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What are antibiotics?
Antibiotics are the chemical substances which have the ability to kill disease causing microorganisms. They are mostly used against bacterial infections. It is an interesting fact that antibiotics are derived from the bacteria and mold. These microbes release such chemicals which can be used as weapons against other harmful microbes. There are also some antibiotics which are synthesized in the laboratory.

There are different varieties of antibiotics depending on the infection a patient is suffering from. During the disease of cancer, the white blood cells become weak and body becomes susceptible to various bacterial infections. Doctors prescribe antibiotics to block these infections. Antibiotics only work against bacterial infections; they do not work against viral infections because viruses are not the living microorganisms.

How do antibiotics work?
Antibiotics work in two different ways either by killing the bacteria or blocking its function. They only attack the bacterial population present in the body and causing the disease, they do not affect the cell of the body. It is an unfortunate fact that though antibiotics are being used constantly but now bacteria have developed resistance against these drugs. It is a very natural process that new antibiotics with more effectiveness are being developed and bacterial genome is revolutionizing against these newly synthesized antibiotics.

An antibiotic has also the ability to convert glucose in the body into energy. It produces a protective wall against bacteria and does not allow them to enter the cell. It also protects the body from further infection and prevents the bacteria to multiply in number.

Side effects of Antibiotics
Though antibiotics are useful in curing the human body against bacterial infections but they also have some side effects. A patient can suffer from slight headache to extreme allergic reaction. Another side effect is diarrhea in which the balance of the intestinal flora gets affected and disrupts the function of the useful bacteria present in the intestine. In some cases, antibiotics can react with other drugs administered along with them and cause other infections.

Advantages of Antibiotics
In the past before the discovery of antibiotics, the diseases like cholera and diarrhea would be fatal as these diseases dehydrate the body and makes the individual weak. Antibiotics have the credit of saving so many lives by killing the microbes causing certain diseases. In the disease of tuberculosis, antibiotics play an important role in eradicating the bacteria. To protect the patient from having side effects, doctors prescribe such antibiotics which suit person’s body.

Disadvantages of Antibiotics
As the saying is, “Excess of everything is bad”, similarly if antibiotics are used in excess amount, they react the other way round. Patient can suffer from diarrhea and abdominal cramps. If antibiotics are used repeatedly, they also are harmful for the body because then the specific bacteria develops resistance against that particular antibiotic and it may result in the cause of cancer. Sometimes doctors do not know about the particular drug and they prescribe the drugs which have broad spectrum, it may lead to the removal of both harmful as well as beneficial bacteria from the body. The other disadvantage is that they may decrease the iron level, magnesium and calcium level from the body. If the iron is removed from the body, it results in sickle cell anemia.

Antibiotic Drugs

Below is the list of few antibiotics used against various bacterial infections:

Levofloxacin
Fosfomycin
Trovafloxacin
Grepafloxacin
Sparfloxacin
Quinupristin
If antibiotics don't prevent against viral infections, why do we take antibiotics in viral fever?
Antibiotics fight against bacterial infections, they are not anti-viral. Taking antibiotics knowingly for viral infections is likely a mistake. Some doctors just prescribe it because without doing couple of tests it is hard to tell whether or not the infection is viral or bacterial.
Antibiotics are also known as antibacterials, and they are drugs used to treat infections caused by bacteria. Bacteria are microorganisms that can sometimes cause disease in humans and animals. The singular word for bacteria is a bacteria. and the work of the Antibiotics A bactericidal antibiotic kills bacteria. Penicillin is a bactericide. A bactericide is generally interferes with the formation of the cell wall of bacteria or their cell contents.
Antibiotics fight against bacterial infections and it does not prevent against viral infections...then why we take antibiotics in viral fever
(08-16-2010, 04:11 PM)protoxin Wrote: [ -> ]If antibiotics don't prevent against viral infections, why do we take antibiotics in viral fever?

The main mechanism for virus to replicate is the presence of host (bacteria)
,if antibiotics is taken this will kill bacteria so virus will now don't have host for replication so they will not multiply. so antibiotics are use during viral infection.
Great posting.
Antibiotics work in two different ways either by killing the bacteria
or blocking its function. They only attack the bacterial population
present in the body and causing the disease.
immune system is essential for our health explain?
(08-16-2010, 04:11 PM)protoxin Wrote: [ -> ]If antibiotics don't prevent against viral infections, why do we take antibiotics in viral fever?

An antibiotic against viral infection or viral fever is wrong terminology. Antibiotics are used for treatment against pathogenic bacteria (Disease causing bacteria) only and not viruses. Antibiotics are one of the types of antimicrobial. The another similar type of antimicrobial used against viruses is termed as Antiviral drugs. Therefore instead of using antibiotics against virus infection, it should be Antiviral drugs or simply Antiviral. Examples of some anti-viral drugs are Abacavir which is an anti-HIV drug. Trifluridine (Trifluorothymidine or TFT) is an anti-herpes virus antiviral drug, used primarily on the eye. Peramivir is used against influenza flu. Peramivir is a neuraminidase inhibitor, which prevent emerging of new viruses from infected host cells. Few other examples of anti viral drugs are Delavirdine, Enfuvirtide, Ganciclovir,Imunovir, Methisazone, etc.

If antibiotics are used for viral diseases/infection, the treatment may not be successful. This is because antibiotics are having different mode of actions on bacteria which are not suitable for viruses having unique characteristics with respect to their size, shape, plasmid biomolecules and life cycle. Sometimes bacteria infect humans and the viruses infect or live inside these bacteria. In such cases bacteria itself are killed by viruses which live inside them. These viruses are called as bacteriophages. In many treatments of bacterial infection, viruses are used. This is known as Phage therapy. Viruses are common in bacterial population and helps in control of their growth in different habitats like intestine, the ocean, and even in soil.
Therefore antibiotics are not used for treatment of viral diseases but they are anti viral drugs or Antiviral which act on different targets of viruses. These may be by interfering with the ability of viruses to infiltrate a target cell, use of viral entry inhibitor technique which make viruses unable to identify the receptors for their entry into host cells and thus control their infection and finally treat the patients from viral disease with the use of antiviral.
(01-18-2012, 08:24 PM)ganesh Wrote: [ -> ]immune system is essential for our health explain?


Immune system is like a defense mechanism of our body, and is very essential for our survival. Human being has three line of defense mechanism. The foreign pathogen which if want to infect us has to cross or pass through our three line of defense. These are nature’s gift to us to protect our own life. The first line is non specific barriers like skin, mucosa, hairs etc., second line is white blood cells or leucocytes and third is the specific immune response which employs immunoglobulin’s or antibodies. Without this three line of defense man would have not been able to survive against the pathogens which are present around us in millions and billion numbers. Therefore immune system is essential for our health.

Immune system includes Bone marrow, thymus gland, lymphatic system, spleen, and many tissues. Our immunity has an ability to give response to antigens in two ways as recognition and response. In first phase immune system can distinguish foreign cell or proteins from body’s own cell or proteins; this is a unique property of our immune system. Once the foreign pathogen is recognized, effectors response kills or neutralizes the pathogen from its actions and protects body from infections. And in second phase it also keeps the memory for these pathogens, so in future if again it encounters, immune system can recognize and quickly kill it in very shorter time.

In modern world many vaccines have develop on this principle of recognitions and keeping the memory of the same for lifetime. Examples are virus vaccines like -Polio vaccines, hepatitis vaccines, influenza vaccines, measles vaccines, etc. and bacterial vaccines like Anthrax vaccines, tetanus, DPT vaccines, Typhoid vaccines etc. We have seen the impact of AIDS virus on our society which attacks our immune system.
So Immune system is very essential for our survival & adaptation during the course of evolution on the earth !
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