Multiple Factors Modulate Biofilm Formation by the Anaerobic Pathogen Clostridium difficile
Multiple Factors Modulate Biofilm Formation by the Anaerobic Pathogen Clostridium difficile
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DOI：
10.1128/jb.01980-12
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发表时间：
2013-02-01
影响因子：
3.2
通讯作者：
Unnikrishnan, Meera
中科院分区：
文献类型：
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作者：
Dapa, Tanja;Leuzzi, Rosanna;Unnikrishnan, Meera
生物膜内的细菌受到保护，免受多种压力，包括免疫反应和抗菌剂。细菌病原体的生物膜形成能力与抗生素耐药性增加和慢性复发性感染有关。虽然生物膜已被很好地研究了几种肠道病原体，但对厌氧肠道物种的生物膜形成知之甚少。专性厌氧菌艰难梭菌引起C。艰难梭菌感染（CDI）是一个主要的卫生保健相关问题，主要是由于复发性感染的高发病率。C.当正常的肠道微生物群落被抗微生物剂破坏时，艰难梭菌在肠道定植;然而，感染期间肠道定植所涉及的因素或过程仍不清楚。我们证明，临床C。艰难菌株，即，菌株630和超毒力菌株R20291在体外形成结构化生物膜，其中R20291积累显著更多的生物膜。显微镜和生化分析显示，多层细菌包裹在含有蛋白质，DNA和多糖的生物膜基质中。采用同基因突变体，我们表明，毒力相关蛋白，Cwp 84，鞭毛，和一个假定的群体感应调节器，LuxS，都需要最大的生物膜形成的C。很难有趣的是，Spo 0A（一种控制孢子形成的转录因子）中的突变体对于生物膜形成是有缺陷的，这表明孢子形成和生物膜形成之间可能存在联系。此外，我们证明梭菌生物膜中的细菌对高浓度的万古霉素（一种常用于治疗CDI的药物）更具耐药性。我们的数据表明，生物膜形成的C。艰难梭菌感染是一个复杂的多因素过程，可能是宿主中梭菌持续存在的关键机制。
Bacteria within biofilms are protected from multiple stresses, including immune responses and antimicrobial agents. The biofilm-forming ability of bacterial pathogens has been associated with increased antibiotic resistance and chronic recurrent infections. Although biofilms have been well studied for several gut pathogens, little is known about biofilm formation by anaerobic gut species. The obligate anaerobe Clostridium difficile causes C. difficile infection (CDI), a major health care-associated problem primarily due to the high incidence of recurring infections. C. difficile colonizes the gut when the normal intestinal microflora is disrupted by antimicrobial agents; however, the factors or processes involved in gut colonization during infection remain unclear. We demonstrate that clinical C. difficile strains, i.e., strain 630 and the hypervirulent strain R20291, form structured biofilms in vitro, with R20291 accumulating substantially more biofilm. Microscopic and biochemical analyses show multiple layers of bacteria encased in a biofilm matrix containing proteins, DNA, and polysaccharide. Employing isogenic mutants, we show that virulence-associated proteins, Cwp84, flagella, and a putative quorum-sensing regulator, LuxS, are all required for maximal biofilm formation by C. difficile. Interestingly, a mutant in Spo0A, a transcription factor that controls spore formation, was defective for biofilm formation, indicating a possible link between sporulation and biofilm formation. Furthermore, we demonstrate that bacteria in clostridial biofilms are more resistant to high concentrations of vancomycin, a drug commonly used for treatment of CDI. Our data suggest that biofilm formation by C. difficile is a complex multifactorial process and may be a crucial mechanism for clostridial persistence in the host.