Dealing with Harmful Microorganisms
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Harmful microorganisms
Harmful microorganisms can spoil our food, leather, clothing etc. One another harmful effect of microorganisms is that they cause diseases in plants, animals and even human beings.

Harmful microorganisms which cause disease are called as infectious agents.  These are harmful in nature and are also called as pathogens.

1) Pathogens can mostly cause communicable diseases.
       •  Communicable diseases are the diseases which are transmitted from one person to another by different modes of infection. Body fluids of the infectious person carry disease causing organisms. e.g. Discharge from nose, mouth, eyes and the faeces carry these pathogens. Healthy person coming in contact with such infected discharges develops the disease and becomes sick.

2) Pathogens select carriers to reach their particular host. Insects, rodents, sometimes even sheep, pigs and many other animals become carriers for pathogens to reach their final host.

3) Pathogens can be microorganisms which obtain nourishment from the host. e.g. Bacteria, Viruses, Fungi, Protozoa, Helminths.



Harmful effects of microorganisms
Microorganisms show many harmful effects on us. Some of them are elucidated.



Modes of infection
Infection is the transmission of pathogens from diseased individual to healthy individual.


 
Common diseases in human beings

DISEASE MICROORGANISM MODE OF TRANSMISSION
Cholera Bacteria Contaminated food and water
Typhoid Bacteria Water
Tuberculosis Bacteria Air
Polio Virus Contaminated water and air
Chickenpox Virus Contaminated air, food, water and direct contact
Measles Virus Air
Hepatitis-B Virus Contaminated water
AIDS Virus Infected needles, blood transfusion and sexual contact.
Malaria Protozoa Mosquitoes
Amoebic dysentery Protozoa Conatminated food and water


Prevention of infection
       •  We can prevent the spread of infection by using a handkerchief while sneezing or coughing.
       •  Antibiotics are widely used to control the infection. Antibiotics are used to cure a variety of diseases caused by fungi, bacteria and protozoa. Penicillin was discovered by Alexander Fleming in 1929.
       •  Antibiotics, insecticides and pesticides are sprayed in the field to control many plant diseases.
       •  Infection can be prevented by using some bacteria or fungi which produce specific chemicals to prevent the growth of microbes causing disease.
       •  Antibiotics are mixed with the feed of livestock and poultry in order to prevent microbial infection in animals and birds.
       •  Vaccination is the process of administering vaccines.  Diseases can be prevented by vaccination.
       •  During vaccination inactivated or weakened microbescalled as vaccines are introduced into the body. They trigger the production of antibodies. When disease-carrying microbes enter our body, self-protecting proteins called antibodies fight against the invader. e.g. Small pox has been completely eradicated from the world by administering vaccine. Several diseases including cholera, tuberculosis and hepatitis, can be prevented by vaccination.

Vaccine
It is a medicine which triggers the immune system to produce antibodies against a particular disease. A vaccine actually contains organisms resembling disease causing microbes whose property of virulence is suppressed or weakened.

Steps in vaccine production:



Common diseases in plants

DISEASE MICROORGANISM MODE OF TRANSMISSION
Rust of wheat Fungi Infected seeds and insects
Smut disease Fungi Infected seeds and insects
Root rot Fungi Infected seeds and insects
Brown spot Fungi Infected seeds and insects
Grain rot Bacteria Air
Bacterial blight Bacteria Air
Citrus canker Bacteria Air
Leaf rolls Virus Insect, air
Yellow vein Virus Insect, air

Summary

Harmful microorganisms
Harmful microorganisms can spoil our food, leather, clothing etc. One another harmful effect of microorganisms is that they cause diseases in plants, animals and even human beings.

Harmful microorganisms which cause disease are called as infectious agents.  These are harmful in nature and are also called as pathogens.

1) Pathogens can mostly cause communicable diseases.
       •  Communicable diseases are the diseases which are transmitted from one person to another by different modes of infection. Body fluids of the infectious person carry disease causing organisms. e.g. Discharge from nose, mouth, eyes and the faeces carry these pathogens. Healthy person coming in contact with such infected discharges develops the disease and becomes sick.

2) Pathogens select carriers to reach their particular host. Insects, rodents, sometimes even sheep, pigs and many other animals become carriers for pathogens to reach their final host.

3) Pathogens can be microorganisms which obtain nourishment from the host. e.g. Bacteria, Viruses, Fungi, Protozoa, Helminths.



Harmful effects of microorganisms
Microorganisms show many harmful effects on us. Some of them are elucidated.



Modes of infection
Infection is the transmission of pathogens from diseased individual to healthy individual.


 
Common diseases in human beings

DISEASE MICROORGANISM MODE OF TRANSMISSION
Cholera Bacteria Contaminated food and water
Typhoid Bacteria Water
Tuberculosis Bacteria Air
Polio Virus Contaminated water and air
Chickenpox Virus Contaminated air, food, water and direct contact
Measles Virus Air
Hepatitis-B Virus Contaminated water
AIDS Virus Infected needles, blood transfusion and sexual contact.
Malaria Protozoa Mosquitoes
Amoebic dysentery Protozoa Conatminated food and water


Prevention of infection
       •  We can prevent the spread of infection by using a handkerchief while sneezing or coughing.
       •  Antibiotics are widely used to control the infection. Antibiotics are used to cure a variety of diseases caused by fungi, bacteria and protozoa. Penicillin was discovered by Alexander Fleming in 1929.
       •  Antibiotics, insecticides and pesticides are sprayed in the field to control many plant diseases.
       •  Infection can be prevented by using some bacteria or fungi which produce specific chemicals to prevent the growth of microbes causing disease.
       •  Antibiotics are mixed with the feed of livestock and poultry in order to prevent microbial infection in animals and birds.
       •  Vaccination is the process of administering vaccines.  Diseases can be prevented by vaccination.
       •  During vaccination inactivated or weakened microbescalled as vaccines are introduced into the body. They trigger the production of antibodies. When disease-carrying microbes enter our body, self-protecting proteins called antibodies fight against the invader. e.g. Small pox has been completely eradicated from the world by administering vaccine. Several diseases including cholera, tuberculosis and hepatitis, can be prevented by vaccination.

Vaccine
It is a medicine which triggers the immune system to produce antibodies against a particular disease. A vaccine actually contains organisms resembling disease causing microbes whose property of virulence is suppressed or weakened.

Steps in vaccine production:



Common diseases in plants

DISEASE MICROORGANISM MODE OF TRANSMISSION
Rust of wheat Fungi Infected seeds and insects
Smut disease Fungi Infected seeds and insects
Root rot Fungi Infected seeds and insects
Brown spot Fungi Infected seeds and insects
Grain rot Bacteria Air
Bacterial blight Bacteria Air
Citrus canker Bacteria Air
Leaf rolls Virus Insect, air
Yellow vein Virus Insect, air

Videos

Activities

Activity 1
Softschools.com has created an interactive activity with a name 'Word Scramble'. Student has to click on 'Start button' and follow instructions. Just clicking on start will allow the user to visualise the scrambled word. Just using the mouse, student has to rearrange the letters and form a meaningful word. Student will also be given score if he does the work within the alloted time. student has to rearrange the letters and click on ' Submit' button Finally student can view his score.  
Go to Activity

Activity 2
Manchester.ac.uk has created an interactive module which allows the student to match the pairs by clicking on the cards displayed. Cards have a printed picture on its back. By just clicking on the card, the picture is unravelled. User has to click and match the cards which have the same picture in the allotted time. The template also provides information about various microorganisms on the side pane of the screen.
Go to Activity

References

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