Thursday, 29 September 2016 13:46

Delays at the Zika Zoo

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Published in Zika Diaries
Agarose gel sitting on an ultraviolet light for detecting plasmid DNAs containing cloned Zika virus genome sequences. Photo by Amy Rosenfeld. Agarose gel sitting on an ultraviolet light for detecting plasmid DNAs containing cloned Zika virus genome sequences. Photo by Amy Rosenfeld.

I have been documenting in Zika Diaries our efforts to begin experiments with Zika virus. Back in March, I wrote about our experience with writing a new IACUC (Institutional Animal Care and Use Committee) animal protocol to do the work and the expense of such work. Here we are at the end of September and we have yet to complete a single mouse experiment!

By the beginning of August we had obtained our first batch of mice, and matings were set up. Amy intravenously inoculated the first batch of pregnant females with Zika virus, with the goal of examining virus replication in the fetus. She harvested specimens on day 0 and day 1 after infection, but day 2 fell on a Saturday, and she was denied entry into the animal BSL2 facility by the security guard. More seriously, she was denied entry into the animal room for the next week—apparently her Columbia ID badge had not been updated to allow access. By the time she got this problem sorted out, she had missed most of the time points, and our first Zika virus mouse experiment was a complete loss.

At this point we decided that it would be better to inoculate the mice subcutaneously, in the footpad—a route that would more closely mimic delivery of virus by mosquito bites (mosquitoes don’t bite the footpad, but it is an easier inoculation site than the skin). But one does not simply decide to change inoculation procedures in an approved animal protocol! It’s necessary to file a modified IACUC protocol, which must be reviewed and approved by the animal use committee before experiments can proceed.

We filed our modifed IACUC protocol at the beginning of August, but it took over a month for the committee to provide their comments. The main issue was that the footpad inoculation had the potential of causing severe pain, and therefore we were told to raise the pain level of this experiment to the highest level. At this level of pain, it is necessary to carry out procedures to mitigate the pain. In our case, it was recommended that we apply a topical analgesic to the footpad post-inoculation.

A topical analgesic: that sounds simple enough! But wait, the analgesic recommended was buprenorphine, an opiate. To use such a drug in my laboratory, I had to apply to the New York State Bureau of Narcotic Enforcement for a license to engage in a controlled substance activity. If I were approved, the drug would then have to be stored in a double-locked container to which only I would have the key.

We had some discussions with a university veterinarian, who did an experiment with us. We injected a few mice in the footpad, and every day applied slight pressure to the injected area. The mice didn’t flinch, indicating that the injections had not caused pain. According to the vet, this observation justified asking the animal use committee to do the experiment without topical buprenorphine. We are waiting for their reply.

It is conceivable that we will do a Zika virus infection of mice in 2016, but I’m not holding my breath. Meanwhile our mice are aging, many are pregnant, and no experiments can be done.

There are many requirements for being a scientist, but perhaps at the top of the list is patience!

Last modified on Wednesday, 12 October 2016 18:36
Vincent Racaniello

Vincent Racaniello, Ph.D. is Professor of Microbiology at Columbia University Medical Center. As principal investigator of his laboratory, he oversees the research that is carried out by Ph.D. students and postdoctoral fellows. He also teaches virology to graduate students, as well as medical, dental, and nursing students.

Vincent entered the world of social media in 2004 with virology blog, followed by This Week in Virology. Videocasts of lectures from his undergraduate virology course are on iTunes University and virology blog. You can find him on WikipediaTwitter, Facebook, and Instagram. His goal is to be Earth’s virology professor. In recognition of his contribution to microbiology education, he was awarded the Peter Wildy Prize for Microbiology Education by the Society for General Microbiology. His Wildy Lecture provides an overview of how he uses social media for science communication.