So the 3+ isn’t referring to types. Micro techs apply swabs to agar plates and streak it out on the plates, generally into 4 quadrants and then depending on what grows and how much grows they report the amount of bacteria out as rare, few, moderate, or many. Some labs report rare as 1+, few as 2+, moderate as 3+, many as 4+.

Labs have different protocols, but the ones I’ve worked for require reporting out any moderate (3+) or many (4+) predominating gram negative rods (in your case this would be the E.coli). The labs I worked for also required reporting out Group B strep in any amount on a woman of child bearing age just in case they were pregnant (as some mentioned because this organism can be problematic during childbirth, and some woman might not know they are even pregnant).

Microbiologists are really only supposed to plate out, report what grows and say whether or not the organisms are sensitive, intermediate or resistant to the appropriate antibiotics. We’re usually not given full clinical history. We many times don’t know if the test was just from a routine physical or if you had it done because of pain, itching etc.

So I’d listen to the dr’s advice and if they were poor at communicating to you, I’d recommend you call them again and ask someone else to explain the results again in a way that makes sense. In the end, you want to know if the dr thinks this is a real infection and worth treating with antibiotics.