Wellcome Sanger Institute, Hinxton, UK.
The Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.
Microb Genom. 2024 Oct;10(10). doi: 10.1099/mgen.0.001307.
is a Gram-negative bacterium found in aquatic environments and is the aetiological agent of cholera, characterized by acute watery diarrhoea and severe dehydration. Cholera presents a significant global health burden of an estimated 1.3-5 million annual cases, with the current pandemic caused by a toxigenic lineage of the O1 El Tor biotype called seventh pandemic El Tor (7PET) that is still ongoing. Whilst it is known that non-7PET lineages can cause sporadic disease, little is known about the transmission of these non-epidemic lineages. Thirty-four isolates were obtained from travellers returning from Indonesia to Australia between 2005 and 2017. These were whole genome sequenced, placed into a global phylogenetic context with 883 isolates, and screened for known genes associated with antimicrobial resistance and virulence. This analysis revealed that 30 isolates fell within non-7PET lineages and four within the 7PET lineage. Both 7PET and non-7PET isolates carried genes for resistance to antibiotics that are commonly used in cholera treatment such as tetracyclines and fluoroquinolones. Diverse virulence factors were also present in non-7PET isolates, with two isolates notably carrying toxin-coregulated pilus genes, which are primarily responsible for intestinal colonization in 7PET . This study demonstrates the role of travel in long-range carriage of epidemic and non-epidemic lineages of and how sentinel travel surveillance can enrich our knowledge of diversity, reveal new biology about the spread of diverse lineages with differing disease potential and illuminate disease presence in endemic regions with limited surveillance data.
是一种革兰氏阴性细菌，存在于水生环境中，是霍乱的病原体，其特征为急性水样腹泻和严重脱水。霍乱对全球健康造成了巨大负担，估计每年有 130 万至 500 万例病例，目前仍在流行的是由 O1 El Tor 生物型的产毒谱系引起的第七次大流行 El Tor（7PET）。虽然已知非 7PET 谱系也可引起散发性疾病，但对这些非流行谱系的传播知之甚少。2005 年至 2017 年间，从印度尼西亚返回澳大利亚的旅行者中获得了 34 株 。对这些菌株进行了全基因组测序，将其与 883 株分离株置于全球系统发育背景下，并筛选了与抗生素耐药性和毒力相关的已知基因。这项分析表明，30 株属于非 7PET 谱系，4 株属于 7PET 谱系。7PET 和非 7PET 分离株都携带了对抗生素的耐药基因，这些抗生素是霍乱治疗中常用的抗生素，如四环素和氟喹诺酮类药物。非 7PET 分离株还存在多种毒力因子，其中两株分离株明显携带毒素调节菌毛基因，该基因主要负责 7PET 的肠道定植。这项研究表明，旅行在携带流行和非流行谱系方面发挥了作用，旅行监测可以丰富我们对 多样性的认识，揭示具有不同疾病潜力的不同谱系传播的新生物学，并阐明在监测数据有限的地方性流行地区存在疾病。
