Original Article

In Vitro Activity of Novel Rifamycins against Gram-positive Clinical Isolates

Christopher K. Murphy, Elena Karginova, Dan Sahm, David M. Rothstein

Received: May 9, 2007 / Accepted: August 20, 2007
© Japan Antibiotics Research Association

Abstract We describe novel rifamycins that have improved activity, compared with rifampin, against clinical isolates of staphylococci and streptococci, with MIC90s of 0.008 and 0.0005 μg/ml, respectively. This enhanced antibacterial activity, along with their potential lack of drug–drug interactions, are considerations that suggest the potential of these novel rifamycins in combination therapy to treat serious Gram-positive infections.

Keywords rifampin, rifalazil, ABI-0043, staphylococci, streptococci, MIC

D. M. Rothstein (Corresponding author), C. K. Murphy: ActivBiotics, Inc., 110 Hartwell Avenue, Lexington, MA 02421, E-mail: drothstein@activbiotics.com
E. Karginova, D. Sahm: Eurofins Medinet, Inc., Anti-Infective Services., 13665 Dulles Technology Drive, Suite 200, Herndon, VA 20171