I'd like to chime in on the fish TB...
This crap is nasty, very nasty, look around on the web, some of the pics are truly ghastly!
And more so, cases of humans infected with this form of TB is on the rise, primarily due to the increase in fishkeepers but also to the disease itself becoming increasingly prevalent and virulent.
Never, never ever put your hands/arms into a tank with even a scratch on'em...
Way too many nasties besides just this.
Always thoroughly wash and rinse before and after entering a tank if you must enter without gloves.
Gloves, get a pair!
I use and love my Coralife Aqua-Gloves, arm-length gloves, very heavy duty and inexpensive.
Great for aggressive critters of all types... Except maybe our electric pets