State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, P.R. China.
Qingyang Center for Animal Disease Prevention and Control, Qingyang, 745000, P.R. China.
Emerg Microbes Infect. 2018 Apr 4;7(1):58. doi: 10.1038/s41426-018-0060-y.
A large-scale survey was conducted in domestic animal populations from 2011 to 2015 in Qingyang, China. A total of 448,398 animals from different districts of Qingyang were tested for the presence of Brucella-specific antibodies using the Rose Bengal Plate Test (RBPT) and the Standard Agglutination Test (SAT). From 2011 to 2015, the yearly average positive rates were between 0.04 and 4.75% in the eight counties tested. In addition, the prevalence rates were between 0 and 9.96% in these eight counties. Sheep was the dominant host of Brucella in Qingyang, and the prevalence rate in sheep (2.74%) was higher than those in the other animals tested. Identification of 10 Brucella isolates from sheep confirmed that the epidemic strains were B. melitensis biovar 3 (n = 9) and B. melitensis biovar 1 (n = 1). MLVA-11 (multiple-locus variable-number tandem repeat analysis) analysis of the 10 isolates showed three genotypes: genotype 116 (n = 8), genotype 115 (n = 1) and genotype 136 (n = 1). Furthermore, analysis of the whole-genome sequences of the representative B. melitensis strain QY1 indicated that this isolate was closely related to isolates from China and India. The results of serum epidemiology confirmed that the region of northern Qingyang was a critical Brucella epidemic area and that the disease showed a rising trend, especially from 2013 to 2015. An analysis of the isolate genotypes suggested that sheep brucellosis mainly resulted from conventional B. melitensis (East Mediterranean group), although the external strain (American group) also occurred in Qingyang.
2011 年至 2015 年期间，在中国庆阳市的家畜群体中进行了一项大规模调查。使用虎红平板试验（RBPT）和标准凝集试验（SAT）对来自庆阳不同地区的 448398 只动物进行了布鲁氏菌特异性抗体检测。2011 年至 2015 年期间，在所检测的 8 个县中，每年的平均阳性率在 0.04%至 4.75%之间。此外，这些县的流行率在 0%至 9.96%之间。绵羊是庆阳市布鲁氏菌的主要宿主，绵羊的流行率（2.74%）高于其他检测动物。从绵羊中分离出的 10 株布鲁氏菌的鉴定证实，流行株为 3 型牛种布鲁氏菌（n=9）和 1 型牛种布鲁氏菌（n=1）。对 10 株分离株的 MLVA-11（多位点可变数串联重复分析）分析显示了 3 种基因型：基因型 116（n=8）、基因型 115（n=1）和基因型 136（n=1）。此外，对代表性 B. melitensis 菌株 QY1 的全基因组序列分析表明，该分离株与来自中国和印度的分离株密切相关。血清流行病学分析结果证实，北部庆阳市是布鲁氏菌病的一个关键流行区，且该病呈上升趋势，尤其是在 2013 年至 2015 年期间。对分离株基因型的分析表明，绵羊布鲁氏菌病主要由传统的 B. melitensis（东地中海群）引起，尽管在庆阳市也存在外部菌株（美洲群）。
