Bacteria and Viruses: How They Differ

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Bubonic plague, HIV/AIDS and COVID-19 are all examples of pandemics, however, the first is caused by bacteria and the other two are caused by viruses. Both viral and bacterial infections have similar effects on the body. Coughing, sneezing, fever, inflammation, vomiting, fatigue, and so forth are signs that your immune system is working to fight off an infection. While bacteria and viruses share similarities, they are classified in different ways.

Doctors need to know the difference between the two so they can properly treat the illness and provide patients with accurate, quality care. Molecular laboratory tools are improving the ability of doctors to identify viral or bacterial infections more quickly and efficiently. At Galaxy Diagnostics, we use these tools to identify stealth bacteria.

Find out more about the advanced technologies Galaxy Diagnostics uses to detect elusive flea- and tick-borne bacterial pathogens.

Bacteria

Bacteria are single-celled complex microorganisms. They can be found in soil, water, plants and animals as well as in extreme locations like radioactive waste, glaciers, and hot springs. Most bacteria have a rigid cell wall with a membrane that surrounds fluid and cell structures. Bacteria are classified as gram-negative or gram-positive based on their cell walls. Gram negative bacteria have an extra outer lipid membrane, while gram positive bacteria lack an extra membrane but have much thicker cell walls.

Bacteria are considered alive since they can exist and reproduce without a host. They reproduce by splitting in half to make two exact copies of the original cell.

Most bacteria are harmless, and some are even helpful. For example:

• Lactobacillus acidophilus: This bacterium resides in the small intestine and helps process dairy products like yogurt. It also helps our bodies make Vitamin K and fight off infection. When the population of acidophilus in the small intestine gets too low, we may be at a higher risk of infection.
• Escherichia coli: While coli may be in the news most often for causing sickness from foods, like Romaine lettuce, most are helpful bacteria that live in your gut. Coli means “from the colon,” which is the bacteria’s natural habitat. Most E. coli aid in digestion and protect humans from harmful microbes.
• Rhizobium: This is a soil bacterium that helps supply ammonia to plants so they can grow. Rhizobium uses oxygen in the atmosphere to convert nitrogen into ammonia. Without these bacteria, plants would not be able grow.

Treating Bacteria

Of all the bacteria in the world, only 1% cause disease. Disease-causing bacteria can be killed using antibiotics. One of the ways to treat a bacterial infection is through antibiotics. Most antibiotics are derived from soil-dwelling bacteria or fungi. In 1928, Alexander Fleming accidentally discovered penicillin from a fungal contamination of a bacterial culture. He noted that this fungus appeared to kill the bacteria.

Antibiotics can work in multiple ways to inhibit the growth of bacteria. They can inhibit the bacteria’s cell wall from being formed, halt replication (reproduction) of the bacteria, and stop the synthesis of proteins essential for the bacteria to live. It is important to know the difference so that antibiotics are not used incorrectly, which could lead to creation of antibiotic-resistant superbugs.

It is important to take antibiotics correctly and only when needed. Overuse and incorrect use leads to antibiotic resistance. Discovering new antibiotics takes time and doesn’t always keep up with the evolving bacteria. Scientists are working to develop new strategies for fighting bacteria that are less likely to be subject to resistance.

Viruses

Viruses are smaller than bacteria and consist of a protein coat and core genetic material. They lack the membrane-bound organelles found in bacteria. Without these “mini organs,” viruses depend on living hosts for everything they need to continue living, including energy production and replication. Scientists do not consider viruses to be living organisms.

When a virus enters the body, it invades some of your cells and then takes over the cell machinery. After taking control of the cell, viruses will use one of two cycles to continue growing and replicating. These are called the lytic or lysogenic cycles. During the lytic cycle, a virus inserts itself into the cell and then reprograms the cell to reproduce the virus. Cells eventually lyse (explode), releasing the virus into the body to infect more cells.

During the lysogenic cycle, the virus inserts itself into the host cell chromosome, the area of the host cell that contains all genetic material needed for reproduction, and it becomes a part of the genetic instructions. Some viruses contain DNA and some viruses contain RNA. If the host cell reproduces, it will continue to do so while containing the viral genetic instructions until the infected cells are destroyed by the immune system.

Treating Viruses

Viral infections can be prevented through immunization and treated with antivirals. Antivirals work by prohibiting viruses from entering healthy cells, boosting the immune system, and by lowering the viral load (amount of active virus) in the body.

Antivirals target specific weaknesses in the virus and are only effective on a specific group of viruses or sometimes only on a very specific genetic type of one virus. Because viruses live inside cells, they are harder to target and develop antivirals for. Since the number of viruses outweigh the number of antivirals, viral infections are often treated with common remedies, such as rest and hydration.

Conclusion

While bacteria and viruses can cause similar symptoms, they are very different from each other. Bacteria do not necessarily need a host to survive and can be treated with antibiotics. Viruses can only survive by infiltrating the cells of a host. They can be treated with antivirals but are often treated with rest and hydration.

It is important to know what type of infection is causing symptoms, so doctors know how to treat the illness most effectively. Advances in diagnostic tools and treatments can improve people’s lives.

References

The University of Queensland Institute for Molecular Bioscience. (2020, April 20). What’s the difference between bacteria and viruses? https://imb.uq.edu.au/article/2020/04/difference-between-bacteria-and-viruses

Tosh, P. K. (2020, November 14). Bacterial vs. viral infections: How do they differ? https://www.mayoclinic.org/diseases-conditions/infectious-diseases/expert-answers/infectious-disease/faq-20058098

the Healthline Medical Network. (2022, February 2). How do antibiotics work? Healthline. https://www.healthline.com/health/how-do-antibiotics-work

Cleveland Clinic. (2021, May 11). Antivirals. https://my.clevelandclinic.org/health/drugs/21531-antivirals

BiologyWise. (n.d.). Helpful bacteria examples. https://biologywise.com/helpful-bacteria-examples