Bacteria bomb

Antibiotics can eliminate bacterial infections in the human body, but may also destroy harmless bacteria and promote drug resistance in the very microbes they are intended to wipe out. Scientists at Nanyang Technological University in Singapore might have sidestepped those problems by creating what may be the first bacterium engineered to fight an infectious disease.

The researchers took an E. coli strain normally found in the human gut and inserted several foreign DNA sequences into its genome. The new genes allowed it to produce a protein that is toxic to Pseudomonas aeruginosa, a drug-resistant bacterium that sometimes causes lethal infections in hospital patients with weakened immune systems. In lab tests, when the modified E. coli bacteria encountered Pseudomonas, they filled themselves with the toxic protein and exploded, killing both themselves and 99 percent of their targets.

Pseudomonas might be less likely to develop resistance to this approach than to antibiotics, say the Nanyang scientists, who published their work in Molecular Systems Biology. This bacterial suicide mission is intriguing but faces obstacles: The modified E. coli bacteria had to be set loose in large numbers to be effective, and they have not yet been tried in animals. Extensive safety testing will be needed before doctors venture to use an engineered bacterium in humans, perhaps in the form of a probiotic supplement.

Enigmatic eel

A researcher diving off the coast of Palau, a West Pacific island nation, discovered a purple, 7-inch-long eel scientists have named a "living fossil." Although no fossils of the eel are actually known to exist, its features are so different from other living eels (it is shorter and has a different jaw structure) and fossilized eels (it has gill features like those in bony fishes) that evolutionists think it diverged from other eel families 200 million years ago.

Named Protoanguilla palau, the eel is only known to live in a cave 115 feet underwater off Palau. Scientists describing the "enigmatic" animal in Proceedings of the Royal Society B compared it to another living fossil, a fish called a coelacanth that was thought to be extinct for 65 million years until a fishing trawler netted one in 1938.

Hideout found

Israeli archaeologists have excavated a 2,000-year-old rainwater drainage tunnel in Jerusalem they believe was used by Jewish rebels during the Great Revolt against the Romans around A.D. 70, when the Second Temple was destroyed. Josephus, a historian who lived during the period, wrote that the rebels hid in such tunnels, many starving or killing themselves, until Roman soldiers pulled up paving stones and found them.

The excavators have found a gold bell that still rings (possibly worn by a Temple priest), a 2-foot-long Roman sword still in its leather scabbard, coins minted with the slogan "Freedom of Zion," and a small stone with a crude sketch of what the Israel Antiquities Authority says is a menorah, the multibranched candlestick once used in the Temple.

The new tunnel is not yet open to the public, but others in Jerusalem are popular tourist attractions. They are a source of tension between Jews and Palestinians: Both groups use archaeological evidence to bolster their historic claims to the city.