We know that our common cold is caused by at least 200 different viruses. Rhino virus, Resp virus, ( RSV) Flu, Ortho myxo, Paramyxo, Coronavirus and so on. Up till now, We have no tecnology to identify them. So we have used the omnibasket term: Viral fever.
After the Covid-19, a new age is going to dawn and each viral fever is going have its own name.
Our immune system.
Humans have a complicated immunity mechanism. We have the B lymphocytes, T lymphocytes, Phagocytes, Killer cells, NK cells and so on.
When ever a threat enters us ( E Coli enters into our kidney) the white cells intercept it at the border check post, imprison it ( swallow it) then drive it to the immunity court. We have special courts for their trial. The Thymus, Spleen. The culprit is photographed and a copy of this handed over to all concerned.
Next time when the culprit is picked up, the B cells already sensitised, would readily spray them with thousand antibodies. The T cells recruit a special force to capture them.
Our body has a trillion cells. We have the luxury to depute few million for our national security.
What about the mono cellular bacteria ?. How do they protect themselves against such threats.
…
The immune system of single cell bacteria is probably billion years old. It is known as the CRISPR -CAS system.
• Bacteria and Viruses are there for 2.5 billion years.
• We humans appeared on this earth 5 million years ago and joined them.
• There are over 380 trillion viruses in our body.
Procreation and protection of Sovereignty of bacterium.
We know that a bacterium is a complete cell equipped with all logistics to divide and multiply. It has a nucleus, it has its own book of codes ( DNA and RNA) to produce two daughter cells.
This is not in case of the virus. It is a nomad. It has got only one strand of DNA or RNA ( book of code) inside an envelope. So how does it multiply ?
..
It invades a bacteria, takes over its logistic, uses them to make a thousand copies. Then the bacterial cell bursts and thousand viruses are released to invade another thousand bacteria. That is definitely a breach of sovereignty of bacteria.
This is going on for billion years.
How do the bacteria counter it ?
Evolution has endowed them with a system called CRISPR. A Bacterium when experiences a threat, it takes a photo copy of virus gene and includes it in its own gene. This is the essence of CRISPR system.
Rouge Gallery
Thus when a bacterium has encountered 600 viruses, it will have copied 600 sequences into its own gene in a reverse order. These are the *Clusters of Short Palindromic Repeats* found in the gene of a bacterium.
This is so accurate that it can pickup a single copy of Viral RNA from a solution and label it.
Advantage CRISPR:
Sensitivity:
Viruses are nano particles. Inside a PCR machine we have to multiply them billion times to muster a signal.
But a CRISPR can pick up the single rogue RNA of Covid when there are only 100 copies around.
Specificity:
CRISPR is nature’s billion years old search engine. Bacteria are using it to detect single threat. It is going to be highly specific. The way our genes are being transmitted truly over generations.
In your Drawing room.
CRISPR -CAS won’t require the massive thermal cycler machine used in PCR. It is a paper dot test like the pregnancy test. It can be developed to a self test for any virus in future.
Cost and Time factor
Today it’s costing Rs 500 and 20 minutes time. In future its going to be further affordable.
Every cloud has a silver lining.
After Antonie van Leeuwenhoek invented the microscope, we have been extremely successful in identifying individual bacteria, malaria, filaria and worms in a sample. We can see them under a microscope, label them and do a culture sensitivity test to choose an appropriate antibiotics. This facility is now universally available.
But viruses cannot be seen in our lab microscope. They need the sophisticated PCR machine to multiply billion times before getting detected. Very few countries can afford them.
For example,we know that our common cold is caused by at least 200 different viruses. Rhino virus, Resp virus, ( RSV) Flu, Ortho myxo, Paramyxo, Coronavirus and so on. Up till now, We have no tecnology to identify them. So we have used the omnibasket term: Viral fever.
After the Covid-19, a new age is going to dawn and each viral fever is going have its own name. In no time, we shall have effective drugs against each individual virus.
The golden age of Penicillin is passe. Let us welcome a new era of one to one antiviral drugs.
Thanks to Covid-19
Dr Ramakanta's Ideas 