Recent Outbreaks of Shigellosis in California Caused by Two Distinct Populations of Shigella sonnei with either Increased Virulence or Fluoroquinolone Resistance.
Recent Outbreaks of Shigellosis in California Caused by Two Distinct Populations of Shigella sonnei with either Increased Virulence or Fluoroquinolone Resistance.
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DOI：
10.1128/msphere.00344-16
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发表时间：
2016-11
期刊：
影响因子：
4.8
通讯作者：
Chaturvedi V
中科院分区：
文献类型：
--
作者：
Kozyreva VK;Jospin G;Greninger AL;Watt JP;Eisen JA;Chaturvedi V
志贺氏菌病是一种急性肠道疾病，在美国每年造成近50万例感染，6，000例住院治疗和70例死亡。宋内氏志贺菌在2014年和2015年在加州引发了两次异常大的疫情。我们使用全基因组测序来了解这些爆发中涉及的细菌的致病潜力。我们的研究结果表明，至少自2008年以来，在加州持续存在当地的宋内氏志贺菌SDi/SJo克隆。最近，原始克隆的衍生物通过与其他细菌交换噬菌体获得了产生滋贺毒素（STX）的能力。STX的产生与更严重的疾病有关，包括血性腹泻。在旧金山弗朗西斯科地区引起暴发的第二个宋内氏志贺菌种群对氟喹诺酮类药物具有耐药性，并显示出与来自南亚的氟喹诺酮耐药谱系有关的证据。必须监测加州宋内氏志贺菌种群中这些新出现的趋势，以防止毒性和耐药性越来越强的克隆在未来传播的风险。宋内志贺菌曾在2014年和2015年在加州引发了不寻常的大规模志贺菌病疫情。初步数据表明，涉及两个不同的细菌种群，一个来自圣地亚哥和圣华金（SDI/SJo），一个来自旧金山弗朗西斯科（SFr）海湾地区。对68株宋内氏志贺菌进行全基因组分析和药敏试验，以探讨与这些暴发相关的微生物因素。SDi/SJo和SFr群体以及几乎所有的宋内氏志贺菌分离株都属于序列类型152（ST 152）。全基因组单核苷酸多态性（SNP）分析将大多数加州（CA）分离株聚类为早期描述的谱系III。SDi/SJo人群中的分离株有一种新的类梭菌噬菌体，携带编码滋贺毒素（STX）的基因，与大肠杆菌O 104：H4中发现的基因最密切相关。然而，来自这种新噬菌体的STX基因（stx 1A和stx 1B）具有与来自福氏志贺菌和沙门氏菌的STX基因最相似的序列。由于gyrA和parC基因的点突变，SFr人群中的分离株对环丙沙星具有耐药性，并且与起源于南亚的谱系III内的氟喹诺酮耐药宋内氏志贺菌分支相关。高毒力宋内氏志贺菌菌株的出现和氟喹诺酮耐药菌株的引入反映了该病原体在加州的变化特征。提倡加强监测，以便及早发现此类菌株引起的未来爆发。志贺氏菌病是一种急性肠道疾病，在美国每年造成近50万例感染，6,000例住院治疗和70例死亡。宋内氏志贺菌在2014年和2015年在加州引发了两次异常大的疫情。我们使用全基因组测序来了解这些爆发中涉及的细菌的致病潜力。我们的研究结果表明，至少自2008年以来，在加州持续存在当地的宋内氏志贺菌SDi/SJo克隆。最近，原始克隆的衍生物通过与其他细菌交换噬菌体获得了产生滋贺毒素（STX）的能力。STX的产生与更严重的疾病有关，包括血性腹泻。在旧金山弗朗西斯科地区引起暴发的第二个宋内氏志贺菌种群对氟喹诺酮类药物具有耐药性，并显示出与来自南亚的氟喹诺酮耐药谱系有关的证据。必须监测加州宋内氏志贺菌种群中这些新出现的趋势，以防止毒性和耐药性越来越强的克隆在未来传播的风险。
Shigellosis is an acute diarrheal disease causing nearly half a million infections, 6,000 hospitalizations, and 70 deaths annually in the United States. S. sonnei caused two unusually large outbreaks in 2014 and 2015 in California. We used whole-genome sequencing to understand the pathogenic potential of bacteria involved in these outbreaks. Our results suggest the persistence of a local S. sonnei SDi/SJo clone in California since at least 2008. Recently, a derivative of the original clone acquired the ability to produce Shiga toxin (STX) via exchanges of bacteriophages with other bacteria. STX production is connected with more severe disease, including bloody diarrhea. A second population of S. sonnei that caused an outbreak in the San Francisco area was resistant to fluoroquinolones and showed evidence of connection to a fluoroquinolone-resistant lineage from South Asia. These emerging trends in S. sonnei populations in California must be monitored for future risks of the spread of increasingly virulent and resistant clones. Shigella sonnei has caused unusually large outbreaks of shigellosis in California in 2014 and 2015. Preliminary data indicated the involvement of two distinct bacterial populations, one from San Diego and San Joaquin (SDi/SJo) and one from the San Francisco (SFr) Bay area. Whole-genome analysis and antibiotic susceptibility testing of 68 outbreak and archival isolates of S. sonnei were performed to investigate the microbiological factors related to these outbreaks. Both SDi/SJo and SFr populations, as well as almost all of the archival S. sonnei isolates belonged to sequence type 152 (ST152). Genome-wide single nucleotide polymorphism (SNP) analysis clustered the majority of California (CA) isolates to an earlier described lineage III. Isolates in the SDi/SJo population had a novel lambdoid bacteriophage carrying genes encoding Shiga toxin (STX) that were most closely related to that found in Escherichia coli O104:H4. However, the STX genes (stx1A and stx1B) from this novel phage had sequences most similar to the phages from Shigella flexneri and S. dysenteriae. The isolates in the SFr population were resistant to ciprofloxacin due to point mutations in gyrA and parC genes and were related to the fluoroquinolone-resistant S. sonnei clade within lineage III that originated in South Asia. The emergence of a highly virulent S. sonnei strain and introduction of a fluoroquinolone-resistant strain reflect the changing traits of this pathogen in California. An enhanced monitoring is advocated for early detection of future outbreaks caused by such strains. IMPORTANCE Shigellosis is an acute diarrheal disease causing nearly half a million infections, 6,000 hospitalizations, and 70 deaths annually in the United States. S. sonnei caused two unusually large outbreaks in 2014 and 2015 in California. We used whole-genome sequencing to understand the pathogenic potential of bacteria involved in these outbreaks. Our results suggest the persistence of a local S. sonnei SDi/SJo clone in California since at least 2008. Recently, a derivative of the original clone acquired the ability to produce Shiga toxin (STX) via exchanges of bacteriophages with other bacteria. STX production is connected with more severe disease, including bloody diarrhea. A second population of S. sonnei that caused an outbreak in the San Francisco area was resistant to fluoroquinolones and showed evidence of connection to a fluoroquinolone-resistant lineage from South Asia. These emerging trends in S. sonnei populations in California must be monitored for future risks of the spread of increasingly virulent and resistant clones.