2. Antibiotics, Chemotherapeutic
agents, anti-infective drugs,
antimicrobial drugs
• Obtained from other microorganisms e.g. bacteria,
fungi etc.
OR
• Produced/derived from microorganisms used to
suppress the growth or to kill the other
microorganisms
NOTE: All antibiotics are chemotherapeutic agents but not all
chemotherapeutic agents are antibiotics.
3. Principle/Base of chemotherapy
• Known as “concept of selective toxicity”.
• Proposed by a scientist “Paul Ehrlich” in 1909. He is now
a days considered as “founder of chemotherapy”.
• For the first time, he treated STD i.e. “syphilis” caused by
“Treponema pallidum” by using “arsphenamine” or
(salvarsan ℞).
• Biochemical difference between microbial cells and
human cells provided base for chemotherapy.
4. Classes of antibiotics
1. Type (1) Nature of microbes/microorganisms
2. Type (2) Mechanism of action
3. Type (3) Nature of spectrum
4. Type (4) Chemistry/chemical structure
5. Type (5) Nature of action
6. Type (6) Source
5. Type (1) Nature of
microbe/microorganisms
a. Antibacterial therapy
b. Antifungal therapy
c. Antiviral therapy
d. Antiparasitic therapy
i. Antimalarial drugs
ii. Antiamoebic drugs
e. Antihelminths/ anthelmintic therapy
6. Type (2) Mechanism of action
a. Cell wall synthesis inhibitors
b. Cell membrane disruptor
c. Protein synthesis inhibitors
d. Folic acid synthesis inhibitors/ folate antagonists
e. DNA, Nucleic acid synthesis/function inbitors
28. a. Microbiological origin
• Fungi:
• E.g. Penicillium species
• Bacteria:
• E.g. Bacillus species
(Bacitracin)
• Soil:
• Streptomycetes,
actinomycetes e.g.
TMC
• Tetracyclines
• Macrolides
• Chloramphenicol