Elhaig Mahmoud M, Wahdan Ali
Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt.
Bacteriology, Immunology and Mycology Department, Faculty of Veterinary Medicine, Suez Canal University, Egypt.
Comp Immunol Microbiol Infect Dis. 2023 Apr;95:101971. doi: 10.1016/j.cimid.2023.101971. Epub 2023 Mar 7.
The study was carried out on six villages in northern Egypt to evaluate the epidemiological situation of bovine brucellosis among 989 unvaccinated household cattle by Rose Bengal Plate Test (RBPT) and indirect ELISA (iELISA) and to investigate the existence of Brucella DNA using real-time PCR in 100 milk and 100 sera from seropositive cattle and 50 sera from seronegative cattle. The overall seroprevalence was 20.7% and 23.7% by RBPT and iELISA, respectively. Based on the iELISA results, the seroprevalence was significantly (P < 0.05) higher in the village II (34.7%) and cattle > 7 years (30.1%). More males than females were non-significant seropositive (P = 0.6). There was 95% agreement between RBPT and iELISA, although iELISA showed a higher positivity rate (23.7%, 95% CI: 0.21-0.26) than RBPT (20.7%, 95% CI: 0.18-0.24). DNA of Brucella was confirmed in 16 milk samples by IS711 qPCR from seropositive cattle, however, no Brucella DNA was detected in serum samples tested positive and negative. Brucella abortus was the only species detected based on the alkB gene. Prevalence is highly related to the sampling site and the age of the animals. In conclusion, although qPCR is more accurate and commonly used in the diagnosis of most infectious diseases but in this situation iELISA is preferred and recommended for continuous screening and animal movement restriction and vaccination protocols, especially in high-risk areas.
该研究在埃及北部的六个村庄开展，通过玫瑰红平板试验（RBPT）和间接酶联免疫吸附测定（iELISA）评估989头未接种疫苗的家庭养殖牛的牛布鲁氏菌病流行病学情况，并利用实时荧光定量聚合酶链反应（qPCR）检测100份来自血清学阳性牛的牛奶样本、100份血清学阳性牛的血清样本以及50份血清学阴性牛的血清样本中布鲁氏菌DNA的存在情况。RBPT和iELISA检测的总体血清阳性率分别为20.7%和23.7%。基于iELISA结果，在村庄II（34.7%）和7岁以上的牛（30.1%）中，血清阳性率显著更高（P<0.05）。雄性血清阳性率高于雌性，但差异不显著（P = 0.6）。RBPT和iELISA之间的一致性为95%，尽管iELISA的阳性率（23.7%，95%CI：0.21 - 0.26）高于RBPT（20.7%，95%CI：0.18 - 0.24）。通过IS711 qPCR在16份来自血清学阳性牛的牛奶样本中确认了布鲁氏菌DNA，然而，在检测的血清学阳性和阴性血清样本中均未检测到布鲁氏菌DNA。基于alkB基因，仅检测到流产布鲁氏菌这一菌种。患病率与采样地点和动物年龄高度相关。总之，虽然qPCR在大多数传染病诊断中更准确且常用，但在这种情况下，iELISA更适合并推荐用于持续筛查、动物移动限制和疫苗接种方案，尤其是在高风险地区。
