Browsing by Author "Wenner, Sigurd"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- Antimicrobial Resistance and Biofilms Underlying Catheter-Related Bloodstream Coinfection by Enterobacter cloacae Complex and Candida parapsilosisPublication . Štefánek, Matúš; Wenner, Sigurd; Borges, Vítor; Pinto, Miguel; Gomes, João Paulo; Rodrigues, João; Faria, Isabel; Pessanha, Maria Ana; Martins, Filomena; Sabino, Raquel; Veríssimo, Cristina; Nogueira, Isabel D.; Carvalho, Patrícia Almeida; Bujdáková, Helena; Jordao, LuisaBiofilm-associated infections are a public health concern especially in the context of healthcare-associated infections such as catheter-related bloodstream infections (CRBSIs). We evaluated the biofilm formation and antimicrobials resistance (AMR) of Enterobacter cloacae complex and Candida parapsilosis co-isolated from a CRBSI patient. Antimicrobial susceptibility of central venous catheters (CVCs) and hemoculture (HC) isolates was evaluated, including whole genome sequencing (WGS) resistome analysis and evaluation of gene expression to obtain insight into their AMR determinants. Crystal violet assay was used to assess dual biofilm biomass and microscopy was used to elucidate a microorganism’s distribution within biofilms assembled on different materials. Bacteria were multidrug-resistant including resistance to colistin and beta-lactams, likely linked to the mcr-9-like phosphoethanolamine transferase and to an ACT family cephalosporin-hydrolyzing class C beta-lactamase, respectively. The R398I and Y132F mutations in the ERG11 gene and its differential expression might account for C. parapsilosis resistance to fluconazole. The phenotype of dual biofilms assembled on glass, polystyrene and polyurethane depends on the material and how biofilms were initiated by one or both pathogens. Biofilms assembled on polyurethane were denser and richer in the extracellular polymeric matrix, and microorganisms were differently distributed on the inner/outer surface of the CVC.
- Biofilmes, micobactérias não tuberculosas e infeçãoPublication . Bandeira, Maria; Wenner, Sigurd; Ferreira, Magda; Carvalho, Patricia Almeida; Jordão, LuísaAs micobactérias não tuberculosas (MNTs) são agentes infeciosos emergentes responsáveis por infeções diversas, nomeadamente infeções associadas aos cuidados de saúde. Neste trabalho foi avaliada a capacidade de formação de biofilmes por duas MNTs (M. smegmatis e M. chelonae). Os biofilmes foram caracterizados utilizando microscopia eletrónica e a eficácia de diversos desinfetantes foi avaliada contra MNTs recuperadas de biofilmes. Os resultados obtidos demonstram que as MNTs são capazes de formar biofilmes em materiais presentes em ambiente hospitalar e de resistir à ação de diversos desinfetantes.
- Biofilms and catheter related bloodstream infection: a tale of two kigdomsPublication . Borges, Vítor; Wenner, Sigurd; Nogueira, Isabel; Faria, Isabel; Pessanha, Maria Ana; Verissimo, Cristina; Sabino, Raquel; Rodrigues, Joao; Matias, Rui; Martins, Filomena; Carvalho, Patricia; Gomes, Joao Paulo; Jordão, LuísaBackground: Biofilm-associated infections are a public health concern in the context of healthcare-associated infections (HAI) such as catheter-related bloodstream infections (CRBSI). Here, we studied two top ten CRBS etiological agents, Enterobacter cloacae and Candida parapsilosis, isolated from a patient with CRBSI in order to understand the role played by biofilms on this HAI. Materials/methods: E.cloacae and C.parapsilosis were isolated from CVC and peripheral blood by standard procedures. EUCAST guidelines were followed for antimicrobial susceptibility evaluation. Single and/or mixed biofilms were assembled on different materials in Mueller-Hinton broth with 2% glucose. Biofilm assembly was assessed by crystal violet assay and scanning electron microscopy (SEM). Fluorescence in situ hybridization (FISH) was used for identification and to assess microorganisms distribution within the biofilm (3D reconstruction). In addition, Focus Ion Beam (FIB)-SEM was used to assess biofilms assembled on inner and outer surfaces of CVCs and construct tomograms. CVC and hemoculture (HC) isolates were subjected to whole-genome sequencing (WGS). Results: All Enterobacter and Candida isolates were antimicrobial resistant. Of note, E. cloacae-CVC revealed an additional resistance (ceftolozame-tazobactam) in comparison to the HC- isolate. Both microorganisms assembled biofilms on glass, polystyrene and polyurethane. Mixed biofilms were denser when both microorganisms were present from the beginning. Biofilm phenotype was not dependent of biofilm initiation by E.cloacae or C.parapsilosis. FISH and SEM analysis showed that biofilm bottom layer was in all cases richer in E.cloacae. Environmental isolates of the same species were also tested, showing that this biofilm phenotype is not a general feature. Using polyurethane catheters (shape/material factor), we observed denser mixed biofilms richer in EPS. FIB-SEM preliminary results suggest that biofilms assembled on inner and outer catheter surface might differ on microorganisms’ distribution. WGS confirmed the genetic identity of the CVC/HC pairs while corroborating the virulence potential and antimicrobial resistant character of the CRBSI-driving pathogens. Conclusions: 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.
- 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.