ERIC PCR-Based Genotyping and Antimicrobial Susceptibility of Brucella melitensis Isolates Recovered from Slaughtered Camels in Egypt

Brucellosis is a zoonotic disease affecting various animals, including camels. Our study aimed to isolate, identify, genotype the Brucella species circulating in camels and to test the antibiotic susceptibility of the Brucella isolates against 8 antibacterial agents commonly prescribed for human brucellosis. Lymph nodes (n = 350) were collected from camels from different Egyptian governorates. As identified by bacteriological and Abortus meltensis ovis suis PCR, 14 Brucella isolates recovered from 350 lymph nodes were identified as B. melitensis biovar 3 (4%). The results of antimicrobial susceptibility assays denoted that all B. melitensis strains tested in this study were susceptible to ciprofloxacin, tigecycline, gentamicin and rifampin whereas 28.6%, 28.6%, 21.4% and 7.1% of the isolates were resistant to doxycycline, tetracycline, trimethoprim-sulfamethoxazole and erythromycin, respectively Meanwhile, 21.4% and 7.1% of the isolates were resistant to trimethoprim-sulfamethoxazole and erythromycin, respectively. The genetic analyses based on ERIC-PCR indicated that B. melitensis isolates of the current study are almost identical to Brucella strains recovered from goats raised away from the study area. In conclusion, The emergence of resistance to the first and second lines of therapeutics prescribed for brucellosis limits the drug choices. Therefore, we strongly advise performing routine antibiotic sensitivity testing and updating zone diameter breakpoints for those drugs prescribed for treatment of human brucellosis. ERIC-PCR is a comparatively swift and affordable method for determining the genetic fingerprinting of Brucella species in developing countries that cannot finance sequence-based fingerprinting techniques. Our findings highlight the role of the mixed species husbandry system in brucella transmission between camels and other livestock.