Veterans Affairs Medical Center, Minneapolis, Minnesota, USA
Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
J Clin Microbiol. 2019 Apr 26;57(5). doi: 10.1128/JCM.01664-18. Print 2019 May.
sequence type 1193 (ST1193) is an emerging multidrug-resistant pathogen. We performed longitudinal and cross-sectional surveillance for ST1193 among clinical and fecal isolates from Minneapolis Veterans Affairs Medical Center (VAMC) patients and their household members, other Minnesota centers, and national VAMCs and compared these ST1193 isolates with archival human and canine ST1193 isolates from Australia (2008). We also developed and extensively validated a novel multiplex PCR assay for ST1193 and its characteristic (type 1 fimbrial adhesin) allele. We found that ST1193-64 (where "64" refers to a phylogenetic subdivision within ST1193 that is characterized by the allele), which was uniformly fluoroquinolone resistant, appeared to emerge in the United States in a geographically staggered fashion beginning around 2011. Its prevalence among clinical and fecal isolates at the Minneapolis VAMC rose rapidly beginning in 2013, peaked in early 2017, and then plateaued or declined. In comparison with other ST14 complex (STc14) isolates, ST1193-64 isolates were more extensively multidrug resistant, whereas their virulence genotypes were less extensive but included (uniquely) K1 capsule and Pulsed-field gel electrophoresis separated ST1193-64 isolates from other STc14 isolates and showed genetic commonality between archival Australian versus recent U.S. isolates, fecal versus clinical isolates, and human versus canine isolates. Three main ST1193 pulsotypes differed significantly in resistance profiles and capsular types; emergent pulsotype 2123 was associated with trimethoprim-sulfamethoxazole resistance and K1 (versus K5) capsule. These findings clarify ST1193-64's temporal prevalence trends as a fluoroquinolone-resistant pathogen and commensal; document clonal subsets with distinctive geographic, temporal, resistance, and virulence gene associations; and establish a new laboratory tool for rapid and simple detection of ST1193-64.
序列类型 1193（ST1193）是一种新兴的多药耐药病原体。我们对明尼苏达州退伍军人事务医疗中心（VAMC）患者及其家庭成员、其他明尼苏达州中心以及全国 VAMC 的临床和粪便分离株中的 ST1193 进行了纵向和横断面监测，并将这些 ST1193 分离株与来自澳大利亚的档案人类和犬 ST1193 分离株（2008 年）进行了比较。我们还开发并广泛验证了一种用于 ST1193 及其特征（1 型菌毛粘附素）等位基因的新型多重 PCR 检测方法。我们发现，ST1193-64（其中“64”是指 ST1193 内的一个系统发育亚群，其特征是等位基因），它对氟喹诺酮类药物具有一致性的耐药性，似乎于 2011 年左右在美国以地理交错的方式出现。自 2013 年以来，明尼苏达州 VAMC 的临床和粪便分离株中 ST1193-64 的流行率迅速上升，在 2017 年初达到高峰，然后趋于平稳或下降。与其他 ST14 复合物（STc14）分离株相比，ST1193-64 分离株具有更广泛的多药耐药性，而它们的毒力基因型则不那么广泛，但包括（独特的）K1 荚膜和脉冲场凝胶电泳将 ST1193-64 分离株与其他 STc14 分离株区分开来，并显示出澳大利亚档案与最近美国分离株、粪便与临床分离株以及人类与犬分离株之间的遗传共性。三个主要的 ST1193 脉冲型在耐药谱和荚膜类型上有显著差异；新兴的脉冲型 2123 与甲氧苄啶-磺胺甲恶唑耐药和 K1（与 K5）荚膜有关。这些发现阐明了 ST1193-64 作为一种氟喹诺酮类耐药病原体和共生体的时间流行趋势；记录了具有独特地理、时间、耐药性和毒力基因关联的克隆亚群；并建立了一种用于快速简单检测 ST1193-64 的新实验室工具。
