Microbes descrimination I say! Call her a microphobe or something (though not to her face, she is still the teacher and deserves respect). Next time your friend should explain the educational potential of the plush and perhaps offer to let her use if she is going to give a lecture on something involving bacteria. Also if he was being disruptive with it that is microbe abuse, tsk tsk!
~~Nonpathogenic microbes are our friends~~