The novel polysaccharide deacetylase homologue Pdi contributes to virulence of the aquatic pathogen Streptococcus iniae
The novel polysaccharide deacetylase homologue Pdi contributes to virulence of the aquatic pathogen Streptococcus iniae
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DOI：
10.1099/mic.0.028365-0
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发表时间：
2010-02-01
期刊：
影响因子：
2.8
通讯作者：
Buchanan, John T.
中科院分区：
文献类型：
--
作者：
Milani, Carlo J. E.;Aziz, Ramy K.;Buchanan, John T.
水生动物源性病原体海豚链球菌对全球水产养殖业构成威胁，并对处理生鱼的人构成风险。由于对S. iniae致病或毒力因子，我们建立了一个高通量系统，结合全基因组焦磷酸测序和转座子诱变，使我们能够识别毒力蛋白，包括Poll，S. iniae，我们在这里描述。使用生物信息学工具，我们确定了一个高度保守的签名基序Pdi也是保守的肽聚糖脱乙酰酶PgdA蛋白质家族。Δ pdi突变体在杂交条纹鲈鱼模型中的毒力和在全鱼血液中的存活率被减弱。此外，发现Pdi促进细菌对溶菌酶杀伤的抗性以及粘附和侵入上皮细胞的能力。另一方面，在自溶能力、抗氧化能力和抗阳离子抗菌肽能力方面，S. iniae野生型和Δ PDI。总之，我们证明了pdi参与了S。研究表明，pdi在S.iniae粘附和侵袭、溶菌酶抗性和鱼血中存活中起重要作用。iniae。Pdi和其它S. iniae毒力蛋白是制定适当的预防和治疗措施以防治该病原体引起的疾病和经济损失的必要的第一步。
The aquatic zoonotic pathogen Streptococcus iniae represents a threat to the worldwide aquaculture industry and poses a risk to humans who handle raw fish. Because little is known about the mechanisms of S. iniae pathogenesis or virulence factors, we established a high-throughput system combining whole-genome pyrosequencing and transposon mutagenesis that allowed us to identify virulence proteins, including Poll, the polysaccharide deacetylase of S. iniae, that we describe here. Using bioinformatics tools, we identified a highly conserved signature motif in Pdi that is also conserved in the peptidoglycan deacetylase PgdA protein family. A Delta pdi mutant was attenuated for virulence in the hybrid striped bass model and for survival in whole fish blood. Moreover, Pdi was found to promote bacterial resistance to lysozyme killing and the ability to adhere to and invade epithelial cells. On the other hand, there was no difference in the autolytic potential, resistance to oxidative killing or resistance to cationic antimicrobial peptides between S. iniae wild-type and Delta pdi. In conclusion, we have demonstrated that pdi is involved in S. iniae adherence and invasion, lysozyme resistance and survival in fish blood, and have shown that pdi plays a role in the pathogenesis of S. iniae. Identification of Pdi and other S. iniae virulence proteins is a necessary initial step towards the development of appropriate preventive and therapeutic measures against diseases and economic losses caused by this pathogen.