Involvement of a Salmonella genomic island 1 gene in the rumen protozoan-mediated enhancement of invasion for multiple-antibiotic-resistant Salmonella enterica serovar Typhimurium
Involvement of a Salmonella genomic island 1 gene in the rumen protozoan-mediated enhancement of invasion for multiple-antibiotic-resistant Salmonella enterica serovar Typhimurium
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DOI：
10.1128/iai.00679-06
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发表时间：
2007-02-01
影响因子：
3.1
通讯作者：
Franklin, Sharon K.
中科院分区：
文献类型：
--
作者：
Carlson, Steve A.;Sharma, Vijay K.;Franklin, Sharon K.
多重抗生素耐药肠道沙门氏菌血清型鼠伤寒沙门氏菌是一种食源性病原体，可能比缺乏多重耐药表型的相关菌株更具毒性。肠道沙门氏菌血清型鼠伤寒噬菌体DT 104型是这些多重耐药/超强毒株中最常见的。DT 104的多重耐药性是由一个整合子结构赋予的，命名为沙门氏菌基因组岛1（SGI 1），而我们最近证明了DT 104的超侵入由瘤胃原生动物（RPz）介导，这是牛的正常植物群。在其他沙门氏菌菌株中也观察到过度侵入，即，其他S。肠道血清型鼠伤寒沙门氏菌噬菌体类型和其它沙门氏菌。肠道沙门氏菌血清型，如S.婴儿肠道血清型具有SGI 1，而缺乏SGI 1的DT 104菌株不是高侵袭性的。在此，我们试图确定SGI 1基因参与的RPz介导的超侵入沙门氏菌菌株轴承SGI 1。转座子诱变，加上一种新的报告系统，揭示了SGI 1基因先前指定SO 13的参与。SO 13表达的破坏导致废除的超侵入评估组织培养侵袭试验和牛的挑战实验。然而，在非SGI 1-轴承工程沙门氏菌表达SO 13菌株中没有观察到超侵入。也就是说，SO 13和另一个SGI 1基因可能协同上调暴露于RPz的DT 104的侵袭。
Multiple-antibiotic-resistant Salmonella enterica serotype Typhimurium is a food-borne pathogen that may be more virulent than related strains lacking the multiresistance phenotype. Salmonella enterica serotype Typhimurium phage type DT104 is the most prevalent of these multiresistant/hypervirulent strains. Multiresistance in DT104 is conferred by an integron structure, designated Salmonella genomic island 1 (SGI1), while we recently demonstrated DT104 hyperinvasion mediated by rumen protozoa (RPz) that are normal flora of cattle. Hyperinvasion was also observed in other Salmonella strains, i.e., other S. enterica serovar Typhimurium phage types and other S. enterica serovars, like S. enterica serovar Infantis, possessing SGI1, while DT104 strains lacking SGI1 were not hyperinvasive. Herein we attempted to identify SGI1 genes involved in the RPz-mediated hyperinvasion of Salmonella strains bearing SGI1. Transposon mutagenesis, coupled with a novel reporter system, revealed the involvement of an SGI1 gene previously designated SO13. Disruption of SO13 expression led to an abrogation of hyperinvasion as assessed by tissue culture invasion assays and by bovine challenge experiments. However, hyperinvasion was not observed in non-SGI1-bearing strains of Salmonella engineered to express SO13. That is, SO13 and another SGI1 gene(s) may coordinately upregulate invasion in DT104 exposed to RPz.