2008-2010 年比利时布鲁塞尔首都大区产志贺毒素大肠埃希菌感染的发生率和毒力决定因素。
Incidence and virulence determinants of verocytotoxin-producing Escherichia coli infections in the Brussels-Capital Region, Belgium, in 2008-2010.
机构信息
National Reference Center for VTEC/STEC, Department for Microbiology and Infection Control, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium.
出版信息
J Clin Microbiol. 2012 Apr;50(4):1336-45. doi: 10.1128/JCM.05317-11. Epub 2012 Jan 11.
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 = 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.
采用 PCR 法对所有来自布鲁塞尔大学医院(UZB)的人类粪便标本和比利时布鲁塞尔首都大区的其他 6 家医院实验室的选定粪便标本进行产志贺毒素大肠埃希氏菌(VTEC)检测,这些标本的采集时间为 2008 年 4 月至 2010 年 10 月。本研究纳入的粪便标本来自溶血尿毒综合征(HUS)患者、有血样腹泻病史的患者、与腹泻聚集有关的患者、6 岁以下儿童和含有肉眼可见血液的粪便。在选定条件下的患者粪便中,VTEC 的检测频率明显高于 UZB 未选定粪便(2.04% vs. 1.20%,P = 0.001)。在 HUS(35.3%)、血样腹泻病史(5.15%)或含有肉眼可见血液的粪便(1.85%)患者中,VTEC 的检出率最高。17 岁以下患者的粪便 vtx 阳性率显著高于 18-65 岁成年患者(P = 0.022)。虽然 65 岁以上患者的粪便 vtx 阳性率也高于 18-65 岁患者,但这种趋势并不显著。从 140 份 vtx 阳性粪便中分离出 VTEC。一个样本产生了两种不同的血清型;因此,能够对 141 株分离物进行特征描述。鉴定出 60 种不同的 O:H 血清型,携带 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 O 岛 122(COI-122);15 株还携带 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 阳性,36 株(33.6%)vtx2 阳性,12 株(11.2%)同时携带 vtx1 和 vtx2。脉冲场凝胶电泳显示出广泛的遗传多样性;然而,确定了一些可能是未识别暴发的小 O157、O26 和 O63:H6 VTEC 集群。在 63 株(44.7%)分离株中观察到抗生素耐药性,其中 34 株(24.1%)表现为多药耐药性。我们的数据表明,VTEC 感染并不仅限于 HUS 或血样腹泻患者。因此,临床实验室应使用选择性培养基和检测志贺毒素或 vtx 基因的方法,对所有粪便进行 O157 和非 O157 VTEC 检测。