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                                                                    EXHIBIT 23.1


               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

         We consent to the incorporation by reference in the Registration
Statement (Form S-8) pertaining to the 1993 Amended Incentive Stock Plan of
Microcide Pharmaceuticals, Inc. of our report dated February 8, 2000, with
respect to the financial statements of Microcide Pharmaceuticals, Inc. for the
year ended December 31, 1999, included in its Annual Report on Form 10-K, filed
with the Securities and Exchange Commission.


                                                               Ernst & Young LLP

San Jose, California
August 30, 2000



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