BIOL 3381 Test 1

HIV, Treponema pallidum, Cytomegalovirus, Rubella, Listeria

Encounter: The endogenous or exogenous agent meets the host
Entry: The agent enters the host
Spread: The agent spreads at the site of entry
Multiplication: The agent multiplies in the host, it may be unsuccessful
Damage: The agent causes tissue damage or the host can respond to the damage
Outcome: The agent wins or the host wins, or the agent and host learns to coexist

The presence of microbes in or on the surface of the human body that can potentially cause diseases.

Toxins produced by bacteria that can cause diseases.

Diseases encountered with agents from the environment

Diseases encountered with agents within the body, caused by normal flora

Blood, cerebrospinal fluid, synovial fluid, and deep tissue

Mouth and large intestine

-skin
-respiratory tract
-digestive tract
-urinary tract
-genital tract

- Negative coagulase staphylococci
- Haemophilus spp.

-Mycobacterium spp.
-Staphylococcus aureus
-Bacillus spp.

-Pseudomonas
-Diphtheroids

-Peptostreptococcus spp.
-Streptococcus

-Gardenerella vaginalis
-Bacteriods
-Candida spp.

- Fusobacterium spp.
- Treponema spp.

-Klebeisella spp.
-Enterococci
-Escherichia coli

-Clostridium
-Lactobacillus

-Viridans streptococci
-Neisseria spp.
-Streptococcus pneumoniae

Each surface has a particular species and changes over time

Do not normally reside, mostly harmless, and some can be pathogens

Microbes that can cause diseases when given the opportunity

The relationship between two kinds of organisms living together

- A relationship where one partner benefits and the other does not benefit or harmed.
- Can prevent establishment of harmful microbes in the human body.
- Commensals ---> Opportunists over time when they become harmful.

- A relationship where one partner benefits and the other is harmed
- Term reserved for protozoa, worms, and insects

- A relationship where both partners benefit
- Usually neither can survive without the other
- No true mutualism exists b/w humans and microbes because no single species are essential to human survival

- 29 different organisms that are beneficial and found on the surface of healthy chickens' intestinal wall.
- They prevent from Salmonella bacteria from establishing themselves on the intestinal walls.
- Salmonella must pass harmlessly out of the chicken's body.

1. Stimulate the immune system and provide a source of antigens to train the immune system
2. Produce Vitamin B12 and K
3. Common cause of infection
4. Microbial antagonism
5. Help digestion

- Sloughing off of dead cells
- The skin has high content salt
- The skin is dry; microbes need a moist area to stick
- The skin is crowded with several other microbes preventing invaders.

- Clostridium difficile
- antibiotic-associated diarrhea
- Arises once commensal bacteria are suppressed by antibiotics. C. difficile are highly resistant and can produce toxins.

1. Nutrition: nutrition is often not available
2. Occupancy: a pathogen must go through EESMDO to remain in a certain habitat.
3. Resistance: must resist damaging agents

- E. coli or Bacteroides fragilis are normal flora in the large intestines.
- They have to cope with a 2-minute feast and 70-minutes of famine 20x every day.
-Pesudomonas and other aerobes cannot survive here
-EFFICIENCY AND ADAPTABILITY are much in demand

-has 3 chromosomes
-gram negative

1. Gram-negative
2. Gram-positive
3. Acid-fast

- have a thick multilayer peptidoglycan murein (cell wall)
- this peptidoglycan maintains the shape
- also has teichoic acid

Cell wall (also called peptidoglycan) made of glycan sugar chains that cross-links via peptides. Found in gram + and gram - BUT plays a big role in gram +

-has an outer and inner membrane, inbetween these membrane is periplasm
-LPS: Lipid A, the core, O-antigen
-the outer membrane has special channels called porins

Special channels in the outer membrane that allows hydrophilic compounds to pass through

-Ex: Mycobacterium tuberculosis
-Contains large amounts of waxes in their cell wall made of mycolic acid
-These waxy cover is found outside of a gram-positive's peptidoglycan layer.

-Vancomycin
-Bacitracin
-Penicillin

compounds produced by bacteria to get Fe from our body

-Bacitracin
-Vancomycin
-Penicillin
-Cephalosporins

-Streptomycin
-Erythromycin
-Chloramphenicol
-Tetracycline

-Rifampin
-Anti-viral agents
-Ciprofloxin

Sulfonamides (first anti-microbial agents used to cure infections in humans)

Polymyxin B
Anti-fungal agents

Treatment of disease with chemicals and radiation

The study of drugs

A drug that will only kill the microbes not the host cells

Developed the concept of the "magic bullet"

Discovered the first antibiotic in 1928

Type of antimicrobial agent made from a microorganism that kills/slows the growth of other microbes

Drugs, chemicals, or other substances that either kill or slow the growth of microbes

Agents that kills microbes

Agents that slows or inhibits the growth of microbes

-Non allergenic
-Reasonable cost
-Selective toxicity
-Solubility in body fluids
-Toxicity not easily altered
-Long shelf-life
-Maintenance of constant, therapeutic [ ] in blood and tissue fluids
-Resistance by microbes not easily aquired

- extrachromosomal, circular, double-stranded, self-replicable
- R factors are carried by plasmid, they encode drug resistance

Methicillin Resistant Staphylococcus aureus

Vancomycin Resistant Enterococci

Vancomycin Resistant Enterococci

yea

Causes meningitis and pulmonary infections, sensitive to ampicillin

1. Drugs must associate w/ the bacteria and penetrate the envelope
2. Drugs must be transported to the site of action
4. Drugs must bind to their specific biochemical target

1. Synthesis of enzymes that inactivate the drug
2. Prevent access to the target site by inhibiting uptake or excretion of the drug
3. Inactivation of drug
4. Modifying target site

1. Not completing the entire prescription even if a broad-spectrum drug is used
2. Use of broad-spectrum drugs when narrow spectrum would work best
3. Subtherapeutic levels must kill all of the bacteria
4. 6 billion animals raised for human consumption each year all get antibiotics at subtherapeutic levels.

Penicillin binding proteins

Yes, two antibiotics given simultaneously can reduce the chance that a bacterium will completely evade antibiotic destruction

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