Sampling animals and specimens
According to the national control program for brucellosis in Egypt, the public health authority has to notify the general organization for veterinary services (GOVS) of any cases of human brucellosis. Hence GOVS collect blood samples from all of the animals owned by the notified positive human cases so as to identify their infection status and slaughter the animal that tested positive. In the current study, samples were collected from animals reared in diverse husbandry systems, across different regions in Kafrelsheikh governorate, Egypt (Table 1 & Figure 1). The isolates were recovered from positive animals on two farms, three flocks, and six households. These animals were targeted upon the confirmed seropositivity, abortion at the third trimester, and/or the notification of a brucellosis case among the humans in contact with these animals. Animals belonging to Herds F and G were only cattle, Flock C included only sheep, while Flock E contained mixed breeding of sheep, goats, cattle, and buffaloes. The remaining samples were taken from individual household animals, animals that could have had contact with other animals. The individual animals were: (five ewes and one cow).
Farm (G) is a dairy farm with 119 cows that had no history of abortion, nor Brucella spp. infection declaration. Farm G had no history of introducing animals from outside the farm and had no contact with small ruminants. In 2017, the farm received a replacement cow of unknown brucellosis status for the first time and 2 months after its introduction, abortions had occurred in 20% of the herd. A total of 47 blood serum samples were collected from this farm and tested serologically against Brucella spp. infection resulting in 22 positive cases. Samples for bacterial isolation and identification were collected from live seropositive animals and upon slaughtering the seropositive animals through the national control program. Supra-mammary and retropharyngeal lymph nodes, testicles, fetal membranes, spleen, and milk samples were collected from live and slaughtered animals.