Browsing by Author "Rodrigues, Joao"
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- Biofilmes de aeromonas sp na água e risco de infeção para o HomemPublication . Meneses, Madalena; Matias, Rui; Rodrigues, Joao; Jordão, Luisaintrodução: As Aeromonas spp. são bactérias oportunistas, responsáveis por infeções no Homem e nos animais. Estas bactérias, frequentemente isoladas do ambiente aquático, possuem diversos fatores de virulência sendo responsáveis pelas infeções intestinais e extraintestinais no ser humano. Os biofilmes são estruturas compostas por microrganismos envolvidos por uma matriz extracelular por eles secretada. No caso dos biofilmes ambientais, existe uma variedade de microrganismos, incluindo, muitas vezes, fungos, microalgas e protozoários. Os biofilmes podem, ou não, estar ligados a superfícies bióticas ou abióticas e diferem, em muitos aspetos, dos seres planctónicos. Em comparação com bactérias isoladas (planctónicas), as que residem em comunidade (biofilme) encontram-se mais protegidas contra vários stresses ambientais. Segundo a literatura, apesar de microrganismos isoladas serem relativamente suscetíveis à desinfeção, populações associadas em biofilmes podem sobreviver a altas doses de cloro.
- 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.
- Environmental biofilms, consequences for health and diseasePublication . Morgado, Patrícia I.; Reis, Lucia; Matias, Rui; Grossinho, Jose; Rebelo, Helena; Rodrigues, Joao; Jordao, LuisaOrnamental waters of easy access and populated with animals are quite attractive and can hide threats to human health. Here we evaluated, during one year, the microbiota of ornamental waters in a Lisbon park in order to assess the risk for human health. A total of 26 different bacterial species were identified during the study. Among these are potential human pathogens such as Aeromonas, E. coli, K. pneumoniae, Pseudomonas and Raoutella. Aeromonas sobria is a resident bacterium whereas other species such as A. hydrophila and A. veronii were sporadically identified. A possible explanation for this result is the presence of a fish population. The presence of E. coli indicates water contamination with fecal materials. We first isolate this bacterium in June when the water temperature increased and then after it was a resident despite the natural temperature drop in the autumn. This might be explained by the replace of the fish population by ducks in October which lead to an increase in water tubirdity and total carbon content. Pseudomonas fluorescens, P. putida and P. oryzihabitans have been considered low-virulence bacteria but recently have been identified as ethiological agents of healthcare assotiated infections (HAI) mostly in immunosupressed individuals. Another recognized HAI agent present is K. pneumoniae. The same bacteria species were isolated from biofilm and water suggesting the existence of an equilibrium between planktonic and biofilm organized bacteria. The role played by biofilm assembly on the emergence of antibiotic resistance is still ongoing for the isolated bacteria, as well as the possible interaction between water chemical composition and bacteria isolates. Potential pathogens (biofilm or planktonic) represent a significant cause of acute bacterial infections mainly in specific populations (paediatric and geriatric). These results support a periodic control of ornamental water microbiota as simple preventive measure to avoid potential health issues.
- Occurrence of persistent organic pollutants at Alqueva's 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, IsabelFreshwater pollution is a huge concern. A study aiming to evaluate water quality and occurence 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. Samples were collected at three spots related to touristic activities (two beaches and one marina) once by season. In addition, we assessed and compared the presence of biofilms on plastic and natural materials. Water quality was acceptable with a low eutrophication level. PAHs concentration levels were lower than the standard limits established for surface waters. PAHs profiles showed significant differences when comparing the dry and rainy seasons, with a higher number of different compounds detected in Spring. Low molecular weight compounds, usually associated with the atmospheric deposition and petroleum contamination, were more prevalent. MPs were detected in all samples except one during Winter. Eight polymers were detected being polyethylene the most frequent. Plastics were more prone to biofilm colonization than natural materials. In addition, biofilms detected on plastics were more complex with higher microbial diversity and richer in EPS. 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.
- 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.
- Pathogens in Ornamental and Recreational Waters: A Risk Assessment StudyPublication . Morgado, Patrícia I.; Rodrigues, Joao; Grossinho, José; Rebelo, Helena; Nogueira, Isabel; Jordão, LuisaOrnamental and recreational waters of easy access are quite attractive and can hide threats to human health. Here we evaluated, the microbiota of ornamental waters in a Lisbon park (1 year), as well as, the microbiota of two dams with nautical recreational activities and fluvial beach to assess the risk for human health. In the microbiota, we identified faecal indicator bacterium, E.coli, and other potential human pathogens such as A.baumannii, Aeromonas, E.cloacae, K.pneumoniae, Pseudomonas and Raoutella. The identification of known healthcare associated infections agents such as K. pneumoniae, as well as species of Pseudomonas (P.fluorescens, P.putida and P.oryzihabitans) that recently have been identified as etiological agents in immunosuppressed individuals is of particular relevance. The same bacterial species were isolated from biofilm and water suggesting the existence of an equilibrium between planktonic and biofilm organized bacteria. The role played by biofilm assembly on the emergence of antibiotic resistance is still ongoing for the isolated bacteria, as well as the possible interaction between water chemical composition and bacteria isolates. Potential pathogens (biofilm or planktonic) represent a significant cause of acute bacterial infections mainly in specific populations (paediatric and geriatric). These results support periodic control of ornamental water microbiota as a preventive messure.
- Pathogens in ornamental waters: a follow up studyPublication . Duarte, Maria; Morgado, Patrícia I.; Rodrigues, Joao; Reis, Lucia; Matias, Rui; Carvalho, Patricia A.; Duarte, Aida; Jordão, LuisaOrnamental waters of easy access and populated with animals are quite attractive and can hide threats to human health. Here we evaluated the microbiota of ornamental waters in a Lisbon park. Water and biofilm samples where collected, in 2 lakes (L1-L2) and ornamental fountains (L3-L4) in February/2015. In May/2015 and monthly during a year (starting March/2016) samples from L4 where collected. Microbiota identification was performed as described previouslya. Biofilm assembly was monitored by crystal violet assay and SEMb and antibiotic susceptibility was performed by conventional methods. The results of the first water sampling (Feb/2015) revealed the presence of Enterobactereaceae and non-fermentative oxidase-positive bacteria. Fountains and lakes presented different microbota being the highest diversity found in L1 hosting a duck population. This result suggested the existence of an interplay between animal inhabitants and microbiota which was confirmed by the second sampling of L4 (May/2015). Between the 2 sampling events a fish population was introduced and the microbiota was completely altered with the appearance of a typical fish pathogen (Aeromonas spp). This tendency was also confirmed over 2016. K. pneumoniae and Aeromonas spp., present as planktonic and biofilm organized bacteria in 2015 showed an enhanced ability to assemble biofilms in vitro at 25 °C than at 37 °C. Bacteria recovered from biofilm showed an increased antibiotic resistance compared to planktonic counterparts. The pilot study conducted during 2015 and the follow up study (still in progress) support a periodic control of ornamental water microbiota as simple preventive measure to avoid potential health issues.
- Prospective observational study of adenoidal biofilms in a paediatric population and their clinical implicationsPublication . Subtil, Joao; Bajanca-Lavado, Maria Paula; Rodrigues, Joao; Duarte, Aida; Reis, Lucia; Nogueira, Isabel; Jordão, LuisaINTRODUCTION: Adenoids are nasopharyngeal lymphoid tissue with a relevant role in host defence against infection of upper respiratory tract. Nevertheless, adenoids are also a reservoir of microorganisms that can cause infections of upper respiratory tract and otitis particularly in children. OBJECTIVE: Evaluate and compare the association between biofilm assembly on adenoids and the incidence of recurrent infections in a paediatric population submitted to adenoidectomy by either infectious or non-infectious indication. METHODS: Scanning electron microscopy was used to assess biofilms on adenoid surface; biofilm assembly in vitro was monitored by crystal violet assay; antibiotic susceptibility was assessed following EUCAST guidelines; Hinfluenzae capsular typing was performed by PCR. RESULTS: Biofilms were present in 27.4% of adenoid samples and no statistical difference was found between infectious and non-infectious groups. In vitro, the most clinically relevant bacteria, H.influenzae, S.aureus, S.pyogenes, S.pneumoniae and M.catarrhalis, were mostly moderate biofilm assemblers (71.7%). 55.3% of these bacteria were intermediate/resistant to at least one of the tested antibiotics. No association was found between the ability to assemble biofilms in vitro and the presence of biofilms on adenoids nor antibiotic resistance. All H.influenzae were characterized as non-typeable. CONCLUSION: The presence of biofilms on adenoid surface was independent from clinical sample background. Bacterial ability to assemble biofilms in vitro cannot be used to predict biofilm assembly in vivo. The lack of correlation between biofilm formation and infectious respiratory diseases found contributes to question the relevance of biofilms on the pathogenesis of infectious diseases.
- Prospective observational study on the role of catheter colonization and multidrug-resistance associated with catheter-related bloodstream infectionsPublication . Pinto, Miguel; Borges, Vitor; Nascimento, Maria; Martins, Filomena; Pessanha, Maria Ana; Faria, Isabel; Rodrigues, Joao; Matias, Rui; Joao Paulo, Gomes; Jordao, LuisaBackground: Central venous catheter (CVC)-related bloodstream infection (CRBSI) is a huge public health consern with considerable impact on mortality and health costs. The emergence of antimicrobial resistant microorganisms associated or not with CVC colonization by biofilms makes the treatment of CRBSI even more challeging. Methods:A 3-year observational study enrolling 3 tertiary hospitals located in Lisbon (Portugal) was designed to identify the major etiological agent of 58 CRBSI, their ability to colonize CVCs and their antimicrobial resistance profiles. Etiological agents of CRBSI were idebtified by VITEK-2. Whole-genome sequencing was used to confirm CRBSI by the most prevalent etiological agents and characteriza their resistome. CVC's colonization (namely by biofilm assembly) was monitored by scanning electron microscopy. Results: Staphylococci were the most prevalent causative agent (36/58, 62%), with S. aureus and coagulase negative S. epidermidis accounting for 24.1% and 36.2% of CRBSIs, respectively. Comparative genomic analysis of CVCs/hemoculture pairs of isolates revealed genomic matches for 35/36 pairs and a good correlation between antibiotic susceptibility phenotype and the presence of antimicrobials resistance genetic determinants. CVCs colonization was observed mainly in the catheter lumen and presented different phenotypes ranging from isolated attached microorganisms to mature biofilms. The latest phenotype, mature biofilms of S. epidermidis and S. aureus were found for 50.0% and 48.6% of the CVCs, respectively. Nevertheless, no statistical significant association was established between biofilm assembly and CRBSI highlighting the need for further studies to elucidate biofilms' role on this HAI. Conclusion: WGS proved to be a valuable tool to confirm CRBSI. Despite staphylococci biofilms identification on a considerable number of CVCs, no statistically significant association was found between CRBSI and biofilms.