Types of Pathogenic Microorganisms

The average human body contains about 10 trillion cells. Imagine how much that is! If our population was 1400 times greater in the entire world, then we still would not be more than the number of cells in the entire body. Amazing isn’t it? 

But what if I tell you the gut alone, contains 100 trillion microorganisms living within it this very minute? And hence the picture above, our world is really a microorganism’s world, we are simply the ones large enough to be seen. 

And thus we see the importance of microbiology, how exactly are these microorganisms affecting our lives? 

Most of these microorganisms are actually beneficial to our body, for example, by aiding in the process of digestion, however, there are microorganisms that are damaging to their host, either by the production of toxic products, or direct infection, and these microorganisms are termed pathogenic. 

To have an idea of this, let us talk about the types of microorganisms, and the pathogenic ones in each type, that is, the one that can give us a disease. 

Microbes that Cause Diseases

Microbes that cause diseases can be divided into 5 groups of organisms:

  1. Bacteria
  2. Fungi
  3. Protozoa
  4. Helminths and Rotifiers
  5. Viruses

There is also a recently discovered type of microbe that can cause a disease, known as a prion. 

Of these microbes, we can classify them in several different ways. 

Classification of Microbes:

Firstly, it is important to consider the status of prions and viruses. Technically, these “microbes” are not living. Prions are simply misfolded proteins, and viruses are only “alive” when they infect an organism. Thus, both prions and viruses have their own classifications. 

As for the other organisms, we can classify them in several ways:

  • Eukaryote vs Prokaryote
    • In this classification scheme, all bacteria are prokaryotes, and fungi, protozoa, helminths and rotifers are eukaryotes. 
      • The prokaryotes are further subdivided into eubacteria and archaebacteria. Eubacteria are the medically important bacteria, while archaebacteria are a group of evolutionarily distinct bacteria. 

Differences between Eukaryotes and Prokaryotes:

  • General Size
    • Eukaryotes are much larger than Prokaryotes, being about 10-100mm in diameter. 
    • Prokaryotes are much smaller, being about only 0.2-2mm in diameter. 
  • Nucleus vs Nucleoid: 
    • Eukaryotic cells contain a true nucleus, with multiple chromosomes, linear DNA, and a nuclear membrane, using mitotic apparatus to ensure chromosomes are equally distributed to the daughter cells. 
    • Prokaryotic cells contain a nucleoid, which is an area of loosely organized, circular supercondensed DNA, lacking nuclear membrane and mitotic apparatus.

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You’ll cry about a lot of things when you get older.

You’ll cry every time one of your best friends move, and let me tell you it never gets any easier. You’ll cry at 3AM on a Tuesday night because you’re thinking about the next year of your life and how you wish you could stay where you are. You’ll cry because you hate the girl you see in the mirror. You’ll cry because the girl who was once your best friend told you she doesn’t want to fix things between the two of you. You’ll cry when you get that math test back that you got a C- on. You’ll cry in the school bathroom because the boy you don’t talk to anymore can’t even look at you because you hurt him so badly. You’ll cry at the gum commercial that comes on before your favorite TV show airs. You’ll cry when you read through old letters your friends wrote you. You’ll cry when your best friend tells you how much she is hurting, and how she hurts herself. You’ll cry when people in crowded hallways call you a slut behind your back. You’ll cry on the plane leaving the place you love so much. You’ll cry when the boy you thought was so kind touches you even after you told him “no”, and your friends will be right there to tell him to never lay his hands on you again. You’ll cry when you are sitting in Biology and can’t remember what the difference between Eubacteria and Archaebacteria is. You’ll cry when you think about him, which is a lot considering every fucking song on your favorite playlist makes you miss him. You’ll cry in the shower, because no one can hear. You’ll cry in the hotel bathroom at prom when the boy you love asks your best friend to dance.

You will cry a lot when you get older, but the important thing to remember is that it’s ok to let yourself be vulnerable.

—  letters to myself // #1