Question

Bacteria can be both useful and harmful. Explain.

Answer 1

Hint: Bacteria or germs are present everywhere, both inside and outside the human body. They may be helpful as rhizobium helps in fixing nitrogen from the soil or harmful as E.coli which causes food poisoning.

Complete answer:
The bacteria are single-celled microscopic organisms that can live in a variety of environments, i.e, hot water, or even ice. They are the simplest form of organisms that constitute a large domain of prokaryotic microorganisms.

Useful bacteria:
Any bacteria that are beneficial to the human body are defined as good or useful bacteria. They are both naturally present and man-installed. For example, many of the useful bacteria reside in our gut and help us in breaking down food and absorbing nutrients. One such bacteria is probiotics.
Other examples of good or useful bacteria are:
-A bacteria Rhizobium found in the soil supplies ammonia to the plants, which is essential for the growth of the plants.
-Streptomyces-The prescription antibiotics that are used to treat bacterial infections are produced using Streptomyces. They are also used to produce antifungal agents and associated medicines, namely – immunosuppressants which are remedial measures prescribed by doctors for certain autoimmune diseases.
-Lactobacillus acidophilus- It converts milk into curd and is usually found residing in the human small intestine.
-Pseudomonas putida, Dechloromonas aromatica, Deinococcus radiodurans - these specific bacteria help in bioremediation.
-Human insulin is produced in the lab from common bacteria. The bacterium Escherichia coli is by far the most widely used.

Harmful bacteria:
A bacteria which causes the infection is called a pathogenic or harmful bacteria. They come from external influences such as food, environmental toxins, or even stress. They are responsible for many infectious diseases like pneumonia, tuberculosis, diphtheria, syphilis, tooth decay. Their effects can be rectified by taking antibiotics and prescribed medication. Some of the examples of harmful bacteria are:
-E.coli can cause serious illness, severe food poisoning, as well as meningitis, and infections can be caused by E.coli.
-Neisseria gonorrhoeae cause gonorrhea. It spreads through sexual contact and causes various infections in both men and women.
-Tuberculosis, caused by Mycobacterium tuberculosis bacteria has been known by many names including scrofula and the White Plague,
-Some strains of one of the better known ‘superbugs’ because of a consistent presence in hospitals around the world, spread a type of diarrhea that can lead to complications in the colon.

Note:
-Some strains of bacteria, viruses, parasites, and fungi were called superbugs because they have developed a resistant mechanism in their body against most of the antibiotics and other medications commonly used to treat the infections they cause.
-Superbug’ is more commonly known as MRSA (which stands for Methicillin-resistant Staphylococcus aureus) can spread very easily through human contact and can cause a range of illnesses from skin disorders to deadly diseases like meningitis and pneumonia.