Microbiology an Introduction: BIOL 2333-A Microbiology Flashcards

Destructive: Few are disease-causing (ex: fever, diarrhea) and spoils food.

Beneficial : produce fermented foods (cheese, bread, vinegar), produces industrial chemicals (ethanol and acetone), decompose organic wastes, are producers in the ecosystem by photosynthesis, produce products used in manufacturing and treatment (insulin)

Established by Carolus Linnaeus (1735)

a genus : Capitalized the first letter

a specific epithet (species ): species/specific epithet all lowercase

Need to be italicized or underlined

genus and species .

Ex: Staphylococcus aureus OR Homo sapiens

D) specific name.

Is the loss of light rays after we passed them through the stained specimen. To avoid we add immersion oil has the same reflation index the glass, the light rays do not refract when passing through.

Bacteria

Archaea

Eukarya

Prokaryotic, unicellular organism

Lack a membrane-bounded nucleus

Reproduce asexually

Heterotrophic by absorption

Prokaryotic, unicellular organisms

Lack a membrane-bounded nucleus

Reproduce asexually

many are autotrophic by chemosynthesis; some are heterotrophic by absorption

Eukaryotic, unicellular to multicellular organisms

Membrane-bounded nucleus

Sexual reproduction

Phenotypes and nutrition are diverse

Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-enclosed organelles.

Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus (that holds genetic material) as well as membrane-bound organelles.

D) Endoplasmic reticulum

C) Nucleus

Anton van Leeuwenhoek

b) Anton von Leeuwenhoek

a. Anton von Leeuwenhoek

1.The same pathogen must be present in every case of the disease
2.The pathogen must be isolated from the diseases host and grown in pure culture
3.The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible lab animal
4.The pathogen must be isolated from the inoculated animal and must be shown to be the original animal

D) The microorganism must secrete a toxin in culture.

b. Robert Koch

the hypothesis that living organisms arise from nonliving matter; a “vital force” forms life.

Ex: three jars were covered with net and there were no maggots

Three open jars maggots appears

d. living organisms could arise from nonliving material.

The hypothesis that the living organisms arise from preexisting life

C) development of aseptic technique

heat (below boiling) for short period of time to kill pathogens and reduce bacteria count, does not kill all bacteria- some survive

A) exposure of food to high temperatures for short periods to destroy harmful microorganisms.

when it gives up an electron to make the valence electrons stable

is when you share electrons to make the valence electrons complete/ balance

atoms are shared unequally

Atoms are shared equally

isotopes .

B) protons

A) neutrons

covalently bonded,

oxygen or nitrogen atom.

C) Hydrogen bond is a weak force between atoms in a molecule but is of enormous importance in physiology.

C)sodium chloride

C) Hydrogen Bond

energy, release;

more

to build up a new molecule (creating polymers from monomers by dehydration synthesis)

breaking down molecules in cell (adding H2O to break down the bond, now you have hydrolysis reaction)

polar molecule,solvent

A) A glycosidic linkage

C) Ester

removal of water to form a bond

adds a water molecule, breaking a bond

dehydration synthesis

B) The bond between two subunits of a macromolecule is broken

dehydration synthesis

hydrolysis

Water + Glucose + Fructose

Sucrose + water

primary (sequence of amino acids)

secondary (helices or pleats)

tertiary (overall three-dimensional structure of a polypeptide)

Quaternary (two or more polypeptide chains).

primary (sequence of amino acids)

secondary (helices or pleats)

tertiary (overall three-dimensional structure of a polypeptide)

Quaternary (two or more polypeptide chains).

400X

GRAM NEGATIVE

GRAM POSITIVE

is circular in structure.

C) Complex wall

B) Gram negative bacteria

coccus

bacillus

Spirillum

It would look like a chain of spheres under the microscope

Answer: Gram positive have a strong PG so the drugs won't destruct it ex: penicillin

Gram negative- have a thin wall so it is susceptible to destruction of chemicals ex:tetracycline

Long appendages. Made of chains of flagellin, attached to a protein hook.

Anchored to the wall and membrane by the basal body.

In bacteria called spirochetes. Its anchored at one end of a cell, and spirals around. When it rotates causing the cell to move

Short appendages that allow attachment ( velcro) not movement

Can be at cell poles/ all over

Facilitate transfer from DNA from 1 cell to another
gliding, and twitching.

cells contain organelles which include mitochondria,chloroplast the endoplasmic reticulum, the Golgi apparatus, and lysosomes

powerhouse of the cell.

synthesize phospholipids,fats, and steroids

Release glucose in blood stream, detoxify drug-alcohol

process plasma membrane, process ribosomes

amino acids and fatty acids are oxidized and protects the cell from toxic effect of H202

break molecules, digest bacteria that enter the cell, and phagocytosis WBC contain lysosomes

Membrane formation and secretion. It is the package house of the cell where macromolecules like proteins and lipids as they are synthesized within the cell.

ALCOHOL

AMINO

CARBONYL

CARBOXYL

METHYL

PHOSPHATE

SULHYDYL

Hydroxy

-Bacteria(cyanobacteria, heterotrophic bacteria)

-Archaea(Halophiles and Thermophiles)

-Eukarya

• Protists

• Fungi

• Plants

• Animals

Answer: Bacteria and archaea

A) Capsule

The main difference between the two is the presence of a “true” nucleus: eukaryotes have one, while prokaryotes do not.

Their cell wall has no peptidoglycan layer.

They have no histone

Their cell wall have a peptidoglycan layer

Reproduce usually by binary fusion

Cell wall has peptidoglycan layer

Dna has histone

They have chemically simple cell walls.

They reproduce by mitosis

The idea that tiny organisms called microbes cause infectious diseases that are easily passed among humans.

D) the microorganism must secrete a toxin in culture.

Normal microbiota or normal flora

refers to the organism that colonizes the body’s surfaces without normally causing disease.

Resident microbiota

permanently colonizes the host and is established during the first months of life.

Transient microbiota

May be present for day, weeks, or month

resistance

The ability to ward off diseases through innate and adaptive immunity

Microbes attach to solid surfaces and grow into masses such as rocks, pipes, teeth and medical implants

Important in oil spills and purifying water.

If they contain a protein coat

Have a nucleic acid genome

Have a capsid

Obligatory intracellular parasites ( need a host cell to replicate)

The Virus is smaller than bacteria

False(Viruses do not have a cellular organization and are therefore not classified with cellular organisms)

D) all of the above

C. crystal violet-iodine-alcohol/acetone-safranin

1) First step use the first stain crystal violet (stains everything purple)

2) Than add the mordant (grams iodine) to help the chemical reaction along

3)Than wash with alcohol to decolorize anything that isn't chemically bonding

4)Than use the last stain: safranin (counterstaining)

The gram POS+ bacteria retain the purple stain after the decolorization step

Gram NEG- bacteria do not and thus appear pink from the counterstain.

Being able to identify the Gram stain also means that in some cases, a clinician can get the patient started on antibiotic treatment even before the actual organism(s) is/are identified.

Drugs directed towards bacteria i.e Gram - because of the peptidoglycan layer (second outer membrane has lipopolysacaride layer which allows it to be resistant to antibiotics).

Gram + have techoic acid, this allows charges to cross into the cell.

Some bacteria have a single, tail-like flagellum or a small cluster of flagella, which rotate in coordinated fashion, much like the propeller on a boat engine, to push the organism forward. The hook: Many bacteria also use appendages called pili to move along a surface.

A resting structure formed inside some bacteria. They can stay latent under their fixed conditions and activate when their nuclear components are activated.

A substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction. AN ENZYME IS A PROTEIN, BUT NOT ALL PROTEINS ARE ENZYME

Step 1 of mechanisms of enzymatic action surface of the substrate contacts a specific region on the surface of the enzyme called the active site

step 2 of mechanisms of enzymatic action a temporary enzyme-substrate complex forms lock and key

step 3 of mechanisms of enzymatic action substrate is transformed to products

step 4 of mechanisms of enzymatic action enzyme and products separate

step 5 of mechanisms of enzymatic action unchanged enzyme can react with other substrate

B) substrate

D. substrates

B) fermentation.

C) obtain a sample of blood or other body fluid from a diseased animal.

A) determination of the cause of a patient's illness in a hospital microbiology lab

C) anthrax

E) bacteria and fungi.

Because the unique arrangement of each enzyme allows it to find the correct substrate from all the diverse molecules in a cell .

Several factors affect the rate at which enzymatic reactions proceed - temperature, pH, enzyme concentration, substrate concentration, and the presence of any inhibitors or activators.

The graph shows that as temperature is increased, the reaction rate of an enzyme increases. However, the graph shows that there is an optimum temperature where the reaction proceeds at its maximum. Above that optimal temperature, the reaction rate decreases.

The presence or absence of endospores has an obvious effect on microbial control.

biocides tend to be more effective against gram-positive bacteria- external lipopolysaccharide layer of gram-negative bacteria, makes them resistant;

mycobacteria have a cell wall that is waxy, lipid-rich. viruses resistance depends on the presence or absence of an envelope.

Drying is often used to preserve foods (e.g. fruits, grains, etc.). Methods involve removal of water from commercial sterilization: product by heat, evaporation, freeze-drying, and addition of salt or sugar.

Normal microbiota permanently colonize the host

Transient microbiota may be present for days, weeks, or months

Opportunistic microorganism: A bacterium, virus, protozoan or fungus that takes advantage of certain opportunities to cause disease. Those opportunities are called opportunistic conditions.They take advantage of a weak immune system.

NOSOCOMIAL INFECTIONS ARE USUALLY ACQUIRED IN HOSPITALS . THEY AFFECT IMMUNO COMPROMISED PATIENTS. I.E FROM CATHETER, OR ON ANTIBIOTIC TREATMENT.

B)nosocomial.

Using aseptic techniques, handling contaminated materials carefully, insisting on frequent hand washing, educate on infection control basics, and use isolation rooms.

C. urinary tract

Cause disease in healthy person with normal immune defenses .

Portal of entry:Mucous membranes -respiratory system, GI tract, and skin

Penetration or Evasion of Host Defenses: Capsules, cell wall components, enzymes, antigenic variation

Damage to Host Cell:siderophores, direct damage, toxins (endotoxins and exotoxins), lysogenic conversion

Portal of exit: same as the portal of entry for a microbe

Portal of entry:Mucous Membrane most common route for pathogens

Respiratory tract, gastrointestinal tract , urinary/genital tract, conjunctiva

Skin (keratinized cutaneous membrane)

some pathogens infect hair follicles and sweat glands

few can colonize surface

unless broken, skin is usually an impermeable barrier to microbes

Parenteral route

penetrate skin: punctures, injections,

bites, cuts, surgery, etc.

deposit organisms directly into deeper tissues

Tissue tropism: particular bacteria are known to have an apparent preference for certain tissues over others

e.g., S. mutans is abundant in dental plaque but does not occur on epithelial surfaces of the tongue; S. salivarius is in high numbers to epithelial cells of the tongue but is absent in dental plaque

Species specificity: certain pathogenic bacteria infect only certain species of animals

e.g., N. gonorrhoeae,

Genetic specificity within a species: certain strains or races within a species are genetically immune to a pathogen

e.g. (malaria)

Cell wall components - M protein ( resist phagocytosis ex: Streptococcus pyogenes), Opa Protein ( inhibit T helper cells, promote attachment and uptake of host cell), Mycolic Acid (resist digestion ex:Mycobacterium tuberculosis)

Exotoxin: Gram +, By-products of growing cell, Protein, No fever, yes neutralize antitoxins, LD50 small

Endotoxin: Gram -, outer membrane, Lipids, glycolipids, yes fever, not neutralized by antitoxins, LD50 large

1.Bacteria produces and releases exotoxin

2.B binding component of exotoxin attaches to host cell receptor

3.A-B exotoxins enters host cells by endocytosis

4.A-B exotoxin enclosed in pinched- off portion of plasma membrane during pinocytosis

5.A-B components of exotoxins separate. A component alters cell function by inhibiting proteins synthesis. The B component is released in the host cell

First Line of Defense: Skin ( dermis & epidermis) Epidermis is tightly compacted top layer contains dead cells called keratin protective protein

Mucous Membrane- thick and moist epithelium

• Less protective than keratinized surface
• Has goblet cells for mucus production
• Mucus ( trap microbes)
• Ciliary escalator- microbes trapped in mucus are transported away from the lungs

Normal microbiota complete with pathogen or alter the environment

More susceptible to infection (presence of normal flora continually challenges the immune system, keeping it active

Microbial Antagonism: Normal flora inhibits overgrowth of harmful microbes.Mechanism includes competition for nutrients and affecting environmental factors such as ph, toxic substances and oxygen availability

Commensalism: one organism benefits, the other is not affected

(Many microbes live off secretions and dead cells and do not benefit or harm host cell)

Answer: Increase during infection

When activated:

most leukocytes will produce cytokines
intercellular signaling
molecules/hormones that function to

trigger, enhance, and coordinate various defense mechanisms

Phagocyte=From Greek, meaning eat, Cyte: From Greek, meaning cell
Phagocytosis=Ingestion of microbes or particles by a cell,

Phagocyte is an organism. I.e macrophage, basophils that ingest pathogen.

Phagocytosis is the process of ingesting an antigen by a macrophage or other phagocytic cells.

Step 1
Chemotaxis and adherence of microbe to phagocyte
Step 2
Ingestion of microbe to phagocyte
Step 3
Formation of phagosome
Step 4
Fusion of the phagosome with a lysosome to form a phagolysosome
Step 5
Digestion of ingested microbe by enzymes
Step 6
Formation of residual body containing indigestible materials
Step 7
Discharge of waste materials

1) Destroy injurious agent and remove byproducts of injury
2) Limit spread of injury
3) Repair damaged tissue

Redness-= Because of vasodilation

Swelling=increase in permeability permits fluid to move from blood to tissue spaces
Pain associated=can be because of nerve damage, irritation by toxin or the pressure of edema

cause: infection from bacteria and their toxins, or viruses. Gram negative endotoxin cause phagocyte to release interleukin-1
effects: body increases rate of metabolism and shivering which raises temperature vasodilation and sweating: body temperature falls (crisis)

Prostaglandins released by the hypothalamus trigger the fever! Lowering the body tempature.

Complement system:activation aids in destructions of microbes

The antibodies attack the cell which activated the complements to lysis the cell.

Interferons:signals proteins,triggers neighboring cells to produce antiviral proteins

1.Viral RNA from an infecting virus enter the cell

2.The infecting virus replicates into new viruses

The infecting virus also induced the host cell to produce interferon mRNA which is translated into alpha and beta

4.Interferons releases by virus infected host cell bind to plasma membrane or nuclear membrane receptors on uninfected neighboring host cells, inducing them to synthesize antiviral proteins. These include oligoadenylate synthetase and protein kinase.

5.New viruses released by infected host cell infect neighboring cells.

6.AVPś degrade viral mRNA and inhibits proteins synthesis and thus interfere with viral infection

Special proteins produced by plasma cell ( B cells) recognize and bind to a specific epitope of an antigen via its antigen binding sites

Recognize and bind to specific shape. They have great specificity and each have 2 antigen binding sites

IgA

is an antibody that plays a crucial role in the immune function of mucous membranes

IgD

is an antibody isotype that makes up about 1% of proteins in the plasma membranes of immature B-lymphocytes

IgE

is a type of antibody (or immunoglobulin (Ig) "isotype") that has only been found in mammals. IgE is synthesised by plasma cells.

IgG

IgG,a monomer, is the predominant Ig class present in human serum

IgM

is one of several forms of antibody that are produced by vertebrates.

reduces number of infectious units to be dealt with

coating antigens with antibodies enhances phagocytosis

Blocks adhesion of bacteria and viruse to mucosa and blocks attack of toxins

dependent cell cell mediated cytotoxins- antibodies attached to target cell causes destruction by macrophages,eosinophils,and NK cells

Causes of inflammations and cell lysis

The Lymphatic system is the transport method of most pathogens. Bacteria or Viruses will travel to the lymph nodes where the CD4 and CD8 cells are located which then target and kills the pathogens.

Sepsis is an infection of the blood.

Fever

Respiratory rate increases.

Heart rate increases(tarchycardia).

Infections that develop into sepsis c

Because it contains a pressurized oxygen-rich atmosphere. The oxygen then saturates the infected tissues of the obligately anaerobic clostridia.

1. Tetanospasmin released from dead cells blocks relaxation pathway in muscles
2. Prevention by vaccination with tetanus toxoid (DTP) and booster (dT)
3. Treatment with tetanus immune globulin

Bacterial toxins are toxic substances that are produced and released by bacteria to target other bacterial or host cells.

1. It is the first line of defense.
2. Made up of a cutaneous membrane ( dermis plus epidermis) The epidermis, (outermost layer of the skin) consists of tightly packed cells made up of keratin.
3. Keratin is a protective protein that protects the skin from abrasions.
4. Therefore pathogens have a hard time penetrating through the skin unless the skin is damaged. It is hydrophobic

1. Meninges- pia mater (innermost layer),
2. arachnoid mater (middle layer), s
3. ubarachnoid (contains CBS-cerebrospinal fluid,
4. dura mater (outermost layer).

1. Hard to penetrate
2. Protection of the brain
3. Astrocytes surrounding brain blood vessel

Incubation phase

period between infection and prodromal.

No signs or symptoms .

Prodromal stage.

Mild symptoms

Period of illness-

most severe signs and symptoms .

if the body’s immune response is unsuccessful deaths can occur.

Period of decline-

signs and symptoms decrease

Convalescence stage

no signs and symptoms .

body returns to normal.

Variety of drug, cancers, infectious diseases.

Integration of viral RNA into chromosomal DNA in the cell’s nucleus.

Graft rejection, graft infection, and graft vs host disease.

CD4 receptor, Gp120, and Gp41

Time period between infection and antibody production.

It was replaced by P. chrysogenum because it was a more prolific strain.

Synergism is when two drugs work together to enhance the effect. Antagonism is when two drugs inhibit the effects of each other

Cephalosporins have the same “nucleus”, which is the beta-lactam ring. If you are allergic to penicillins, then you are most likely allergic to cephalosporins.

They inhibit folic acid as result inhibiting DNA/RNA and protein synthesis. They do not harm us because we can get folic acid via our diet.

mean that it specifically targets the bacteria cells and not the human cells.

one benefits, one isn’t harmed/ not affected (+/0) (ex: bacteria lives off dead skin)

both benefit from living together (+,+) (e.coli synthesis vitamin k and vitamin B)

one organism benefits, the other is harmed (+/-) , causing disease in the host.

Latent is dormant or recessive and chronic is ongoing and long term.

Acute is sudden and severe.