Halloween, also known as the day of spooky things, is one of the most important events in human history. This scary celebration brings fear among all. Whether you’re a child, teen, adult or elderly, there is always going to be some spooky stuff to make you fall off your chair. Think about ghosts, vampires, zombies, witches, etc. Hopefully, all these creatures don’t exist (including ghosts, which aren’t proved scientifically).
Unfortunately, reality definitively hates us since it brings us some spooky beauties such as murders, starvation, and diseases. The latter is more interesting since we commonly deal with these in our society. Murder and starvation rates decreased quite a bit over the years. Yet, diseases are still common. Even though they’re less problematic nowadays, it doesn’t change the fact that they’re one of the most dangerous enemies of health.
Before the end of the 19th century, scientists agreed that living organisms could appear directly from non-living objects. For instance, they thought that the flu appeared out of nowhere. This theory is more commonly known as “spontaneous generation”. We had to wait until 1668 for Francesco Redi’s experiment to first contradict this theory. In his experiment, he used three different jars, some meat, and flies. The first one was closed, the second one only had a gauze, and the third one had nothing to protect the meat. He discovered that, obviously, the third jar had fly offspring, but he also discovered that in the second one . Therefore, he provided the first clue that demonstrated that spontaneous generation is an incorrect theory.
Yet, we had to wait until Louis Pasteur’s 1859 experiment to have definitive evidence that this theory wasn’t accurate. In his experiment, Pasteur used three flasks: one air-opened, one with a S-shape opening and one closed. According to scientists, the first two flasks would have been contaminated as air contains bacteria. However, the second one was still sterile in some parts but , but bacteria was found isolated from the air in the s-shape opening. Therefore, Pasteur proved once and for all that spontaneous generation was an incorrect theory.
The point of making this historical context is to prove that nobody is free from misinformation. Moreover, it helps to link this unnecessary too-long introduction and the main subject: pathogenic microbes. Because diseases are common yet dangerous, also more present, I judge that vulgarization of these is necessary. It isn’t necessarily fun to inform you on this subject as it looks like a hard biology class. For that reason, I’m gonna describe four interesting facts regarding diseases which, according to me, are important to know. Of course, the facts are not going to be hard to understand and only need some basic understanding of biology.
Topic 1 – What Are Pathogenic Microbes?
Simply put, living organisms are objects that have specific criteria and conditions to respect to be considered alive. For instance, they have to produce their own energy, to be composed of cells, to respond to their environment, to be able to produce offspring, etc…
Logically, we categorize their size by our capacity to see them. If we can see an organism with the naked eye, we call it macroscopic. On the other hand, if we can’t, we call them microscopic. Remember that macro means “large scale” and micro means “small scale”. Most diseases are caused by the latter since they cannot be observed without a microscope. However, there are some diseases caused by macroscopic parasites such as taeniasis (which is caused by Taenia solium, you know, that beautiful worm that can be present inside uncooked pork).
Even though we tend to use the term microbe to talk about those that cause diseases, it isn’t exactly the case in biology. Of course, we can still use this definition; however, we prefer adding the term pathogenic to microbes that are disease-related. As such, the term “microbes” is only a synonym for microorganisms.
You might be wondering what the term pathogenic means. After all, it is not a term that people frequently use usually see outside of the health system. It is a derivative of the noun pathogens which pinpoints microbes such as fungi (mushrooms), bacteria and viruses that cause diseases. Yet, it is important to emphasize that the latter is probably one of the most controversial ones as the definition of life doesn’t properly apply to it. It is also important to note that all pathogenic agents are transmissible.
Therefore, by the analysis of the term, it is possible to conclude that pathogenic microbes are living organisms that are too small to be seen with the naked eye and that can potentially cause diseases.
Topic 2 – How Do Microbes that Cause Diseases Work?
Every living system is a beautiful machine that produces some proteins thanks to its genetic material. This process uses mainly RNA as a factor, thanks to protein-making organelles (cell structures) called ribosomes, and, if it has DNA instead of RNA, a living being can transform it into the latter. The living organisms are inside each of the three main domains of life: bacteria, archaea and eukarya. Of course, the production of proteins is only beneficial for the user itself. Don’t forget that life is selfish!
Excluding viruses, which are an exclusion to the following rule, a few germs can survive outside for a while before dying. In fact, many of them have lost their ability to survive outside. Plus, being inside a warm body is very tempting as it helps them to survive longer than normal. They don’t have to risk their life to find food; everything is already there and offered on a silver platter. We call that living style parasitism or symbiosis, depending on whether the host is beneficial in the story. It kinda reminds me of a very popular species that has taken over the world!
Symbiosis is the case in which everyone is happy and is helping each other. It’s like the happy ending that anyone would like to have. For instance, bacteria in our stomach produce a powerful acid that breaks down food so that the body can absorb the nutrients and, consequently, helps us to gain even more energy.
On the other hand, we have the bad boys: those who are villainous and narcissistic. I’m obviously talking about parasites, or, in the context of this text, pathogenic microorganisms. Fundamentally, they just want to survive and they have found that being narcissistic and stealing all the nutrients from its host is the smartest way to live. In addition to following the mathematical rules of game theory, natural selection might encourage that kind of behavior as their reproduction rate increases, nevertheless.
As such, parasites use the protein-making process of their host to their advantage by exploiting its ribosomes and injecting their genetic material into the whole system. It means that the host starts to produce the parasite nutrients instead of its own, which is going to result in the death of the host’s cells.
Topic 3 – Study Case: Viruses
In biology, there are so many debates. However, the classification of whether something is alive or not isn’t subject to debate. Most scientists agree on the characteristics of life and the different species that are susceptible to it…at least at the tip of the iceberg. Viruses are responsible for that confusion, sadly or not, depending on how you see it, my favorite kind of microbes.
Viruses are missing a few characteristics of life such as cellular structure and the ability to maintain homeostasis. Yet, they do have genetic material which is probably the most important key to life. Because of that, they can be described as living beings. We can illustrate a family tree, the classification (thanks to kingdoms, classes, etc…), and the sequence of their RNA or DNA.
They also act as perfect parasites. They enter living organisms, including bacteria, and use the protein-making process of the cell to produce their own little substances. The vast majority of these result in cellular death as they suck all the energy of their host. In fact, only retroviruses, those that integrate their RNA into our DNA thanks to an enzyme (reverse transcriptase), keep our cells alive. However, it is way worse as it makes the related diseases less noticeable. That’s why HIV and its related illness (AIDS) are problematic (in addition to other factors such as being a goodie for our immune system). It doesn’t also help physicians that viruses come in different shapes, material genetics, specific to a species, etc…
As said earlier, viruses can be present not only in animals but also in plants and in other microorganisms. For instance, a virus called tobacco mosaic virus can infect tobacco plants which reduces its production. It is, by the way, the first of its kind to be discovered. On the other hand, there are some viruses that can contaminate bacteria; we call these bacteriophages, and, weirdly enough, they have the shape of an (and gosh, I never thought that I was going say that): alien spaceship.
To conclude, viruses aren’t solely special because they are organisms that interact with cells in a parasitic situation, but also because they kinda mock all biologists and physicians by making their job even more difficult than it should be (either with its definition of life or with their vast variety).
Topic 4 – How to fight back our enemies?
The last section of this text (and probably the most important one as it can directly impact people’s lives): How do we fight back microbes that are susceptible to introducing themselves in us, and how do we fight them back if they’re already inside of us? It is also very important to emphasize that the sentence “directly impact people’s lives” mustn’t be taken lightly as many people can die.
As such, what are these solutions? Simply put, they’re separated into two big categories. The first one is prevention while the second one is treatment. Even though the second one is often thought of by people, prevention is the most important category as it is the most direct way to helping others.
Yet, we’re going to talk about the treatment first. Treatments can range from administering medication such as cough syrup to providing air to a patient. They are often the last resort that physicians use in order to save a life because their utilization might result in health complications and financial losses. That’s why people in the United States have to pay a huge amount of money when they’re in need. Hopefully, in Quebec, these kinds of services are provided by the government and paid by taxes.
Yet, people might abuse the current system; physicians tend to overuse antibiotics to treat virus-related diseases. The abuse of these often brings resistance among microorganisms (notably bacteria) since they specifically target bacteria. By using them when it is unnecessary, these microbes become used to their defense mechanism. Therefore, they become more resistant. Few solutions were offered but due to the fact that antibiotics have the monopoly of treatments, few people in the economy are interested in researching other solutions such as bacteriophages.
Now, let’s talk about real business here. I’m talking of course about prevention. It is simple to understand as methods of prevention can be summarized and only require a basic understanding of physics and the immune system. Let’s start with the simplest one: masks.
Masks work as a barrier to microparticles coming out from the mouth. In fact, when we talk, cough, have a nasal infection, etc…we tend to project microparticles containing pathogenic agents that can infect others. That’s the way they’re being transmitted. As such, by offering a barrier to our mouth that filters these but still lets air enter, we can avoid contaminating others. Things can enter but cannot leave. Consequently, masks are used to avoid transmission, not avoiding the development of a disease.
On the other hand, our second solution, vaccines, work on that issue. They train our immune system to produce antibodies against very specific organisms. Our antibodies then already know who to attack when the time comes. It means that, once an enemy enters, our immune system is going to directly fight back instead of waiting patiently and letting its front barrier do the dirty job.
Bibliography:
Harvard Library. “Germ Theory.” Contagion – CURIOSity Digital Collections, 2022, curiosity.lib.harvard.edu/contagion/feature/germ-theory.
Carr, Steven. “Redi Experiment.” Www.mun.ca, 2018, www.mun.ca/biology/scarr/4270_Redi_experiment.html.
“1.1C: Pasteur and Spontaneous Generation.” Biology LibreTexts, 6 May 2017, bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Boundless)/01%3A_Introduction_to_Microbiology/1.01%3A_ Introduction_to_Microbiology/1.1C%3A_Pasteur_and_Spontaneous_Generation.
“What Are Microbes?” Learn.genetics.utah.edu, learn.genetics.utah.edu/content/microbiome/intro.
Koonin, Eugene V, and Petro Starokadomskyy. “Are viruses alive? The replicator paradigm sheds decisive light on an old but misguided question.” Studies in history and philosophy of biological and biomedical sciences vol. 59 (2016): 125-34. doi:10.1016/j.shpsc.2016.02.016
Miller, Christine. “Protein Synthesis.” Humanbiology.pressbooks.tru.ca, Thompson Rivers University, 1 Sept. 2020, humanbiology.pressbooks.tru.ca/chapter/5-6-protein-synthesis/.
“Symbiosis and Parasitism.” Encyclopedia of the Environment, 30 June 2016, www.encyclopedie-environnement.org/en/life/symbiosis-and-parasitism/.
Louten, Jennifer. “Virus Structure and Classification.” Essential Human Virology (2016): 19–29. doi:10.1016/B978-0-12-800947-5.00002-8
Hu, Wei-Shau, and Stephen H Hughes. “HIV-1 reverse transcription.” Cold Spring Harbor perspectives in medicine vol. 2,10 a006882. 1 Oct. 2012, doi:10.1101/cshperspect.a006882
Kaiser, Gary. “10.2: Size and Shapes of Viruses.” Biology LibreTexts, 8 Mar. 2016, bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Kaiser)/Unit_4%3A_Eukaryotic_ Microorganisms_and_Viruses/10%3A_Viruses /10.02%3A_Size_and_Shapes_of_Viruses.
“CIHI.” Yourhealthsystem.cihi.ca, yourhealthsystem.cihi.ca/hsp/inbrief?lang=en#.
Habboush Y, Guzman N. Antibiotic Resistance. [Updated 2023 Jun 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513277/
Mayo Clinic. “Can Face Masks Protect against the Coronavirus?” Mayo Clinic, Mayo Clinic Staff, 20 Aug. 2020, www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-mask/art-20485449.
“How Vaccines Work: Immune Response and the Body’s Reaction | Pfizer.” Www.pfizer.com, 5 May 2020, www.pfizer.com/news/articles/how_vaccines_work_immune_response_and_the_body_s_reaction.
