The aim of this study was to investigate the effects that prebiotic and candidates for prebiotics on Clostridium difficile strains to adhere to various human epithelial cell lines and to compare the adhesive properties of specific C. difficile strains. We also sought to examine the effect of different concentrations of fructooligosaccharides and mannose on the formation of biofilms by C. difficile strains. The influence of cellobiose, fructooligosaccharides, inulin, mannose, and raffinose on the adherence properties of various C. difficile strains, including motile 630, non-motile M120, and 10 clinical motile ribotype 027 strains, to non-mucous secreting HT-29, mucous secreting HT-29 MXT, and CCD 841 CoN cells lines. The most effective prebiotics were used in biofilm formation assays. We demonstrated that all C. difficile strains adhered to all cell lines. However, the C. difficile M120 non-motile strain was statistically more likely to adhere to all three cell lines (CFU median, 40) compared to the motile strains (CFU median, 3; p < 0.001). Furthermore, among the carbohydrates examined, only fructooligosaccharides and mannose were found to significantly decrease adhesion (p < 0.001) of C. difficile strains. Alternatively, using a biofilm assay, we observed, via confocal laser scanning microscopy, that sub-inhibitory concentrations (1%) of fructooligosaccharides and mannose functioned to increase biofilm formation by C. difficile. We demonstrated that specific prebiotics and candidate prebiotics exhibit varying anti-adhesive properties towards C. difficile in vitro and that treatment with sub-inhibitory concentrations of prebiotics can cause an increase in biofilm formation by C. difficile.

Bacterial adhesion is the first stage of colonisation and biofilm formation by Clostridioides difficile. Cell wall proteins (Cwp) 84 and 66 play crucial roles in the pathophysiology of C. difficile and may affect bacterial adhesion. Sialylated human milk oligosaccharides (HMOs) have potential to inhibit bacterial adhesion in vitro. The aim of this study was to investigate how 3'-sialyllactose (SL) and 6'-SL affect adhesion and C. difficile biofilm formation. Also, the influence of these substances on cwp84 and cwp66 genes expression by C. difficile was assessed. An adhesion assay was performed using three human colon cells in vitro, and biofilm formation was evaluated using crystal violet staining and confocal laser scanning microscopy. The effect of 3'-SL and 6'SL on cwp expression was measured using real time-PCR. Both tested HMOs decreased expression of the cwp84 gene, adhesion of C. difficile to human colon cells in vitro and biofilm formation.

Aim: The objective of this study was to determine the effect of standard and candidate prebiotics on the adhesion and biofilm formation of Bacteroides sp. in monoculture and co-culture with Clostri...

Clostridioides difficile is a predominant nosocomial pathogen within the healthcare setting able to produce biofilms. Sub-minimum inhibitory concentrations (sub-MICs) of antibiotics trigger mechanisms affecting bacterial virulence, including increased adhesion and biofilm formation. The aim of this study was to investigate how sub-MICs of metronidazole affect the biofilm formation of C. difficile strains. We tested 14 reference and clinical C. difficile strains, including hypervirulent strains of RT027. The MICs of metronidazole for the tested strains were determined using the broth microdilution method. Biofilm formation was evaluated using confocal laser scanning microscopy. The C. difficile strains belonging to RT027 produced the highest amounts of biofilm. The results of confocal laser scanning microscopy showed that all the tested C. difficile strains developed larger biofilms with diversified architectures upon exposure to sub-MICs of metronidazole. In our study, we reveal that sub-MIC concentrations of metronidazole affect the biofilm formation of clinical and reference strains of C. difficile. Importantly, metronidazole induces biofilm formation via hypervirulent RT027 strains.

Understanding the potential antimicrobial properties of natural compounds and their impacts on Clostridioides difficile virulence factors may aid in developing alternative strategies for preventing and treating C. difficile infections (CDI). In this study, we investigated the bactericidal effects of ginger oil (GO), peppermint oil (PO), curcumin (CU), cinnamon aldehyde (CI), and trans-cinnamaldehyde (TCI) on the adhesion and biofilm disruption of C. difficile. We used three reference and five clinical C. difficile strains of different ribotypes. The bactericidal activity was assessed using the broth microdilution method. The adhesion was evaluated using human epithelial cell lines, and biofilm formation was visualized by confocal laser scanning microscopy. All tested strains exhibited susceptibility to CU, with minimum inhibitory concentration (MIC) values ranging from 128 µg/mL to 2048 µg/mL. Similarly, all strains were susceptible to CI and TCI, with MIC values ranging from 6.25% (v/v) to 25% (v/v). Most of the tested substances reduced the adhesion of C. difficile strains, while two tested strains showed significantly higher adhesion when co-incubated with the tested substances. Similar observations were made for biofilm formation, with observed density and morphology varied depending on the strain. In conclusion, the tested products demonstrated bactericidal activity and reduced the adhesion of C. difficile strains. They may be considered for further studies as potential antimicrobial agents targeting biofilm-related infections.

Background: Clostridioides difficile infection (CDI) is a major concern in hospital-acquired infections. C. difficile spores can survive on surfaces for months and require sporicidal disinfection for elimination. The use of disinfectants should be based on laboratory-confirmed sporicidal activity, tested according to current standards in suspension and carrier tests. Further evaluation of disinfectant efficacy should occur in clinical settings by analyzing reductions in CDI incidence. This study aims to conduct a retrospective analysis of the impact of a new disinfection protocol and concurrent changes in antibiotic consumption on the incidence of healthcare-acquired CDI (HA-CDI). Methods: This retrospective, single-center study assessed the impact of a chlorine dioxide-based disinfection protocol on HA-CDI across three periods: pre-intervention, intervention, and post-intervention. An interrupted time series analysis (ITS) with a Poisson distribution was used to evaluate the incidence of HA-CDI, while antibiotic consumption data were analyzed to identify any correlation with CDI infection rates. Results: Incidence Rate Ratio (IRR) before the intervention is 1.00, serving as the reference value. During the intervention period, the IRR is 0.79 (95% CI: 0.42–1.36; p = 0.43), indicating a decrease in the incidence of infections compared to the pre-intervention period, although this result is not statistically significant. After the intervention, the IRR is 0.53 (95% CI: 0.26–0.97; p = 0.057), suggesting a further reduction in the incidence of CDI; this result is on the borderline of statistical significance (p = 0.057), indicating a potential effect of the intervention, albeit without full statistical certainty. Conclusions: The absence of a CDI surge despite increased antibiotic consumption highlights the synergistic relationship between antibiotic stewardship and rigorous infection control practices. The combination of the improved disinfection protocol and comprehensive staff training proved remarkably effective in mitigating CDI risk. Cleaning and disinfection in healthcare facilities is crucial for the prevention of healthcare-associated infections.