Westerström Pontus, Gabrielsen Ås Christina, Bak Dragsted Ulrik
Department of Medical Microbiology, Clinic of Laboratory Medicine, St. Olavs University Hospital, Trondheim, Norway.
Department for Multimorbidity, North Zealand Hospital, Hilleroed, Denmark.
Heliyon. 2024 Sep 10;10(18):e37205. doi: 10.1016/j.heliyon.2024.e37205. eCollection 2024 Sep 30.
is a major human pathogen that can cause life-threatening acute diarrhea. are classified according to O-antigen polysaccharide outer membrane properties, where the serotypes O1 and O139 are strains that cause pandemics and epidemics while non-O1/non-O139 usually cause mild disease. The dynamic evolution of involves acquisition of new virulence factors through horizontal gene transfer and formerly nontoxigenic serogroups are increasingly being reported to cause severe forms of human disease. In this study we have serotyped one isolate (ST588-CPH) of imported from Vietnam to Denmark and performed whole genome sequencing to identify known virulence genes and furthermore studied the pattern of virulence in closely related pathogenic strains of . ST558-CPH was found to be a non-O1/non-O139 strain. Initial analysis from the whole genome sequencing gave a 96,6 % match to the O139-specific gene, but in a second analysis with a higher identification threshold, the gene was absent. We suggest a "de novo" display of a database misannotation, which explains the conflicting results. The MLST analysis revealed that the isolate belongs to the nontoxigenic non-O1/non-O139 sequence type ST558. ST558 has recently been reported as a sequence type forming a cluster of ST's that should be monitored, as it has shown to have virulence causing moderate to severe illness. Our analysis of virulence genes identified , a recently discovered toxin, which seems to be generally present in both toxigenic and nontoxigenic strains.
是一种主要的人类病原体，可导致危及生命的急性腹泻。根据O抗原多糖外膜特性进行分类，其中血清型O1和O139是导致大流行和流行的菌株，而非O1/非O139通常引起轻度疾病。的动态进化涉及通过水平基因转移获得新的毒力因子，并且越来越多地报道以前无毒的血清群会导致严重形式的人类疾病。在本研究中，我们对一株从越南进口到丹麦的菌株（ST588-CPH）进行了血清分型，并进行了全基因组测序以鉴定已知的毒力基因，此外还研究了密切相关的致病菌株中的毒力模式。发现ST558-CPH是一株非O1/非O139菌株。全基因组测序的初步分析显示与O139特异性基因有96.6%的匹配，但在第二次具有更高鉴定阈值的分析中，该基因不存在。我们认为这是数据库错误注释的“从头”显示，这解释了相互矛盾的结果。多位点序列分型分析表明，该分离株属于无毒的非O1/非O139序列型ST558。最近有报道称ST558是一种序列型，形成了一组应予以监测的序列型，因为它已显示出具有导致中度至重度疾病的毒力。我们对毒力基因的分析鉴定出一种最近发现的毒素，该毒素似乎普遍存在于产毒菌株和无毒菌株中。
