Sterilization

Is the removal or destruction of all forms of microbial life absence of prions

Sterilant

A sterilizing agent such as heat liquid or gas.  filtration.

Botulinum

Range for survival

(temperature)

above 45c for botulinum

Disinfection

control directed at destroying harmful microorganisms

Antisepsis

The use of a chemical disinfectant to treat an inerts surgace or subtance when directed at a living tissue.

Endospores and Non endospores

The rate of Microbial death

Time vs. deaths per min vs.

# of survivors

The factors that influence microbial death

the # of microbes

Environmental influences

time of exposure

microbial chatacteristics

What are the target of any microbial agents

damage to proteins and nucleic acids

Enzymes are primarily proteins and 

are vital to all cellular activities

If damage takes place to DNA and RNA 

what happens

Physical methods of microbial control

moist heat 

boiling 

autoclaving

pasteurization

dry heat

filtration low temp and high temp

radiation

TDP

Thermal death point

lowest temp all microbes can be killed in 10 min

TDT

Thermal death time

the minimal length of time for all bacteria in a particular liquid culture to be killed at a given temp

DRT

decimal reduction time

the time in minutes in which 90 of a population of bacteria at a given temp will be killed

How moist heat kills microbes

How does an atoclave work

Pasteurization

mild heating sufficient enough to kill the organisms that cause particular spoilage problem without seriously damaging taste.

HTST

High temp short time pasteurization

milk is heated to 72c for only 15 seconds

UHT

Ultra high temperature pasteurization

can stay warm

Dry heat sterilization

Direct flaming

dry heat killing by oxidation

Hot air sterilization

generally a temp of about 170c maintained for nearly 2 hours to maintain sterilization

Filtration

the passage of a liquid or a gas through a screenlike material with pores small enough to retain microoganisms.

HEPA

high efficiency particulate air filter

remove almost all microbes

Membrane Filters

filters composed of such substance as cellulose esters or plastic polymers 

Physical methods used to control microbial growth

Heat 

Filtration

cold

High pressure

desiccation

osmotic pressure

radiation

heat

Filtration

cold

high pressure

Alters the molecular structures of proteins and carbs resulting in the rapid inactivation of vegetative bacterial cells.

desication

The absence of water. microbes cannot grow can remain viable for years

osmotic pressure

The concentration of salts and sugars create a hypertonic environment that causes water to leave the microbial cell  denying the cell the moisture it needs for growth.

radiation

Ionizing destroys DNA

Nonionizing damage DNA

Phenol

Carbolic acid

Used to control surgical infections and sewage odor.

phenolics

less irritating than phenol and has increased antibacterial activity in combination with a soap or detergent. they injure lipid containing plasma membranes resulting in leakage of cellular contents.

Biophenols

derivative of phenol that contains 2 phenolic groups connected by a bridge.  kills staph and streph

Biguanides

primarily affec bacterial cell membranes especially effective against gram positive bacteria.

Halogens

particularly iodine and chlorine are effective antimicrobial agents both alone and as constituents ot inorganic or organic compounds.  Active against all kinds of bacteria many endospores various fungi and some viruses.

Alcohol

Effectively kills bacteria and fungi but not endospores and non enveloped viruses. Usually done by protein denaturation, but can also disrupt membranes and dissolve many lipids including the lipid envelope in many viruses.

Variolation

Injecting smallpox into your veins.

Vaccine

A suspension of organisms or fractions of organisms that is used to induce immunity.

Why does vaccination work

The injection by skin scratches provoked a primary immune response in the recipients leading to the formation of antibodies and long term memory cells. 

Attenuated 

use living but attenuated or weakened microbes.

Inactivated

use microbes that have been killed  usually by fomalin or phenol

Toxid

are inactivated toxin are vaccines directed at the toxins produced by a pathogen.

Subunit

use only those antigenic fragments of a microorganism that best stimulate an immune response.

Conjugated vaccines

Have been developed in recent years to deal with the poor immune response of children to vaccines base on capsular polysaccharides.  polysaccharides are ti independent antigens  that children's immune response don't respond to till 15 to 24 months.

Whole agent vaccines

ex.

Recombinant vaccine

ex.

DNA vaccines

Sensitivity

Is the probability that the test is reactive if the specimen is a true positive.

Specificity

Is the probability that a positive test will not be reactive if a specimen is a true negative.

Monoclional Antibodies

hybridoma antibody secreting cells 

Hybridoma

The comibination of a immortal cancerous b cell with an antibody producing normal b cell.

Monocional antibodies/MABS

Identify the six stages of production of monoclonal antibodies 

Immunotoxins

Conjugated monoclonal antibodies

Chimeric monoclonal antibodies

Humanized antibodies

are constructed so tha the murine portion is limitied to the antigen bindings sites.  the balance of the variable region and all of the constant region are dirived from human sources

Identify the precipitation curve

Precipitation reactions

Involve the reaction of sluble antigens with igg or igm antibodies to form a large interlocking molecular aggregates called lattices.

Precipitation ring test

Immuno diffusion test

Immune electrophoresis

combining the techniques of immunodiffusin and electrophoresis. Used to speed up the movement of antigen and antibody in a gel.

Paul Ehrlich and alexander fleming

magic bullet that would selctively find and destroy pathogens but not harm the host.

discovered penicillin. 

Antibiotics

Sreptomyces

Bacillus

endospore forming bacteria used in antibiotics

penicillium

mold used in antibiotics

cephalosporium

Spectrum of microbial activity

Broad spectrum antibiotics

Superinfection

Identify 5 modes of action of microbial drugs

the inhibition of nucleic acid sythesis

PABA

Natural Penicillins

Semisynthetic penicillins

Cephalosporins

Aggulutination

antigens  linked together by antibodies  to form visible aggregates 

Direct agglutination test

Titer

the concentration of serum antidody.

Passive test

The antibody react with the soluble antigen adhering to the particles.

Hemagglutination