近期《自然—遗传学》公布了从全球范围内的卫生保健环境中获取的艰难梭菌（C. difficile）分离菌株汇集群的基因组测序数据。
艰难梭菌是发达国家中抗生素相关性腹泻和卫生保健有关感染的常见致病因素之一。
艰难梭菌的感染以及疾病流行在过去20年有所增加，归其原因为高毒性艰难梭菌的产生。
Trevor Lawley等人在全球各地搜集了151种现存的艰难梭菌分离菌株以及英国的145种额外的分离菌株，并对其进行了全基因组测序。他们追踪到有关艰难梭菌疾病的暴发和传播的信息，还发现其中一个菌种027/BI/NAP1包含了两种不同的细菌世系，与先前的只有一种细菌世系存在的研究报告不一致。
他们在论文中公布了这两种本世纪初出现在北美的细菌世系，其各自都产生了相同的氟喹诺酮耐药突变。他们认为，这一时期氟喹诺酮抗生素的普遍使用可能产生了选择性压力，从而导致了这两种细菌世系的产生以及艰难梭菌流行病的出现。(生物谷Bioon.com)
doi:10.1038/ng.2478
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Emergence and global spread of epidemic healthcare-associated Clostridium difficile
Miao He, Fabio Miyajima, Paul Roberts, Louise Ellison, Derek J Pickard, Melissa J Martin,Thomas R Connor, Simon R Harris, Derek Fairley, Kathleen B Bamford, Stephanie D'Arc,Jon Brazier, Derek Brown, John E Coia, Gill Douce, Dale Gerding, Hee Jung Kim, Tse Hsien Koh, Haru Kato, Mitsutoshi Senoh, Tom Louie, Stephen Michell, Emma Butt, Sharon J Peacock, Nick M Brown, Tom Riley, Glen Songer, Mark Wilcox, Munir Pirmohamed, Ed Kuijper, Peter Hawkey, Brendan W Wren, Gordon Dougan, Julian Parkhill & Trevor D Lawley
Epidemic C. difficile (027/BI/NAP1) has rapidly emerged in the past decade as the leading cause of antibiotic-associated diarrhea worldwide. However, the key events in evolutionary history leading to its emergence and the subsequent patterns of global spread remain unknown. Here, we define the global population structure of C. difficile 027/BI/NAP1 using whole-genome sequencing and phylogenetic analysis. We show that two distinct epidemic lineages, FQR1 and FQR2, not one as previously thought, emerged in North America within a relatively short period after acquiring the same fluoroquinolone resistance–conferring mutation and a highly related conjugative transposon. The two epidemic lineages showed distinct patterns of global spread, and the FQR2 lineage spread more widely, leading to healthcare-associated outbreaks in the UK, continental Europe and Australia. Our analysis identifies key genetic changes linked to the rapid transcontinental dissemination of epidemic C. difficile 027/BI/NAP1 and highlights the routes by which it spreads through the global healthcare system.
