The lipopolysaccharide biosynthesis core of the Mexican pathogenic strain Serratia entomophila is associated with toxicity to larvae of Phyllophaga blanchardi.
The lipopolysaccharide biosynthesis core of the Mexican pathogenic strain Serratia entomophila is associated with toxicity to larvae of Phyllophaga blanchardi.
复制标题
墨西哥致病菌株嗜虫沙雷氏菌的脂多糖生物合成核心与对白色飞虱幼虫的毒性有关。
DOI：
10.1016/j.jip.2012.01.008
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发表时间：
2012
影响因子：
3.4
通讯作者：
M. Nuñez
中科院分区：
文献类型：
--
作者：
Zitlhally Rodríguez;Jian;F. Villalobos;S. Gill;M. Nuñez
墨西哥细菌嗜虫沙雷氏菌菌株Mor4.1（肠杆菌科）对被认为是重要的土壤害虫的Phyllophaga属的鞘翅目物种是致病性的。Mor4.1在口服和注射生物测定后通过细菌或无细胞培养液接种引起幼虫的拒食活性和死亡。Mor4.1的致病决定因素尚未阐明。我们假设Mor4.1产生几种毒素和其他毒力因子，一些作用于昆虫肠道水平，另一些作用于血腔。为了鉴定和表征毒力因子，构建了S.虫媒菌Mor4.1是在大肠杆菌中制备的。通过将单个克隆注射到Phyllophaga blanchardi幼虫中，分离到5个不同的杀虫克隆。测定了克隆G8的40kb DNA全序列和基因组结构。通过比较基因组学研究，共发现21个与毒力相关的基因。通过转座子（Tn5）插入突变的G8和进一步的生物测定，我们表明，一个dUTR，黄素蛋白和庚糖基转移酶III，是G8毒性活性的关键因素。庚糖基转移酶III是脂多糖（LPS）生物合成核心的一部分。我们通过注射生物测定证实了从G8和Mor4.1中纯化的LPS对布氏原螯虾幼虫具有毒性。
The Mexican bacteria Serratia entomophila strain Mor4.1 (Enterobacteriaceae) is pathogenic to coleopteran species of the Phyllophaga genus, which are considered important soil-dwelling pests. Mor4.1 causes anti-feeding activity and mortality to larvae after oral and injection bio-assay either, by bacteria or by cell free culture broth inoculation. The pathogenic determinants of Mor4.1 have not been elucidated. We hypothesize that Mor4.1 produces several toxins and other virulence factors, some acting at the level of the insect gut and others at the hemocoel. To identify and characterize virulence factors, a fosmid library of S. entomophila Mor4.1 was made in Escherichia coli. Five different insecticidal clones were isolated by injecting individual clones into Phyllophaga blanchardi larvae. The complete 40kb DNA sequence and gene organization of clone G8 was determined. By comparative genomics, 21 genes were associated with virulence. By transposon (Tn5) insertion mutagenesis of G8 and further bio-assays we show that a dUTPase, a flavoprotein and a heptosyltransferase III, are key factors for G8 toxic activity. The heptosyltransferase III, is part of the lipopolysaccharide (LPS) biosynthesis core. We demonstrated that purified LPS from G8 and Mor4.1 are toxic to P. blanchardi larvae by injection bio-assay.