In part 1, I told you that Scott O’Neill wanted to know whether infecting Aedes aegypti mosquitos with a commensal bacteria called Wolbachia would make them resistant to the dengue virus, which they spread to tens of millions of people every year. So he and his team set out to infect A. aegypti, which don’t normally carry Wolbachia, with strains of the bacteria harvested from fruit flies. (Bear in mind that this requires getting the bacteria into the mosquitos’ abdomens without killing the mosquito. They call the technique microinjection, but that doesn’t really convey how ridiculously difficult it is.) Finally, they got it to work. And what happened? Well, it turned out that A. aegypti carrying Wolbachia are resistant to infection with dengue viruses. The mosquitos don’t live as long, and the virus doesn’t grow very well, so they carry fewer of them. When you put those two things together, the likelihood that a mosquito will pick up a dengue virus while feeding on an infected human and then transmit it to another person is doubly reduced. Introducing Wolbachia into wild mosquito populations should drastically reduce, or even eliminate, the transmission of dengue virus.
Remember, there were five reasons I loved Scott O’Neill’s talk so much. They were: