2. ▶ Introduction
▶ Classification Of Antimicrobial Agents
▶ Selection Of Antimicrobial Agents
▶ Antibiotics
▶ Classification Of Antibiotics
▶ Antimicrobial Resistance
▶ Factors Involved In The Usage Of Antibiotics Rationally
▶ Ideal Antibiotics
▶ Antibiotics Combination
Contents
3. An antimicrobial is an agent that kills or inhibits the growth of
microorganisms without harming the cells of the host.
The antimicrobial agent may be a chemical compounds and
physical agents. These agents interfere with the growth and
reproduction of causative organisms like bacteria, fungi, parasites
, virus
Introduction
4. ⦁ Before penicillin introduction there was no effective treatment for
infections. In 1928 penicillin, the first true antibiotic, was
discovered by Alexander Fleming, Professor of Bacteriology at
St. Mary's Hospital in London. Alexander Fleming was a bit
disorderly in his work. He left his petridishes uncovered. Upon
returning from holidays he noticed that a fungus, Penicillium
notatum, had contaminated a culture plate of Staphylococcus
bacteria.
4
Conti……..
5. ⦁ The fungus had created bacteria-free zones wherever it grew on the
plate. Fleming isolated and grew the mould in pure culture. He
found that P. notatum proved extremely effective even at very low
concentrations, preventing Staphylococcus growth even when
diluted 800 times. Fleming published his findings in the British
Journal of Experimental Pathology in June 1929.
6. Classification of Antimicrobial Agents
Drugs by susceptible organisms
▶Antibacterial
▶Antiviral
▶Antifungal
▶Antiprotozoal
▶Anthelmintic
7.
8. 1. Antibacterial drug: A drug that is used to inhibit the pathogenic
activity of bacteria is called an antibacterial drug.
Example: Zithromax.
2. Antifungal drug: A drug that is used to prevent fungal activity in
the host is called an antifungal drug. Example: Miconazole
9. 3. Antiviral agent: A drug which is used to stop the pathogenic
action of a virus is called antiviral agents.
Example: Tamiflu
4. Antiparasitic drug: A drug that is used to prevent the growth
of pathogenic parasites. Example: Anthelmintic
10. Classification of antibiotics
1. Based on chemical structures
2. Based on the sources
3. Based on mechanism of action
4. Based on spectrum of action / activity
5. Based on modes of action
11. Classification Based on Chemical Structure
1. β-lactam antibiotics
These antibiotics (most of which end in the suffix -cillin)
contain a nucleus of penicillin. Example: penicillin G,
ticarcillin, ampicillin, nafcillin, cloxacillin
12. 2. Aminoglycoside antibiotics
Aminoglycosides are characterized by a core structure of amino
sugars connected via glycosidic linkages to a dibasic
aminocyclitol, which is most commonly 2-deoxystreptamine.
Example: gentamicin, amikacin, tobramycin, neomycin, and
streptomycin
13. 3. Tetracycline antibiotics
Tetracyclines (tetracycline, doxycycline, minocycline,
tigecycline) are a class of medication used to manage and treat
various bacterial infections.
14. 4. Polypeptide antibiotics
Polypeptide antibiotics are a chemically diverse class of anti-
infective and antitumor antibiotics containing non-protein
polypeptide chains.
Examples of this class include actinomycin, bacitracin, colistin,
and Polymyxin.
15. 5. Macrolide antibiotics
Macrolides are naturally occurring compounds comprised of a
lactone ring with deoxy sugars attached.
Certain macrolides have antibiotic or antifungal properties
and are used in pharmaceutical antimicrobial therapy.
Example of Macrolide antibiotics: erythromycin, roxithromycin,
azithromycin and clarithromycin.
16. 6. Lincomycins
Lincomycin is an antibiotic indicated only for the treatment of
serious infections and is typically reserved for use in cases of
penicillin allergy or where penicillin is inappropriate.
