Tick by tick

Aug 19, 2013

When University of Texas Medical Branch at Galveston researchers set out to study Crimean-Congo hemorrhagic fever virus, they faced a daunting challenge.

The requires biosafety level 4 containment, and it's carried by . That meant that if scientists wanted to study the transmission of the virus, they had to do something that had never been done before: find a way to work safely with the tiny, tough bugs in a maximum "spacesuit lab."

"It was completely new territory for us," said UTMB assistant professor Dennis Bente, senior author of a paper describing the BSL4 tick work in Frontiers in Cellular and Infection Microbiology. "Ticks are very small, and in the BSL4 you have two pairs of gloves on, you have this bulky suit, you have the plastic visor—all these things are a huge handicap. So how do you make sure you contain them?"

The answer: step by painstaking step. Bente and his collaborators first attached small "feeding capsules" onto mice, and then placed ticks of a species that carries Crimean-Congo virus into the capsules. Unlike that feed quickly and fly off, most ticks attach and feed slowly over the course of several days. Once the ticks were attached and began feeding, they and the mice were moved into a room in the Galveston National Laboratory BSL4 set aside for tick research.

There, in a sealed glove box lined with to capture any ticks attempting to escape, the mice were inoculated with Crimean-Congo hemorrhagic fever virus. The feeding-capsule enclosed ticks, each of which, tick by tick, was individually accounted for at every stage of the experiment, then acquired the virus when they fed on the infected mice.

"We did hours upon hours of testing to get this system working," Bente said. "We tested different types of sticky tape to determine the one that best inhibited the ticks' mobility, we tried different gloves, we tested the work flow, we checked to see how long a tick could last if you submerge it in disinfectant." (The answer: more than 24 hours)

The result, Bente said, is a tool that will give researchers a crucial window into a virtually unknown aspect of one of the world's most widely distributed hemorrhagic fever viruses— a pathogen responsible for outbreaks from Greece to India to South Africa. "Ticks play such a vital role in the epidemiology of the disease—they're not only the vector but they are also the reservoir for the virus, yet nobody really knows what's happening to the virus in the ticks, because there's been no way to study it in the laboratory," Bente said. "Now we can look at the complete transmission cycle in a controlled setting, examining how the virus is passed from infected animal to the uninfected tick, and from the infected tick to the uninfected animal. That's something that people studying this in the field haven't been able to do before now."

Among other things, the new system will enable the researchers to study the virus' transmission by a variety of tick species. On the list are North American ticks, to investigate the possibility that Crimean-Congo hemorrhagic fever virus, like West Nile virus, could be introduced into the United States.

Explore further: Life's extremists may be an untapped source of antibacterial drugs

add to favorites email to friend print save as pdf

Related Stories

Migratory birds can spread haemorrhagic fever

Oct 23, 2012

A type of haemorrhagic fever that is prevalent in Africa, Asia, and the Balkans has begun to spread to new areas in southern Europe. Now Swedish researchers have shown that migratory birds carrying ticks are the possible ...

Recommended for you

Cohesin molecule safeguards cell division

Nov 21, 2014

The cohesin molecule ensures the proper distribution of DNA during cell division. Scientists at the Research Institute of Molecular Pathology (IMP) in Vienna can now prove the concept of its carabiner-like ...

Nail stem cells prove more versatile than press ons

Nov 21, 2014

There are plenty of body parts that don't grow back when you lose them. Nails are an exception, and a new study published in the Proceedings of the National Academy of Sciences (PNAS) reveals some of the r ...

Scientists develop 3-D model of regulator protein bax

Nov 21, 2014

Scientists at Freie Universität Berlin, the University of Tubingen, and the Swiss Federal Institute of Technology in Zurich (ETH) provide a new 3D model of the protein Bax, a key regulator of cell death. When active, Bax ...

Researchers unwind the mysteries of the cellular clock

Nov 20, 2014

Human existence is basically circadian. Most of us wake in the morning, sleep in the evening, and eat in between. Body temperature, metabolism, and hormone levels all fluctuate throughout the day, and it ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.