I have a friend who's a microbiologist and hanging out with him and his lab, "bug" is the preferred US slang term for any kind of microbe. In a more formal sett

I have a friend who's a microbiologist and hanging out with him and his lab, "bug" is the preferred US slang term for any kind of microbe. In a more formal setting they'd be specific about the type of microbe. I don't think anyone is getting insects and microbes confused.