Bacteria
Bacteria are microscopic organisms that thrive in diverse environments; they can live in ocean, soil and human gut. Bacteria are living organisms with a simple cell structure that contains organelles, DNA and RNA that are immersed within the cytoplasm and surrounded by a cell wall.
Most bacteria reproduce by a process known as binary fission whereby a single bacteria cell makes a copy of its DNA and grows large in size by doubling its cellular content. The doubled contents are pushed out to the end of the cell.
Bacteria can be beneficial as well as detrimental to human health. Examples of bacteria that can be beneficial to humans include gut bacteria, Escherichia coli, Rhizobium, Bifidobacterium, lactobacillus etc. on the other hand, bacteria that can be detrimental to human health include streptococcus pneumonia, staphylococcus aureus, Helicobacter bacteria etc.
Virus
A virus is a small infectious agent that multiplies only inside the living cells of an organism. Viruses can infect all types of life forms from animals and plants to microorganisms. They lack capacity to thrive and reproduce outside of a host body.
Viruses contain the key elements that make up all living organisms (the nucleic acids, DNA or RNA). The DNA or RNA found in the core of the virus can be single stranded or double stranded. It constitutes the genotype or the sum total of a virus’s genetic information. Viral genome are generally small in size, coding only for essential proteins such as capsid proteins, enzymes and protein necessary for replication within a host cell.
Examples of viruses include HIV, Ebola, papillomavirus, Zika, hepatitis C virus, influenza, nairovius, zoonosis, cytomegalovirus, lymphotropicvirus etc.
Bacteria Vs. Virus: The difference
Description
Bacteria live almost anywhere including within other organisms, on inorganic surfaces and on other organisms. They infect eukaryotic organisms such as animals, plants and fungi. Viruses on the other hand, can be found in almost any environment. They are pathogens that infect prokaryotic and eukaryotic organisms including animals, plants, bacteria and archeans.
Living characteristics
Bacterial are prokaryotic cells that display all of the characteristics of living organisms. Their cells contain organelles and DNA that float freely within the cytoplasm and surrounded by a cell wall. On the other hand, viruses are not considered cells but exist as particles of nucleic acid enclosed within a protein shell.
Cell Shape
Bacteria can be found in variety of shapes, common bacterial cell shapes include spherical (cocci), rod-shaped (bacilli), spiral and vibrio. The shape of viruses is determined by the amount of nucleic acid and protein they contain.
Size
Bacterial typically range in size from 200-1000 nanometers in diameter whereas viruses generally range in size from 20-400 nanometers in diameters.
Reproduction
Most bacteria reproduce by a process known as binary fission whereby a single bacteria cell makes a copy of its DNA and grows large in size by doubling its cellular content. Viruses’ on the other hand only replicates with the aid of a host cell because viruses do not have the organelles necessary for reproduction of viral components, they must use the host’s organelles to replicate.
Infection
Pathogenic bacteria that cause infections by producing toxins that destroy cells. They cause food poisoning, gastritis, pneumonia, boils, abscesses, tuberculosis, meningitis etc. After viruses have entered a cell and continue to replicate deases such as Ebola, zika, AIDs, influenza, chicken pox etc may emerge.
Benefit
Some bacteria are beneficial to humans (normal flora) whereas, viruses have no any benefit to humans; they can only be beneficial in genetic engineering.
Also Read: Difference Between Gram-Positive And Gram-Negative Bacteria
The Differences Between Bacteria And Virus In Tabular Form
| Structure | Bacteria | Virus |
| Description | Bacteria are found in every habitat on earth (soil, rocks and oceans). Some live in or on other organisms including humans. | A virus is a small infectious agent that replicates only inside the living cells of other organisms. |
| Size | Range in size from (200 to 1000 nm) | Generally range in size from (20 to 400 nm) |
| Cell wall | Peptidoglycan/ Lipopolysaccharide | The cell wall is absent instead a protein coat is present. |
| Infection | Localized | Systemic |
| Reproduction | Reproduce asexually through binary fission | It invades a host cell and changes or destroys its DNA/RNA, making the host cell to produce new viruses. |
| Visibility | Visible under a light microscope | Not visible under light microscope, only visible under electron microscope. |
| Benefits | Some bacteria are beneficial to humans (normal flora) | Viruses have no any benefit to humans; they can only be beneficial in genetic engineering. |
| How they are treated | Use of Antibiotics | Viruses cannot be treated by antibiotics; their activity can only be inhibited by antivir drugs. |
| Examples | Staphylococcus aureus, Bacillus, Spirillum, mycoplasma, Rickettsia, Helicobacter etc | Ebola, HIV, avian influenza, zika, adenovirus, herpes virus, poxyvirus etc.. |
| Ribosomes | Present | Absent |
| Cell Shape | Bacteria can be found in variety of shapes, common bacterial cell shapes include spherical (cocci), rod-shaped (bacilli), spiral and vibrio. | The shape of viruses is determined by the amount of nucleic acid and protein they contain. |
| Cellular Machinery | Has cellular machinery. | Does not possess cellular machinery. |
| Living characteristic | Bacteria display all characteristics of a living organism. | Viruses are not considered cells but exist as particles of nucleic acid |
| DNA/RNA structure | Bacteria cells contain organelles and DNA/RNA that are immersed within the cytoplasm and surrounded by a cell wall. | DNA/RNA is enclosed within a protein shell |
| Resulting Diseases | Food poisoning, pneumonia, meningitis, gastritis etc. | Influenza, AIDs, chicken pox, polio, Ebola, common cold etc. |
| Cell type | Unicellular (single cell) | Has no cells, not living |
Also Read: Difference Between Staphylococcus And Streptococcus Bacteria
Similarities Between Bacteria And Viruses
- Both virus and bacteria does not have nucleus
- Enzymes are always found in bacteria and in some viruses
- Virulence is present in both bacteria and virus
- They both cause diseases
- They are both microscopic in size.
Summary
Also Read: Difference Between Flagella And Pili
What is the main difference between virus and bacteria?
Bacteria are found in every habitat on earth (soil, rocks and oceans). Some live in or on other organisms including humans. A virus on the other hand, is a small infectious agent that replicates only inside the living cells of other organisms.