Antibiotics are antibacterial drugs made synthetically or obtained from the living organisms, such as fungus or mould, that inhibit the growth of or destroy bacteria. Antibiotics destroy bacteria but do not harm human body cells. Specific antibiotics can be used to combat specific pathogenic bacteria.
The first antibiotic was discovered by Alexander Fleming in 1928. Since then, thousands of antibiotics have been prepared or synthesized and hundreds are prepared every year. Some common antibiotics are ampicillin, tetracycline, streptomycin, gentamycin, kanamycin, etc.
An antibiotic is a drug that kills or retards the growth (reproduction) of bacteria. They are the chemicals produced or derived from micro-organisms (bacteria and fungi).
Bactericidal and Bacteriostatic Antibiotics
Antibiotics are used to treat many different bacterial infections. Some antibiotics are ‘bactericidal’, meaning that kill bacteria. Others are ‘bacteriostatic’, meaning that they work by stopping bacterial growth.
Three major groups of antibiotics are following:
Cephalosporins interfere with the synthesis of the bacterial cell wall and so are bactericidal. Cephalosporins are used to treat pneumonia, sore throat, tonsillitis, bronchitis etc.
These are broad-spectrum bacteriostatic antibiotics and inhibit bacterial protein synthesis. Tetracyclines are used in the treatment of infections of respiratory tract, urinary tract, intestine etc. tetracyclines are not used in children under the age of 8, and especially during periods of tooth development.
Sulpha drugs are synthetic antibiotics that contain sulfonamide group. Sulfonamides are the broad spectrum bacteriostatic antibiotics. They inhibit the folic and synthesis in bacteria. They are used to treat pneumonia and urinary tract infections.
Antibiotics are extremely important in medicine, but unfortunately, bacteria are capable of the developing resistance to them. Such bacteria are not affected by commonly used antibiotics. Bacteria have a number of ways of developing resistance. Sometimes, their internal mechanisms stop the working of antibiotic.
Bacteria can also transfer the genes responsible for the antibiotics resistance between them. So such resistance bacteria make it possible for the bacteria to acquire resistance.
Another reason for increasing antibiotic resistance in bacteria is their use in disease in which they have no efficacy (e.g. antibiotics are not effective against infections caused by viruses). Resistance to antibiotics poses a serious and growing problem because some infectious diseases are becoming more difficult to treat.
Some of the resistant bacteria can be treated with more powerful antibiotics, but there are some infections that do not eliminate even with new antibiotics.