Methods of measuring susceptibility of anaerobic bacteria to trovafloxacin, including quality control parameters

Abstract

Three methods approved by the National Committee for Clinical Laboratory Standards for testing the susceptibility of anaerobic bacteria were used to evaluate the fluoroquinolone, trovafloxacin. The methods gave essentially comparable results with 126 anaerobes and with three quality control strains. A collaborative study defined the quality control range for trovafloxacin MICs. Trovafloxacin had good in vitro activity against the more common anaerobes (MIC 90 <- 2.0 (Μg/ml).

Trovafloxacin (CP-99,219) is a fluoroquinolone with a broad spectrum of antibacterial activity (1–3). Its in vitro spectrum includes many anaerobic bacteria (4).The National Committee for Clinical Laboratory Standards (NCCLS) currently recommends three different methods for testing the susceptibility of anaerobic bacteria (5). The standard reference method is an agar dilution procedure using Wilkins-Chalgren agar. Two alternative methods are an agar dilution technique using Brucella blood agar and a microdilution procedure using a broth version of Wilkins-Chalgren medium. It is important to determine whether these three procedures actually produce identical test results with each antimicrobial agent likely to be tested against anaerobes.