Bacteria are said to occupy the large domain of the prokaryotic cell, while the virus is known as minor infection causing agent. Secondly, bacteria reproduce by themselves through asexual method whereas virus needs a host cell to replicate as they lack cellular machinery but consist of DNA and RNA.
When people fall ill, the first thing that struck to their mind is about any contamination, related to bacteria, fungi or virus. This routine is typical in all age of peoples, as these terms like bacterial or viral infection are very familiar to us these days and can affect any time.
These microbes (bacteria and virus) are invisible from the naked eyes and mark their presence since more than 3500 million years. Bacteria cause localized infection, while virus causes systemic infection in the body, both are present widely and in various forms. Most importantly antibiotics drugs effectively work upon bacteria, but it is not the same as the viruses.
There are many more differences and interesting points to notice about bacteria and virus, which we will be discussing in this article, with a brief summary.
Content: Bacteria Vs Virus
Comparison Chart
| Basis for Comparison | Bacteria | Virus |
|---|---|---|
| Meaning | Bacteria are the single-celled living organisms, comes under prokaryotes and so have poorly developed cell organelles and nucleus. | Viruses lie between living and non-living things, as they have their own DNA/RNA as their genetic material but lack other cellular machinery. |
| Size | It's around 1000 nm. | Vary from 20 - 400 nm. |
| Kind | Unicellular. | They do not have cells. |
| Classifications | There are various ways to classify, which is on the basis of shapes, size, mode of nutrition, gram positive and gram negative, etc. | Classification is on the basis of the type of DNA (double/single-stranded) and RNA. |
| Cellular Structure | The cell wall is made up of lipopolysaccharide or peptidoglycan. | As they do not have the cell, so the cell wall is also absent, instead have a protein coat (capsid), which protects the genetic material. |
| Ribosomes are present. | No ribosomes. | |
| The genetic material (DNA and RNA ) freely floats in the cytoplasm. | The genetic material is enclosed within a protein coat. | |
| The bacteria reproduce asexually generally by fission method. | They attack a host cell, thereby controlling its activities and causing it to make multiple copies of the viral DNA/RNA, releasing in the destruction of the host cell and releasing the new viruses. | |
| Infection | A bacterial infection remains for the 8-10 days and results in fever. | A viral infection remains for 2-10 days and may cause a fever. |
| Ulcers, meningitis, food poisoning, gastritis, etc. | Chickenpox, common colds, AIDS, herpes, etc. | |
| Bacterial infection is treated by taking antibiotics. | The virus does not have any effects of antibiotics. Infection is treated by anti-viral drugs. | |
| Examples | Coccus, Bacillus, Spirillum, Rickettsia, Vibrio cholerae, Staphylococcus aureus, etc. | Papilloma virus, HIV, Hepatitis A virus, TMV, T4 bacteriophage, etc. |
Definition of Bacteria
Bacteria are a prokaryotic, unicellular organism, that is found in the deep earth, ocean, air and inside the human’s body. The whole body of the bacteria is made up of the single cell and is very simple to understand in comparison to the eukaryotic one.
They are not always harmful as viruses, and they proved to benefit economically, as well as scientifically. The outer structure of the bacterial cell is made up of two layers, the outer one and the inner one, the cell organelles are not well developed, the nucleus is free floating. Certain bacteria have extra circular DNA also, known as a plasmid.
There are various ways to classify bacteria, which can be on the basis of the cell wall, their size, shape. The bacteria multiply asexually by the process of binary fission or budding. There are three methods of gene transfer, which are transformation, transduction, and conjugation.
Bacteria are environment-friendly too, they help in nitrogen fixation for plants, and in cellulose and biodegradation. Bacteria are also used in food and chemical preparation. They are used in preparing antibiotics too.
Definition of Virus
The virus is a Latin word, which means “poison” or “slimy liquid” and is known as a very small infectious agent, visible through an electron microscope. They do not have any cellular structure but contain genetic material within a protein coat. The study of the virus is called as ‘virology’.
The virus is being placed under special taxonomic position and has their own kingdom because these are not animals, nor plants and neither comes under any category of prokaryotic cells. They do not have the capability to reproduce and divide by their own, hence cannot be said as organisms.
The only thing they have is the DNA or RNA and protein as their genetic material. Almost all the virus is susceptible to infection, and different types of virus invade different type of host cell.
Virus penetrates into the host cells inside the body, and use their machinery to get replicate and spread, and further, they destroy the invaded or infected cell. The infection caused by a virus is called as viral, and these can attack any type of cell, that is it can be a plant cell, a human cell, a bacterial cell, etc. and thus resulting in different types of viral infection. These viral infections can last up to a certain time, or they can be permanent and life-threatening too.
The Dutch scientist ‘Martinus W. Beijrinck‘ was the first to inform that virus are the new infectious agent and named it as ‘vivum fluidum‘, which means a new live reproducing organism, which is different from other organisms. Before this, the Russian scientist ‘Dmitry I. Ivanovsky’ in the year 1892, noticed the activity of the viruses. Later on, both the scientist came to know about the disease of tobacco plants called as tobacco mosaic virus.
The protein coat is called the capsid, protects the nucleic acid. The nucleic acid is the main constituent, which can be DNA (deoxyribonucleic acid) or RNA or ribonucleic acid). The virus attaches to the cell’s receptor present on the surface of the cell, these are very specific for every surface, and then the virus infects and gets attached to cells machinery. Here they (virus) start replicating, and later the virus kills the host cells and gets itself release and further attacks a new cell.
Key Differences Between Bacteria and Virus
Following are the important points to differentiate between bacteria and virus:
- Bacteria are the single-celled living organisms, comes under prokaryotes. They are found everywhere from the extremely hot temperatures to the coldest one, inside and outside the body, or in any type of environment. Bacteria are not always harmful, and they can be beneficial too. Viruses lie between living and non-living things, as they have their own DNA/RNA as their genetic material enclosed within a protein coat, but do not have a cellular structure and need a host to replicate.
- Size of the bacteria is around 1000 nm, whereas viruses size varies from 20 – 400 nm.
- There are various ways to classify bacteria, which is on the basis of shapes, size, mode of nutrition, gram positive and gram negative, etc., while viruses are classified on the basis of the type of DNA (double/single-stranded) and RNA.
- Cellular Structure like cell wall of bacteria is made up of lipopolysaccharide or peptidoglycan, ribosomes present, the genetic material floats freely in the cytoplasm. In the case of the virus, they have protein coat instead of any cell wall, any kind of cellular structure is absent, but they have single or double stranded DNA, linear or circular inside the protein coat only.
- The bacteria reproduce asexually generally by binary fission method, but virus invades a host cell, thereby controlling its activities and causing it to make multiple copies of the viral DNA/RNA, releasing in the destruction of the host cell and releasing the new viruses.
- A bacterial infection remains for the 8-10 days and results in fever, and it causes infections such as pneumonia, ulcers, tuberculosis, leprosy, meningitis, food poisoning, gastritis, etc. On the other hand, a viral infection remains for 2-10 days and may cause a fever, and it causes chickenpox, common colds, AIDS, herpes, etc.
- Most importantly bacterial infections are localized and are treated by taking antibiotics, but viral infections do not have any effects of antibiotics, rather anti-viral treatment is provided to the person.
- Coccus, Bacillus, Spirillum, Rickettsia, Vibrio cholerae, Staphylococcus aureus, etc., are some of the common names of bacteria, whereas Papilloma virus, HIV, Hepatitis A virus, TMV, T4 bacteriophage, etc., are the names of different types of viruses.
Similarities
- Visible under electron microscope.
- Nucleus absent in both.
- Both are a disease-causing agent.
Conclusion
In the above article, we discussed the points on which the bacteria and the virus differ. These microbes affect every form of life and are found everywhere. As said that bacteria can be useful in many ways, but not virus, as they cause harm to every living being in one or the other way. So, one should be careful and take precautionary when caught by any kind of bacterial or viral infection.
Kus Sularso says
Good explanation. Prion for the next.
Chetana says
Very informative article which gives us idea to differentiate both waiting for more onformation