|Playing With Germs:||Just How Safe Are Those |
250 Million Year Old Bacterium, Guys?
|Scientists Revive Ancient Bacteria |
By MATTHEW FORDAHL
OCTOBER 18, 2000 - In what sounds like something out of "Jurassic Park,'' bacteria that lived before the dinosaurs and survived Earth's biggest mass extinction have been reawakened after a 250-million-year sleep in a salt crystal, scientists say.
The bacteria's age easily beats longevity records set by other organisms revived from apparent suspended animation — not to mention Hollywood's "Jurassic Park'' dinosaurs, cloned from prehistoric DNA encased in amber.
''`Jurassic Park' was neat, but this beats it hands down,'' said Paul Renne, a geologist at the University of California at Berkeley. "The idea of having a living glimpse of what life looked like 250 million years ago is pretty spectacular.''
If the discovery by Pennsylvania and Texas researchers holds true, the bacteria could open a window onto a prehistoric world that was both dying and being reborn. It would also show the tenacity of life in the toughest conditions.
Its genetic makeup also could help biologists calibrate the evolutionary clock for the bacterium and its present-day relatives, said Russell Vreeland, a study author and biologist at Pennsylvania's West Chester University.
DNA tests indicate the prehistoric germ is related to present-day Bacillus, a type of bacteria found in soil, water and dust.
"We all feel reasonably comfortable that this particular organism isn't going to attack anything,'' Vreeland said.
The organism was found in a tiny, fluid-filled bubble inside a salt crystal 1,850 feet underground, about 30 miles east of Carlsbad, N.M.
At the end of the Paleozoic Era, the area was a vast and barren salt lake. The world was then experiencing its greatest loss of life ever. Up 95 percent of all marine species became extinct. The first known dinosaurs date to about 230 million years ago.
"The end of the Paleozoic was such a curious time and we don't really know what happened,'' said Renne, who was not involved in the research. "This offers the possibility that we may be able to interrogate some of the organisms that were around.''
The findings were published in Thursday's issue of the journal Nature.
The researchers are confident that the germ has been locked away in the crystal all these years. Fossils and radiation tests show that the formation where the sample was found is 250 million years old, they said.
Still, there is the possibility the bacteria somehow seeped into the salt more recently in small drops of water, said Chris McKay, a biologist at NASA's Ames Research Center.
"Unlike amber or rocks or permafrost, salt is not an impermeable material,'' he said.
The scientists pulled about 220 pounds of rock salt from the Waste Isolation Pilot Plant, an underground nuclear waste dump. Fifty-six crystals that showed no signs of contamination were sampled for the presence of bacteria.
One crystal the size of a large postage stamp contained the organism. Two other strains of bacteria were found and are being studied.
The testing was done inside a containment lab at the Pennsylvania campus. The scientists said they took pains to prevent contamination.
The researchers believe the bacteria survived as a spore and metabolized very little or not at all over the years.
Spores are well-known for their longevity. They have been found in a 118-year-old can of meat, and yeast has been cultured from a 166-year-old bottle of porter ale, R. John Parkes of England's University of Bristol said in a Nature commentary.
In 1995, researchers at California Polytechnic State University reported reviving Bacillus bacteria spores from the gut of a bee stuck in amber. The bee was estimated to be 25 million to 30 million years old.
Since 1960, researchers have reported finding organisms up to 650 million years old in salt, but the findings were met with skepticism because of contamination fears.
In any case, the latest study shows that life can exist inside a salt crystal.
"So the next time you sprinkle salt on your food, think of what else you might be eating,'' Parkes said.
Scientists Discover Oldest Living Creature
By Patricia Reaney
|US Experts Help Uganda on Ebola |
By CHRIS TOMLINSON
OCTOBER 20, 2000 - GULU, Uganda (AP) — Ugandan and international health workers broke up into teams Friday to tackle an outbreak of the deadly Ebola virus, and officials reported a slowing in the spread of the epidemic that has killed 47 people and possibly infected 75 more.
Local health officials and experts from the World Health Organization briefed workers from Uganda and around the world on the spread of the disease at a headquarters in Gulu, the town at the center of the outbreak.
Dr. Guenael Rodier, the head of the WHO team and a veteran of a half dozen past Ebola outbreaks, said teams were established to treat patients, trace the outbreak, operate an advanced laboratory and provide health education. Each team combined international, national and local expertise.
"It's getting better organized,'' Rodier said. "Now we have much less transmission than we did two weeks ago, but we have many cases coming in from previous exposure.''
Ebola can take up to two weeks to incubate in a new victim and during this period, the patient is not contagious. But once the first flu-like symptoms develop, the patient can transmit the virus through bodily contact. In the later stages, the victim begins bleeding internally, producing vomit and diarrhea mixed with blood. At this point, and for a time after death, the patient is extremely contagious.
When the outbreak's very first victims died in Gulu, 225 miles north of Kampala, they were given traditional burial rites, including the washing the body of the deceased and then washing hands in a communal basin as a sign of unity. That turned many of the mourners into new victims.
Once the virus was first identified on Oct. 14, funerals were banned and now dead bodies are reported to authorities and carefully buried to avoid any chance of transmitting the disease.
Rodier said he was confident that area hospitals are now safe and that most people in the community had been reached by health workers going hut to hut looking for more cases.
"The vast majority of the cases are in the hospital today,'' Rodier said. But he added that it will take the length of an incubation period, about 10 days, before the number of new cases begins to shrink as a result of the measures taken this week.
Rodier was optimistic though that there would only be two more cycles of outbreaks and that the last case should be isolated within a month, after which there will be a six-week surveillance period to make sure the outbreak is over.
"To declare the epidemic over takes about three months,'' he said.
On Thursday, experts from the U.S. Centers for Disease Control arrived in Gulu with a mobile laboratory to help separate actual Ebola cases from those who have other diseases with similar symptoms.
Pierre Rollin, the head of the CDC team, said the virus had been identified as the Sudan strain of Ebola, one of three strains of the virus, that was last detected near the Ebola river in Sudan in 1979. The identification, which was confirmed by WHO on Friday, reinforced suspicions that the virus may have been inadvertently introduced to Uganda by rebels based in southern Sudan.
The Lord's Resistance Army has been fighting a 13-year war against President Yoweri Museveni's government and has kidnapped thousands of children, according to the United Nations and human rights organizations. Some have been turned into child soldiers or porters and others into sex slaves.
Gene Found That Makes Malaria Resist Quinine
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - A single gene makes the malaria parasite resistant to the preferred drug used to treat it, researchers said on Thursday -- a finding that could make it easier to develop drugs to treat the infection.
The discovery could also make it possible to bring back chloroquine -- a cheap and effective drug that has eventually become useless in many regions around the world because of the mutated parasite.
Malaria infects between 300 million and 500 million people worldwide each year and more than a million people -- most of them young children -- die from it each year.
It is caused by a parasite carried by mosquitoes.
The drug chloroquine, based on the same tree-bark compound that is used in quinine, was developed as part of a crash treatment program in the 1940s.
But the parasite gradually developed resistance, and the mutant form has spread to all continents affected by malaria.
"Chloroquine resistance didn't arise until the 1950s," Dr. Thomas Wellems, chief of the malaria genetics section at the National Institute of Allergies and Infectious Disease (NIAID), said in a telephone interview.
"It took a long time. That long time means it was a complicated genetic process." Chloroquine-resistant malaria did not reach Africa until the 1970s, he said.
Scientists thought that must mean that many different genes must be involved, and that chloroquine resistance would be a tough nut to crack.
But Wellems and colleagues found that instead, between four and eight small mutations in a gene known as pfcrt seem to account for chloroquine resistance in parasites from Asia, Africa and South America.
Writing in the Oct. 20 issue of the journal Molecular Cell, Wellems' team said their finding meant it might be possible to rework chloroquine's formula a bit so that it will work against the mutant parasite.
"We know there are certain reversal agents out there that can be administered with chloroquine to give it a new lease on life," Wellems said.
"A good working hypothesis is we can eventually move ahead and alter the drug chloroquine in specific ways and those may be active against specific strains."
The knowledge might make it easier for doctors and researchers to pick out resistant strains in the field, as well, Wellems said.
"The Department of Defense has these hand-held polymerase chain reaction or PCR devices, these fantastic devices that can detect anthrax in the field and so on," Wellems said.
The devices use PCR to quickly grow and identify DNA -- the best way of identifying a strain of bacteria, virus or parasite.
"The same method can be used in drug resistance," Wellems added. "Now with this knowledge and knowing that mutations in this one gene are the core player, we can devise methods to detect chloroquine-resistant strains in the field."
In place of chloroquine, doctors recommend mefloquine, sold in the U.S. under the brand name Lariam by Swiss drug maker Roche. But complaints are mounting that Lariam can cause strange psychiatric side-effects such as bizarre dreams and sleep disturbances.
UN Says Uganda Ebola Death Toll Climbs To 47
GENEVA (Reuters) - The death toll in Uganda's Ebola fever outbreak has climbed to 47 out of a total of 122 cases reported so far, the World Health Organization said on Friday.
Spokesman Valery Abramov of the Geneva-based U.N. agency told a news briefing there had been six fresh deaths overnight.
The outbreak has struck Gulu district in northern Uganda, where a team of U.S. medical experts arrived on Thursday to help fight the virus.
Members of the six-man team from the Atlanta-based Centers for Disease Control and Prevention said their first goal would be to confirm the diagnosis of the disease and identify its first victim.
Before the outbreak in Uganda, WHO says Ebola fever had claimed 793 lives in nearly 1,100 documented cases since the virus was first discovered in 1976 in the Democratic Republic of the Congo, where an epidemic killed more than 270 people.
The exact origin of the virus and how and why it flares up are unknown. Symptoms include sudden onset of fever, weakness, headache, muscle ache, abdominal pain and sore throat, followed by vomiting, diarrhea and internal and external bleeding.
The latest outbreak is the first time Ebola has struck in Uganda, although an outbreak of Marburg fever, which has similar characteristics, killed 19 people there in 1976.
WHO says it expects the number of cases to rise.
But officials were unable to say whether the outbreak was set to match one that killed 245 people in the Congolese town of Kikwit in 1995.
Further Reading on bacterium:
On the Net: West Chester University: http://www.wcupa.edu
Nature magazine: http://www.nature.com