Varroa and the role of bacteria

A new paper in Proceedings of the National Academy of Science on varroa has been published which has all the usual information about the role of viruses, but then there is a bit that is new to me:

While researchers know that the Varroa mite is behind the death of bee colonies, the mechanism causing the deaths is still unknown. Yang and Dr. Diana L. Cox-Foster, Penn State professor of entomology, now believe that a combination of bee mites, deformed wing virus and bacteria is causing the problems occurring in hives across the country.

“Once one mite begins to feed on a developing bee, all the subsequent mites will use the same feeding location,” Cox-Foster said today. “Yang has seen as many as 11 adult mites feeding off of one bee. Other researchers have shown that both harmful and harmless bacteria may infect the feeding location.”

...Yang and Cox-Foster injected bacteria into bees. In mite-infested bees, the deformed wing virus blossomed rapidly. In mite-free bees, it didn't change.

A final, fatal step is involved. Worker bees put a sterilizing agent into honey and the colony's food. Mite-infested bees can't produce as much of the agent. Cox-Foster suspects the honey then carries more bacteria.