normal microbiota

normal microbial flora

indigenous microbiota

Candida albicans, mycobacterium, clostridium difficile

1.     Direct contact w/ animals or its waste

2.    Bloodsucking arthropods as vectors that transmit the microbe from animal to human

3.    Contaminationof food and water

4.    Indirect Contact with contaminated hides, fur, (wooler’s disease), feathers

5.     Consumption of animal meat or milk of infected animal products

Biting arthropods; mosquitoes, ticks, lice, fleas, bloodsucking flies, mites, and bloodsucking bugs.

which drug is the drug of choice

which drug is the microbe most susceptible to

Both are produced by Gram – bacteria, both can be fetal, both heat stable, but differ in their mechanism of release and composition

Also produced by Gram + bacteria.

Are proteins or peptides that are secreted, leaving the cell intact, toxicity is higher than Endotoxins, not stable above 60*C, produce a strong immune response and therefore toxoid immunization is possible.

Cytoxins

Neurotoxins

Enterotoxins

Hemolysins

Clostridium perfringens

Clostridium botulinum

Clostridium tetani

Staphylococcus aureus = exfoliate toxin

Streptococcus pyogenes

Vibrio cholera

Bordetella pertussis

E. coli: O157 = Shiga toxin

Portals of Entry = getting in

Attaching to the Host = staying in

Surviving Host Defenses = defeat host’s defenses

Causing the Disease = damage the host

Portals of Exit = getting out, transmitted to another host

Incubation, prodromal period, illness, decline, convalenscence

Removal of microbes from a surface by scrubbing, whether that surface is human skin or a table top), REMOVAL RATHER THAN KILLING OF MICROBES

Coronavirus causes àcommon cold

Influenza virus causesà flu

Malarial protozoan causesà malaria

microorganism that may cause a disease under certain circumstances.

When host’s immune defenses are weakened or host is immunocompromised

When introduced into an unusual location

Opportunist pathogens May be members of the normal flora or common in the environment

Candida

E. coli

Pseudomonas= common in environment

historical pasteurization (batch)

flash pasteurization

ultrahigh-temp pasteurization

ultrahigh temp sterilization

Milk flows through heated tubes that raise its temp to 72* for only 15 seconds. This treatment effectively destroys all pathogens.

Heats milk to 140*c for 1-3 seconds.

Denatures proteins and destroys membranes

Sterilization of dairy products.

resistant to one antibicrobial agent

may confer resistance to similar drugs

especially when drugs have similar structures

Hospitals and nursing homes

Where the constant use of many kinds drugs eliminates sensitive cells and allow the growth of resistant strains

Multiple Resistance and Cross Resistance create?

Dairy industry and other food processors use Ultrahigh-temperature sterilization to rid liquids of all living microbes.Can now be stored indefinitely at room temperature 134C or 273F;

Flash heating milk or other liquids to rid them of all living microbes;

Passing the liquid through superheated steam at 140*C for 1-3 sec, then cooling rapidly

arise from outside the hosts or from normal microbiota. They are not spread from one host to another, and diseased patients are not a source of contamination.

Pharmaceuticals (drugs)

Disposable dental & medical supplies

Syringes, gloves, catheters

Tissues for grafts: bone, skin, heart valves

Mail to certain D.C. zip codes

Food

Used for disinfection rather than sterilization

Kills microbes on the surface

Disinfecting air

Transparent fluids

Hospital rooms

Operating rooms

Food prep areas

Dental offices

the use of chemical methods for eliminating or reducing microbes and viruses (particularly pathogens) on the skin or living tissue.

Antisepsis is a modification of disinfection.

Antiseptic are disinfectants whose strength is reduced to make them safe for living tissue.

phenols

Lysol is a disinfectant

Lysol active ingredient is Orthophenylphenol

Betadine is a iodophore.

Iodine based products such as Betadine are Halogens.

Is an iodine-containing organic compound found in such antiseptics as betadine.

Combination of iodine and carrier which realeases iodine slowly.

Iodophores are less irritating that iodine tinctures.

a.    More realistic method for determining the effectiveness of a disinfectant or antiseptic

b.    Swabs are taken from actual objects (operating room equipment) before & after application of disinfectant or antiseptic

c.    The swabs are inoculated onto nutrient agar plates & then incubated

d.    The plates are monitored for growth before & after the disinfectant was used

is the smallest amount of the drug that will inhibit growth/reproduction of the pathogen.

§  MIC = attempts to quantify the smallest amount of drug that will inhibit a pathogen

 ü  The MIC is determined by broth dilution test

ü  After incubation, clear broth indicates that bacteria were either inhibited or killed

o   Determined by E-test

M.B.C = Minimum bactericidal concentration test = MBC test

Ø  MBC àdetermines the dosage of the drug to be an effective bacteriocidal

  Samples are transferred to plates containing a Drug-free growth medium.

 ANY growth of bacterial colonies on a plate indicates that concentration of antimicrobial drug is… Only bacteriostatic.

- discovered that Penicillium chrysogenum, killed Staphylococcus aureus.

- Fleming coined word Antibiotics

- the metabolic pathway

- sulfa drugs are structural analogs of PABA

-          Produced Arsenic compound that killed Trypanosoma brucei = African sleeping sickness.  

- Produced Arsenic compound that killed Treponema pallidum = Syphilis Called it Salvarsan (salvation from syphilis)

-Compete with PABA for enzymes active site

-Are antimetabolites

-When sulfa drugs bind to the pathogens enzyme the sulfa drug blocks the pathway for formation of Folic Acid

-Sulfa drugs bind irreversible to enzyme’s active site & block metabolic pathway

-Competitively inhibit the enzyme’s active site that PABA normally binds to

-This stops the metabolic pathway & production of folic acid

-No enzyme = No metabolic pathway (to manufacture the bacteria’s folic acid)

skin

mucous membranes

placenta

parenteral route

- Inoculate influenza virus in nose and person gets flu but if the virus contacts only the skin, no infection results.

-Contact with fungi in cracks in toe webs results in athlete’s foot infection But inhaling the fungal spores will not cause athlete’s foot

Manner in which disease develops

§  The structural and functional changes brought about by the disease

§  The final effects on the body

-    As we development in the womb, it is free of microbes (axenic)

-    Microbiota: begins to develop during the birthing process:

-    When amniotic membrane is ruptured:

-    Passage through the birth canal microorganisms enter mouth and nose;  First breath, First meal, Microbes from parents and hospital staff all contributes to normal microbiota.

A major source of infection in the world is what?

Hyaluronidase=bacteria go deeper into tissue

Collagenase=bacteria go deeper into tissue

Coagulase== coagulates blood proteins, bacteria hide

Kinases=breaks clot and releases bacteria

Mucinasedigest mucus= bacteria go deeper in tissue

Keratinase=digest keratin, bacteria go deeper in tissue

Contaminated needles

ü  Toothbrushes

ü  Paper tissues

ü  Toys

ü  Money

ü  Bed sheets

ü  Medical equipment

ü  Doorknobs

ü  Telephones

ü  Faucet handles

ü  Paper cups

ü  Towels

- Placenta forms an effective barrier to most pathogens but in 2% of pregnancies pathogens cross the placenta and cause abortion, birth defects, or premature birth.

-STORCH =syphillis, toxoplasmosis, other, rubella, cytomegalovirus, herpes

-Other= (Hepatitis B, HIV, chlamydia (Listeria moncytogenes, Parvovirus)

- Lipid A is an endotoxin that stimulates the body to release chemicals that cause; 

*Inflammation, diarrhea, hemorrhaging, shock, and blood coagulation. Lipid A can cause fatal endotoxic shock and can be fatal in high doses.

No they treat bacterial infections!

Beta-lactam antibiotics have an effect on bacterial cell walls

**Antiviral

-          Why? Anything effective against the virus is toxic to the host as well.  Antiviral medications frequently block unique enzymes to prevent production of new virus

A sterilizing agent; Sterilization of air and heat-sensitive ophthalmic and enzymatic solutions, vaccines, and antibiotics

Features with filtration:

o   Nitrocellulose or plastic membrane filters

o   Sterilization of heat-sensitive materials

o   Use of HEPA filters to filter air

o   Ability of some filters to trap viruses and proteins

 **prions**

1.Bacterial endosproes:Endospores of Bacillus and Clostridium are the most resistant life forms
2.Species of Mycobacterium :cell walls have a waxy coat that prevents:
The entrance of water based chemical& Dehydration
3.Cysts of protozoa:Protozoal cysts wall prevents entry of Most disinfectants, 
Protects protozoa against drying & Shields protozoa against heat, and radiation

T/F Abx are produced by bacteria and fungi?

Toxoids are toxinsthat have been treated with: Heat, Formaldehyde & Chlorineto to make them nontoxic