Authors: Emily Stone, Emily Durkin, Elise Richardson, Brian Lazzaro, Nick Keiser
Faculty Mentor: Dr. Emily Durkin
College:Â College of Liberal Arts and Sciences
The Keiser lab is examining the ability of facultative parasites to transmit bacterial infections using a local species of mite (Macrocheles muscaedomesticae). Previous work has shown that facultatively parasitic mites can transmit vertically-transmitted microbes between fly hosts during feeding. We wanted to determine if facultatively parasitic mites can serve as a competent vector in the transmission of horizontally communicable microbes in flies. We use a local facultatively parasitic mite (Macrocheles muscaedomesticae) and fruit fly host (Drosophila melanogaster) model system to test whether mites are competent vectors for a deadly bacterial arthropod pathogen Serretia marcescens. Thus far, the Keiser lab has observed that flies infected with S. marcenscens will expire within 24-48 hours. Mites have also been shown to contract S. marcescens after attaching to and feeding on an infected fly host. Currently, continuing research is underway to determine if M. muscaedomesticae can transmit S. marcescens from an infected fly host to a second, uninfected fly.
Hello! My name’s Emily Stone; I’m the student presenting this poster today.
Unfortunately, I have been experiencing technical issues with my microphone and will only be able to respond via comment. I will be happy to answer any questions you may have during the 3:00 PM – 4:00 PM session. Thank you for taking the time to check out my lab’s work! 🙂
Thank you everyone for your questions! I hope you’ve enjoyed the session and that you have a great rest of your day!
Why did you choose to use this specific bacteria for transmission? Does it have any unique properties in terms of transmission?
Zachary,
Good afternoon! Thank you for your question.
We chose this bacteria because it is easily identifiable on a plate (red colonies), can grow on nonspecific LB Agar, and has previously been demonstrated to cause mortality in insects.
What was responsible for the red pigment?
Zoe,
Good afternoon! Thank you for your question. This bacteria produces a pigment called prodigiosin that is responsible for the red coloration of its colonies.
How did you keep the animals alive?
Olivia,
Hello! Thank you for your question.
We maintained colonies of mites and flies in the lab for this project. Flies were kept in large tubes topped with a cotton stopper and given a molasses-and-agar mixture to feed on. Mites were kept in a 4 L bucket with a mixture of wheat bran, nutritional yeast, wheat bran, and a small amount of water which served as media.
Olivia,
I’m so sorry! My computer wouldn’t show that I had already replied to you. Hope this answers your question.
It totally does! Thank you so much! Everything is so detailed!
Olivia,
Hi! Thank you for your question.
We maintained fly and mite colonies in the lab for this experiment. We kept small numbers of flies in plastic tubes topped with a cotton stopper; they were fed a molasses-agar mixture. Mites were maintained in a 4 L bucket and maintained on media composed of wheat bran, wood chips, nutritional yeast, and a small bit of water.
Hi Emily!
In your abstract, you discuss horizontal and vertical transmission of microbes. Can you explain the difference between the two?
Christian,
Good afternoon! Thank you for your question.
Vertical transmission refers to the transmission of a pathogen from parent to offspring. Horizontal transmission refers to the transmission of a pathogen from one individual to another.
Has this kind of mite-to-fly transmission been established in other species?
Emily,
Hi! Thank you for your question.
To the best of my knowledge, this specific species of mite has not been used to mediate the transmission of Serratia before in flies. However, previous studies have found that Serratia causes mortality in many species of insects and other species of mites have been found to transmit bacterial infections to their host. For example, in one study I read, Spiroplasma poulsonii could transmit bacterial infections between fly hosts.
What exactly are mites?
Hugh,
Good afternoon! Thank you for your question.
Mites are arthropods closely related to ticks. Our species is facultatively parasitic, meaning it can either parasitize a host which it feeds upon or it can live in the environment with no host.
Nice job! Need to come by the lab some time when face to face research starts up again and check out your inoculation system– one Drosophilist to another. 😉 Good video, very clear.
Dr. Wayne,
Good afternoon! I’m glad my video worked well. Thank you very much for your kind words–we’ll definitely have to confer once labs are back in session! I’m excited to see where this project takes us. 🙂