Brucella spp. of amphibians comprise genomically diverse motile strains competent for replication in macrophages and survival in mammalian hosts
Brucella spp. of amphibians comprise genomically diverse motile strains competent for replication in macrophages and survival in mammalian hosts
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DOI：
10.1038/srep44420
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发表时间：
2017-03-16
影响因子：
4.6
通讯作者：
Scholz, Holger C.
中科院分区：
文献类型：
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作者：
Al Dahouk, Sascha;Koehler, Stephan;Scholz, Holger C.
从15只患系统性疾病的非洲牛蛙（Pyxicephalus edulis）中分离到21株革兰氏阴性运动球杆菌，经标准微生物鉴定系统初步鉴定为人苍白杆菌。系统发育重建，使用组合的分子分析和比较全基因组分析的最多样化的牛蛙菌株验证属布鲁氏菌的隶属关系，并放置在一个集群包含B的菌株。inopinata和其他非经典的布鲁氏菌物种，但也揭示了显着的遗传差异组内。四个代表性的，但分子和表型不同的菌株用于体外和体内感染实验。所有这些细胞在巨噬细胞样小鼠J774-细胞中均易于增殖，其总体巨噬细胞内生长速率与B相当。inopinataBO 1，略高于B。第4915章.在BALB/c小鼠感染模型中，这些菌株在脾和肝中复制，但效率低于B。suis 1330.一些菌株在哺乳动物宿主中存活长达12周。这些新菌株的异质性阻碍了单一物种的描述，但它们的表型和遗传特征表明，它们代表了土壤相关祖先和哺乳动物宿主适应性致病布鲁氏菌物种之间的进化联系。
Twenty-one small Gram-negative motile coccobacilli were isolated from 15 systemically diseased African bullfrogs (Pyxicephalus edulis), and were initially identified as Ochrobactrum anthropi by standard microbiological identification systems. Phylogenetic reconstructions using combined molecular analyses and comparative whole genome analysis of the most diverse of the bullfrog strains verified affiliation with the genus Brucella and placed the isolates in a cluster containing B. inopinata and the other non-classical Brucella species but also revealed significant genetic differences within the group. Four representative but molecularly and phenotypically diverse strains were used for in vitro and in vivo infection experiments. All readily multiplied in macrophage-like murine J774-cells, and their overall intramacrophagic growth rate was comparable to that of B. inopinata BO1 and slightly higher than that of B. microti CCM 4915. In the BALB/c murine model of infection these strains replicated in both spleen and liver, but were less efficient than B. suis 1330. Some strains survived in the mammalian host for up to 12 weeks. The heterogeneity of these novel strains hampers a single species description but their phenotypic and genetic features suggest that they represent an evolutionary link between a soil-associated ancestor and the mammalian host-adapted pathogenic Brucella species.