Search results for "biofilm."
showing 10 items of 382 documents
Shared effects of organic microcontaminants and environmental stressors on biofilms and invertebrates in impaired rivers
2016
Land use type, physical and chemical stressors, and organic microcontaminants were investigated for their effects on the biological communities (biofilms and invertebrates) in several Mediterranean rivers. The diversity of invertebrates, and the scores of the first principal component of a PCA performed with the diatom communities were the best descriptors of the distribution patterns of the biological communities against the river stressors. These two metrics decreased according to the progressive site impairment (associated to higher area of agricultural and urban-industrial, high water conductivity, higher dissolved organic carbon and dissolved inorganic nitrogen concentrations, and high…
Integrated fixed-film activated sludge membrane bioreactors versus membrane bioreactors for nutrient removal: A comprehensive comparison
2018
Abstract This research elucidates the pollutants (nutrients and carbon) removal performance and nitrous oxide (N2O) emissions of two pilot plants. Specifically, a University of Cape Town (UCT) Membrane Bioreactor (MBR) plant and an Integrated Fixed Film Activated Sludge (IFAS)-UCT-MBR plant were investigated. The plants were fed with real wastewater augmented with acetate and glycerol in order to control the influent carbon nitrogen ratio (C/N). The short-term effect of the inlet C/N ratio variation (C/N = 5 mgCOD/mgN and C/N = 10 mgCOD/mgN) on the behaviour of both plants was investigated. The results showed that the IFAS-UCT-MBR configuration provided the best performance in terms of poll…
Novel strategies in the war against antibiotic resistance
2021
The global threat of antibiotic resistance is steadily growing. Antibiotic resistancemay involve any class of antibiotic, including second- and third-line agents that have been considered to date the last-resort drugs to counteract common infections. We may lose our capability to keep under control many common bacterial infections [1]. Despite this, in the past decade significant research efforts have been made to develop new antibacterial strategies able to treat multidrug-resistant infections; however, no new therapeutic approach has yet reached the clinic [2,3]. In order to identify new valuable antimicrobial drugs, it is important to consider the main bacterial resistance mechanisms in …
Therapeutic Strategies To Counteract Antibiotic Resistance in MRSA Biofilm‐Associated Infections
2021
Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as one of the leading causes of persistent human infections. This pathogen is widespread and is able to colonize asymptomatically about a third of the population, causing moderate to severe infections. It is currently considered the most common cause of nosocomial infections and one of the main causes of death in hospitalized patients. Due to its high morbidity and mortality rate and its ability to resist most antibiotics on the market, it has been termed a “superbug”. Its ability to form biofilms on biotic and abiotic surfaces seems to be the primarily means of MRSA antibiotic resistance and pervasiveness. Importantly, more tha…
Listeria monocytogenes Differential Transcriptome Analysis Reveals Temperature-Dependent Agr Regulation and Suggests Overlaps with Other Regulons
2012
Listeria monocytogenes is a ubiquitous, opportunistic pathogenic organism. Environmental adaptation requires constant regulation of gene expression. Among transcriptional regulators, AgrA is part of an auto-induction system. Temperature is an environmental cue critical for in vivo adaptation. In order to investigate how temperature may affect AgrA-dependent transcription, we compared the transcriptomes of the parental strain L. monocytogenes EGD-e and its Delta agrA mutant at the saprophytic temperature of 25 degrees C and in vivo temperature of 37 degrees C. Variations of transcriptome were higher at 37 degrees C than at 25 degrees C. Results suggested that AgrA may be involved in the regu…
Anodic biofilm vitality during operation of microbial fuel cells at various load conditions
2016
Effect of sludge age on microbial consortia developed in MFCs
2017
BACKGROUND This work is focused on the assessment of the performance of mini-scale air-breathing microbial fuel cells (MFCs), by monitoring the evolution of the bio-electrogenic activity for a period of 40 days and by comparing the microorganisms populations developed in each of the MFC after this period. RESULTS Five MFCs were operated at sludge ages ranging from 1.4 to 10.0 days. Results showed the superb performance of the MFC operating under a sludge age of 2.5 days. Desulfuromonas, Syntrophothermus, Solitalea, Acholeplasma, Propionicimonas, Desulfobacula and Sphaerochaeta are proposed as potential responsible for the bio-electrogenic activity. CONCLUSIONS Microbial population analysis …
Voriconazole inhibits biofilm formation in different species of the genus Candida
2012
To determine the ability of voriconazole to inhibit the formation of biofilms.A total of 38 blood isolates of Candida spp. (8 Candida albicans, 10 Candida tropicalis, 10 Candida glabrata, 7 Candida parapsilosis sensu stricto and 3 Candida orthopsilosis) and C. albicans ATCC 90028 and ATCC 64548 were assessed. Biofilm formation was quantified using XTT reduction assays. The inhibition of biofilm formation was determined (i) in the presence of 0.06 and 0.25 mg/L voriconazole, and (ii) on surfaces previously coated with 0.06, 0.25, 1, 4 and 16 mg/L voriconazole.Voriconazole reduced biofilm formation under both conditions, the extent depending on the species, isolate and drug concentration. In …
Biofilm development by potentially pathogenic non-pigmented rapidly growing mycobacteria
2008
Abstract Background A study to evaluate the biofilm-development ability in three different media (Middlebrook 7H9, sterile tap water and PBS-5% glucose) was performed with 19 collection strains from 15 different species on non-pigmented rapidly growing mycobacteria (NPRGM). A microtiter plate assay was developed to evaluate the percentage of covered surface of the microtiter plate wells in different days from day 1 to day 69. Results All strains were able to develop biofilm in all the tested media. Middlebrook 7H9 showed the fastest growth, followed by sterile tap water and PBS-5% glucose. A sigmoid growth curve was detected in all the strains both in Middlebrook 7H9 and in sterile tap wate…