Harmful Microorganisms: Overview, Classification, Effects

Which microorganism causes Malaria? Is it airborne? Microorganisms have evolved to survive in extreme environments over billions of years on Earth. They can be found in nearly every part of the biosphere on Earth, and new microbes are discovered all the time. Some are harmful, causing disease and illness and are considered Harmful Microorganisms.

Furthermore, some other microorganisms are beneficial to us, i.e., useful microorganisms. They play an important role in ecosystems. This article covers different harmful effects of microorganisms, modes of infections, etc. To know more about Harmful Microorganisms, scroll down the article.

What are Microorganisms?

Microorganisms are too tiny to be seen without a microscope. They may be found in the atmosphere, soil, and water, as well as in the bodies of plants and animals. Microorganisms are extremely vital in our existence. Some are useful in a variety of ways, while others are toxic and cause sickness. Some microbes may fix nitrogen from the air into the soil, therefore improving soil fertility.

Classification of Microorganisms

Microorganisms are classified into five major groups and are given through a flowchart below:

1. Bacteria are prokaryotic unicellular organisms and cause diseases like typhoid, tuberculosis, cholera, etc.
2. Fungi are eukaryotic, multicellular organisms and are saprophytic in nature. These are usually seen as bread moulds and are responsible for major spoilage of food and causes skin diseases in humans and animals.
3. Protozoans are parasitic and cause malaria, sleeping sickness, etc.
4. Algae are photosynthetic organisms and are responsible for algal blooms and responsible for water pollution.
5. Viruses are intracellular obligate parasites that require host cells to survive, and these viruses are responsible for deadly diseases such as AIDS, Corona, Syphilis, etc.

What are Harmful Microorganisms?

Some bacteria produce diseases that can be fatal. Pathogens are microorganisms that cause disease. These pathogens infect other species, causing a variety of signs and symptoms.

Fig: Harmful Microorganisms

Transmission of Infectious Diseases or Mode of Infection

Every day, we come into touch with a variety of hazardous bacteria, whether it’s when we open the door to a toilet or when we use a shopping cart. Pathogens may infect people and other creatures in a variety of ways, including:

1. In droplets from the air that we breathe: When an infected individual sneezes or coughs, the virus spreads to another person in the drops of spit or mucus.
2. In untreated and contaminated water: The disease is spread through untreated and polluted water, especially if it has come into touch with human waste. These illnesses, such as cholera and typhoid, are known as waterborne diseases and cause diarrhoea.
3. In contaminated food: Food that has been polluted: When individuals make food without properly washing and sanitising their hands, the food might get contaminated.
4. Through cuts or wounds: Cuts and wounds are a common way for germs to invade our systems. Tetanus bacteria, for example, exist in the soil and can infect someone who is injured by a piece of rusted metal.
5. Through bites from animals: Some pathogens can spread even from the bites from infected animals. For example, the rabies virus from infected animals and malaria is transmitted by mosquitoes to human beings.

Harmful Effects of Microorganisms

The harmful effects of microorganisms are as follows:

1. Pathogens can mostly cause communicable diseases. 
2. Communicable diseases are microbial infections that can transmit from an infected person to a healthy person by the air, water, food, or personal contact. Colds, chickenpox, cholera, and tuberculosis are examples of such diseases.

Fig: Communicable Diseases

3. Pathogens choose carriers in order to reach their target host. Insects, rats, sheep, pigs, and a variety of other animals serve as carriers for diseases on their way to their final host.
4. Pathogens are germs that feed on the host’s nutrients. Bacteria, Viruses, Fungi, Protozoa, Helminths, and so on.
5. Some of the diseases that are caused by microorganisms in animals are:
a. Anthrax: Anthrax is a deadly disease produced by a bacteria called Bacillus anthracis that affects humans and cattle.
b. Foot and mouth disease in Cattle: The virus that causes it is known as the Foot-and-Mouth Disease Virus (FMDV).

Fig: Foot and Mouth Disease in Cattle

6. Some of the diseases that are caused by microorganisms in plants are:
a. Citrus canker is caused by bacteria called Xanthomonas citri and spreads through Air.
b. Rust of Wheat is caused by Fungi called Puccinia triticina and spreads through Air or Seeds.
c. The Yellow Vein Mosaic of Okra (lady’s finger) is caused by Virus and spreads through Insects. A combination of the monopartite begomovirus Bhendi yellow vein mosaic virus (BYVMV, family: Geminiviridae) plus a tiny satellite DNA beta component causes this disease.

Fig: Images (a): Citrus canker; (b) Rust of Wheat; (c) Yellow Vein Mosaic of Okra

7. Disease-causing Microorganisms in Humans are:
a. Pathogens enter our bodies in a variety of ways, including through the air we breathe, the water we drink, and the food we consume. 
b. They can also be spread through animals or by direct contact with an affected person.
c. Some insects and animals can carry disease-causing microorganisms.
d. For example, a housefly is one such carrier that sits on the waste or the garbage and animal excreta. Pathogens stick to their bodies. These flies spread diseases to exposed food when they rest on it. Anyone who consumes the infected food is likely to become ill.
e. As a result, it’s best to keep the food covered at all times. The female Anopheles mosquito, which carries the malaria parasite, is another example of a carrier microorganism. Dengue virus is spread by female Aedes mosquitos.
f. AIDS is a sexually transmitted disease and is caused by the HIV virus in human beings.

Fig: Female Anopheles Mosquito

Harmful Microorganisms and their Diseases

Some of the Harmful diseases are tabulated below:

Attempt Mock Tests

Prevention of Microbial Infection

Some of the preventing measures of microbial infection are as follows:

1. When sneezing or coughing, we can avoid the transmission of illness by holding a handkerchief.
2. Antibiotics are frequently used to treat infections. Antibiotics are used to treat fungus, bacteria, and protozoa-related illnesses. Alexander Fleming discovered penicillin in 1929.
3. Many plant diseases are controlled by antibiotics, insecticides, and pesticides applied in the field.
4. Infection can be avoided by employing bacteria or fungi that generate chemicals that inhibit the development of disease-causing microorganisms.
5. Antibiotics are added into livestock and poultry feed to protect animals and birds from microbial infection.
6. The procedure of delivering vaccinations is known as vaccination. Vaccination can help to avoid diseases.
7. Vaccines are inactivated or weakened microorganisms that are injected into the body during immunisation. 
8. Antibodies are produced as a result of them. Self-protecting proteins called antibodies fight disease-carrying microbes when they enter our systems. 
9. By giving vaccination, smallpox has been entirely eradicated from the world. Several diseases, including tuberculosis, cholera and hepatitis, can be prevented by vaccination.

Summary

Microorganisms are organisms that are naked and are visible through a microscope. These microorganisms are both useful as well as harmful for humans, plants and animals. Through this article, we understood that Harmful microorganisms might contaminate our food, leather, and clothes, among other things. Another negative impact of microbes is that they cause illness in plants, animals, and humans, such as rust, anthrax and malaria, respectively. To prevent these microbial infections and the growth of microbes, the proper precautionary measures should be taken and followed.

FAQs on Harmful Microorganisms

Q.1. What are some harmful microorganisms?
Ans: Some of the harmful microorganisms are Mycobacterium tuberculosis, Xanthomonas citri, Streptococcus species, etc.

Q.2. What are 3 harmful effects that microorganisms can have?
Ans: The three harmful effects that microorganisms can have is tuberculosis, typhoid, malaria.

Q.3. Are all microorganisms harmful?
Ans: The majority of microorganisms are harmless and do not cause illness. Some parasitic microorganisms, on the other hand, can be harmful to their hosts.

Q.4. What causes malaria?
Ans: The Plasmodium parasite causes malaria. Infected mosquitoes can transmit the parasite to humans through bites.

Q.5. What are 3 diseases caused by viruses?
Ans: The three diseases that are caused by viruses are Chickenpox, Dengue and AIDS.

Study About The Structure Of Viruses

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