A virus's virus

Researchers have discovered the first virus to infect another virus, according to a study appearing tomorrow in Nature. The new virus was found living inside a new strain of the viral giant, mimivirus. "This is one parasite living on another parasite, which is really fascinating," linkurl:Michael Rossman,;http://bilbo.bio.purdue.edu/~viruswww/Rossmann_home/index.shtml microbiologist at Purdue University, who was not involved in the study, told The Scientist. linkurl:Didier Raoult;http://www.antimicrobe.org/authors/didier_raoult.asp and colleagues at the Universitee de la Mediterranee in Marseilles, France, discovered Mimivirus in 2003 from a water cooling tower in the UK. It primarily infects amoeba, although antibodies have been found to the virus in some human pneumonia cases. It measures in diameter about 400 nanometers (nm), while medium-sized viruses such as adenovirus and linkurl:HIV;http://www.the-scientist.com/2007/9/1/40/1/ measure closer to 100-200 nm. In this study, Raoult's team found a new strain of mimivirus in water from a cooling tower in Paris. This new strain was even larger...