Microorganisms: Common bacteria, virus

Microorganisms

Microscopic organisms, commonly known as microorganisms or microbes, are found all around us and even inside our bodies. The category ‘Microbes’ includes a massive range of organisms including bacteria, Fungi, viruses, algae, archaea and protozoa. Some of these, such as bacteria and fungi, are well known, but others such as archaea much less so.

The vast majority of microbes on the earth pose no real threat to humans, Plants or animals; in fact they actually work alongside humans to make world go round, aiding decomposition, decay and even helping us to digest our food. However, there are some microorganisms which negatively impact our lives, causing illness, bad odours and damaging products and surfaces. Some of the names we regularly hear in the media are Salmonella, E.Coli, MRSA, Malaria and Bird flu.

common bacteria

The types of bacteria prevalent in an Environment are determined by several factors. However, bacteria are found in every habitable place on earth. They survive in Soil, rocks, Oceans, Volcanoes-2/”>Volcanoes, and even arctic snow. Some have been found living in or on other organisms including plants, animals, and humans. The common types of bacteria found in buildings are not harmful when in low numbers. However, just like with mold, elevated levels of bacteria particularly the gram negative type are potentially a Health hazard.Microorganisms

Some types of bacteria in buildings are brought in with occupants and with outdoor air. Others are human-gut-associated bacteria such as Lactobacillus, Staphylococcus and Clostridium. These types of bacteria are most common in bathroom environment. Research has shown that the types of bacteria in a building are also influenced by the type of ventilation, i.e., mechanically or naturally ventilated. For example, naturally ventilated buildings are associated with more plant- and soil-associated bacteria while mechanically ventilated buildings are likely to be dominated by human-associated bacteria.

Virus

Virus, an infectious agent of small size and simple composition that can multiply only in living cells of animals, plants, or bacteria. The name is from a Latin word meaning “slimy liquid” or “poison.”

The earliest indications of the biological nature of viruses came from studies in 1892 by the Russian scientist Dmitry I. Ivanovsky and in 1898 by the Dutch scientist Martinus W. Beijerinck. Beijerinck first surmised that the virus under study was a new kind of infectious agent, which he designated contagium vivum fluidum, meaning that it was a live, reproducing organism that differed from other organisms. Both of these investigators found that a disease of tobacco plants could be transmitted by an agent, later called tobacco mosaic virus, passing through a minute filter that would not allow the passage of bacteria. This virus and those subsequently isolated would not grow on an artificial medium and were not visible under the Light Microscope. In independent studies in 1915 by the British investigator Frederick W. Twort and in 1917 by the French Canadian scientist Félix H. d’Hérelle, lesions in cultures of bacteria were discovered and attributed to an agent called bacteriophage (“eater of bacteria”), now known to be viruses that specifically infect bacteria.

Microorganisms
Diagram showing different kinds of viruses illustration

The unique nature of these organisms meant that new methods and alternative models had to be developed to study and classify them. The study of viruses confined exclusively or largely to humans, however, posed the formidable problem of finding a susceptible animal host. In 1933 the British investigators Wilson Smith, Christopher H. Andrewes, and Patrick P. Laidlaw were able to transmit influenza to ferrets, and the influenza virus was subsequently adapted to mice. In 1941 the American scientist George K. Hirst found that influenza virus grown in Tissues of the chicken embryo could be detected by its capacity to agglutinate (draw together) red blood cells.

A significant advance was made by the American scientists John Enders, Thomas Weller, and Frederick Robbins, who in 1949 developed the technique of culturing cells on glass surfaces; cells could then be infected with the viruses that cause polio (poliovirus) and other diseases. (Until this time, the poliovirus could be grown only in the brains of chimpanzees or the spinal cords of monkeys.) Culturing cells on glass surfaces opened the way for diseases caused by viruses to be identified by their effects on cells (cytopathogenic effect) and by the presence of antibodies to them in the blood. Cell culture then led to the development and production of Vaccines (preparations used to elicit immunity against a disease) such as the poliovirus vaccine.

Scientists were soon able to detect the number of bacterial viruses in a culture vessel by measuring their ability to break apart (lyse) adjoining bacteria in an area of bacteria (lawn) overlaid with an inert gelatinous substance called agar—viral action that resulted in a clearing, or “plaque.” The American scientist Renato Dulbecco in 1952 applied this technique to measuring the number of animal viruses that could produce plaques in layers of adjoining animal cells overlaid with agar. In the 1940s the development of the electron microscope permitted individual virus particles to be seen for the first time, leading to the Classification of viruses and giving insight into their structure.

Advancements that have been made in chemistry, physics, and molecular biology since the 1960s have revolutionized the study of viruses. For example, electrophoresis on gel substrates gave a deeper understanding of the protein and nucleic acid composition of viruses. More-sophisticated immunologic procedures, including the use of monoclonal antibodies directed to specific antigenic sites on proteins, gave a better insight into the structure and function of viral proteins. The progress made in the physics of crystals that could be studied by X-ray diffraction provided the high resolution required to discover the basic structure of minute viruses. Applications of new knowledge about cell biology and biochemistry helped to determine how viruses use their host cells for synthesizing viral nucleic acids and proteins.

Logic originally dictated that viruses be identified on the basis of the host they infect. This is justified in many cases but not in others, and the host range and distribution of viruses are only one criterion for their classification. It is still traditional to divide viruses into three categories: those that infect animals, plants, or bacteria.

Virtually all plant viruses are transmitted by insects or other organisms (vectors) that feed on plants. The hosts of animal viruses vary from protozoans (single-celled animal organisms) to humans. Many viruses infect either invertebrate animals or vertebrates, and some infect both. Certain viruses that cause serious diseases of animals and humans are carried by arthropods. These vector-borne viruses multiply in both the invertebrate vector and the vertebrate host.

Certain viruses are limited in their host range to the various orders of vertebrates. Some viruses appear to be adapted for Growth only in ectothermic vertebrates (animals commonly referred to as cold-blooded, such as fishes and reptiles), possibly because they can reproduce only at low temperatures. Other viruses are limited in their host range to endothermic vertebrates (animals commonly referred to as warm-blooded, such as mammals).,

Bacteria

Bacteria are single-celled organisms that are found in almost every environment on Earth. They are incredibly diverse, with over 100 times as many species as plants and animals combined. Bacteria play a vital role in the environment, helping to decompose organic matter, recycle nutrients, and fix nitrogen. They are also important in human health, both beneficial and harmful.

Bacteria are classified into two domains: Eubacteria and Archaea. Eubacteria are the most common type of bacteria, and they include the familiar rod-shaped bacteria, cocci, and spiral-shaped bacteria. Archaea are less common than Eubacteria, but they are found in extreme environments such as hot springs, acidic lakes, and the deep ocean.

Bacteria are prokaryotes, which means that they do not have a nucleus or other membrane-bound organelles. Their DNA is contained in a nucleoid, which is not surrounded by a nuclear envelope. Bacteria also lack mitochondria and chloroplasts, which are organelles that are found in eukaryotic cells.

Bacteria reproduce by binary fission, which is a process in which the cell divides into two identical daughter cells. This process can occur very quickly, and some bacteria can divide every 20 minutes.

Bacteria are classified into two groups based on their shape: cocci (round or spherical), and bacilli (rod-shaped). Cocci can be arranged in pairs (diplococci), chains (streptococci), or clusters (staphylococci). Bacilli can be arranged in single file (monobacilli), in pairs (diplobacilli), or in chains (streptobacilli).

Bacteria are also classified based on their Gram stain reaction. Gram-positive bacteria have a thick cell wall that retains the purple dye used in the Gram stain procedure. Gram-negative bacteria have a thin cell wall that does not retain the purple dye.

Bacteria are found in almost every environment on Earth, including soil, water, air, and the human body. They are also found in extreme environments such as hot springs, acidic lakes, and the deep ocean.

Bacteria play a vital role in the environment. They help to decompose organic matter, recycle nutrients, and fix nitrogen. They are also important in human health, both beneficial and harmful.

Beneficial bacteria are used in the production of food, such as yogurt, cheese, and sauerkraut. They are also used in the production of antibiotics and other pharmaceuticals. Beneficial bacteria also play a role in human health by helping to maintain a healthy gut microbiota.

Harmful bacteria can cause diseases such as pneumonia, strep throat, and food poisoning. They can also cause serious infections, such as meningitis and sepsis.

Viruses

Viruses are tiny, infectious particles that can replicate only inside the living cells of other organisms. They are not considered to be living things because they do not have the ability to reproduce on their own.

Viruses are made up of a nucleic acid core surrounded by a protein coat. The nucleic acid can be either DNA or RNA, and the protein coat can be made up of one or more proteins. The size of viruses varies, but most are about 100 nanometers in diameter.

Viruses are classified into families based on their structure and the type of nucleic acid they contain. The most common types of viruses are animal viruses, bacteriophages, plant viruses, fungal viruses, viraloids, and viroids.

Animal viruses infect animals, including humans. Some animal viruses cause diseases such as the common cold, influenza, measles, and AIDS.

Bacteriophages infect bacteria. They are often used in research to study bacteria and to develop new antibiotics.

Plant viruses infect plants. Some plant viruses cause diseases such as tobacco mosaic virus and yellow fever virus.

Fungal viruses infect fungi. They are not well-studied, but they are thought to play a role in the development of fungal diseases.

Viraloids are small, non-coding RNA viruses that do not have a protein coat. They are thought to be the smallest infectious agents known.

Viroids are even smaller than viraloids. They are single-stranded RNA Molecules that do not have a protein coat. They are thought to be the smallest infectious agents known.

Viruses are transmitted in a variety of ways, including through contact with infected animals or humans, through contact with contaminated surfaces or objects, and through the bite of an infected insect.

There is no cure for viral infections. Treatment is aimed at relieving the symptoms of the infection and preventing complications.

Conclusion

Bacteria and viruses are both important groups of microorganisms. Bacteria play a vital role in the environment, while viruses can cause diseases in humans and other animals. It is important to understand the differences between these two groups of microorganisms in order to protect ourselves from

What are microorganisms?

Microorganisms are tiny living things that can only be seen with a microscope. They include bacteria, viruses, fungi, and protozoa.

What are common bacteria?

Some common bacteria include Escherichia coli (E. coli), Staphylococcus aureus, and Salmonella. E. coli is a type of bacteria that lives in the intestines of humans and other animals. It is usually harmless, but some strains can cause food poisoning. S. aureus is a type of bacteria that can cause skin infections, pneumonia, and food poisoning. Salmonella is a type of bacteria that can cause food poisoning.

What are common viruses?

Some common viruses include the common cold virus, the flu virus, and the HIV virus. The common cold virus is a virus that causes the common cold. The flu virus is a virus that causes the flu. The HIV virus is a virus that causes AIDS.

What are the benefits of microorganisms?

Microorganisms play an important role in the environment. They help to break down dead plants and animals, and they produce Oxygen. Microorganisms are also used in many industries, such as the food Industry and the pharmaceutical industry.

What are the risks of microorganisms?

Microorganisms can cause disease. Some microorganisms, such as bacteria, can cause food poisoning. Other microorganisms, such as viruses, can cause the flu. Some microorganisms, such as HIV, can cause AIDS.

How can microorganisms be prevented?

Microorganisms can be prevented by practicing good hygiene. This includes washing your hands often, cooking food properly, and avoiding contact with sick people.

How can microorganisms be treated?

Microorganisms can be treated with antibiotics, antivirals, and antifungals. Antibiotics are used to treat bacterial infections. Antivirals are used to treat viral infections. Antifungals are used to treat fungal infections.

What are the latest research findings on microorganisms?

Researchers are constantly Learning more about microorganisms. Recent research has found that microorganisms can be used to produce biofuels, clean up pollution, and fight cancer.

  1. Which of the following is not a type of microorganism?
    (A) Bacteria
    (B) Virus
    (C) Fungi
    (D) Plants

  2. Which of the following is the most common type of microorganism?
    (A) Bacteria
    (B) Virus
    (C) Fungi
    (D) Plants

  3. Bacteria are single-celled organisms that lack a nucleus.
    (A) True
    (B) False

  4. Viruses are not considered living organisms because they cannot reproduce on their own.
    (A) True
    (B) False

  5. Fungi are eukaryotic organisms that reproduce by spores.
    (A) True
    (B) False

  6. Plants are multicellular organisms that photosynthesize.
    (A) True
    (B) False

  7. Microorganisms are found in all environments, including soil, water, and air.
    (A) True
    (B) False

  8. Microorganisms play an important role in the environment by breaking down organic matter and recycling nutrients.
    (A) True
    (B) False

  9. Some microorganisms can cause disease in humans and animals.
    (A) True
    (B) False

  10. Antibiotics are used to treat diseases caused by microorganisms.
    (A) True
    (B) False