How to Classify Bacteria and Viruses

Understanding the basic characteristics of viruses and bacteria can go a long way in helping you understand their behavior, as well as the proper treatment for their removal. The two terms are used very commonly, yet few people know the difference between them. Here's how to distinguish bacteria from viruses.

Instructions

1. Determine the size of the microorganism you are looking at. Both of them are very tiny organisms that are measured in micrometers or microns. It takes about 25,000 microns to make up one inch, so you can only see them with a high-powered microscope. Bacteria tend to be about .5 microns at the smallest and up to 2 or 3 microns for the larger ones. Viruses by contrast are quite a bit smaller, measured in nanometers, and can only be seen under an electron microscope

2. Watch their behavior. Viruses can only live within a host cell. They are basically parasites, bringing their own strands of DNA or RNA into the host cell and taking over. If you isolate them from fresh host cells, they cannot reproduce. Many scientists debate whether they should even be classified as a living organism, as they have no life of their own. Bacteria are single-celled organisms that can live on their own and multiply rapidly in the right medium.

3. Understand the treatment. Viruses cannot be treated with antibiotics, since most of them are effective by way of a chemical interruption of their reproductive stage. Viruses are living within a host cell, and use its innate form of reproduction, so to stop the host cell from reproducing would cause death. Instead, the innate immune system and the adaptive immune system of the host must recognize and isolate the intruder or virus. In this way, an immunity is developed, which is why vaccines (small portions of virus-laden cells) have been so successful in controlling many viral diseases, like polio, measles and mumps.

4. Watch the reaction. Most active viral infections cause fevers between 101 and 104 degrees Fahrenheit and last from two to four days, going away on their own. (This is a very generalized explanation, as there are viruses such as HIV or Epstein-Barr that are lifelong). However, if the fever goes above 104 degrees Fahrenheit, medical attention is critical, as it signifies a probable overwhelming bacterial infection that the immune system cannot handle. Antibiotics are usually the only course of treatment. Bacterial infections usually need to be treated aggressively with antibiotics.