In vitro antimicrobial susceptibility testing of human Brucella melitensis isolates from Qatar between 2014 – 2015

BACKGROUND: Brucellosis is one of the most common zoonotic disease affecting humans and animals and is endemic in many parts of the world including the Gulf Cooperation Council region (GCC). The aim of this study was to identify the species and determine the antimicrobial susceptibility pattern of Brucella strains isolated from clinical specimens, from Qatar. RESULTS: We evaluated 231 Brucella isolates. All isolates were identified as B. melitensis. All the isolates were susceptible to doxycycline, tetracycline, streptomycin, gentamicin, trimethoprim / sulfamethoxazole and ciprofloxacin except rifampicin, where 48 % of the strains showed elevated MICs (>1 mg/L). The rifampicin-resistance related hotspots within the rpoB gene were amplified and sequenced using PCR and no rpoB mutations were found in strains with rifampicin MICs of >2 mg/L. CONCLUSION: This study identified B. melitensis as the etiological agent of brucellosis in Qatar. No resistant isolates were detected among conventionally used antimicrobial agents.