ALBUQUERQUE—The foot-long Tokay gecko's polka-dot skin and wide eyes have made it popular with pet stores, where it can sell for less than $20. But the adorable Asian lizards are also a mixing pot for 10 types of salmonella from local livestock, poultry and rodents, a researcher said today.

For the last several years, Katherine Smith at Brown University and colleagues have worked to document the pet trade's potential to bring new and dangerous diseases to the United States. As Smith reported in Science earlier this year, the U.S. imported 1.5 billion live animals between 2000 and 2006, just 14 percent of which have been identified to species in government records. Even less well-known are the pathogens they may contain. In 2003, for instance, a Gambian pouched rat started an outbreak of monkeypox in the Midwest.

At the Ecological Society of America meeting here today, Smith described new results from a study of 150 wild-caught Tokay geckos imported from Indonesia. She found that 60 percent of the geckos tested positive for Salmonella, which was not too surprising considering that 10 percent of salmonella cases are caused by reptile pets, such as slider turtles and iguanas.

"What was surprising," she said, "was the diversity ... we found."  Most studies have identified one or two strains of salmonella in reptile species, but Smith found a total of 10 strains, called serotypes, in just these geckos. Two of the serotypes are well known from reptiles, but others came from livestock, poultry and rodents. One type is extremely rare in the U.S. and is primarily known from Asian samples. "Why are these reptiles carrying so much salmonella?" she wondered.

When she contacted her Indonesian supplier, he explained that Tokay geckos are the "pigeons of Indonesia." The lizards are collected from locations including bathrooms and livestock pens. "These are the animals that make it into the pet trade," she says.

Currently, imported reptiles are never tested or placed in quarantine. However, pet dealers could face tighter restrictions if the controversial Nonnative Wildlife Invasion Prevention Act gets voted into law.