Background: A search was initiated to identify inhibitors of the acetyltransferase domain of GlmU that could be exploited as starting points for new antimicrobials. Results: Sulfonamide inhibitors were identified that upon chemical modification displayed antimicrobial activity mediated via GlmU. Conclusion: Enzymatic inhibition of GlmU can lead to antimicrobial activity. Significance: For the first time, GlmU was validated as an antimicrobial target in vitro.