1. Dr. Saba Abdi Assistant Professor Department Of Biochemistry King Saud University

2.  Greek. anti, "against"; bios, "life") An antibiotic is a chemical substance produced by one organism that is destructive to another. The word antibiotic (given by Waksman) came from the word antibiosis a term coined in 1889 by Louis Pasteur's pupil Paul Vuillemin which means a process by which life could be used to destroy life.  Current Definition: Antibiotics are products(metabolites) of various organisms (bacteria, fungi, algae, higher plants,lower and higher animals) which at low concentrations cause inhibition of life processes of any living object.

3.  3000 years ago ancient Egyptians, Chinese and people of central America used molds to cure diseases.  19th century: – Louis Pasteur & Robert Koch: Bacteria as causative agents & recognised need to control them

4.  Alexander Fleming observed the killing of staphylococci by a fungus (Penicillium notatum) observed by others - never exploited  Florey & Chain purified it by freeze drying (1940) - Nobel prize 1945  first use in a patient: 1942  World War II: saved 12-15% of lives

5. Selman Waksman - Streptomycin (1943) from soil bacteria – active against all Gram-negatives – first antibiotic active against Mycobacterium tuberculosis Is the first of the new class of drugs called aminoglycosides – extracted from Streptomyces – 20 other antibiotics, incl. neomycin, actinomycin

6. 1955 Tetracyclin was patented by Lloyd Conover, which became the most prescribed broad spectrum antibiotic in the United States. 1957 Nystatin was patented and used to cure many disfiguring and disabling fungal infections. 1981SmithKline Beecham patented Amoxicillin or amoxicillin/clavulanate potassium tablets, and first sold the antibiotic in 1998 under the tradenames of Amoxicillin, Amoxil, and Trimox. Amoxicillin is a semisynthetic antibiotic.

7. 1. Cyanobacteria 2. Bacteria 3. Actinomycetes 4. Fungi 5. Higher Organisms

8.  Mostly produce toxins that kill higher organisms.  Malingolide is an antibiotic produced by a cyanobacteria.

9.  Out of the 19 different principal groups into which bacterias can be divided (Bergey’s Classification ) the following groups mostly are source of antibiotics Bacterial group numberBacterial type 2Gliding bacteria 7Gram –ve aerobic rods & cocci 8Gram –ve facultatively anaerobic rods 14Gram +ve cocci 15Bacillus 16Gram +ve,asporogenous rods 17Actinomycetes & related organisms 12Mycoplasmas

10.  It is the largest source of antibiotics.  90%-95% of which is produced by the genus “Streptomyces”(soil bacteria).  Another genus important for antibiotics production is Micromonospora

11.  Richest source is the genera “penicillium” and “aspergillus”

12.  Such as algae, lichens, higher plants, protozoa, insects, molluscs, sponges, worms and vertebrates.