ormaechei肠杆菌,阴沟肠杆菌复合体中的一个物种,是医疗保健相关感染的相关代理。此外,它已经获得了相关性,因为分离株已经显示出抵抗几种抗生素的能力,尤其是碳青霉烯类。然而,关于Hormaechei大肠杆菌的定植和毒力机制的知识没有像大肠杆菌或肺炎克雷伯菌等其他肠杆菌科细菌一样进步。这里,我们描述了3型菌毛的存在和作用,一个陪护者组装的Fimbria,首先在克雷伯菌属中描述。,并在肠杆菌科的其他代表中检测到。检查了8个智利阴沟肠杆菌分离株,其中,发现了四个E.hormaechei分离株产生3型菌毛。这些分离株被鉴定为E.hormaechei亚种。霍夫曼尼,已知的五个亚种之一。变种E.hormaechei亚种。缺乏mrkA基因的hoffmannii菌株,编码主要结构亚基,对塑料表面和Caco-2细胞的粘附能力显着降低,与野生型菌株相比。在诱导型启动子控制下补充mrkA基因的突变菌株中未观察到粘附能力降低的这种表型。因此,这些数据表明,3型菌毛在E.hormaechei亚种的粘附能力中起作用。霍夫曼尼.NCBIRefSeqAssembly数据库中包含的E.hormaechei基因组的筛选表明,3型菌毛的整体存在并不常见(5.94-7.37%),尽管在五个E.hormaechei亚种的代表中检测到编码该结构的基因。对完整基因组的探索表明,在大多数情况下,mrkABCDF基因座,编码3型纤毛,位于质粒中。此外,目前在医疗保健相关感染中发现的序列类型被发现含有编码3型菌毛的基因,主要是ST145、ST78、ST118、ST168、ST66、ST93和ST171。因此,尽管3型菌毛在物种中并不普遍,这可能是E.hormaechei代表子集适合度的决定因素。
Enterobacter hormaechei, one of the species within the Enterobacter cloacae complex, is a relevant agent of healthcare-associated infections. In addition, it has gained relevance because isolates have shown the capacity to resist several antibiotics, particularly carbapenems. However, knowledge regarding colonization and virulence mechanisms of E. hormaechei has not progressed to the same extent as other Enterobacteriaceae species as Escherichia coli or Klebsiella pneumoniae. Here, we describe the presence and role of the type 3 fimbria, a chaperone-usher assembled fimbria, which was first described in Klebsiella spp., and which has been detected in other representatives of the Enterobacteriaceae family. Eight Chilean E. cloacae isolates were examined, and among them, four E. hormaechei isolates were found to produce the type 3 fimbria. These isolates were identified as E. hormaechei subsp. hoffmannii, one of the five subspecies known. A mutant E. hormaechei subsp. hoffmannii strain lacking the mrkA gene, encoding the major structural subunit, displayed a significantly reduced adherence capacity to a plastic surface and to Caco-2 cells, compared to the wild-type strain. This phenotype of reduced adherence capacity was not observed in the mutant strains complemented with the mrkA gene under the control of an inducible promoter. Therefore, these data suggest a role of the type 3 fimbria in the adherence capacity of E. hormaechei subsp. hoffmannii. A screening in E. hormaechei genomes contained in the NCBI RefSeq Assembly database indicated that the overall presence of the type 3 fimbria is uncommon (5.94-7.37%), although genes encoding the structure were detected in representatives of the five E. hormaechei subspecies. Exploration of complete genomes indicates that, in most of the cases, the mrkABCDF locus, encoding the type 3 fimbria, is located in plasmids. Furthermore, sequence types currently found in healthcare-associated infections were found to harbor genes encoding the type 3 fimbria, mainly ST145, ST78, ST118, ST168, ST66, ST93, and ST171. Thus, although the type 3 fimbria is not widespread among the species, it might be a determinant of fitness for a subset of E. hormaechei representatives.