National and OIE Reference Laboratory for Brucellosis, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Teramo, Italy.
Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Foggia, Italy.
PLoS One. 2020 Oct 2;15(10):e0240178. doi: 10.1371/journal.pone.0240178. eCollection 2020.
Brucella ceti infections have been increasingly reported in cetaceans, although a very limited characterization of Mediterranean Brucella spp. isolates has been previously reported and relatively few data exist about brucellosis among cetaceans in Italy. To address this gap, we studied 8 cases of B. ceti infection in striped dolphins (Stenella coeruleoalba) stranded along the Italian coastline from 2012 to 2018, investigated thanks to the Italian surveillance activity on stranded cetaceans. We focused on cases of stranding in eastern and western Italian seas, occurred along the Apulia (N = 6), Liguria (N = 1) and Calabria (N = 1) coastlines, through the analysis of gross and microscopic findings, the results of microbiological, biomolecular and serological investigations, as well as the detection of other relevant pathogens. The comparative genomic analysis used whole genome sequences of B. ceti from Italy paired with the publicly available complete genomes. Pathological changes consistent with B. ceti infection were detected in the central nervous system of 7 animals, showing non-suppurative meningoencephalitis. In 4 cases severe coinfections were detected, mostly involving Dolphin Morbillivirus (DMV). The severity of B. ceti-associated lesions supports the role of this microbial agent as a primary neurotropic pathogen for striped dolphins. We classified the 8 isolates into the common sequence type 26 (ST-26). Whole genome SNP analysis showed that the strains from Italy clustered into two genetically distinct clades. The first clade comprised exclusively the isolates from Ionian and Adriatic Seas, while the second one included the strain from the Ligurian Sea and those from the Catalonian coast. Plotting these clades onto the geographic map suggests a link between their phylogeny and topographical distribution. These results represent the first extensive characterization of B. ceti isolated from Italian waters reported to date and show the usefulness of WGS for understanding of the evolution of this emerging pathogen.
鲸类动物中的贝氏柯克斯体感染的报道日益增多，尽管此前仅对地中海布氏菌属分离株进行了非常有限的表征，而且有关意大利鲸类动物中的布鲁氏菌病的数据相对较少。为了解决这一差距，我们研究了 2012 年至 2018 年期间在意大利沿海搁浅的条纹海豚（Stenella coeruleoalba）中 8 例贝氏柯克斯体感染病例，这些病例是通过对搁浅的鲸类动物的意大利监测活动发现的。我们重点研究了发生在意大利东部和西部海域的搁浅病例，这些病例发生在普利亚（N=6）、利古里亚（N=1）和卡拉布里亚（N=1）沿海地区，通过对大体和显微镜检查结果、微生物学、生物分子和血清学调查结果以及其他相关病原体的检测进行分析。比较基因组分析使用了来自意大利的贝氏柯克斯体全基因组序列，并与公开的完整基因组进行了配对。在 7 只动物的中枢神经系统中检测到与贝氏柯克斯体感染一致的病理变化，表现为非化脓性脑膜脑炎。在 4 例病例中检测到严重的合并感染，主要涉及海豚麻疹病毒（DMV）。贝氏柯克斯体相关病变的严重程度支持了这种微生物作为条纹海豚原发性神经嗜性病原体的作用。我们将 8 株分离株分类为常见的序列型 26（ST-26）。全基因组 SNP 分析表明，来自意大利的菌株聚类为两个遗传上不同的分支。第一个分支仅包含来自爱奥尼亚海和亚得里亚海的分离株，而第二个分支包含来自利古里亚海的分离株和来自加泰罗尼亚海岸的分离株。将这些分支绘制在地理地图上表明，它们的系统发育和地理分布之间存在联系。这些结果代表了迄今为止报道的来自意大利水域的贝氏柯克斯体的首次广泛特征描述，并显示了 WGS 用于理解这种新兴病原体进化的有用性。
