Unexpected effects of ivermectin and selamectin on inducible Cre activity in mice.

Anti-parasitics are frequently used in research animal facilities to treat a multitude of common infections, with pinworms and fur mites being amongst the most common. Ivermectin and selamectin are common oral and topical treatments for these infections, respectively. Although commonly thought to be innocuous to both the research animals and any transgenic elements that the animals may carry, evidence exists that ivermectin is capable of activating the recombinase activity of at least one Cre. The goal of the current study was to determine if there was an effect of either anti-parasitic agent on the activity of Cre proteins in transgenic mice.