Genomic and phenotypic variation in epidemic-spanning Salmonella enterica serovar Enteritidis isolates.
Genomic and phenotypic variation in epidemic-spanning Salmonella enterica serovar Enteritidis isolates.
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DOI：
10.1186/1471-2180-9-237
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发表时间：
2009-11-18
期刊：
影响因子：
4.2
通讯作者：
Chabalgoity JA
中科院分区：
文献类型：
--
作者：
Betancor L;Yim L;Fookes M;Martinez A;Thomson NR;Ivens A;Peters S;Bryant C;Algorta G;Kariuki S;Schelotto F;Maskell D;Dougan G;Chabalgoity JA
肠炎沙门氏菌(S.Enteritidis，S.Enteritidis)在许多不同的国家引起了胃肠道感染的大流行。在这项研究中，我们调查了乌拉圭疫情之前、期间和之后分离的肠炎沙门氏菌的基因组差异和致病潜力。对266株肠炎沙门氏菌进行了基因分型，并对其中一株进行了PFGE分析。其中，29个不同时期、不同遗传图谱和不同分离来源的分离株被检测了它们感染人上皮细胞的能力，并以沙门氏菌PAN阵列和测序菌株PT4 P125109为参考进行了比较基因组杂交。来自遥远国家的另外六个分离株被纳入为外部参照物。在肠炎沙门氏菌分离株中发现233个染色体基因和毒力质粒是可变的。不同菌株之间的16个染色体区域中有10个对应于类似噬菌体的区域。两个最古老的流行前分离株缺乏噬菌体SE20，并含有其他噬菌体编码基因，这些基因在测序菌株中是不存在的。除了原噬菌体的变异外，我们还发现了与新陈代谢和细菌适应性有关的基因的变异。5株流行株缺乏完整的沙门氏菌毒力质粒。值得注意的是，遗传模式难以区分的菌株在感染上皮细胞的能力方面仍然显示出重大差异，这表明所使用的方法不足以检测这种差异行为的遗传基础。最近乌拉圭肠炎沙门氏菌感染的流行是由引入了与之密切相关的4型噬菌体血统菌株所推动的。我们的结果证实了先前的报道，表明肠炎沙门氏菌分离株具有高度的遗传同质性。然而，在这里描述的可变区中，有10个在肠炎沙门氏菌中是第一次被报告为可变的。特别是，最古老的流行前分离株携带以前在肠炎沙门氏菌中未报告的噬菌体相关基因区域。总体而言，我们的结果支持这样的观点，即噬菌体在肠炎沙门氏菌遗传多样性的产生中起着关键作用，噬菌体SE20可能是能够引起流行病的特定菌株出现的关键标志。
Salmonella enterica serovar Enteritidis (S. Enteritidis) has caused major epidemics of gastrointestinal infection in many different countries. In this study we investigate genome divergence and pathogenic potential in S. Enteritidis isolated before, during and after an epidemic in Uruguay. 266 S. Enteritidis isolates were genotyped using RAPD-PCR and a selection were subjected to PFGE analysis. From these, 29 isolates spanning different periods, genetic profiles and sources of isolation were assayed for their ability to infect human epithelial cells and subjected to comparative genomic hybridization using a Salmonella pan-array and the sequenced strain S. Enteritidis PT4 P125109 as reference. Six other isolates from distant countries were included as external comparators. Two hundred and thirty three chromosomal genes as well as the virulence plasmid were found as variable among S. Enteritidis isolates. Ten out of the 16 chromosomal regions that varied between different isolates correspond to phage-like regions. The 2 oldest pre-epidemic isolates lack phage SE20 and harbour other phage encoded genes that are absent in the sequenced strain. Besides variation in prophage, we found variation in genes involved in metabolism and bacterial fitness. Five epidemic strains lack the complete Salmonella virulence plasmid. Significantly, strains with indistinguishable genetic patterns still showed major differences in their ability to infect epithelial cells, indicating that the approach used was insufficient to detect the genetic basis of this differential behaviour. The recent epidemic of S. Enteritidis infection in Uruguay has been driven by the introduction of closely related strains of phage type 4 lineage. Our results confirm previous reports demonstrating a high degree of genetic homogeneity among S. Enteritidis isolates. However, 10 of the regions of variability described here are for the first time reported as being variable in S. Enteritidis. In particular, the oldest pre-epidemic isolates carry phage-associated genetic regions not previously reported in S. Enteritidis. Overall, our results support the view that phages play a crucial role in the generation of genetic diversity in S. Enteritidis and that phage SE20 may be a key marker for the emergence of particular isolates capable of causing epidemics.
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影响因子：
2.8
作者：
Klumpp, Jochen;Fuchs, Thilo M.
通讯作者：
Fuchs, Thilo M.
影响因子：
4.4
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作者：
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通讯作者：
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