from cyanobacteria.