Nilsson Anna, Johansson Cecilia, Skarp Astrid, Kaden René, Engstrand Lars, Rautelin Hilpi
Department of Medical Sciences, Clinical Microbiology, Uppsala University, Uppsala, Sweden.
Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, and Science for Life Laboratory, Stockholm, Sweden.
PLoS One. 2017 Dec 7;12(12):e0189222. doi: 10.1371/journal.pone.0189222. eCollection 2017.
Campylobacter jejuni is the most common cause of bacterial gastroenteritis. Major reservoirs are warm-blooded animals, poultry in particular, but Campylobacter can also be transmitted via water. In this paper, we have taken a closer look at the biology and potential virulence of C. jejuni water isolates. Seven C. jejuni isolates from incoming surface water at water plants in Sweden were characterized with whole genome sequencing and phenotypical testing. Multi locus sequence typing analysis revealed that these isolates belonged to groups known to include both common (ST48CC) and uncommon (ST1275CC, ST683, ST793 and ST8853) human pathogens. Further genomic characterization revealed that these isolates had potential for arsenic resistance (due to presence of arsB gene in all isolates), an anaerobic dimethyl sulfoxide oxidoreductase (in three isolates) and lacked the MarR-type transcriptional regulator gene rrpB (in all but one isolate) earlier shown to be involved in better survival under oxidative and aerobic stress. As putative virulence factors were concerned, there were differences between the water isolates in the presence of genes coding for cytolethal distending toxin (cdtABC), Type VI secretion system and sialylated LOS, as well as in biofilm formation. However, all isolates were motile and could adhere to and invade the human HT-29 colon cancer cell line in vitro and induce IL-8 secretion suggesting potential to infect humans. This is, to the best of our knowledge, the first study where C. jejuni water isolates have been characterized using whole genome sequencing and phenotypical assays. We found differences and shared traits among the isolates but also potential to infect humans.
空肠弯曲菌是细菌性肠胃炎最常见的病因。主要宿主是温血动物，尤其是家禽，但空肠弯曲菌也可通过水传播。在本文中，我们更深入地研究了空肠弯曲菌水分离株的生物学特性和潜在毒力。对瑞典水厂进厂地表水的7株空肠弯曲菌分离株进行了全基因组测序和表型测试。多位点序列分型分析表明，这些分离株属于已知包含常见（ST48CC）和罕见（ST1275CC、ST683、ST793和ST8853）人类病原体的菌群。进一步的基因组特征分析表明，这些分离株具有抗砷潜力（所有分离株均存在arsB基因）、一种厌氧二甲基亚砜氧化还原酶（3株分离株中存在），并且缺乏先前显示在氧化和有氧应激下能更好存活的MarR型转录调节基因rrpB（除1株分离株外所有分离株均缺乏）。就假定的毒力因子而言，编码细胞致死性扩张毒素（cdtABC）、VI型分泌系统和唾液酸化脂寡糖的基因的存在情况以及生物膜形成方面，水分离株之间存在差异。然而，所有分离株都具有运动性，并且在体外能够黏附并侵入人HT - 29结肠癌细胞系并诱导IL - 8分泌，表明具有感染人类的潜力。据我们所知，这是首次使用全基因组测序和表型分析对空肠弯曲菌水分离株进行特征分析的研究。我们发现了分离株之间的差异和共同特征，以及它们感染人类的潜力。
