question: I am currently being treated for pyleonephritis in the left kidney.  I am receiving outpatient Invanz infusions as the bacteria was previously noted to be a rare E-coli strain.  However, before I began the infusion therapy, my urine was sent for a culture from the urologist's office.  I received a call telling me that the culture was negative.  I am still suffering from moderate to severe left flank pain and occasional night sweats.  I am 55 yrs old, female, diabetic.  I am 5'3" and weigh 240.  Thank you