Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
Int J Mol Sci. 2022 Aug 12;23(16):9005. doi: 10.3390/ijms23169005.
Adherent-invasive (AIEC) is a pathotype associated with the etiopathogenesis of Crohn's disease (CD), albeit with an as-yet unclear role. The main pathogenic mechanisms described for AIEC are adherence to epithelial cells, invasion of epithelial cells, and survival and replication within macrophages. A few virulence factors have been described as participating directly in these phenotypes, most of which have been evaluated only in AIEC reference strains. To date, no molecular markers have been identified that can differentiate AIEC from other pathotypes, so these strains are currently identified based on the phenotypic characterization of their pathogenic mechanisms. The identification of putative AIEC molecular markers could be beneficial not only from the diagnostic point of view but could also help in better understanding the determinants of AIEC pathogenicity. The objective of this study was to identify molecular markers that contribute to the screening of AIEC strains. For this, we characterized outer membrane protein (OMP) profiles in a group of AIEC strains and compared them with the commensal HS strain. Notably, we found a set of OMPs that were present in the AIEC strains but absent in the HS strain. Moreover, we developed a PCR assay and performed phylogenomic analyses to determine the frequency and distribution of the genes coding for these OMPs in a larger collection of AIEC and other strains. As result, it was found that three genes (, , and ) are widely distributed and significantly correlated with AIEC strains, whereas they are infrequent in commensal and diarrheagenic strains (DEC). Additional studies are needed to validate these markers in diverse strain collections from different geographical regions, as well as investigate their possible role in AIEC pathogenicity.
黏附侵袭性（AIEC）是与克罗恩病（CD）发病机制相关的一种病原型，尽管其作用尚不清楚。 已描述的 AIEC 的主要发病机制包括黏附上皮细胞、侵袭上皮细胞以及在巨噬细胞中存活和复制。 已经描述了一些毒力因子直接参与这些表型，其中大多数仅在 AIEC 参考菌株中进行了评估。 迄今为止，尚未鉴定出可将 AIEC 与其他病原型区分开来的分子标记，因此目前根据其发病机制的表型特征来鉴定这些菌株。 鉴定可能的 AIEC 分子标记不仅可以从诊断角度受益，还有助于更好地理解 AIEC 致病性的决定因素。 本研究的目的是鉴定有助于筛选 AIEC 菌株的分子标记。 为此，我们对一组 AIEC 菌株的外膜蛋白（OMP）图谱进行了表征，并将其与共生 HS 菌株进行了比较。 值得注意的是，我们发现了一组存在于 AIEC 菌株中而不存在于 HS 菌株中的 OMP。 此外，我们开发了一种 PCR 检测方法，并进行了系统基因组分析，以确定这些 OMP 编码基因在更大的 AIEC 和其他菌株集合中的频率和分布。 结果发现，三个基因（，和）广泛分布，与 AIEC 菌株显著相关，而在共生和腹泻性菌株（DEC）中则很少见。 需要进一步研究来验证这些标记在来自不同地理区域的不同菌株集合中的有效性，并研究它们在 AIEC 致病性中的可能作用。
