Resistance of Brucella abortus isolated from Lebanese dairy-based food products against commonly used antimicrobials

Abstract

Considering the marked importance of Brucella organisms as food-borne pathogens and the lack of published literature on the evaluation of the microbiological quality of dairy-based food products in the Middle East, this study was performed to address this gap. The main aim of the present study was to assess the antimicrobial resistance patterns of Brucella isolates recovered from a total of 164 cultured samples of Lebanese dairy-based food products (Baladi cheese, Shankleesh and Kishk). Standard polymerase chain reaction (PCR) was used to stereotype colonies previously confirmed by biochemical tests to be Brucella strains and to distinguish between the RB51 vaccine and field Brucella strains. Real-time PCR was applied to differentiate among the various Brucella species. Confirmed PCR field Brucella abortus isolates were evaluated for their susceptibility to eight commonly used antimicrobials. The highest number of resistant B. abortus isolates (n = 4 out of 6) was shown against Streptomycin and Ciprofloxacin, whereas 3 out of 6 isolates tested were resistant to Gentamicin. A lower number of resistant isolates were noted against Rifampicin, Tetracycline and Trimethoprim-sulfamethoxazole (n = 2 out of 6) and the lowest number for Doxycycline and Ceftriaxone (n = 1 out of 6). Such results are alarming and reflect the significance and importance of implementing more strict hygiene standards and regulations to reduce food-borne illnesses and control the excessive use of antimicrobials in this region.