Ticks stopped bothering senior biology major Randi Block after she had to collect and crack them open for a year’s worth of research.
Block studied the American dog tick as a carrier of rickettsia, a pathogenic bacteria that causes Rocky Mountain Spotted Fever.
Even though she said ticks disgusted her at the beginning of the project, she still decided to follow Associate Professor of Biology Jeffrey VanZant’s suggestion to research them.
“My original question was looking at the population of deer ticks which carry Lyme disease and they were unknown whether they were present in Hillsdale County,” Block said. “I had all the primers to run stuff for Lyme disease detection, but we never actually found any deer ticks.”
But after months of hard work, Block did discover that there are ticks carrying rickettsia in Hillsdale County and in Northern Michigan, where Hillsdale’s G.H. Gordon Biology Station is located.
Although a majority of ticks carry a noninfectious form of rickettsia, Block looked for the presence of a surface protein that is commonly found in ticks carrying an infectious form of rickettsia.
“We found that in Hillsdale County, about 10.8 percent of ticks carry rickettsia, which means they can cause disease. I also did the same study up in Lake County, which is where we have our biostation, and up there it was about 7.2 percent,” Block said.
In order to begin her search for rickettsia, she first had to collect hundreds of ticks. She began collecting them at the biostation and in Hillsdale County last summer.
Block collected about 250 dog ticks by dragging a piece of canvas through brush and grass for the ticks to grab on to.
“Then you check your legs, because they are also all over you,” Block said. “So you get about half on the canvas, half on yourself, pluck them off, and stick them in ethanol.”
During collection, Block had the help of sophomore Luke Woltanski in gathering the ticks, even though he said he was originally terrified of the critters.
“I got to draw this big corduroy cloth all over these areas at the biostation,” Woltanski said. “We put our bodies on the line for it. There was one that Dr. Houghton had to pull out of the back of my head. He really got in there and in his effort to dig in under the tick’s mouthpiece, he rammed my head into the table. It was hilarious.”
Block said she also quickly got over her aversion to ticks.
“You get past a certain point where you are just covered with like 20 of them, and you don’t even care anymore, you just get them off,” Block said.
After Woltanski helped Block collect all her ticks, sophomore Andrew Rademacher helped her with DNA sequencing in the lab. While working in the conservation genetics lab, Rademacher ended up playing a significant role in the ticks’ genetic analysis.
Rademacher had to replicate and extract the DNA from the ticks so that Block could determine whether or not that particular tick carried the bacteria.
“I would homogenize the ticks, so basically destroy it, and pull all the DNA out. Then from that DNA, I would take it and I would optimize for a system called PCR, which then replicates a single strand to an obscene amount,” Rademacher said.
Based on the analysis, Block determined that some of the ticks containing the surface protein only contained an older form of rickettsia — not the rickettsia that causes spotted fever. It is unclear whether that older form of rickettsia can cause disease, Block said.
Optimization usually takes several months, but Rademacher was lucky and found effective PCR conditions in only two weeks. But even with this good luck, there was a lot of hard work he had to put in.
“It smelled bad,” Rademacher said. “Ticks have a really weird smell, and they look alive no matter what you do. You poke them and even when they’re dead, they move. But it was fun.”
Luckily neither Block, Woltanski, or Rademacher contracted any diseases after dealing with ticks for months.
“I only got bit once,” Block said. “And the tick that bit me didn’t have rickettsia — I checked.”