Transcriptomic analysis of biofilm formation in strains of Clostridioides difficile associated with recurrent and non-recurrent infection reveals potential candidate markers for recurrence

Abstract

The transcriptomic profile in a biofilm model of ribotypes (RT) 001 and 027 associated with recurrentClostridioides difficileinfection (R-CDI) and not associated with recurrent (NR)-CDI was analyzed to identify genes that may favor the recurrence. Twenty strains were selected, 10 RT001 and 10 RT027. From each ribotype, 5 were R-CDI and 5 NR-CDI. Biofilm and nonadherent cells were prepared from each clinical isolate, and the RNA was extracted. RNA samples were pooled in 8 combinations implying ribotype, recurrence, and biofilm formation. Each pool was separately labeled with Cy3 dye and hybridized on a microarray designed for this study. Slides were scanned, analyzed, and gene expression was compared between unique and grouped pools using the Student’s t-test with Benjamini-Hochberg correction when appropriate. Validation was carried out by qRT-PCR for selected genes. Results: After comparisons of differentially expressed genes from both ribotypes of R-CDI strains (nonadherent cells vs. biofilm) and both ribotypes in biofilm (R-CDI vs. NR-CDI), we found 3 genes over-expressed and 1 under-expressed in common (adj. p ≤ 0.05). Overexpressed genes wereCAJ70148(a putative dehydrogenase),CAJ68100(a secretion type II system protein from the GspH (pseudopilins) family), andCAJ69725(a putative membrane protein); under-expressed wasCAJ68151(a segregation and condensation protein A). BecauseCAJ70148,CAJ68100,CAJ69725andCAJ68151were differentially expressed in biofilm in strains associated with R-CDI, they may support the biofilm favoring the recurrence of CDI. However, further studies will be needed for poorly studied genes.