Bangladeshi scientists discover how harmless viruses turn into deadly ones
A group of Bangladeshi scientists made a breakthrough discovery of how a group of viruses can turn harmless bacteria into deadly cholera causing ones.
The finding will have far-reaching global implications in predicting cholera epidemic, and will make it easier to produce preventive vaccine, the chief of the group claimed.
Dr Shah M Faruque, head of molecular genetics at ICDDR,B (the International Centre for Diarrhoeal Disease Research, Bangladesh) and his research team recently discovered how otherwise harmless vibrio cholerae bacteria turn pathogenic, causing cholera.
“We have discovered the sequences,” said Dr Faruque.
Thousands of vibrio cholerae float in any kind of normal surface water.
“It does not mean we are going to be infected, if we just drink the water. It needs a total of five viruses to infect the bacterium that will cause cholera,” he said.
In 1996, a group of scientists led by John Mekalanos of Harvard Medical School in Boston found a virus called toxin CTX bacteriophage, which infects vibrio cholerae bacteria and make it cause the disease cholera.
“But none knew how and when it infects the bacteria. Now we know that,” Dr Faruque said.
“We discovered and characterised the TLC phage which changes, albeit slightly, the chromosomal sequence of the cholera bacterium,” he added.
“The subtle change in bacteria enables an incoming toxigenic CTX virus to be incorporated. Eventually a harmless strain of vibrio cholerae transforms into a dangerous killer,” Dr Faruque told The Daily Star yesterday.
“Although some of these mechanisms have already been known, our work advances the understanding,” he said.
The research was conducted in collaboration with Dr John Mekalanos, and was published yesterday in the Nature, the internationally reputed science magazine.
World Health Organisation (WHO) estimates that cholera kills more than 1,00,000 people, mainly children, every year, and infects over a million in poor countries in Africa and Asia.
Scientists say around 70 percent cholera patients would die if proper medication were not provided.
Recently many died in flood-hit Pakistan due to cholera. Some sub-Saharan African countries also have prevalence of the disease.
Bangladesh is comparatively safer from cholera due to continual intervention.
