Biotypes and antimicrobial susceptibilities of Brucella isolates

41 Brucella strains isolated from blood and cerebrospinal fluid cultures were identified to species level and biotypes detected. All of the isolates were Brucella melitensis: 2 strains of B. melitensis biotype-1 and 39 strains of B. melitensis biotype-3. In vitro activities of these strains were detected by the E test method. According to the 90% minimal inhibitory concentration (MIC90) values, the most active agent was doxycycline (MIC90 0.064 microg/ml), followed by ciprofloxacin (MIC90 0.25 microg/ml), trimethoprim-sulfamethoxazole and ceftriaxone (MIC90 0.38 microg/ml). Rifampin exhibited the highest MIC90 value (0.75 microg/ml).