Is antibiotic ointment safe to use after microneedling?

Good job on the snail serum, I believe you are referring to Tensage Ampoules by Biopelle. That will help to stimulate collage and speed up the healing process by decreasing erythema. I NEVER have my patient put anything other then the serum on their skin for 12- 24 hours post treatment. The antibiotic ointment is occlusive and the petroleum will clog up the openings in the skin caused by the micro needling device and can cause some major breakouts, milia and will not allow the snail serum to penetrate. If the procedure is done properly there is no need for antibiotic ointment. Just stick with the snail serum and follow it up with (after 12 hours) with CeraVe or Cetaphil moisturizer and SPF x 1 week.

Hi heda44,
The problem here is that your skin had microwounds that are susceptible to infection given what you had applied. I hope that by microneedling, you are referring to a procedure that was professionally done and not a home-based procedure. Breakouts occur because of clogged pores and since you can't wash your after microneedling, I'm crossing my fingers that germs weren't trapped. 
When you have your next microneedling, please follow your doctor's advice. This might man just applying Cerave or TNS Serum to promote healing. Antibiotics should be prescribed.
All the best, 
Justin Harper, M.D.