Had a wasp sting, is there any bacteria in the sting?

Possibly: Any time there is a break in the integument (skin and mucous membranes) bacteria may be introduced into the break, but wasp stings seldom result in secondary bacterial infection if the stinger is removed. They can, but seldom do.

Due to lack of a : Barb on the stinger, most wasps don't leave a stinger in the victim. However, on occasion the stinger becomes lodged, breaks off the wasps body and is stuck in your skin. The stinger introduces venom. There is possibility for a secondary bacterial infection ; even tetanus. Insure you have had a tetanus shot within the last ten years.