Microorganisms friend and foe

Introduction :-

The organisms that cannot be seen with the naked eyes and can be viewed only under the microscope are called microorganisms or microbes. Microbes are diverse and include bacteria, fungi, protozoa and some algae. Viruses are also microscopic but they are generally considered as non-living. They reproduce only inside a host cell, which can be bacteria, plants or animals. There are some microorganisms that are unicellular, that is, they are made up of only one cell, for example, bacteria, whereas there are some microorganisms that are made up of more than once cells and are called multicellular microorganisms, for example, moulds.

Microorganisms are broadly divided into four groups: algae, bacteria, fungi and protozoa.Microorganisms could be found anywhere in the biosphere, that is, in soil,oceans, air, hot springs, deserts, etc. They are even present inside the body of animals. The study of microorganisms is termed as microbiology. Depending upon their effects on human health, are two types of microbes, namely useful 

or harmful.

Useful microorganisms :- There are many microorganisms that are beneficial to human beings. Some of the examples based on their uses are given below.

Microorganisms in Food Industry :-

Microorganisms are widely used for the production of curd, bread, alcohol, etc. Curd contains bacteria called Lactobacillus that convert milk into curd. Yeast can be used in the baking industry for making breads, pastries, cakes, etc. Yeast can also be used in the large-scale production of alcohol, wine, vinegar (acetic acid), etc. The basis of using yeast in wine production is fermentation. Fermentation is the process of converting sugar into alcohol.

Microorganisms in Medicinal Industry :- 

Microorganisms are used to make antibiotics. These antibiotics are used to kill or stop the growth 

of other disease-causing microorganisms. A simple example is penicillin. Penicillin can be 

obtained from the fungus Penicillium. These antibiotics can be used to cure many diseases that are caused by microorganisms, (except viral diseases). Microorganisms can also be used in the production of vaccine. A vaccine is a biological preparation that consists of either dead or weakenedmicrobes. When a vaccine is introduced into the body, the body produces antibodies against the vaccine, which remains in the body and protects the body from attack by the same microbe in the future. The common examples are rabies and tuberculosis vaccines.

Sir Alexander Fleming was the person who introduced to the world, the greatest discovery of that time, the antibiotic ‘Penicillin’. It saved the lives of thousands of soldiers during the second world war. He was awarded the Nobel Prize in Physiology or Medicine along with Florey and Chain in the year 1945. Florey and Chain developed processes to produce penicillin in sufficient quantites to become widely available.

Microorganisms in Agricultural Practices :- 

Microorganisms act as decomposers in the soil that decompose the dead plant and animal wastes. Decomposition releases organic nutrients to the soil that can be again used up by plants. Microbes increase soil fertility by fixing atmospheric nitrogen, for example, Rhizobium. This microbe lives in root nodules of leguminous plants and increases the nitrogen content in the soil.

Microorganisms in Commercial Industries :

There are many microbes that are used in the manufacturing or processing of various products used commercially. For example, there are certain bacteria that are used to manufacture linen. Red algae produces ‘Algin’ that is used for thickening cosmetics and food products like jelly. Red algae also produces ‘Agar’ that is used as a solidifying agent in microbial research at a large scale.

Harmful Microorganisms :-

 Besides their several uses, microorganisms also cause some harmful effects on other living organisms. Microorganisms cause a number of diseases in humans, animals and plants. The microorganisms that cause diseases are called pathogens. The most common are viruses that cause common cold. Microorganisms also cause food spoilage and damage to clothes, leather, etc.

Human Health and Immunity :-

 Health may be referred to as the well being of an individual in all aspects, that is, physically, mentally and socially. While immunity is the ability of a person to resist infections and remain disease free.

Immunity are of two types:

1. Innate immunity:

Inborn immunity or immunity that is inherited from parents, for example, skin (prevents entry of foreign invaders).

2. Acquired immunity:

Immunity acquired after birth is called acquired immunity or adaptive immunity, for example, Immunity to chickenpox.

Immune System

Human immune system is composed of a network of cells, tissues, organs that function together to defend us against infectious microbes (bacteria, virus, etc.). The coordinated response of the immune system towards any foreign particles is known as immune response. The white blood cells and the various lymphatic organs constitute the components of immune system.

Components of Immune System :

The immune system forms the first line of defense against foreign particles which seek entry inside our body. Skin is the first barrier of the immune system which prevents entry of disease causing microorganisms (pathogens). Upon gaining entry inside a living body, the pathogens are encountered with various blood cells which specialize in neutralizing and killing pathogens. These are discussed below in detail :

White Blood Cells :

Lymphocytes, monocytes, macrophages, neutrophils, eosinophils and basophils all come under white blood cells and provide immunity to the body against infectious diseases and foreign invaders.

Organs :

Thymus and bone marrow are the primary lymphoid organs where development of lymphocytes 

take place whereas spleen, tonsils, lymph vessels and lymph nodes are the secondary lymphoid organs where immune responses are initiated.

Working of Immune System : Our immune system must be able to differentiate self from non-self. It does so by detecting certain molecules like proteins that are found on the surface of all cells. It guides itself to ignore its own or self-proteins at an early stage. An immunogen is a substance that can initiate an immune response. In many cases, an immunogen is a bacterium, fungus, virus or toxin.

Human Diseases : 

Disease can be referred to as the state of disturbed ease, or being uncomfortable.Disease affects the proper functioning or structure of body organs or systems. The changes in the body due to diseases give rise to certain signs and symptoms.

Type of Diseases : 

According to the duration of diseases, they can be divided into two types, that is, acute and chronic. An acute disease is the one in which the symptoms appear suddenly, worsen rapidly and then disappear as it heals, example, flu or common cold. Whereas a chronic disease is the one which develops gradually and worsens over a long period of time, example, chronic back pain.According to whether or not caused by microorganisms, diseases are of two types:

1. Infectious

2. Non-infectious

Infectious Diseases : 

Following are the characteristics of infectious diseases:

• Infectious diseases are caused by pathogens, such as bacteria, viruses, fungi and protozoa, like chicken-pox, TB, etc.

• Multicellular organisms like worms can also cause infectious diseases like filariasis. 

• Diseases that can spread from one person to another are called communicable 

diseases. 

• Diseases that spread through air, water, food, physical contact with patient, sexual contact, aerosols (sneeze or cough droplets, etc.) also come under infectious diseases.

Non-infectious Diseases :- 

Diseases that are not caused by microorganisms or infectious agents are called non-infectious diseases. Some of the examples, are:

Genetic diseases:

Caused due to abnormalities in DNA, for example, cancer, cystic fibrosis, sickle cell anemia etc

Lifestyle diseases: Some diseases can be caused by lifestyle habits, like overeating, under eating, lack of exercise, etc., for example, obesity, nutrient deficiency diseases, high blood pressure, etc.

Drug and Alcohol Abuse :-

Abuse of drug and alcohol can have serious consequences on human health. Nowadays, drug abuse is very common among teenagers who later on get addicted to it.

Smoking:

Tobacco is mainly used for smoking and inhaling, tobacco smoke can cause diseases of heart; lungs, etc.

Alcohol abuse: Excessive alcohol consumption is called alcohol abuse. It can have many ill effects on human health, such as nutrient deficiency, liver diseases, fertility problems, etc.

Ways to Maintain Proper Health

‘Health is wealth’, hence maintaining proper health is very essential. Some of the measures that can be taken to maintain proper health are:

• Healthy food habits: 

* Eat nutrient-rich food or balanced diet. 

* Avoid junk foods.

* Include more vegetables, fruits into      the diet.

*  Have food that is properly.

• Proper exercise:

Exercising regularly in any form lowers the risk of various diseases. It also helps to maintain an active metabolism.

• Avoid drug and alcohol abuse: Intake of drugs and excessive consumption of alcohol may lead to adverse health effects, such as liver damage, kidney diseases, neural diseases, etc.

• Maintain personal and public hygiene :

~ Always keep personal hygiene

~ Drink boiled water

~ Do not leave food uncovered.

~ Keep the surroundings clean.

~ Proper waste disposal.

• Control of disease spreading :

~ Diseases spread by mosquitoes can be controlled by avoiding water stagnation, using mosquito nets, repellents, etc. 

~ Diseases spread by droplets from sneezing or cough can be prevented by using towels to mask nose while sneezing. 

~ Avoid breeding of flies.

POINTS TO REMEMBER

• The organisms which are too small to be seen by naked eye and are visible only through microscopes are called microorganisms.

• The study of microorganisms is termed as microbiology.

• Microorganisms are widely used for the production of curd, bread, alcohol, antibiotics, etc.

• Microorganisms can also be harmful and cause a number of diseases in humans, animals and plants.

• Health is referred to as the well being of an individual in all aspects, that is, physically, mentally and socially.

• Immunity is the ability of an individual to resist diseases.

• The coordinated response of the immune system towards any foreign particles is known as an immune response.

• Diseases that can spread from one person to another are called communicable diseases, example common cold.

• Diseases that do not spread from one person to another are called non-communicable diseases, for example, diabetes.

• Health can be maintained by following some good habits, such as eating nutrient-rich food 

or balanced diet, avoiding junk foods, including more vegetables and fruits into the diet and 

exercise.