Search results for "biofilm."
showing 10 items of 382 documents
Phenotypic characterization and adhesive properties of vaginal Candida spp. strains provided by the CHU Farhat Hached (Sousse, Tunisia).
2015
Abstract Background Vulvovaginal candidiasis is a common infection among women worldwide, being Candida albicans the most commonly isolated species. Therefore, controlling this opportunistic yeast is one of the key factors for reducing nosocomial infection. Aims We investigated several virulence properties of 28 vaginal strains of Candida isolated from Tunisian women suffering from vulvovaginitis. We also analyzed the virulence properties of a clinical Candida krusei strain and five Candida reference strains. Methods Candida strains were subjected to microscopic analysis and culture in Candida ID2 chromogenic medium. The adhesive properties of these strains were estimated by the microtiter …
Sensitivity to acetic acid, ability to colonize abiotic surfaces and virulence potential of Listeria monocytogenes EGD-e after incubation on parsley …
2010
International audience; Abstract Aim: To investigate how the survival of Listeria monocytogenes on parsley leaves may affect its ability to sustain process-related harsh conditions and its virulence. Methods and Results: Parsley seedlings were spot inoculated with stationary phase cells of L. monocytogenes EGD-e and incubated for 15 days. Each day, bacterial cells were harvested and enumerated, and their ability to survive acetic acid challenge (90 min, pH 4.0), to colonize abiotic surfaces and to grow as biofilms was assessed. After a 3-log decrease over the first 48 h, the population stabilized to about 10(6) CFU g(-1) until the sixth day. After the sixth day, L. monocytogenes was no long…
Preceding Host History of Conjugative Resistance Plasmids Affects Intra- and Interspecific Transfer Potential from Biofilm
2023
Conjugative plasmids can confer antimicrobial resistance (AMR) to their host bacterium. The plasmids disperse even between distantly related host species, rescuing the host from otherwise detrimental effects of antibiotics. Little is known about the role of these plasmids in the spread of AMR during antibiotic treatment. One unstudied question is whether the past evolutionary history of a plasmid in a particular species creates host specificity in its rescue potential or if interspecific coevolution can improve interspecific rescues. To study this, we coevolved the plasmid RP4 under three different host settings; solely Escherichia coli or Klebsiella pneumoniae, or alternating between both …
La rilevanza medico-legale dei biofilms batterici nelle infezioni nosocomiali
2007
Paperitehtaan jätevesien käsittely termofiilisellä aktiiviliete- ja biofilmiprosessilla
2005
Monilla teollisuudenaloilla muodostuu kuumia jätevesiä, jotka jäähdytetään biologista kä- sittelyä varten. Käsittely totuttua korkeammassa lämpötilassa voi tuoda taloudellisia sekä prosessin toimintaan liittyviä etuja. Kuitenkin useimpien termofiilisestä jätevedenkäsittelystä saatujen kokemusten mukaan lietteen erotus on vaikeampaa kuin tavanomaisessa jäteveden käsittelyssä. Myös joidenkin liukoisten aineiden poisto voi monimutkaistua. Tämän tutkimuksen tavoite oli verrata termofiilisen (55 °C) aktiiviliete- ja biofilmiprosessien toimintaa pilot-mittakaavassa. Toimintaa verrattiin myös täyden mittakaavan mesofiiliseen (35 °C) aktiivilieteprosessiin, mutta painotus on termofiilisten prosessi…
Identità dei formaggi tradizionali: sicurezza igienica e preservazione della tipicità
2020
Negli ultimi anni, si sta registrando una sempre maggiore richiesta di alimenti tradizionali, principalmente in relazione all’immagine “naturale” percepita dal consumatore; questo fenomeno pone una contraddizione per il sistema di produzione alimentare. Se è vero che le innovazioni delle tecnologie di trasformazione delle materie prime hanno determinato l’aumento della shelf-life e la riduzione dei rischi connessi al consumo di molti alimenti, è anche vero che molti alimenti hanno perso la loro identità derivante non solo dalle materie prime, ma anche dal processo applicato durante la trasformazione
Analysis of Biomass Characteristics in MBR and MB-MBR Systems Fed with Synthetic Wastewater: Influence of a Gradual Salinity Increase
2014
The paper presents the results of a field gathering campaign carried out on two different pilot scale membrane bioreactor (MBR) systems, treating synthetic wastewater subject to a gradual increase of salinity. One was a conventional MBR system, while the other was a moving bed biofilm membrane bioreactor (MB-MBR), which combines suspended biomass and biofilm. Indeed, the presence of suspended carriers inside the bioreactor seems to give benefits due to the collisions between the circulating media and the membrane. The aim of the study was the comparison of two configurations in terms of biomass activity characterization and performance (pollutants removal and hydraulic behaviour). The resul…
Characterisation of the microflora contaminating the wooden vats used for traditional Sicilian cheese production
2015
Traditional Sicilian cheese productions are carried out employing traditional wooden vats, called <em>tina.</em> Many studies have highlighted the beneficial role of wooden dairy equipment by contributing to enriching the milk microflora and improving the acidification processes. The present work was undertaken to evaluate the safety of the wooden vats used to coagulate milk. To this purpose, the different microbial populations hosted onto the internal surfaces of the vats used to produce two different stretched cheeses, namely <em>Caciocavallo Palermitano</em> and <em>Vastedda della valle del Belìce DOP</em>, were investigated for the presence of spoilag…
Evidence of autoinduction heterogeneity via expression of the agr system of listeria monocytogenes at the single-cell level
2011
ABSTRACT To investigate if the primary function of the Agr system of Listeria monocytogenes is to monitor cell density, we followed Agr expression in batch cultures, in which the autoinducer concentration was uniform, and in biofilms. Expression was heterogeneous, suggesting that the primary function of Agr is not to monitor population density.
Dark matters : contrasting responses of stream biofilm to browning and loss of riparian shading
2022
Concentrations of terrestrial-derived dissolved organic carbon (DOC) in freshwater ecosystems have increased consistently, causing freshwater browning. The mechanisms behind browning are complex, but in forestry-intensive regions browning is accelerated by land drainage. Forestry actions in streamside riparian forests alter canopy shading, which together with browning is expected to exert a complex and largely unpredictable control over key ecosystem functions. We conducted a stream mesocosm experiment with three levels of browning (ambient vs. moderate vs. high, with 2.7 and 5.5-fold increase, respectively, in absorbance) crossed with two levels of riparian shading (70% light reduction vs.…