DEP Press Advisory on Deer Hunting Cancellation, October 2, 2001

NYC 9/11 Public Portal Document

The bacterium prefers to live in DNA Map rats and spreads by hitching rides on rat fleas. But when rats are scarce, gut and. presumably, reflect the plague bacterium’s ancestral style the rat fleas will bite people. Among of life before it moved from gut to For Bacterium people, plague can spread via human fleas, a different variety, or directly blood. Dr. Brendan Wren, who stud­ ies gut-infecting bacteria at the Lon­ on exhaled droplets. don School of Hygiene and Tropical OfPlague . Once in the human bloodstream. the bacteria infect and swell the lymph nodes, a condition called bu­ Medicine, said the inactive genes provided a useful list of what a bacte­ rium requires to colonize the gut. Is Decoded bonic plague. When the bacteria spread to the lungs the disease is called pneumonic plague and is By NICHOLAS WADE swiftly fatal. Biologists have decoded the full To be sure of decoding a variety DNA, or genome, of the bacterium that can spread by direct inhalation, that causes plague, a disease that the research team used a sample has caused three world epidemics in from a Colorado veterinarian who recorded history and killed some 200 died in 1992 after an infected cat had million people. sneezed on him while he was trying The decoding of the genome is to rescue it from beneath a house. widely expected to help devise better With the genome in hand, vaccine vaccines against the bacterium, designers can pick out particular which is endemic in some parts of genes like those that specify the pro­ the world, including the western teins of bacterium’s coat as promis­ United States. Plague is also a possi­ ing targets for a vaccine. ble agent of biological warfare, be­ “Having the complete genome cause the bacterium, when caught by means you’re not reduced to scrab­ inhalation, is almost always fatal bling around,’’ Dr. Julian Parkhill of within days. the Sanger Center said. “You can go The genome was decoded by scien­ into the genome and select candi­ dates.” tists at the Sanger Center near Cam­ Reflecting a possible use in biologi­ bridge, England, who describe their cal warfare, the team included Dr. work in the issue of Nature released Rick Titball, an expert from Brit- today. Decodingqs the spelling out of ain’s biological warfare-establish­ the sequence of units in DNA. the ment at Porton Down. Dr. Titball chemical that encodes an organism’s said he saw no danger in publishing genetic information. the bacterium’s genome. The likeli­ From the genome, the biologists hood of using the genome to design a have been able to identify many of worse pathogen was small, he said. the genes that underlie the bacter­ because nature had already designed ium’s complex life cycle and its abili­ one that “causes devastating dis­ ty to infect different species like rats. ease, with near 100 percent mortality fleas and people. after one or two days’ incubation. "The work goes some way to ex­ and is almost impossible to treat.” plaining the relative speed with - Biological warfaremongers can. which plague evolved. Previous stud­ however, make bacteria resistant to ies have suggested that the bacteri­ antibiotics by standard methods. um. Yersinia pestis. emerged at be­ Hence, defenders prefer to rely on tween 1.500 and 20.000 years ago. a vaccines, which are much harder to blink of an eye in evolutionary time. defeat. An old vaccine against plague ■ The bacterium’s ancestor evident­ exists, but it has many side effects. ly lived in the mammalian gut. The Since the Persian Gulf war in 1991, decoded genome shows that at some Dr. Titball has been developing a stage the ancestral bacterium ac­ new vaccine that he said was being quired large suites of genes from tested in people, though just for safe­ other bacteria, including some that ty, because tests of effectiveness let it move from the gut to the blood. can. for ethical reasons, be done just and others that conferred the ability in animals. to colonize fleas. The Sanger team found that the Thus armed, the bacterium plague genome consists of four rings changed from being probably a mi­ of DNA. a large circular chromo­ nor cause of stomach upsets to a some made up of 4.653.728 bases of scourge that has three times erupted DNA and three much smaller rings. on the world stage, causing the Jus­ or plasmids. tinian plague in the sixth to eighth ^An interesting feature of the ge­ centuries A.D.; the Black Death. nome is that 150 of its genes have which killed a third of the population I of Europe from 1347 to 1350; and inodern plague, which first spread from southern China in 1894 and still been rendered inactive by natural mutation, a process that affects any gene that the organism no longer needs. The inactive genes include N^TimGS causes 3,000 reported cases a year several that are known in other bac­ around the world. teria to be involved in colonizing the

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