Bacteria Vs. Virus

When you hear about bacterial infection or viral infection, you would wonder how to distinguish both of them from each other. Read on to find out the difference between the two of them.
BiologyWise Staff
Last Updated: Jun 5, 2018
Usually, there are two types of germs, which cause most infections - bacteria and virus. Bacteria vs. virus is a very common confusion most of us have.
The former are unicellular microorganisms, which are typically a few micrometers long and come in many shapes, such as curved, spherical, rods, and spirals (the singular form is called bacterium); while the latter are sub-microscopic particles, which are 10,000 times smaller than a bacterium.
A clear understanding of both types of infectious agents is essential to be able to wrap our heads around their mutual differences. Information regarding both pathogens is presented in the next two paragraphs.
bacteria cell
They are single-celled, prokaryotic organisms, which can be found everywhere in air, soil, water, plants and animals. They are all surrounded by a cell wall, and can reproduce independently.
There are both - useful and harmful  bacteria. The useful type carry out many useful functions, like making vitamins, breaking down waste, turning milk into cheese, etc. In fact, the human mouth is home to more than 500 species of this type. Some of them that reside in the human body can prevent infections and produce useful elements, like Vitamin K.
The ones present in the stomachs of cows and sheep help them to digest grass. They are also necessary for the production of yogurt, cheese, and a lot of other food products that undergo fermentation prior to consumption. The infections caused due to this agent are strep throat, urinary tract infections, ear infections, stomach ulcers, septicemia, etc.
It is the smallest and tiniest of microbes, which are extremely small and are about 20 to 250 nanometers in size. It is the smallest and simplest of life forms known, if it can be called a lifeform at all, given that it cannot undergo metabolism or reproduce independently.
The virus consists of a small collection of genetic material, which is encased in a protective coat known as capsid. When it is present outside a living cell, it is dormant; but, when it is inside, it takes over the resources of the host cell and begins to replicate into more particles.
The capsid actually triggers the cells to engulf the particles, and connects itself to these cells and releases their DNA into the cell. Then, it takes over the cellular machinery to reproduce, overrides the host cell's normal function, shuts down the production of protein, and directs the resources for new production.
There are some viruses, which insert their genetic material into the DNA of the host cell where they begin to directly copy their genes or simply lie asleep either for lifetime or for years. In either case, it is the host cell, which does all the actual work, and the virus simply gives direction.
Comparison between Bacteria and Virus
  • It can multiply on non-living surfaces.
  • They are inter-cellular organisms.
  • Some of these organisms are useful.
  • It can be killed by antibiotics.
  • It must have a living host to multiply.
  • They are intracellular organisms.
  • They are all harmful.
  • It cannot be killed by antibiotics.
There are certain ailments, such as, pneumonia, meningitis, diarrhea, etc., which can be caused due to either of the microbes, as it is very difficult to ascertain what has actually caused the ailment.
The information here has made the difference between two of the chief mammalian pathogens, clear. However, it is recommended you do not treat yourself by going for self-medication, as inappropriate use of antibiotics or any other medicines can create strains of a disease, which may become resistant to antibiotic treatment.
Disclaimer: This is for informative purposes only, and should not be used as a replacement for expert medical advice.