 several closely related new delhi metallo b lactamase ndm producing escherichia coli isolates were identified in southeast michigan using whole genome sequencing wgs an epidemiologic investigation identified duodenoscope and gastroscope exposures as likely sources of transmission that impacted nine patients between july 2021 and february 2023 this investigation showed how epidemiologic analyses coupled with wgs can facilitate outbreak investigations by rapidly identifying linked cases and potential sources to prevent further transmission 