 CAMBRIDGE, Mass., Dec. 16, 2020 GLOBE NEWSWIRE -- Spero Therapeutics, Inc. Nasdaq: SPRO, a multi-asset clinical-stage biopharmaceutical company focused on identifying, developing and commercializing treatments in high unmet need areas involving multi-drug resistant bacterial infections and rare diseases, today announced that it has been selected for addition to the NASDAQ Biotechnology Index Nasdaq: NBI, effective prior to market open on Monday, December 21, 2020. 