The Pandemic H30 Subclone of Sequence Type 131 (ST131) as the Leading Cause of Multidrug-Resistant Escherichia coli Infections in the United States (2011-2012)
The Pandemic H30 Subclone of Sequence Type 131 (ST131) as the Leading Cause of Multidrug-Resistant Escherichia coli Infections in the United States (2011-2012)
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DOI：
10.1093/ofid/ofx089
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发表时间：
2017-03-01
影响因子：
4.2
通讯作者：
Castanheira, Mariana
中科院分区：
文献类型：
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作者：
Johnson, James R.;Porter, Stephen;Castanheira, Mariana
背景肠外大肠埃希菌感染越来越具有挑战性，因为新出现的抗生素耐药性，包括对超广谱β-内酰胺类和氟喹诺酮类的耐药性。序列类型131（ST 131）是主要贡献者。三百六十E。来自美国各地的大肠杆菌临床分离株（2011-2012年），从SENTRY收集的3个耐药类别中随机选择（超广谱头孢菌素[ECS]-降低敏感性[RS];氟喹诺酮耐药，ESC敏感;和氟喹诺酮敏感的，ESC敏感的）被分型为ESTs组，序列类型复合体（STc），其子集，毒力基因型，O型，和β-内酰胺酶基因。将分子结果与易感性特征、标本类型、年龄和性别进行比较。系统群B2占绝大多数，尤其是氟喹诺酮类耐药菌株（83%）。B2组来源的ST 131及其H30亚克隆（分为H30 Rx和H30 R1）占主导地位，特别是在ESC-RS和氟喹诺酮耐药菌株中。相比之下，在氟喹诺酮类敏感分离株中，B2组来源的STc 73和STc 95占主导地位。在每个耐药类别中，ST 131分离株比非ST 131分离株表现出更广泛的耐药性和/或毒力特征。ST 131-H30在地理区域、年龄和标本类型上分布广泛，并显示出独特的β-内酰胺酶基因。反算结果表明，在来源人群中，ST 131占总体分离株的26.4%（2007年为17%），其中ST 131-H30占19.8%，ST 131-H30 R1占13.2%，ST 131-H30 Rx和非H30 ST 131各占6.6%。ST 131-H30及其ESC耐药相关的H30 Rx亚群引起大多数耐药的E. 2011-2012年，美国各地的大肠杆菌感染率上升，自2007年以来，相对流行率上升了50%以上。关注这种菌株可以帮助对抗目前的E。大肠杆菌耐药性流行。
Background. Extraintestinal Escherichia coli infections are increasingly challenging due to emerging antimicrobial resistance, including resistance to extended-spectrum beta-lactams and fluoroquinolones. Sequence type 131 (ST131) is a leading contributor.Methods. Three hundred sixty E. coli clinical isolates from across the United States (2011-2012), selected randomly from the SENTRY collection within 3 resistance categories (extended-spectrum cephalosporin [ECS]-reduced susceptibility [RS]; fluoroquinolone- resistant, ESC-susceptible; and fluoroquinolone-susceptible, ESC-susceptible) were typed for phylogroup, sequence type complex (STc), subsets thereof, virulence genotype, O type, and beta-lactamase genes. Molecular results were compared with susceptibility profile, specimen type, age, and sex.Results. Phylogroup B2 accounted for most isolates, especially fluoroquinolone-resistant isolates (83%). Group B2-derived ST131 and its H30 subclone (divided between H30Rx and H30R1) predominated, especially among ESC-RS and fluoroquinolone-resistant isolates. In contrast, among fluoroquinolone-susceptible isolates, group B2-derived STc73 and STc95 predominated. Within each resistance category, ST131 isolates exhibited more extensive resistance and/or virulence profiles than non-ST131 isolates. ST131-H30 was distributed broadly by geographical region, age, and specimen type and exhibited distinctive beta-lactamase genes. Back-calculations indicated that within the source population ST131 accounted for 26.4% of isolates overall (vs 17% in 2007), including 19.8% ST131-H30, 13.2% ST131-H30R1, and 6.6% each ST131-H30Rx and non-H30 ST131.Conclusions. ST131-H30, with its ESC resistance-associated H30Rx subset, caused most antimicrobial-resistant E. coli infections across the United States in 2011-2012 and, since 2007, increased in relative prevalence by > 50%. Focused attention to this strain could help combat the current E. coli resistance epidemic.