CHICAGO - Researchers in Canada have found bedbugs carrying antibiotic-resistant superbugs, a surprise finding because scientists had thought the pests were not capable of spreading infections.

The study was done by a team in a poor corner of Vancouver, where both bedbug infestations and strains of antibiotic resistant bacteria are increasing.

Related readings:   No new case of superbug NDM-1 found in China  Govt tries to head off feared superbug

Dr. Marc Romney, a medical microbiologist at St. Paul's Hospital/Providence Health Care in Vancouver, decided to see if the two were related.

Romney and colleagues removed five of the pests from the clothes and skin of infested patients and tested them.

They found bedbugs carrying two types of drug-resistant bacteria, methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci.

"I was a little surprised. Historically, bedbugs have not been associated with infections," Romney said in a telephone interview.

He said scientists have tested bedbugs to see if they carry blood-borne diseases, such as hepatitis or HIV. But so far, they have not been reported to carry infection.

Infestations of the bloodsucking bugs, which can cause severe itching, have made a comeback in cities such as Paris and New York in recent years.

Romney said the strain of MRSA they found requires skin to be somewhat compromised, and he thinks the bedbugs are providing that as people scratch their bites.

"Maybe the bedbug's bite is breaking down the patient's skin," he said.

He said that some of these pests may be carrying MRSA and going from individual to individual.

"The data are preliminary, but it suggests maybe there is an association," Romney said.

"Even though they can't carry hepatitis B and HIV, maybe they can carry resistant bacteria."

"Maybe it is yet another factor that could be responsible for this large increase in resistant bacteria in inner cities in North America," he said.