[Biology Class Notes] on Antibiotics Pdf

Antibiotics can be defined as the substances that can be used to treat bacterial infections. Some antibiotics also act as antiprotozoal substances, which suggests they’re effective against protozoan infections. However, no antibiotics are effective at combating viruses,; hence, to curb viral infections, antiviral drugs are used.

 

The origins of the term “antibiotics” are often traced back to the 1800s’ when French bacteriologist Jean Paul Vuillemin introduced the term “antibiosis”, which meant “against life”. He used this term to explain the properties of early antibacterial drugs. The actual term “antibiotics” was first employed by Selman Waksman in 1942 to explain the inhibitory effects of drugs produced by microorganisms to other microorganisms. The first antibiotic was discovered by Alexander Fleming in the year 1928 while working on the influenza virus. 

 

Uses of Antibiotics

Today, the name antibiotic is synonymous for drugs that kill bacteria. And as a result, there has been an increased lifespan along with a reduction in the mortality rates.

 

These microbial infections can wipe out a whole population of organisms which can adversely affect the ecosystem. For instance, anthrax may be a disease that infects livestock and may spread to humans, which is usually fatal unless it’s treated.

 

Prevention against any microorganism’s growth can be done through antimicrobial therapy. However, it might not stop the damage that is already done. For example, the anthrax-causing bacterium Bacillus anthracis doesn’t actually kill the host, instead, it’s the toxins that are produced which does the deed. Although the bacteria might get killed due to antibiotics, the toxins still remain in the body which can cause damage.

 

Nowadays, there are  two types of antimicrobial therapies available:

1. Microbicidal therapy – It helps to kill the microorganisms.

2. Microbiostatic therapy – It helps to prevent microorganism growth.

Examples of Antibiotics

Penicillin

Penicillin was the first ever “true” antibiotic and it had been discovered by a Scottish bacteriologist, Fleming in 1928 to treat plague and several other bacterial infections. Ironically, Penicillin was an accidental discovery, but it had been a landmark discovery within the field of drugs. It is made from Penicillium notatum, which is a mould.

 

Types of Penicillin

There are different types of penicillin, which are grouped based on their effectiveness.

• Penicillin VK and Penicillin G are natural Penicillin.

• Penicillin VK is used against several bacterial infections such as ear infections.

• Penicillin G is used against several bacterial infections caused by gram-positive and gram-negative cocci. Example: susceptible bacterial infections in the stomach.

Quinolones

They are the type of antibiotics that have the ability to inhibit or kill the growth of bacteria. Developed in 1962, quinolones are made up of an artificial compound called NegGram. Quinolones are used as a treatment against the urinary tract bacterial infections, sinusitis, bronchitis, and pneumonia.

Strain Improvement in Antibiotic or Drug Production

Genetic engineering is a set of techniques that are used to modify the biological characteristics of various living organisms. Example: Recombinant DNA technology, Microinjection, etc. A technique that helps to produce genetically improved strains of antibiotics is called the R-DNA technology or recombinant DNA technology.

 

The wild strain of microorganisms is transformed into the mutant strain so as to extend the yield and quality of antibiotics. The improvement of biosynthetic pathway design and recombinant deoxyribonucleic acid techniques are often achieved so as to enhance antibiotic production.

 

Role of Antibodies in Antibiotics

Antibody that is also commonly called immunoglobulin is produced by our immune system. This is produced as a form of protective protein to protect our immune system from any foreign substance. This foreign substance is called an antigen. Antibodies, recognize and attack ntigens in order to remove them from the body. They bind to foreign particles and invade them. As foreign particles are always attacked by antibodies, these antibodies work against these antigens.

 

Antigens are known to be foreign pathogens that invade the body. It binds with the antibodies and produces a response from our immunity system by grouping up with a large molecule.  Hence, the invasion of antigens stimulates the production of antibodies by the immune system.