Incidence and Virulence Determinants of Verocytotoxin-Producing Escherichia coli Infections in the Brussels-Capital Region, Belgium, in 2008-2010
Incidence and Virulence Determinants of Verocytotoxin-Producing Escherichia coli Infections in the Brussels-Capital Region, Belgium, in 2008-2010
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DOI：
10.1128/jcm.05317-11
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发表时间：
2012-04-01
影响因子：
9.4
通讯作者：
Pierard, Denis
中科院分区：
文献类型：
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作者：
Buvens, Glenn;De Gheldre, Yves;Pierard, Denis
通过 PCR 对 2008 年 4 月至 2010 年 10 月期间收集的布鲁塞尔 Ziekenhuis 大学 (UZB) 的所有人类粪便以及比利时布鲁塞尔首都地区其他六家医院实验室的选定粪便中产生维罗细胞毒素的大肠杆菌 (VTEC) 进行了调查。血性腹泻、与聚集性腹泻相关的患者、6 岁以下儿童以及粪便中含有肉眼可见的血液。与未选择的 UZB 患者粪便 (1.20%) 相比，在选定病症患者的粪便中 (2.04%) 检测到 Verocytotoxin 基因 (vtx) 的频率显着更高（P 类似于 0.001）。 VTEC 最常见于患有 HUS (35.3%)、有血性腹泻病史 (5.15%) 或大便含有肉眼可见血液 (1.85%) 的患者。 17 岁以下患者的粪便中 vtx 阳性的频率明显高于 18 岁至 65 岁成年患者的粪便 (P = 0.022)。尽管 65 岁以上患者的粪便中 vtx 阳性的频率也高于 18 至 65 岁患者的粪便，但这种趋势并不显着。从 140 份（67.9%）vtx 阳性粪便中分离出 VTEC。一份样本产生了两种不同的血清型；因此，可以对 141 个分离株进行表征。鉴定出 60 种不同的 O:H 血清型，其中包含 85 种不同的毒力谱。血清型 O157:H7/H- (n = 34)、O26:H11/H- (n = 21)、O63:H6 (n = 8)、O111: H8/H- (n = 7) 和 O146:H21/H- (n = 6) 占分离株的 53.9%。所有 O157 分离株均携带 vtx2、eae 和完整的 O 岛 122 (COI-122)； 15还携带vtx1。然而，非 O157 分离株 (n = 107) 占分离株的大部分 (75.9%)。 59 株（55.1%）分离株 vtx1 呈阳性，36 株（33.6%）vtx2 阳性，12 株（11.2%）同时携带 vtx1 和 vtx2。脉冲场凝胶电泳揭示了广泛的遗传多样性；然而，发现了 O157、O26 和 O63: H6 VTEC 的小簇，这些簇可能是不明爆发的一部分。在 63 株（44.7%）分离株中观察到抗生素耐药性，其中 34 株（24.1%）表现出多重耐药性。我们的数据表明，VTEC 感染并不局限于 HUS 或血性腹泻患者。因此，临床实验室应使用选择性培养基和检测 verocytotoxins 或 vtx 基因的方法来筛查所有粪便中的 O157 和非 O157 VTEC。
The incidence of verocytotoxin-producing Escherichia coli (VTEC) was investigated by PCR in all human stools from Universitair Ziekenhuis Brussel (UZB) and in selected stools from six other hospital laboratories in the Brussels-Capital Region, Belgium, collected between April 2008 and October 2010. The stools selected to be included in this study were those from patients with hemolytic-uremic syndrome (HUS), patients with a history of bloody diarrhea, patients linked to clusters of diarrhea, children up to the age of 6 years, and stools containing macroscopic blood. Verocytotoxin genes (vtx) were detected significantly more frequently in stools from patients with the selected conditions (2.04%) than in unselected stools from UZB (1.20%) (P similar to 0.001). VTEC was detected most frequently in patients with HUS (35.3%), a history of bloody diarrhea (5.15%), or stools containing macroscopic blood (1.85%). Stools from patients up to the age of 17 years were significantly more frequently vtx positive than those from adult patients between the ages of 18 and 65 years (P = 0.022). Although stools from patients older than 65 years were also more frequently positive for vtx than those from patients between 18 and 65 years, this trend was not significant. VTEC was isolated from 140 (67.9%) vtx-positive stools. One sample yielded two different serotypes; thus, 141 isolates could be characterized. Sixty different O: H serotypes harboring 85 different virulence profiles were identified. Serotypes O157:H7/H- (n = 34), O26:H11/H- (n = 21), O63:H6 (n = 8), O111: H8/H- (n = 7), and O146:H21/H- (n = 6) accounted for 53.9% of isolates. All O157 isolates carried vtx2, eae, and a complete O island 122 (COI-122); 15 also carried vtx1. Non-O157 isolates (n = 107), however, accounted for the bulk (75.9%) of isolates. Fifty-nine (55.1%) isolates were positive for vtx1, 36 (33.6%) were positive for vtx2, and 12 (11.2%) carried both vtx1 and vtx2. Pulsed-field gel electrophoresis revealed wide genetic diversity; however, small clusters of O157, O26, and O63: H6 VTEC that could have been part of unidentified outbreaks were identified. Antimicrobial resistance was observed in 63 (44.7%) isolates, and 34 (24.1%) showed multidrug resistance. Our data show that VTEC infections were not limited to patients with HUS or bloody diarrhea. Clinical laboratories should, therefore, screen all stools for O157 and non-O157 VTEC using selective media and a method for detecting verocytotoxins or vtx genes.