Do you want 5 gallons of malt vinegar? Actic acid will likely predominate even if you add other souring bugs. Pedio will form a pellicle to prevent oxygen and acetobacter. But if you already have it, forget about that.
Fruit flies are notorious for introducing acetobacter. Dust can also harbor this bacteria, now that you have it. I agree that you should probably drink it soon or dump it, bleach bomb all your equipment, and start over.