In vitro antimicrobial susceptibility of Brucella melitensis isolates from sheep in an area endemic for human brucellosis in Turkey.

The aim of this study was to assess in vitro antimicrobial susceptibility of Brucella melitensis isolates isolated from naturally infected sheep cases in an area where human brucellosis is endemic, focusing on rifampin (RIF), streptomycin (SM), ciprofloxacin (CPFX), trimethoprim/sulfamethoxazole (TMP/SMZ), gentamicin (GM) and tetracycline (TC) and on 11 other antimicrobials. The identification and typing of Brucella isolates were carried out using standard classification tests and polymerase chain reaction (PCR) methods. Antimicrobial susceptibility testing was carried out on Mueller-Hilton agar. The resistance to SM, CPFX and GM was determined at the rate of 7.3% and to RIF at the rate of 9.7%. The highest (46.3%) resistance was determined against TMP/SMZ. All strains were found to be sensitive to TC at the rate of 100.0%. In conclusion, ovine origin B. melitensis strains evaluated in this study were resistant to at least one antimicrobial (51.2%) that is commonly used in human clinical medicine against brucellosis.