Interactions Between Clostridioides difficile and Fecal Microbiota in in Vitro Batch Model: Growth, Sporulation, and Microbiota Changes.

Sabina Horvat,Maja Rupnik

doi:10.3389/fmicb.2018.01633

Abstract

Disturbance in gut microbiota is crucial for the development of Clostridioides difficile infection (CDI). Different mechanisms through which gut microbiota influences C. difficile colonization are known. However, C. difficile could also affect gut microbiota balance as previously demonstrated by cultivation of fecal microbiota in C. difficile conditioned medium. In current study, the interactions of C. difficile cells with gut microbiota were addressed. Three different strains (ribotypes 027, 014/020, and 010) were co-cultivated with two types of fecal microbiota (healthy and dysbiotic) using in vitro batch model. While all strains showed higher sporulation frequency in the presence of dysbiotic fecal microbiota, the growth was strain dependent. C. difficile either proliferated to comparable levels in the presence of dysbiotic and healthy fecal microbiota or grew better in co-culture with dysbiotic microbiota. In co-cultures with any C. difficile strain fecal microbiota showed decreased richness and diversity. Dysbiotic fecal microbiota was more affected after co-culture with C. difficile than healthy microbiota. Altogether, 62 OTUs were significantly changed in co-cultures of dysbiotic microbiota/C. difficile and 45 OTUs in co-cultures of healthy microbiota/C. difficile. However, the majority of significantly changed OTUs in both types of microbiota belonged to the phylum Firmicutes with Lachnospiraceae and Ruminococcaceae origin.

Highlights

Clostridium difficile, recently reclassified as Clostridioides difficile (Lawson et al, 2016), is an ubiquitous, anaerobic, spore-forming, Gram-positive bacterium that is currently the leading cause of nosocomial and community associated diarrhea worldwide (Martin et al, 2016)
The colonization of C. difficile is strongly associated with disturbance in gut microbiota and several studies explored the mechanisms through which gut microbiota influences C. difficile (Britton and Young, 2012; Pérez-Cobas et al, 2015)
While for some enteric pathogens (e.g., Salmonella) mechanisms involved in the pathogen-promoting physiological changes in the gut have already been described (Stecher et al, 2007), little is known about possible impact of C. difficile on gut microbiota

Summary

Introduction

Clostridium difficile, recently reclassified as Clostridioides difficile (Lawson et al, 2016), is an ubiquitous, anaerobic, spore-forming, Gram-positive bacterium that is currently the leading cause of nosocomial and community associated diarrhea worldwide (Martin et al, 2016). Success of enteric pathogen to cause a disease depends mainly on two phases, i.e., the initial colonization phase of pathogen in the gut, followed by pathogen-promoting physiological changes. The colonization of C. difficile is strongly associated with disturbance in gut microbiota (i.e., dysbiosis) and several studies explored the mechanisms through which gut microbiota influences C. difficile (Britton and Young, 2012; Pérez-Cobas et al, 2015). While for some enteric pathogens (e.g., Salmonella) mechanisms involved in the pathogen-promoting physiological changes in the gut have already been described (Stecher et al, 2007), little is known about possible impact of C. difficile on gut microbiota. Changed bacterial groups detected in in vitro model using C. difficile conditioned medium were comparable to those described in CDI patients

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Results

Conclusion