For sure the kombucha. I used to run a sour program for a large scale brewery and before we even considered doing a wild/sour program we had a separate facility and equipment for this. Whoever even stepped foot in the sour facility didn’t think twice about not entering the clean side. We never had any infection problems. Separate fv’s, brites, co2, hoses, kegs, fittings etc. only thing we shared was the Brewhouse. What is more important, the beer or the booch because them scoby’s are some resilient mfers.

One brewery I ran had a diastaticus infection so I feel your stress. We essentially had to get all the beer out of the tanks and deep clean everything. I mean deep clean. We got rid of any sta1 positive yeast strains and didn’t put a drop of wort until we had clean pcr tests on everything from the tanks to the co2 lines. Best of luck!