The crate you loaned out that was used for Turkeys more than likely brought this in, and the hen being in it, she more than likely started getting symptoms between 5 and 15 days of being in that crate, and then she's spread it to the rest of your birds, and yes Turkeys can have Mycoplasmas, don't bother with Oxine, it won't kill Mycoplasmas, call them and ask them I did, and they told me it didn't. 10 to 15 percent bleach to water will kill the Mycoplasmas in the environment and Tek=trol will too, how are the chicks, I'm almost betting you lost some of them, if you got the Denagard, don't use other drugs with it before or after it for 7 days and be sure to put whatever chicks you have on it, and do them for 3 to 5 days a month at 2cc's to a quart of water, repeat every 3 weeks until they are over 4 months of age, then do monthly for the 3 to 5 days a month. And continue to use the Denagard for the older ones monthly even if you don't see any symptoms, you know they are infected, and it will continue to deteriorate their bodys even when you don't see symptoms, hopefully you caught it soon enough and can get it reduced in their systems. As far as hatching out chicks from these birds, you need to use the Denagard to try and keep it from passing to the eggs, it helps to stop it from passing to the eggs and getting carriers for it.
I hope your chickens are improved now, be sure to take care of the chicks, it will help to keep the lesions from forming in the chicks. I keep a can of Tek=trol Aerosol to spray whenever I've went near other birds or farms or the feed stores. A can costs about 8 dollars and is well worth it.
You need to get rid of those mites too, they will spread diseases. Use Hay for bedding or pine shavings, don't use straw it's hollow and harbors mites. And we all have to watch our birds for mites.