Anti-Bacterial Drugs

Less than a century ago, infectious diseases were the leading causes of death in the world.  Pathogenic (disease-causing) microorganisms caused infections.   With the discovery of anti-bacterial drugs (compounds that inhibit the growth of microorganisms) infections can thus be controlled and most of the diseases can be treated.  Three types of anti-bacterial drugs are the sulfa drugs, penicillins and cephalosporins and broad-spectrum antibiotics. 

Sulfa drugs work by preventing the bacteria from synthesizing folic acid (a chemical essential to their growth).  As sulfa drugs are similar to the chemical structure of para-aminobenzoic acid (PABA – key ingredient in bacterial synthesis of folic acid), bacteria mistakenly try to convert the drug instead of PABA into folic acid.  Thus, the normal growth of the bacteria is inhibited.  Due to the development of resistance in formerly susceptible microorganisms, only a few sulfa drugs are used today and they are sulfadiazine and sulfisoxazole.  

Penicillins and cephalosporins are antibiotics, which are chemicals produced by a living organism, usually a mold or fungus, that kills or inhibits the growth of other microorganisms.  As they are chemically similar in their structures, both antibiotics served as powerful antibacterial agents in the treatment of bacterial infection. 

Broad-spectrum antibiotics are drugs that are effective against a wide variety of bacteria.  Tetracycline belongs to this type of antibiotics.  Two important tetracyclines are Aureomycin and Terramycin.  Aureomycin was isolated from a gold-coloured fungus whereas Terramycin was discovered after testing 116,000 different soil samples.