Molecular Study of the Prevalence of Brucella Abortus and Brucella Melitensis in the Blood and Lymph Node Samples of Slaughtered Camels by Polymerase Chain Reaction (PCR) in Iran

Abstract Brucellosis is a zoonotic disease which is characterized by reduced fertility and abortion in several species of animals, as well as humans. Camel brucellosis is caused by Brucella abortus and Brucella melitensis. To overcome the limitations posed by other techniques such as culture and serology, a sensitive technique (PCR) was employed for the detection of brucellosis in 123 camels. Findings from this PCR study indicated a total of 11.38% of blood samples as positive for Brucella spp. and 13.01% of the lymph node samples were positive for Brucella spp. In this study, 5 out of 123 (4.065%) and 3 out of 123 (2.439%) camel blood samples were positive for B. abortus and B. melitensis, respectively. Also, 4 out of 123 (3.252%) and 2 out of 123 (1.626%) camel lymph node samples were positive for B. abortus and B. melitensis, respectively. Young camels were the most commonly infected age group, while adult camels were the less often infected age group. Also, higher prevalence of brucellosis was observed in female camels. These results have indicated that PCR is a sensitive technique which could be used as a confirmatory test for the detection of brucellosis in live camels, at the same time with the lowest risk of infection of laboratory personnel. The obtained results suggest that control and eradication programs for Brucella spp. infection seem to be necessary in camels. Our findings support the power of PCR test for Brucella spp. detection in the blood and lymph node samples and it could be easily used for routine diagnosis. Abstract Bruceloza je zoonoza koja se karakteriše smanjenom sposobnošću reprodukcije i abortusima kod nekoliko vrsta životinja i ljudi. Brucelozu kod kamila izazivaju Brucella abortus i Brucella melitensis. Standardne dijagnostičke tehnike kao što su izolacija na hranljivim podlogama i serološke reakcije nisu pouzdane i imaju značajna ograničenja. Da bi se to izbeglo, radi dokazivanja bruceloze kod 123 kamile, uptorebljena je osetljiva dijagnostička molekularna metoda: PCR. Rezultati su pokazali da je 11,38% ispitanih uzoraka krvi i 13,01% uzoraka limfnih čvorova bilo pozitivno na Brucella spp. U studiji, od ukupno 123 uzoraka krvi, 5 uzoraka (4,065%) je bilo pozitivno na B. abortus, a 3 (2,439%) na B. melitensis. Od ukupno 123 uzorka krvi, 4 uzorka (2,252%) su bila pozitivna na B. abortus, a 3 (1,626%) na B. melitensis. Najveća prevalencija je bila u grupi mladih životinja, a starije kamile su retko oboljevale. Veća je prevalencija ustanovljena kod ženki. Rezultati ukazuju da je PCR osetljiva metoda koja može da se koristi kao potvrdni test za dokazivanje bruceloze kod živih životinja uz minimalan rizik od infekcije laboratorijskog osoblja koje obavlja dijagnostiku. Dobijeni rezultati ukazuju da postoji neophodnost definisanja programa kontrole i iskorenjivanja bruceloze kamila. Istovremeno, rezultati ukazuju na pouzdanost PCR metode u dokazivanju Brucella spp bakterija, u uzorcima krvi i limfnih čvorova, što čini ovaj metod pogodnim za rutinsku dijagnostiku bruceloze.