Browsing by Author "Nogueira, Isabel D."
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- 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.
- 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.
- Occurrence of polycyclic aromatic hydrocarbons, microplastics and biofilms in Alqueva surface water at touristic spotsPublication . Raposo, Ana; Mansilha, Catarina; Veber, Alexander; Melo, Armindo; Rodrigues, Joao; Matias, Rui; Rebelo, Helena; Grossinho, José; Cano, Manuela; Almeida, Cristina; Nogueira, Isabel D.; Puskar, Ljiljana; Schade, Ulrich; Jordão, LuisaFreshwater pollution is a huge concern. A study aiming to evaluate physico-chemical characteristics, microbiota, occurrence of two groups of persistent environmental pollutants with similar chemical properties (polycyclic aromatic hydrocarbons- PAHs and microplastics - MPs) in Alqueva's surface water was performed during 2021. Water samples were collected at three spots related to touristic activities (two beaches and one marina) during the Winter, Spring, Summer and Autumn seasons. In addition, the presence of biofilms on plastic and natural materials (stone, wood/ vegetal materials) were assessed and compared. Water quality based on physicochemical parameters was acceptable with a low eutrophication level. PAHs concentration levels were lower than the standard limits established for surface waters by international organizations. However, carcinogenic compounds were detected in two sampling locations, which can pose a problem for aquatic ecosystems. PAHs profiles showed significant differences when comparing the dry seasons with the rainy seasons, with a higher number of different compounds detected in Spring. Low molecular weigh compounds, usually associated with the atmospheric deposition and petroleum contamination, were more prevalent. MPs were detected in all samples except one during the Winter season. The polymers detected were poly(methyl-2-methylpropenoate), polystyrene, polyethylene terephthalate, polyamide, polypropylene, styrene butadiene, polyvinyl chloride and low /high density polyethylene with the last being the most frequent. Biofilms were more often detected on plastics than on natural materials. In addition, biofilms detected on plastics were more complex with higher microbial diversity (e.g., bacteria, fungi/yeast and phytoplancton organisms) and richer in extrapolymeric material. Based on morphological analysis a good agreement between microbiota and microorganism present in the biofilms was found. Among microbiota were identified microorganisms previously linked to plastic and PAHs detoxification suggesting the need for further studies to evaluate the viability of using biofilms as part of a green bioremediation strategy to mitigate water pollution.