Department of Microbiology and Infection Control, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis, Brussels, Belgium.
Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis, Brussels Interuniversity Genomics High Throughput core (BRIGHTcore) platform, Brussels, Belgium.
Virulence. 2022 Dec;13(1):2032-2041. doi: 10.1080/21505594.2022.2147735.
Pathogenic strains can be classified into two major groups, based on the presence of specific virulence factors: extraintestinal pathogenic (ExPEC) and diarrheagenic (DEC). Several case reports describe that DEC can cause bloodstream infections in some rare cases. This mainly concerns a few specific sequence types that express virulence factors from both ExPEC and DEC. In this study, we retrospectively analysed 234 blood isolates with whole genome sequencing (WGS). WGS was performed on an Illumina NovaSeq6000. Genotyping was performed using BioNumerics software. The presence of genes was determined with a minimum percentage sequence identity (ID) threshold of 95% and a minimum length for sequence coverage of 95%. Three of the 234 (1.28%) isolates were defined as DEC, 182 (77.78%) as ExPEC, and 49 (20.94%) did not carry pathotype-associated virulence genes. We identified 112 different virulence genes, 48 O-antigens, and 28 H-antigens 82 STs, among the 234 analyzed isolates. ST131 and ST88 were related to healthcare-associated infections. This study provides insight into the prevalence of virulence factors in a large set of blood isolates from the UZ Brussel. It illustrates high diversity in virulence profiles and highlights the potential of DEC to carry virulence factors associated with extraintestinal infections, making it possible for unusual pathotypes to invade and survive in the bloodstream causing bacteraemia. Diarrheagenic strains causing bacteremia are rare and presently underreported, but modern sequencing techniques will better underscore their importance.
基于特定毒力因子的存在，致病菌株可分为两大主要群，即肠外致病性（ExPEC）和腹泻性（DEC）。有几个病例报告描述了 DEC 在某些罕见情况下可引起血流感染。这主要涉及少数表达 ExPEC 和 DEC 毒力因子的特定序列型。在本研究中，我们回顾性分析了 234 株血培养分离株的全基因组测序（WGS）数据。WGS 是在 Illumina NovaSeq6000 上进行的。基因分型使用 BioNumerics 软件进行。使用最小百分比序列同一性（ID）阈值为 95%和最小序列覆盖率为 95%的标准来确定基因的存在。在 234 株分离株中，有 3 株（1.28%）被定义为 DEC，182 株（77.78%）为 ExPEC，49 株（20.94%）未携带与发病型相关的毒力基因。在分析的 234 株分离株中，我们鉴定了 112 种不同的毒力基因、48 种 O-抗原和 28 种 H-抗原，有 82 种 ST。ST131 和 ST88 与医疗机构相关感染有关。本研究提供了在布鲁塞尔 UZ 大学附属医院大量血培养分离株中有关毒力因子流行情况的深入了解。它说明了毒力谱的高度多样性，并强调了 DEC 携带与肠外感染相关的毒力因子的潜力，使得罕见的发病型有可能入侵和在血液中存活，导致菌血症。引起菌血症的腹泻性菌株很少见且目前报道较少，但现代测序技术将更好地突出它们的重要性。
