Bacteria – a colourful world under the microscope 15th January 2024 – Tags:

With the development of medicine, we began to look more and more closely at the factors causing all kinds of diseases. Using the microscope, we were able to see colonies of colorful objects in many different shapes. After much research, scientists named them bacteria, which we will learn more about in today’s article. How are bacteria structured and what diseases do they cause?

The structure of a bacterial cell

Unlike the cells that make up our body, bacterial cells have a structure typical of a prokaryotic cell. They differ from eukaryotic cells in many features typical of this type of cell. The most important feature differentiating both types is the presence of genetic material in the bacterial cell. Well, it is not located in the cell nucleus, but is contained in the cytoplasm – in this case we call it a nucleoid. Additionally, bacterial cells have a characteristic cell wall made of murein. Based on the arrangement of membranes and cell walls, we can divide bacteria into Gram positive and Gram negative. Bacteria often also have special legs called cilia, which enable them to move nimbly around the body. An additional interesting fact is that the genetic material in bacteria is in a spherical form, which in animal cells occurs only in mitochondria.

Prokaryote cell diagram bacteria
In the diagram we can see individual organelles and structures of the bacterial cell. We can see that many of them also occur in eukaryotic cells.

The most common bacterial diseases:

  • Sepsis – caused by large numbers of rapidly multiplying bacteria
  • Pneumonia – caused by Streptococcus pneumoniae
  • Urinary tract infections – most often caused by the Escherichia coli bacteria
  • Meningitis – can occur through both viral and fungal infection, but bacterial is the most common
  • Tuberculosis – is a disease caused by the bacterium Mycobacterium tuberculosis
  • Diarrhea – its most common cause is infection with the E. coli bacteria

How to recognize a bacterial infection?

There are several routes of infection with bacteria that cause bacterial infections. The most common are through droplets, direct contact with a sick person, contact with infected food or water, and through insects. The most common symptoms of a bacterial infection are:

  • Fever
  • Chills
  • Weakness
  • Headache

Additionally, we can also notice:

  • Skin changes – redness, swelling, ulcers
  • Symptoms in the digestive system – diarrhea, abdominal pain, nausea and vomiting
  • Changes in the lungs – cough, shortness of breath, chest pain and phlegm
  • Changes in the urogenital system – pain when urinating, secretions from the reproductive organs, increased urine output and pain during intercourse

If you notice any disturbing symptoms, contact your family doctor, who will then prescribe appropriate medications and plan therapy. Most often, bacterial infections are treated with antibiotics administered orally.

Bacterial infections and involved species
The image shows numerous bacterial infections occurring in the human body, highlighting the bacteria that cause them
A common symptom of a bacterial infection is fever. In the photo we see the temperature measured with a thermometer.

Bacterial culture:

In order to obtain pure bacterial cultures, which can then be used in microbiological tests, bacterial cultures are performed. They involve taking a small sample of a bacterial colony and covering it on a plate with an appropriate medium. Inoculation is performed by linearly covering the substrate. After inoculation, the plates are closed and left in appropriate conditions to obtain newly formed, clean, isolated bacterial colonies.

The photo shows the isolation of bacteria by culture.
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