Analysis of biofilm production and expression of adhesion structures of circulating Clostridioides difficile strains from Mexico.

Introduction: Clostridioides difficile biofilms are believed to protect the pathogen from antibiotics, in addition to potentially contributing to recurrent infections.

Methodology: Biofilm production of 102 C. difficile isolates was determined using the crystal violet staining technique, and detachment assays were performed. The expression levels of cwp84 and slpA genes were evaluated by real-time PCR on selected isolates.

Results: More than 70% of isolates (75/102) were strong biofilm producers, and the highest detachment of biofilm was achieved with the proteinase K treatment (>90%). The overall mean expression of cwp84 was higher in RT027 than in RT001 (p=0.003); among strong biofilm-producing strains, the slpA expression was lower in RT027 than in RT001 (p<0.000).

Conclusions: Proteins seem to have an important role in the biofilm's initial adherence and maturation. slpA and cwp84 are differentially expressed by C. difficile ribotype and biofilm production level.