Persistence of Rare Salmonella Typhi Genotypes Susceptible to First-Line Antibiotics in the Remote Islands of Samoa.
Persistence of Rare Salmonella Typhi Genotypes Susceptible to First-Line Antibiotics in the Remote Islands of Samoa.
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作者：
几十年来，偏远的岛国萨摩亚（人口约20万）尽管在水质、卫生和经济发展方面有所改善，但仍面临着地方性伤寒。我们最近描述了2008年至2019年萨摩亚伤寒的流行病学，按人，地点和时间;然而，当地的伤寒沙门氏菌（S。伤寒）的种群结构、进化起源和基因组特征仍然未知。本文报道了306株S. 1983年至2020年收集的萨摩亚伤寒分离株。系统发生学揭示了罕见基因型3.5.4和3.5.3的优势群体，共包括292/306（95.4%）的萨摩亚人和2/4934（0.04%）的全球S。伤寒杆菌。确定了三个不同的3.5.4基因组亚系，并确定了它们的定义多态性。这些占主导地位的萨摩亚基因型可能出现在20世纪70年代，与来自南美洲，东南亚和大洋洲的其他3.5进化枝分离株共享祖先。此外，在1992年萨摩亚S.在106/306（34.6%）的萨摩亚分离株中鉴定出伤寒分离株;这是在全球收集的含pHCM 2分离株中观察到的比例的两倍多。与全球S.伤寒趋势，耐药赋予多态性检测到只有15/306（4.9%）的萨摩亚S。伤寒，表明对抗生素的压倒性敏感性，在南亚和东南亚的大部分地区不再有效。这个国家级的基因组框架可以帮助当地卫生当局进行伤寒监测和控制工作，并填补了在伤寒沙门氏菌方面的关键知识空白。来自大洋洲的伤寒基因组数据。
For decades, the remote island nation of Samoa (population ~200,000) has faced endemic typhoid fever despite improvements in water quality, sanitation, and economic development. We recently described the epidemiology of typhoid fever in Samoa from 2008 to 2019 by person, place, and time; however, the local Salmonella enterica serovar Typhi (S. Typhi) population structure, evolutionary origins, and genomic features remained unknown. Herein, we report whole genome sequence analyses of 306 S. Typhi isolates from Samoa collected between 1983 and 2020. Phylogenetics revealed a dominant population of rare genotypes 3.5.4 and 3.5.3, together comprising 292/306 (95.4%) of Samoan versus 2/4934 (0.04%) global S. Typhi isolates. Three distinct 3.5.4 genomic sublineages were identified, and their defining polymorphisms were determined. These dominant Samoan genotypes, which likely emerged in the 1970s, share ancestry with other 3.5 clade isolates from South America, Southeast Asia, and Oceania. Additionally, a 106-kb pHCM2 phenotypically cryptic plasmid, detected in a 1992 Samoan S. Typhi isolate, was identified in 106/306 (34.6%) of Samoan isolates; this is more than double the observed proportion of pHCM2-containing isolates in the global collection. In stark contrast with global S. Typhi trends, resistance-conferring polymorphisms were detected in only 15/306 (4.9%) of Samoan S. Typhi, indicating overwhelming susceptibility to antibiotics that are no longer effective in most of South and Southeast Asia. This country-level genomic framework can help local health authorities in their ongoing typhoid surveillance and control efforts, as well as fill a critical knowledge gap in S. Typhi genomic data from Oceania.
影响因子：
3.8
作者：
Guevara PD;Maes M;Thanh DP;Duarte C;Rodriguez EC;Montaño LA;Dan THN;Nguyen TNT;Carey ME;Campos J;Chinen I;Perez E;Baker S
通讯作者：
Baker S