All about bacteria: both good friends and dangerous enemies!

When you get a stomach ache after eating something from the store, you think, "Oh, I don't know if I got some bacteria," right? Or when a doctor says, "This is a bacterial infection," we get a little scared. When we hear the word 'bacteria', bad things like diseases and germs come to mind. But did you know that the real story is much different? In this world of bacteria, there are good friends who help us, as well as dangerous enemies who make us sick. Today, let's understand everything about these bacteria in a very simple, conversational way.

What exactly are bacteria?

Simply put, bacteria are tiny organisms made up of a single cell . They are invisible to the naked eye, and can only be seen through a microscope. We call a single bacterium a ``bacterium''.

Just think, there are trillions of bacteria everywhere in this world. In the soil, in the water, in the air, on the bodies of animals, and even inside and on your body. Yes, bacteria live everywhere, on your skin, in your mouth, inside your nostrils, in your intestines, in your urinary tract. According to scientists, we have ten times as many bacterial cells as human cells in our bodies! Amazing, right? But it's true.

Are all bacteria bad? Are there "good" bacteria?

Here's something that many people don't know. Most bacteria don't do us any harm. In fact, some bacteria are absolutely essential to our bodies. These helpful bacteria that live in our bodies are what we call "friendly bacteria" or the ``microbiome''. It's like an army of little helpers inside our bodies.

These people are mostly found on our skin and digestive system (intestines).

• Helps with digestion: Some of the foods we eat are indigestible by our bodies. These good bacteria break down those foods, digest them, and help the body absorb nutrients from them.
• Vitamins are made: Some vitamins, for example vitamin K and some B vitamins, are made by these bacteria in our intestines.
• Protects against bad bacteria: As long as we have these good bacteria in our intestines, we don't allow bad, disease-causing bacteria from outside to come in and settle easily. Just like it's difficult for a thief to enter our house while we're there.

There are a lot of these good bacteria in things like skim milk and yogurt that we eat. We also call them ``Probiotics``. These help a lot in the health of our intestines.

"Bad" bacteria that make us sick

Along with good bacteria, there are also dangerous types of bacteria that can cause us illness. We call these pathogenic bacteria , or `Pathogens`.

When these pathogenic bacteria enter our bodies, they divide and spread very quickly. As they spread, they produce toxins. These toxins cause symptoms like fever, pain, and vomiting. We call this a bacterial infection .

Imagine drinking water that has not been properly purified, or eating undercooked meat, and getting stomach upset and diarrhea. Most of the time, the cause is bacteria like `(Escherichia coli)`.

Let's look at some of the types of bad bacteria we commonly see in the table below.

Sometimes these bad bacteria can enter our bloodstream. We call this ``Septicemia'' or "blood poisoning." This is very dangerous. When these germs spread throughout the body through the bloodstream, our body's immune system goes into overdrive, causing a serious, life-threatening condition called ``Sepsis.''

How do doctors identify these types of bacteria?

When you have a bacterial infection, your doctor may prescribe an antibiotic. But not all bacteria are treated the same way. Therefore, it is important to know exactly what bacteria are causing your infection. To do this, scientists and doctors use several methods to classify bacteria.

1. Sort by shape

Bacteria have three main shapes.

• Cocci: Round in shape, like small balls.
• Rod-shaped (Bacilli): They are elongated, like small sticks.
• Spirochetes: Spiral-shaped, like a thread.

2. According to oxygen requirement

• Aerobes: These organisms need oxygen to survive.
• Anaerobes: These people do not live in places where oxygen is present. Oxygen is like poison to them.
• Facultative: These can live with or without oxygen.

3. A special test called Gram Staining

This is a very important test used in the classification of bacteria. It involves adding special chemicals (dyes) to a sample of bacteria. Depending on how the bacteria react to these dyes, they can be divided into two main groups. These are Gram-positive and Gram-negative .

Because the cell wall structure of these two types is different, they respond differently to pigments. Also, the types of antibiotics that should be given to these two types are different.

Bacteria and Viruses - What's the difference?

This is where many people get confused. Bacteria and viruses are two different things. Although both cause illness, there are big differences between the two. The most important thing is that the treatments for the two are completely different.

Antibiotics and the dangerous resistance

When we get a bacterial infection, our body's immune system fights it off. But sometimes we need outside help to win that battle. That's where antibiotics come in. These drugs work by destroying the bacteria's cell walls or damaging their DNA so that they can't reproduce.

However, we need to be very careful when using antibiotics. Because when antibiotics are used excessively or incorrectly, bacteria begin to become resistant to those drugs. This is called ``Antibiotic resistance''.

Imagine that when we keep using the same medicine, the bacteria gradually 'get used to' that medicine. It's like an enemy adapting to our weapons. Then, even if we give them the medicine, the bacteria won't die. `(MRSA - methicillin-resistant Staphylococcus aureus)` is an example of a dangerous type of bacteria that is resistant to such drugs.

A mistake that many people make in our country is to go to the pharmacy and ask for an antibiotic as soon as they have a slight fever or cold. This is a very dangerous thing to do. If you have a viral infection, that medicine will not help at all. Also, when you use these without the advice of a doctor , the bacteria can get used to these medicines, and one day when you actually have a serious bacterial infection, there may be a situation where there is no medicine to use.

Therefore,

• Only take antibiotics if prescribed by a doctor .
• Take the medicine prescribed by your doctor for the full prescribed period . Even if your symptoms improve in a couple of days, take the medicine for the full prescribed number of days. If you don't, the bacteria that haven't been completely killed can grow back in your body and become resistant to the medicine.

More surprising stories about bacteria

• How do bacteria reproduce? Most bacteria reproduce by a process called ``binary fission.'' This means that one bacterial cell divides in two, creating two new cells. This happens very quickly. That's why an infection spreads quickly.
• Plastic-eating bacteria! In 2016, a group of scientists in Japan discovered a species of bacteria that eats plastic bottles (`Ideonella sakaiensis`). Normally, bacteria eat organic matter. But this bacterium digests the chemical ``(PET)`` that makes up plastic bottles. Scientists hope that bacteria like this will one day find a solution to the world's plastic waste problem.

Bacteria, Infections, Antibiotics, Virus, Health, Gram stain, microbiome