Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Department of Microbiology and Infection Control, Belgian National Reference Centre for STEC/VTEC, Brussels, Belgium.
PLoS One. 2018 Jul 2;13(7):e0199968. doi: 10.1371/journal.pone.0199968. eCollection 2018.
Since 1987 all fecal samples referred to the clinical microbiology laboratory of the UZ Brussel were screened for the presence of Shiga toxin-producing E. coli (STEC). In this study all STEC strains isolated over a period of 27 years (1987-2014) were reexamined to achieve deeper insight in the STEC infections in our patient population.
A total of 606 STEC strains from 604 patients were subjected to molecular methods for shiga toxin (stx) subtyping, detection of additional virulence genes, typing of the O-serogroups, and phylogenetic relatedness assessment of STEC O157:H7/H-.
Since the introduction of PCR in 1991 the annual positivity rates varied between 1.1% and 2.7%. The isolation rate of STEC O157:H7/H- remained stable over the years while the isolation rate of non-O157 serotypes increased, mainly since 2011. The majority of the patients were children. Uncomplicated- and bloody diarrhea were the most prevalent gastrointestinal manifestations (respectively 51.9% and 13.6%), 4.3% of the strains were related to the hemolytic uremic syndrome (HUS), and 30.2% of the patients showed none of these symptoms. The strains were very diverse; they belonged to 72 different O-serovars and all stx subtypes except stx1d and stx2g were identified. Out of the 23 stx2f-positives one was associated with HUS and one belonged to the E. albertii species. As seen in other studies, the frequency of strains of the O157:H7/H- serotype and strains carrying stx2a, eaeA and ehxA was higher in patients with HUS.
The characteristics and trends of STEC infection seen in our patient population are similar to those noted in other countries. STEC infections in our hospital are mainly sporadic, and a substantial portion of the patients were asymptomatic carriers. Human STEC Stx2f infection was less rare than previously assumed and we report the first Belgian STEC stx2f HUS case and stx2f positive E. albertii infection.
自 1987 年以来，所有送往布鲁塞尔 UZ 临床微生物学实验室的粪便样本均进行了志贺毒素产生大肠杆菌（STEC）检测。在这项研究中，对 27 年来（1987-2014 年）分离的所有 STEC 菌株进行了重新检查，以更深入地了解我们患者人群中的 STEC 感染情况。
对 604 名患者的 606 株 STEC 菌株进行了分子方法检测，包括志贺毒素（stx）亚型、其他毒力基因检测、O 血清型分型以及 STEC O157:H7/H-的系统发育相关性评估。
自 1991 年引入 PCR 以来，每年的阳性率在 1.1%至 2.7%之间变化。STEC O157:H7/H-的分离率多年来保持稳定，而非 O157 血清型的分离率增加，主要是自 2011 年以来。大多数患者为儿童。无并发症和血性腹泻是最常见的胃肠道表现（分别为 51.9%和 13.6%），4.3%的菌株与溶血尿毒综合征（HUS）有关，30.2%的患者无上述任何症状。菌株非常多样化；它们属于 72 种不同的 O 血清型，除 stx1d 和 stx2g 外，所有 stx 亚型均被鉴定。在 23 株 stx2f 阳性菌株中，有 1 株与 HUS 相关，1 株属于 E. albertii 种。与其他研究一样，在 HUS 患者中，O157:H7/H-血清型菌株和携带 stx2a、eaeA 和 ehxA 的菌株的频率更高。
我们患者人群中观察到的 STEC 感染特征和趋势与其他国家相似。我们医院的 STEC 感染主要是散发性的，相当一部分患者是无症状携带者。人类 STEC Stx2f 感染比以前认为的要罕见得多，我们报告了首例比利时 STEC stx2f HUS 病例和 stx2f 阳性 E. albertii 感染。
