Patterns of resistance to β-lactams and β-lactamase inhibitors in uropathogenic Escherichia coli strains isolated from animals in Portugal

FMV 1953 uropathogenic Escherichia coli isolate was extremely resistant to amoxicillin, co-amoxiclav, ticarcillin, mecillinam, cefoxitime, cefixime, cefuroxime, cefotaxime, ceftazidime, ceftriaxone and aztreoname. From the resistance patterns observed we deduce the phenotype as producing a TEM-1 β-lactamase, a hyperproduced Amp-C β-lactamase and an OXA-3 β-lactamase or a PBP-2 mutation isolate.Key words: Antibiotic resistance, uropathogenic Escherichia coli, phenotype characterization

The effect of non-absorbent hydrophobic sand litter on the urine protein-to-creatinine ratio in feline urine

BACKGROUND: Proteinuria can be quantified through the measurement of the urine protein‐to‐creatinine ratio (UPC). Voided urine samples in cats are often exposed to a non‐absorbable litter substrate prior to collection and urinalysis. Little is known about the effect exposure to such substrates has on pre‐analytical variability of UPC measurements. OBJECTIVES: The aim of this study was to assess agreement between UPC measurements from urine obtained by cystocentesis before and after exposure to non‐absorbent hydrophobic sand for 24 hours. METHODS: UPCs were measured in 40 urine samples obtained by cystocentesis from 39 cats (baselineUPC). Urine was then exposed to non‐absorbent hydrophobic sand litter for 24 hours, recovered, and repeat UPCs were measured (litterUPC). Agreement between paired measurements and the presence of any bias or error was evaluated using Bland–Altman analysis Passing–Bablok regression analysis, respectively. Cohen's kappa was used to measure agreement for the International Renal Interest Society (IRIS) proteinuria classification of samples. Observed total error (TE(obs)) was calculated for the laboratory analyzer and compared against absolute percentage changes in paired UPC measurements. RESULTS: Neither proportional nor constant error was identified using Passing‐Bablok regression between baselineUPC and litterUPC. Visual inspection of the Bland–Altman plot revealed good agreement, with 95% of paired measures falling within the limits of agreement (LOA). Cohen's kappa demonstrated almost perfect agreement for the IRIS classification of proteinuria between baselineUPC and litterUPC. Absolute percentage changes of paired UPC measurements outside of the LOAs were lower than the inter‐assay TE(obs). CONCLUSIONS: Feline urine exposed to non‐absorbent hydrophobic sand litter appears acceptable for UPC measurements

Biodegradation of diethylketone by two fungi

Two morphologically different fungi (one green and one white) from contaminated bioreactors with an aqueous solution of diethylketone and Streptococcus equisimilis were isolated and characterized at molecular level by sequencing the amplified ITS region. The ITS region sequence showed 99% match with Alternaria genera for the green fungi and 99% match with the Penicillium genera for the white fungi. The performance of these two fungi to biodegrade different concentrations of diethylketone from aqueous solutions was evaluated. The biodegradation of diethylketone was studied for an initial diethylketone concentration ranging from 0.5 to 4g/L in a batch mode of operation. The biodegradation rate found for both fungi followed the pseudo-second order kinetics for initial concentrations higher than 0.5 g/L and the resulting kinetic parameters are reported. The removal percentages obtained were approximately 100%, for all the initial concentrations tested

Surgical resolution of an oesophageal duplication cyst causing regurgitation in a domestic shorthair cat

Case summary An 18-month-old female domestic shorthair cat was referred for investigation of a 6 month period of regurgitation. Contrast radiography indicated an intramural oesophageal structure. Ultrasound-guided fine-needle aspiration of the area retrieved viscous fluid containing high numbers of squamous epithelial cells. Computed tomography disclosed a thin-walled contrast-enhancing structure containing non-enhancing homogenous contents. Exploratory thoracotomy confirmed an intramural cystic oesophageal structure, which was resected. Histopathological analysis of the resected tissue demonstrated an intramural oesophageal duplication cyst. A 12 month follow-up period has seen complete resolution of the cat’s clinical signs. Relevance and novel information This is the first report of successful oesophageal duplication cyst removal in a cat. Oesophageal duplication cysts should be included on the differential list for dysphagia and regurgitation in cats. Complete surgical removal in this cat carried a good long-term outcome

Biodegradation of diethylketone by Penicillium sp. and Alternaria sp.: a comparative study biodegradation of diethylketone by fungi

Two contaminating fungi were isolated from a bioreactor containing diethylketone and Streptococcus equisimilis, subsequently characterized at molecular level and identified as belonging to the Alternaria and Penicillium genera. The ability of these fungi to biodegrade DEK is evaluated. The kinetic parameters are estimated using four growth kinetic models for biodegradation of organic compounds available in literature. The experimental data for Alternaria sp. and Penicillium sp. was found to be better fitted by the Haldane and the Luong respectively. Biodegradation rate kinetics was evaluated using zero-order, pseudo-first order, pseudo-second order and three-half order models. The pseudo-second-order model was found suitable for all the concentrations of DEK tested for the biodegradation assays using Penicillium sp. whereas for the Alternaria sp. this model just describes properly the assays with initial concentrations of DEK higher than 0.5 g/L. The percentage of biodegraded DEK were approximately 100%, for all the initial concentrations tested

Refractive index inhomogeneity within an aerogel block

Evaluating local inhomogeneities of the refractive index inside aerogel blocks to be used as Cherenkov radiator is important for a high energy physics experiment where angular resolution is crucial. Two approaches are described and compared. The first one is based on the bending of a laser beam induced by refractive index gradients along directions normal to the unperturbed optical path. The second method exploits the Cherenkov effect itself by shooting an ultra-relativistic collimated electron beam through different points of the aerogel surface. Local refractive index variations result in sizable differences in the Cherenkov photons distribution. © 2005 Elsevier B.V. All rights reserved

Green optimization of glutaraldehyde vapor-based crosslinking on poly(vinyl alcohol)/cellulose acetate electrospun mats for applications as chronic wound dressings

In the last years, chronic wounds have become more prevalent, leading to a huge burden on the healthcare and social systems by requiring specialized protection. Indeed, wound dressings capable of assisting in the healing process are in urgent need. To that effect, nanofibrous dressings with a structure resembling the extracellular matrix have been engineered by electrospinning from combinations of poly(vinyl alcohol) (PVA) and cellulose acetate (CA) and optimized to endure physiological media contact and mechanical stress after crosslinking. Mats were prepared at different PVA/CA ratios, 100/0, 90/10 and 80/20 v/v%, at 10 w/v% concentration in acetic acid and water in a 75/25 v/v% proportion and processed via electrospinning. Processing conditions were optimized to obtain uniform, continuous, bead free mats, with a flexible structure. The instant solubilization of the PVA portion of the mat in aqueous media was surpassed via crosslinking. Even though there are many chemical agents available to accomplish such task, glutaraldehyde (GA) is by far the most common due to its efficiency, ease of access and processing, and low cost. Further, in its vapor form, GA has demonstrated reduced or no cytotoxic effects. The amount of GA, crosslinking time, temperature, and drying procedure were optimized to guarantee mechanically resilient mats by means of the greenest methodology possible. Indeed, it was determined that GA vapor at 25% in water could be applied for 7 h at 60 °C, using 6 mL of solution, in a 130 × 120 mm2 mat with optimal results. All traces of GA were then eliminated from the mats in a controlled environment (41% relativehumidity and 19 °C). In the end, it was seen that the mechanical resilience and thermal stability of the mats were improved after the application of the modified, green GA-based crosslinking, revealing the engineered methodology potential for applications in biomedical devices.Authors acknowledge the Portuguese Foundation for Science and Technology (FCT), FEDER funds by means of Portugal 2020 Competitive Factors Operational Program (POCI) and the Portuguese Government (OE) for funding the project PEPTEX with reference PTDC/CTMTEX/28074/2017 (POCI-01-0145-FEDER-028074). Authors also acknowledge project UID/CTM/00264/2021 of Centre for Textile Science and Technology (2C2T), funded by national funds through FCT/MCTES. M.A.T. acknowledges FCT for the PhD grant with reference SFRH/BD/148930/2019. SEM studies were performed at the Materials Characterization Services of the University of Minho (SEMAT/UM)

Histological biomarkers in liver and gills of juvenile Solea senegalensis exposed

Young juvenile Solea senegalensis were exposed to three sediments with distinct contamination profiles collected from a Portuguese estuary subjected to anthropogenic sources of contamination (the Sado estuary, western Portugal). Sedimentswere surveyed formetals (cadmium, chromium, copper, nickel, lead and zinc), ametalloid (arsenic) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide, dichloro-diphenyl-trichloroethane plus itsmetabolites), aswell as total organic matter, redox potential and particle fine fraction. The fish were exposed to freshly collected sediments in a 28-day laboratorial assay and collected for histological analyses at days 0 (T0), 14 (T14) and 28 (T28). Individual weighted histopathological indices were obtained, based on presence/absence data of eight and nine liver and gill pathologies, respectively, and on their biological significance. Although livers sustained more severe lesions, the sediments essentially contaminated by organic substances caused more damage to both organs than the sediments contaminated by both metallic and organic contaminants, suggesting a possible synergistic effect. Correlation analyses showed that some alterations are linked, forming distinctive histopathological patterns that are in accordance with the severity of lesions and sediment characteristics. The presence of large eosinophilic bodies in liver and degeneration of mucous cells in gills (a first-time described alteration)were some of the most noticeable alterations observed and were related to sediment organic contaminants. Body size has been found to be negatively correlated with histopathological damage in livers following longer term exposures. It is concluded that histopathological indices provide reliable and discriminatory data even when biomonitoring as complex media as natural sediments. It is also concluded that the effects of contamination may result not only from toxicant concentrations but also from their interactions, relative potency and sediment characteristics that ultimately determine bioavailability.peerreviewe

Biochemical endpoints on juvenile Solea senegalensis exposed

Juvenile Solea senegalensis were exposed to fresh sediments from three stations of the Sado estuary (Portugal) in 28-day laboratory assays. Sediments revealed distinct levels of total organic matter, fine fraction, redox potential, trace elements (arsenic, cadmium, chromium, copper, nickel, lead and zinc) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide: dichloro diphenyl trichloroethane). Organisms were surveyed for contaminant bioaccumulation and induction of two hepatic biochemical biomarkers: metallothionein (MT) and cytochrome P450 (CYP1A), as potential indicators of exposure to metallic and organic contaminants, respectively. Using an integrative approach it was established that, although bioaccumulation is in general accordance with sediment contamination, lethality and biomarker responses are not linearly dependent of the cumulative concentrations of sediment contaminants but rather of their bioavailability and synergistic effects in organisms. It is concluded that metals and organic contaminants modulate both MT and CYP1A induction and it is suggested that reactive oxygen species may be the link between responses and effects of toxicity.peerreviewe

Assessment of the genotoxic potential of contaminated estuarine sediments in fish peripheral blood: laboratory versus in situ studies

Juvenile Senegalese soles (Solea senegalensis) were exposed to estuarine sediments through 28-day laboratory and in situ (field) bioassays. The sediments, collected from three distinct sites (a reference plus two contaminated) of the Sado Estuary (W Portugal) were characterized for total organic matter, redox potential, fine fraction and for the levels of metals, polycyclic aromatic hydrocarbons (PAHs) and organochlorines, namely polychlorinated biphenyls (PCBs) and dichloro diphenyl tricholoethane plus its main metabolites (DDTs). Genotoxicity was determined in whole peripheral blood by the single-cell gel electrophoresis (SCGE or ‘‘comet’’) assay and by scoring erythrocytic nuclear abnormalities (ENA). Analysis was complemented with the determination of lipid peroxidation in blood plasma by the thiobarbituric acid reactive substances (TBARS) protocol and cell type sorting. The results showed that exposure to contaminated sediments induced DNA fragmentation and clastogenesis. Still, laboratory exposure to the most contaminated sediment revealed a possible antagonistic effect between metallic and organic contaminants that might have been enhanced by increased bioavailability. The laboratory assay caused a more pronounced increase in ENA whereas a very significant increase in DNA fragmentation was observed in field-tested fish exposed to the reference sediment, which is likely linked to increased lipid peroxidation that probably occurred due to impaired access to food. Influence of natural pathogens was ruled out by unaltered leukocyte counts. The statistical integration of data correlated lipid peroxidation with biological variables such as fish length and weight, whereas the genotoxicity biomarkers were more correlated to sediment contamination. It was demonstrated that laboratory and field bioassays for the risk assessment of sediment contamination may yield different genotoxicity profiles although both provided results that are in overall accordance with sediment contamination levels. While field assays may provide more ecologically relevant data, the multiple environmental variables may produce sufficient background noise to mask the true effects of contamination.info:eu-repo/semantics/publishedVersio