microbiosciences.com

The Pandemic H1N1

admin — Sat, 06 Mar 2010 12:08:45 +0000

H1N1, influenza A virus type has been in the news for a long time and it seems as if it is here to stay, because a column in the newspapers still reads the death toll due to this fatal virus. It is most commonly called the Swine Flu. Why is it called the Swine Flu? If the name suggests the natural host of the virus is the Swine, then how are we human beings being affected the most? Why the term pandemic associated with it? The World Health Organization has termed H1N1 pandemic.

What is Pandemic?

The word Pandemic is derived from the Latin word ‘pandemos’, meaning of the people. In other words, it means that it is an epidemic spread over a wide geographical area affecting a large proportion of the population. Epidemics in contrast involve a very small community or a single state or a single village or even as small as a single family.

The WHO has declared the Swine Flu as a pandemic as it has spread over several continents having originated in Mexico. India is one of the countries that have been affected with about 1060 deaths and Gujarat alone has about 250 deaths (Report by Press Trust of India, 7 Feb. 2010) registered due to this deadly virus.

Why is it called Swine Flu?

H1N1 is a swine influenza virus (SIV) endemic in pigs. SIVs are of Influenza C type and some subtypes of Influenza A virus which includes H1N1, H1N2, H3N1, H3N2 and H2N3. Pigs are the natural hosts for these viruses throughout the world and it is very rare that such viruses are transmitted to humans. When transmitted to humans causing influenza, it is called zoonotic (transmission from non-human to human) swine flu. However, there are chances that people frequently exposed to pigs may get infected. Pork eating population may be susceptible but only if it is not cooked properly (J Midwifery Womens Health. 2009; 54(6):517-518. © 2009 Elsevier Science, Inc.).

The ability of viruses to change their hosts is attributed to genetic changes. This is also known as antigenic shift. The flu strain could have originally been present in a bird or a duck or any aquatic animal, which then shifted to a chicken, then to a pig and then finally to a human. This transmission from one host to the other host would have been possible only because of changes in the genetic make up. This is how presumably the swine flu must have infected the humans (Reported by National Institute of Allergy and Infectious Diseases (NIAID). Researchers found that the virus was derived from several viruses circulating in swine, and that the initial transmission to humans occurred several months before recognition of the outbreak (Smith GJ, et al. Origins and evolutionary genomics of the 2009 swine-origin H1N1 influenza A epidemic. Nature. 2009 Jun 25;459(7250):1122-5).

Symptoms of zoonotic swine flu in humans are similar to those of influenza and of influenza-like illness in general, namely chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort. The recommended time of isolation is about five days.

Treatment of Swine Flu

The best treatment for H1N1 is vaccination. The first vaccine introduced in October 2009 was a nasal spray vaccine and contains live attenuated viruses. Attenuated viruses are viruses that are living but with weak virulence and hence not able to cause the disease. However, there is always a risk of its reverting back to its virulent form and hence should not be given to pregnant, immunocompromised and elderly people.

Two antiviral agents have been reported to help prevent or reduce the effects of swine flu. They are Relenza and Tamiflu, both of which are also used to prevent or reduce influenza A and B symptoms. Latest research by scientists at UTAH State University (Funded by NAID) also suggested that a combination of two drugs could be effective in treating Swine Flu. The research was carried out on mouse model and the results suggest that the combined drug treatment is better than an individual drug treatment.

Some important events in the development of microbiology.

admin — Wed, 13 Jan 2010 08:04:32 +0000

Year	Scientists	Discovery(s)
1590-1608	Jansen	Develops first useful microscope.
1676	Antony van Leeuwenhoek	1^st to observe and accurately record and report microorganisms.
1688	Francesco Redi	Publishes work on spontaneous generation of maggots.
1786	Miller	Proposes 1^st classification of bacteria.
1798	Edward Jenner	Introduces cowpox vaccination for small pox.
1838-1839	Schwann and Schleiden	Proposed the cell theory.
1809-1885	Jacob Henle	Establishes principles for germ theory of disease
1822-1895	Louis Pasteur	Establishes germ theory of disease and germ theory of fermentation, developed immunization techniques.
1827-1912	Joseph Lister	Developed aseptic techniques for isolation of bacteria in pure culture.
1850-1934	Fanny Hesse	Suggested use of agar as a solidifying material for microbial media.
1843-1910	Robert Koch	Develops pure culture technique and Koch’s postulates. Discovered causative agents of anthrax and tuberculosis and rabies vaccine.
1853-1933	Hans Christian Gram	Gram staining method.
1863	Mendel	Discovers laws of genetics.
1887-1890	Sergei Winogradsky	Nitrogen fixing bacteria in soil.
1887	Richard Petri	Developed petri plate.
1889-1901	Martinus Beijrinck	Concept of a virus, enrichment culture method.
1902	Landsteiner	Discovers blood groups.
1908	Paul Ehrlich	Chemotherapeutic agents.
1923		1^st edition of Bergey’s Manual of Systematic Bacteriology.
1928	Griffith	Discovers bacterial transformation.
1929	Alexander Fleming	Discovery of penicillin.
1944	Selman Waksman	Discovery of streptomycin.
1946	Lederberg and Tatum	Describe bacterial conjugation.
1952	Zinder and Lederberg	Discover generalized transduction.
1953	Watson and Crick	Proposed the double helix structure of DNA.
1959	Rodney Porter	Immunoglobulin structure.
1959	F. Macfarlane Burnet	Clonal selection theory.
1961	Jacob and Monod	Proposed the operon model of gene regulation.
1970	Arber and Smith	Discovery of restriction endonuclease.
1972	Cohen and Boyer	Develop recombinant DNA technology.
1975	Georges Kohler and Cesar Milstein	Monoclonal Antibodies.
1977	Gilbert and sanger	Develop technique for DNA sequencing.
1983-1984	Kary Mullis	Developthe Polymerase Chain Reaction.
1982		Genbank database established.
1983	Luc Montagnier	Discovery of HIV, the cause of AIDS.
1996		Dolly- the sheep was cloned.

When was this science of microbes started?

admin — Wed, 13 Jan 2010 08:02:58 +0000

The science of microbes started when people learnt to grind glass and make lenses of different thickness out of them. We developed the curiosity to see through them. This gave us the amazing power to see beyond the limits of our vision. It was then we realized that our world was inhabited with a near infinite number and varieties of microorganisms. They were found everywhere, in rain water poodles and tooth scum, in vinegar and alcohols. Microorganisms were revealed from a variety of specimens. Initially these observations were a great source of curiosity. During the period from 1600 to 1800, considerable information accumulated about the occurrence of these microscopic forms of life. Great debates emerged as the origin of these microbes.

Are all the diseases in this world caused by microbes?

admin — Wed, 13 Jan 2010 08:00:38 +0000

There are many diseases that are caused by microbes but not all diseases are caused by them, for example diseases like malaria, typhoid, cholera and AIDS are caused by microbes but diseases like diabetes, hypertension and many cancers are not caused by them at all.

Are they friends or foes?

admin — Wed, 13 Jan 2010 06:57:43 +0000

The interaction of microbes within nature, with humans and other animals makes them our friends or foes. Some of microbes are friends and some are foes, Microbes that are friendly perform some of the most important activities that make life possible on this earth, like the nitrogen fixation taking place in the soil that makes it available for the growth of the plants. Some are able to degrade complex substances into simple nutrients thus making them available for plant nutrition, some microbes are used for the making of curd, cheese and production of antibiotics and vaccines. Some activities of microbes make them our foes, like their growth in human, plant or animal body and damage to the body that is called disease. Some microbes produce chemical substances like acids that damage materials like metal pipes, fabric and wood. This called as biodeterioration. Also the microbes that are friendly may become nuisance if they get displaced from their habitats. But the usefulness of microbes outweighs the damage caused by them.

What is Microbiology?

admin — Wed, 13 Jan 2010 06:40:00 +0000

Microbiology is the field of biology that deals with micro organisms.

Study of micro organisms is Microbiology.

It is the study of living organisms of microscopic size. It is the study of organisms that are usually too small to be seen by the unaided eye. The microorganisms include bacteria, fungi, algae, protozoa, and the viruses.

To observe, study, and understand them microscopes are required. The study of microbes was possible with the invention of microscopes.

To understand how they live, grow, reproduce and their role in the nature. It is concerned with their form, structure, reproduction, physiology, metabolism and classification.

It includes the study of their distribution in nature, their relationship to each other and to other living organisms, their effects on human beings and on other animals and plants, their abilities to make physical and chemical changes in our environment, and their reactions to physical and chemical agents.