Bacteria – Infection, Transmission & Diseases
Bacteria
Bacteria occur in and on humans in large numbers. While some bacteria promote health, other bacteria can be harmful to health. Bacteria should not be confused with bacilli , a rod-shaped genus of motile bacteria.
What are bacteria?
Bacteria are microorganisms and reach an average size of 0.5 to 5 micrometers. Bacteria are unicellular and multiply by simple cell division. Unlike many living cells, bacteria do not have a nucleus.
Depending on their shape and structure, bacteria can be divided into three basic forms. These basic types include the cocci (e.g. staphylococci ), the rods (e.g. bacilli or salmonella ) and the helical bacteria. The term cocci is derived from the Greek and means something like berries or balls.
The approximate diameter of these bacteria is one micron. Bacteria called rods are rod-shaped to match their naming convention. The whorls of helical bacteria are often clearly visible under a light microscope.
Meaning & Function
In a healthy body, bacteria perform many important functions. For example, there are many types of health-promoting bacteria in the human gut. In their interaction, these bacteria form the so-called intestinal flora, which has a beneficial effect on the digestive processes. Approx. 99% of all microorganisms in the human body are found here.
There are also a large number of bacteria on human skin, which form the so-called skin flora . One of the tasks of the skin flora is to protect the skin and the organism from invading, pathogenic (disease-causing) germs. Other health-promoting bacteria are found in the small intestine, the pharynx, the oral cavity or on the mucous membrane of the female vagina.
In order for health-promoting bacteria to be able to take over their tasks without restriction, it is important that the bacterial flora of the organism is composed correctly; useful bacteria must be present in a constant and sufficient amount.
Many bacteria are able to produce enzymes or antibiotic substances that are important for humans. This property is also used in medicine. For example, drugs such as antibiotics or insulin are produced with the help of bacteria such as the so-called Escherichia coli bacteria . This is done by using the metabolism of the corresponding bacteria in a targeted manner.
Bacteria in the human body that bring neither a scientifically measurable benefit nor measurable harm are referred to as so-called commensals. Furthermore, there are bacteria in the human body that draw nutrients from the body, but can also prevent harmful bacteria from settling. These forms of bacteria are therefore called symbionts.
Diseases
Occasionally, bacteria that are actually health-promoting can also have harmful effects on the body. This is the case, for example, when bacteria leave their actual milieu in the human body and enter another milieu. For example, beneficial bacteria in the large intestine can lead to bladder infections in the urinary tract .
In addition to the beneficial bacteria, there are a variety of bacteria that damage the human body and are therefore also referred to as pathogens. The harmful influence of such bacteria comes from the so-called bacterial toxins, which are secreted by bacteria. Various toxins released by living bacteria can, for example, trigger infectious diseases such as scarlet fever , tetanus (also known as tetanus), whooping cough or diphtheria (an illness of the upper respiratory tract).
Toxins can also emanate from dying bacteria in the course of degradation. For example, a certain form of typhoid fever can be caused by salmonella (rod-shaped bacteria). Some bacteria can release toxins so powerful that they are used as biological weapons.
Depending on the form, pathogenic bacteria can be transmitted from one person to another in different ways. A possible transmission of bacteria is possible through the air, through water or through various body fluids such as saliva, urine or blood.
Bacteria are also able to mutate within a certain period of time, so that they can no longer be combated with drugs such as certain antibiotics, for example. These bacteria develop so-called resistance and therefore pose a major health threat. For the latter, read our articles: MRSA infection and ESBL infection .
Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.