Browsing by Issue Date, starting with "2022-09-02"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
- Catheter related bloodstream infection caused by E. cloacae and Candida parapsilosis: Are biofilms guilty?Publication . Štefánek, Matúš; Borges, Vítor; Wenner, Sigurd; Nogueira, Isabel D.; Pinto, Miguel; Faria, Isabel; Pessanha, Maria Ana; Veríssimo, Cristina; Sabino, Raquel; Rodrigues, João; Matias, Rui; Carvalho, Patrícia Almeida; Gomes, João Paulo; Bujdáková, Helena; Jordao, LuisaBiofilm-associated infections is a public health concern in the context of healthcare associated infections (HAI) such as catheter related bloodstream infections (CRBSI). Here the dynamics of two top ten etiological agents of CRBSI, Enterobacter cloacae and Candida parapsilosis isolated from a CRBSI’s patient, were studied to get insights on the role played by biofilms on this HAI. Antimicrobial susceptibility of CVC and HC’s isolates was evaluated according to EUCAST guidelines. Single and/or mixed biofilms assembled on different materials in Mueller-Hinton broth with 2% glucose were assessed by crystal violet assay and scanning electron microscopy (SEM). Fluorescence in situ hybridization (FISH) was used for identification purposes and to assess microorganisms distribution within the biofilm (3D reconstruction) complemented with Focus Ion Beam (FIB)-SEM to assess biofilms assembled on the inner/outer CVC’s surfaces (tomograms). Whole-genome sequencing (WGS) was performed for all isolates. All isolates were antimicrobial resistant. Of note E.cloacae resistance to collistin and an additional resistance of the CVC compared to HC-isolate (ceftolozame-tazobactam) probably linked to a mutation in rpoB gene. Candida resistance to fluconazol might be explained by ERG11 gene mutation. Enterobacter and Candida assembled biofilms on glass, polystyrene and polyurethane being mixed biofilms denser when both microorganism were present from the beginning. FISH and SEM analysis showed that biofilm bottom layer was in all cases richer in E.cloacae. Using environmental isolates of the same species we showed that this biofilm phenotype is not a general feature. Using polyurethane catheters (shape/material factor), denser mixed biofilms richer in EPS were observed. A distinct phenotype was present on the patient’s CVC by SEM and FIB/SEM. WGS confirmed the genetic identity of the pair CVC/HC isolates, while corroborating the virulence potential and observed antimicrobial resistant character of the studied CRBSI-driving pathogens. The results suggest that biofilms allow interaction and adaptation of microorganisms belonging to different kingdoms (Bacteria and Fungi). Adaptation might affect virulence in a transitory or permanent fashion, with potential impact on microorganisms’ potential to cause CRBSI.