Active immunization Immunology and microbiology 2011

Outline of the lesson Immunization vaccination

What is an immunization? Any process that develops resistance to a specific disease. The production of immunity in an individual by artificial means. the creation of immunity usually against a particular disease; especially : treatment (as by vaccination) of an organism for the purpose of making it immune to a particular pathogen

Active immunization (vaccination) Involves the introduction of, either orally or by injection (inoculation), of specially treated bacteria, viruses or their toxins to stimulate the production of antibodies.

Active immunization…… Active immunization is achieved by injecting( or administering orally) small amount of antigen, called the vaccine into the body of an individual. The process is called vaccination.

If the whole organism is used as the vaccine, it is first made safe by being killed or attenuated. The antigen stimulates the body to manufacture antibodies against the antigen. Often a second, booster injection is given and this stimulates a much quicker production of antibody which is longer lasting and which protects the individual from the disease for a considerable time.

Types of vaccines used 1. Toxoids 2.Killed organisms 3. Live vaccines ( attenuated organisms)

Toxoids Toxins produced by tetanus and diphtheria bacteria are detoxified with formaldehyde, yet their antigen properties remain. Therefore, vaccination with toxoids will stimulate antibody production without producing symptoms of the disease.

Killed organism. Some dead viruses and bacteria are able to provoke a normal antibody response and are used for immunization purpose Example: Flu vaccine which contains dead flu virus.

Live vaccines( attenuated organism) Attenuated organism may be a mutant variety with the same antigen but lacking the ability to cause disease. Attenuated vaccine for the bacterial disease tuberculosis (TB), and for measles, mumps, rubella and polio are in general use.

Name of the diseaseVaccine InfluenzaKilled virus: must be of right strain MumpsLiving attenuated virus MeaslesLiving attenuated virus PoliomyelitisLiving attenuated virus given orally DiptheriaToxoids Tubercuolosisliving attenuated bacteria Whooping coughKilled bacteria TetanusToxoids CholeraKilled bacteria Typhoid feverPolysaccharide extract from the bacterial capsule.

vaccine BCG- tuberculosis OPV- Poliomyelitis DPT- Diphtheria, whooping cough and tetanus.

Passive immunization Is induced by the injection of preformed antibodies.

Antibiotics

What are antibiotics? Chemotherapeutic agent usually obtained from living organism. Metabolic product of one organism that in minute quantity inhibits the growth of other microorganism. antagonism.

Wakshman 1945, chemical substances of microbial origin which in small amounts exert antimicrobial activity. In 1929 Alexander Fleming, on agar plate inoculated S. aureus, became contaminated with a mold that mold appeared surrounded by a clear zone, indicating inhibition of bacterial growth or lysis of the bacteria. Mold was identified as a Penicillium species. Antibiotic as penicillin.

Common antibiotics includes penicillin, ampicillin, cephalosporin, bacitracin, streptomycin and etc.

They are used to treat various infections but tend to weaken the body’s natural defense mechanisms and can cause allergies. Overuse of antibiotics can leads to the development of resistant strains of microorganism.

Characteristics of antibiotics Broad spectrum Prevent development of resistant form of the parasites. Should not produce side effects to the host. Should not eliminate the normal flora of the body.

How does antibiotic work? Inhibits cell wall formation Disrupts cell membrane Inhibits nucleic acid synthesis. Inhibit protein synthesis. Inhibits specific enzyme system.

Task What are the antimicrobial action of different kinds of antibiotics?

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