You know that when you get sick the cause is usually a virus or bacteria. However, if you were asked what they are, could you answer? Find out what you need to know about these pathogens and the differences between the two.
Bacteria are a large diverse group of living one-celled microorganisms. Their shapes vary, but most bacteria are either spherical (cocci) or rod shaped (bacilli). Because they are so numerous, their morphological characteristics help classify and organize them into groups.
Internally, bacteria consist of a cell membrane enclosing cellular components like a single, circular genome, proteins and cytoplasm. Unlike a human cell, they lack a nucleus, mitochondria and other organelles like golgi bodies. Externally, the bacterial cell wall encases the membrane and is made up of various proteins. There are two common classifications of the cell wall, called gram-positive and gram-negative. Gram positive bacteria are thick-walled and contain many layers of certain proteins, while gram-negative bacteria have a thin wall and few protein layers. Gram stains are commonly performed in laboratories to help identify unknown bacteria.
Bacteria are capable of asexual reproduction, meaning they can reproduce on their own through binary fission, creating identical clones of themselves, usually quite rapidly.
Even though bacteria are most commonly known for creating disease, they actually exist everywhere, all the time. From the highest mountain tops to the deepest volcanoes, in every extreme temperature imaginable, right down to the soil in your backyard, your skin, and your own gastrointestinal system. Most bacteria are harmless and you don’t even know they are there. They can even have useful functions, like making vitamins, or breaking down garbage.
However, there are many types of pathogenic bacteria that cause disease in animals or humans. Each type interacts with its host differently, and can cause different reactions, or different infections/diseases. Some common diseases that are caused by bacteria are strep throat, pneumonia, urinary tract infections, meningitis, tuberculosis, tetanus, syphilis, chlamydia, salmonella, anthrax, and many more.
Bacterial infections are usually treated with antibiotics, which kill or inhibit the growth of bacteria. A growing concern in the health industry is the development of antibiotic-resistant bacteria, which mutate and evolve as they reproduce, to withstand whatever antibiotic they have been exposed to. However, there are great advancements in technology to help us stay safe and healthy when it comes to these pesky germs,
So how are viruses different? Actually, viruses are considered non-living, and are not technically considered a “microorganism” like bacteria, but they are still studied under the field of Microbiology. Viruses are much smaller than bacteria, as much as tens of thousands times smaller, and have numerous shapes and morphologies.
A virus contains a small amount of genetic material which could either be DNA or RNA, encased in a protective protein shell called a capsid.
Viruses are not capable of replicating on their own. They require the use of a host (plants, animals, or humans) to survive by invading cells and redirecting them to produce more of the virus. Viruses basically cause a host cell to engulf them, and then “hijack” the cell’s machinery to make multiple copies of themselves. The viruses are then released by lysing, or bursting the host cell.
Viral infections can cause various effects to the host cell. The virus can remain latent or dormant inside a cell for ages, not causing any symptoms at all. Depending on the species of virus, it can cause disease by different mechanisms. Common diseases caused by viruses include the common cold, influenza, chickenpox, herpes, AIDS, ebola, and more.
Unlike bacteria, illnesses caused by viruses cannot be helped with antibiotics. This is because viruses use the metabolism of the host cell so they are difficult to eliminate without causing some toxicity to the host cell. Any cold or flu remedies you find in the stores are only useful in reducing symptoms. Vaccines are the most effective method to prevent infection, and the development of antiviral drugs is constantly continuing.
So even though bacteria and viruses both can cause disease, they are very different kinds of microorganisms, and as such, need to be treated differently, in order to get the best treatment possible.