Under which circumstances will a "normal" e.coli gain on its activity? is a positive serum beta glucuronidase test related to such activity? ty.

Hard to say/depends: This likely depends on what is considered "normal" about the E. coli and it's activity. E. coli is part of the normal "gut" flora. It's when certain other forms of E. coli like the O157:H7 strain get in the digestive tract that issues occur. So it's hard to say how activity would be affected unless abnormal E. coli get in there. The Bgluc test is homologous to the E. coli Bgalact enzyme.