Scientists Decipher Cholera Microbe Makeup

Aug. 2 -- Researchers have deciphered the genetic makeup of one ofhumanity’s oldest, deadliest and hardiest adversaries — the choleramicrobe.

Scientists say the research may help spur new vaccines or drugsto treat cholera, one of the most efficient killers of alldiseases.

“This will be the starting point for most future studies,”said microbiologist Matthew Waldor of Tufts Medical School inBoston. He co-wrote an accompanying commentary on the research,which was being published Thursday in the journal Nature.

Researchers at The Institute for Genomic Research in Rockville,Md., led the study team that successfully analyzed the entiregenetic structure of the bacterium Vibrio cholerae.

They found that the germ carries two chromosomes with a total of3,885 genes. They are formed from about 4 million chemical buildingblocks known as base pairs.

The researchers identified the genes by chemically breaking upstrands of the germ’s DNA. They analyzed the fragments separatelyand later figured out how to reassemble them in order. Similartechniques have been used to identify the genes of other diseasemicrobes and humans.

A 2,000-Year-Old Disease

Cholera, which has afflicted humans for more than 2,000 years,is largely eradicated from the United States and other industrialnations. Yet epidemics still plague parts of Asia, Africa and LatinAmerica, where water supplies are often contaminated. More than220,000 cases were reported to the World Health Organization lastyear, with over 8,400 deaths. Tens of thousands have died in someepidemic years.

The bacterium, which can live in brackish water and estuaries,attacks the intestine of humans and can cause death by severedehydration.

Claire Fraser, director of the institute, said the knowledge ofcholera’s genes is most likely useful in developing vaccines. Theynow exist but confer immunity only for several months.

Fraser added, though, that even knowing the genetic makeup, itis an “unrealistic goal” to wipe out cholera.