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Southern hemisphere humpback whale (Megaptera novaeangliae, SHHW) breeding populations follow a high-fidelity Antarctic krill (Euphausia superba) diet while feeding in distinct sectors of the Southern Ocean. Their capital breeding life history requires predictable ecosystem productivity to fuel migration and migration-related behaviours. It is therefore postulated that populations feeding in areas subject to the strongest climate change impacts are more likely to show the first signs of a departure from a high-fidelity krill diet. We tested this hypothesis by investigating blubber fatty acid profiles and skin stable isotopes obtained from five SHHW populations in 2019, and comparing them to Antarctic krill stable isotopes sampled in three SHHW feeding areas in the Southern Ocean in 2019. Fatty acid profiles and δ 13 C and δ 15 N varied significantly among all five populations, however, calculated trophic positions did not (2.7 to 3.1). Similarly, fatty acid ratios, 16:1ω7c/16:0 and 20:5ω3/22:6ω3 were above 1, showing that whales from all five populations are secondary heterotrophs following an omnivorous diet with a diatom-origin. Thus, evidence for a potential departure from a high-fidelity Antarctic krill diet was not seen in any population. δ 13 C of all populations were similar to δ 13 C of krill sampled in productive upwelling areas or the marginal sea-ice zone. Consistency in trophic position and diet origin but significant fatty acid and stable isotope differences demonstrate that the observed variability arises at lower trophic levels. Our results indicate that, at present, there is no evidence of a divergence from a high-fidelity krill diet. Nevertheless, the characteristic isotopic signal of whales feeding in productive upwelling areas, or in the marginal sea-ice zone, implies that future cryosphere reductions could impact their feeding ecology., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

β-Galactosidase supplementation plays an important role in the life of people with lactose intolerance. However, these formulations are rendered ineffective by the low pH and pepsin in the stomach and pancreatic proteases in the intestine. Therefore, it is necessary to develop oral transport systems for carrying this enzyme in the active form up to the intestine, where the lactose digestion occurs. In this research, a new hydrogel was developed that could potentially be used for enzyme supplement therapy. In this regard, the chitosan-based β-Gal formulations described in the manuscript are an alternative long-acting preparation to the so far available preparations that allow for enzyme protection and mucosal targeting. These hydrogels were prepared from chitosan and polyethylene glycol and contained a covalently immobilized β-galactosidase from Aspergillus oryzae. The β-galactosidase in the hydrogel was protected from degradation in a gastric medium at a pH of 2.5 and retained 75 % of its original activity under subsequent intestinal conditions. In the case of a simulated gastric fluid with a pH of 1.5, a copolymer containing methacrylic acid functional groups was sufficient to protect the hybrid hydrogel from the extremely acidic pH. In addition, the surface of the hydrogel was chemically modified with thiol and amidine groups, which increased the binding to intestinal mucin by 20 % compared with the unmodified hydrogel. These results represent a promising approach for oral transport as a reservoir for β-galactosidase in the small intestine to reduce the symptoms of hypolactasia., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Niuris Acosta and Julia Revuelta reports financial support was provided by Community of Madrid., (Copyright © 2023. Published by Elsevier B.V.)

Wastewater-based surveillance (WBS) of infectious diseases is a powerful tool for understanding community COVID-19 disease burden and informing public health policy. The potential of WBS for understanding COVID-19's impact in non-healthcare settings has not been explored to the same degree. Here we examined how SARS-CoV-2 measured from municipal wastewater treatment plants (WWTPs) correlates with workforce absenteeism. SARS-CoV-2 RNA N1 and N2 were quantified three times per week by RT-qPCR in samples collected at three WWTPs servicing Calgary and surrounding areas, Canada (1.4 million residents) between June 2020 and March 2022. Wastewater trends were compared to workforce absenteeism using data from the largest employer in the city (>15,000 staff). Absences were classified as being COVID-19-related, COVID-19-confirmed, and unrelated to COVID-19. Poisson regression was performed to generate a prediction model for COVID-19 absenteeism based on wastewater data. SARS-CoV-2 RNA was detected in 95.5 % (85/89) of weeks assessed. During this period 6592 COVID-19-related absences (1896 confirmed) and 4524 unrelated absences COVID-19 cases were recorded. A generalized linear regression using a Poisson distribution was performed to predict COVID-19-confirmed absences out of the total number of absent employees using wastewater data as a leading indicator (P < 0.0001). The Poisson regression with wastewater as a one-week leading signal has an Akaike information criterion (AIC) of 858, compared to a null model (excluding wastewater predictor) with an AIC of 1895. The likelihood-ratio test comparing the model with wastewater signal with the null model shows statistical significance (P < 0.0001). We also assessed the variation of predictions when the regression model was applied to new data, with the predicted values and corresponding confidence intervals closely tracking actual absenteeism data. Wastewater-based surveillance has the potential to be used by employers to anticipate workforce requirements and optimize human resource allocation in response to trackable respiratory illnesses like COVID-19., Competing Interests: Declaration of competing interest The authors have declared no conflicts of interest., (Copyright © 2023. Published by Elsevier B.V.)

In this study, water-soluble chitosan salts (chitosan amine sulfopropyl salts) were prepared from chitosan samples with different molecular weights and deacetylation degrees. These soluble-in-water polymer salts allowed us to produce, in an eco-friendly and facile method, silver nanoparticles (AgNPs) with better control on size and polydispersity, even at large silver concentrations than their corresponding chitosan sample. Chitosan salt-based materials (films and scaffolds) were analyzed in terms of antibacterial properties against Staphylococcus aureus ATCC23915 or Pseudomonas aeruginosa ATCC 27853. 3D scaffolds enhanced the effect of the chitosan-AgNPs combination compared to the equivalent films., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The purpose of this study was to develop and characterize chitosan (Ch)-based films incorporated with varying molecular weight (Mw) and acetylation degree (AD) chitosan-depolymerization-products (CDP), to be applied as drug delivery materials. As compared to Ch-film, optical and antioxidant potentials of Ch/CDP-based films were improved, particularly using low Mw and AD-CDP. Whereas, films water resistance, mechanical and antibacterial properties increased as CDP-Mw increased and AD decreased. For the thermal and swelling behaviors, better values were obtained using higher Mw and AD-CDP. Further, to assess their in vitro ciprofloxacin (CFX)-release behavior, loaded-CFX Ch/CDP-based films, crosslinked using glutaraldehyde, were prepared. Expect of elongation at break, crosslinked CFX-loaded films showed increased optical, water resistance, tensile strength and thermal properties, as compared to unloaded films. The CFX-release profiles indicated that a slower and sustained release was observed, particularly when using lower Mw and AD-CDP, and mainly for the crosslinked films during 48 h. These films can release CFX for up to 54% in 6 and 24 h, at pH 1.2 and 7.4, respectively. Through this study, novel biodegradable, swellable and pH-sensitive crosslinked Ch/CDP-based films may be considered as suitable and promising drug delivery systems., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Streptococcus mutans plays an important role in caries etiology and eventually in systemic infections. However, it is often found in infected root canals, but the pathophysiological characteristics of strains residing in this site are largely unknown. Here, we characterized strains of S. mutans isolated from root canals of primary (PI) and secondary/persistent (SI) endodontic infections in relation to serotype and genotype; presence of genes coding for collagen binding proteins (CBPs); collagen binding activity and biofilm formation capacity; ability to withstand environmental stresses; systemic virulence in Galleria mellonella; and invasion of human coronary artery endothelial cells and human dental pupal fibroblasts. Samples from 10 patients with PI and 10 patients with SI were collected, and a total of 14 S. mutans isolates, belonging to 3 genotypes, were obtained. Of these, 13 were serotype c, and 1 was serotype k. When compared with the reference strains, the clinical isolates were hypersensitive to hydrogen peroxide. Remarkably, all 14 strains harbored and expressed the CBP-encoding gene cbm, showing increased binding to collagen, enhanced systemic virulence in G. mellonella, and ability to invade human coronary artery endothelial cells and human dental pupal fibroblasts when compared with CBP-negative strains. Whole genome sequence analysis of PI and SI isolates revealed that these strains are phylogenetically related but genetically distinct from each other. Our findings highlight the importance of CBPs in facilitating colonization and persistence of S. mutans in collagenous substrates such as root canals and their potential role in the pathogenesis of endodontic infections., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

This study reports the enzymatic depolymerization of chitosan by the chitosanolytic preparation of Bacillus licheniformis GA11. For this purpose, chitosanase production and biochemical characterization of the crude enzyme preparation from GA11 were firstly investigated. The highest chitosanase production was obtained in a culture medium containing 50.0 g/l of a mixture of soluble starch/shrimp shells/crab shells and 5.0 g/l tryptone, after incubation during 5 days, at 30 °C with a pH i of 6.0 and under continuous agitation at 200 rpm. Then, the chitosanolytic preparation, exhibiting maximum activity at 65 °C and pH 5.0, was used to hydrolyze chitosan, leading to various chitosan-depolymerization products (CDP) with different physicochemical characteristics. Finally, the antioxidant and antimicrobial potentials of CDP were evaluated, allowing to conclude that the molecular weight and the acetylation degree highly affect the biological activities of CDP., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2019. Published by Elsevier B.V.)

Background: To improve clinical outcomes, cystic fibrosis (CF) patients with chronic Pseudomonas aeruginosa infections are prescribed inhaled anti-pseudomonal antibiotics. Although, a diverse microbial community exists within CF airways, little is known about how the CF microbiota influences patient outcomes. We hypothesized that organisms within the CF microbiota are affected by inhaled-antibiotics and baseline microbiome may be used to predict therapeutic response., Methods: Adults with chronic P. aeruginosa infection from four clinics were observed during a single 28-day on/off inhaled-aztreonam cycle. Patients performed serial sputum collection, CF-respiratory infection symptom scores (CRISS), and spirometry. Patients achieving a decrease of ≥2 CRISS by day 28 were categorized as subjective responders (SR). The airway microbiome was defined by Illumina MiSeq analysis of the 16S rRNA gene., Results: Thirty-seven patients (median 37.4 years and FEV 1 44% predicted) were enrolled. No significant cohort-wide changes in the microbiome were observed between on/off AZLI cycles in either alpha- or beta-diversity metrics. However, at an individual level shifts were apparent. Twenty-one patients (57%) were SR and fourteen patients did not subjectively respond. While alpha-diversity metrics did not associate with response, patients who did not subjectively respond had a higher abundance of Staphylococcus and Streptococcus, and lower abundance of Haemophilus., Conclusions: The CF microbiome is relatively resilient to AZLI perturbations. However, associated changes were observed at the individual patient level. The relative abundance of key "off-target" organisms associated with subjective improvements suggesting that the microbiome may be used as a tool to predict patient response - potentially improving outcomes., (Copyright © 2019. Published by Elsevier B.V.)

In this study, a digestive chitosanase from blue crab (Portunus segnis) viscera was extracted, characterized and applied. The crude chitosanase showed optimum activity at pH 4.0 and 60 °C and retained >80% of its activity over a pH range from 3.0 to 10.0. Subsequently, the crude chitosanase was applied to produce bioactive varying molecular weight (M w ) and acetylation degree chitosan-depolymerization products (CDP) with specially sequences composition determined by MALDI-TOF MS owing to an endo-cleavage mode. This hydrolysis process allowed to the preparation, after 24 h of incubation at 40 °C, of a low Mw water soluble CDP (H 24h, <4.4 kDa) with DP up to 6 and a high Mw CDP (C 24h, 142.19 kDa). Following their physicochemical characterization, the functional properties, antioxidant and antimicrobial activities of CDP were investigated. Interestingly, as compared to the native chitosan, CDP, especially low M w derivatives (H 24h ) exhibited potent antioxidant activities, while high M w derivatives, especially C 24h , markedly inhibited the growth of all tested bacteria and fungi. These results may provide novel insights into the efficiency of chitosan depolymerisation using the Portunus segnis digestive crude chitosanase as a simple, inexpensive and easily method to produce bioactive chitosan-derivatives and that this bioactivity depends highly on their attractive characteristics., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The aim of this paper is to study the catalytic behaviour of silver nanoparticles (AgNps) produced using low molecular weight chitosan (LMWC) samples depolymerized by an enzymatic method, using either lysozyme or chitosanase. The ability of four sets of silver nanoparticles to reduce Toluidine Blue (TBO) was used as test reaction, and the effect of both catalyst concentration and reaction temperature on the effectiveness of the catalytic reduction was assessed. Generally speaking, AgNps produced through chitosan depolymerization with lysozyme showed better performance than those ones produced using chitosanase. On the other hand, colloidal silver nanoparticles stabilized with LMWC were mixed with medium molecular weight chitosan (MMWC) sample, in order to generate different scaffolds by using beta-glycerol phosphate. These scaffolds were analyzed by microscopy, XRD, ATR-FTIR, and their swelling capacity was evaluated. Their catalytic ability for reducing TBO, as well as their reusability, was assessed. Our results showed that the catalytic properties of the colloidal AgNps were remarkably affected by the properties of the LMWC used for their synthesis. Once again, AgNps-chitosan scaffolds produced with chitosan depolymerized with lysozyme were more effective., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ants are ecologically dominant members of terrestrial communities. Ant foraging is often strongly associated with plants and depends upon associative learning of chemicals in the environment. As a result, plant chemicals can affect ant behaviors and, in so doing, have strong multi-trophic indirect effects. Plant chemicals mediate ant behaviors in the contexts of floral visitation, seed dispersal and predation, leaf cutting, interactions with ant-mutualist host plants, interactions with mutualist and prey insects in plant canopies, and plant predation of ants by carnivorous plants. Here, we review what is known about these differing contexts in which plant chemicals influence ant behavior, the mechanisms by which ants are affected by plant chemicals, and future directions within these topics., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Inward rectifier K + (Kir) channels contribute to a variety of physiological processes in insects and are emerging targets for insecticide development. Previous studies on insect Kir channels have primarily focused on dipteran species (e.g., mosquitoes, fruit flies). Here we identify and functionally characterize Kir channel subunits in a hemipteran insect, the soybean aphid Aphis glycines, which is an economically important insect pest and vector of soybeans. From the transcriptome and genome of Ap. glycines we identified two cDNAs, ApKir1 and ApKir2, encoding Kir subunits that were orthologs of insect Kir1 and Kir2, respectively. Notably, a gene encoding a Kir3 subunit was absent from the transcriptome and genome of Ap. glycines, similar to the pea aphid Acyrthosiphon pisum. Heterologous expression of ApKir1 and ApKir2 in Xenopus laevis oocytes enhanced K + -currents in the plasma membrane; these currents were inhibited by barium and the small molecule VU041. Compared to ApKir2, ApKir1 mediated currents that were larger in magnitude, more sensitive to barium, and less inhibited by small molecule VU041. Moreover, ApKir1 exhibited stronger inward rectification compared to ApKir2. Topical application of VU041 in adult aphids resulted in dose-dependent mortality within 24 h that was more efficacious than flonicamid, an established insecticide also known to inhibit Kir channels. We conclude that despite the apparent loss of Kir3 genes in aphid evolution, Kir channels are important to aphid survival and represent a promising target for the development of new insecticides., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Chronic fluid overload is frequent in hemodialysis patients (P) and it associates with hypertension, left ventricular hypertrophy (LVH) and higher mortality. Moreover, echocardiographic data assessing fluid overload is limited. Our aim was to evaluate the relationship between fluid overload measured by bioimpedance spectroscopy (BIS) and different echocardiographic parameters., Methods: Cross-sectional observational study including 76 stable patients. Dry weight was clinically assessed. BIS and echocardiography were performed. Weekly time-averaged fluid overload (TAFO) and relative fluid overload (FO/ECW) were calculated using BIS measurements., Results: Based on TAFO three groups were defined: A- dehydrated, TAFO <-0.25 L 32 P (42%); B- normohydrated, TAFO between -0.25 and 1.5 l: 26 (34%); C- overhydrated, TAFO>1.5 l: 18 (24%). We found significant correlation between TAFO and left atrial volume index (LAVI) (r: 0.29; p=0.013) but not with FO/ECW (r 0.06; p=0.61). TAFO, but not FO/ECW kept a significant relationship with LAVI (p=0.03) using One-Way ANOVA test and linear regression methods. LVH was present in 73.7% (concentric 63.2%, eccentric in 10.5%). No differences between groups in the presence of LVH or left ventricular mass index were found., Conclusions: We found that left atrial volume index determined by echocardiographic Area-length method, but not left ventricle hypertrophy or dimensions of cavities, are related on hydration status based on bioimpedance measured time-averaged fluid overload (TAFO), and not with FO/ECW., (Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.)

Parastrongylus cantonensis is a parasite of murid rodents that can infect humans and cause health problems as eosinophilic meningitis. Although it is endemic in south Asia, the Pacific islands, Australia, USA, and a few Caribbean islands, it has been extended to new geographical regions. In the Canary Islands (Spain) a survey of helminths of Rattus rattus, Rattus norvegicus and Mus musculus domesticus was carried out. Furthermore, five species of molluscs were examined for nematode larvae to determine whether they are potential intermediate hosts of P. cantonensis. Nematodes were found in the lungs of 15% of 67 R. rattus examined in Tenerife, one of the four studied islands, with a prevalence of 20% in the highest focus of infection. Based on morphological and molecular analysis, with the complete internal transcribed spacer 2 (ITS-2) and a fragment of the small subunit ribosomal RNA (SSU rRNA) nucleotide sequences, nematodes were identified as P. cantonensis. Larval nematodes found from snails and slugs were identified as third-stage (L(3)) Metastrongyloidea, but the molecular study showed that they did not belong to P. cantonensis. This is the first finding of angiostrongyliasis in rats in the Canary Islands (Spain). New molecular data for this species and Parastrongylus dujardini are reported. The presence of P. cantonensis in Tenerife could be of importance from the public health point of view. Further studies are required in order to look for other potential foci of infections in the Canary Islands., ((c) 2010 Elsevier B.V. All rights reserved.)

Giardia duodenalis (syn. Giardia lamblia, Giardia intestinalis) is a wide-spread intestinal protozoa of both humans and animals. Although giardiosis in goat is commonly asymptomatic, young kids may bear an enteric disease associated with persistent diarrhoea and delayed weight gain. In the present study we have analysed the occurrence of Giardia in 315 young goat kids (2-6 months old) from Gran Canaria Island (Spain) through visualization of faecal cysts. The identification of genotypes of G. duodenalis among the farms was attained by nested PCR of the triophosphate isomerase (TPI) and single PCR of beta-giardin genes and subsequent sequencing. Positive samples were found in 42.2% of the animals and 95.5% of the farms. Goat faecal specimens were positive for only livestock-associated G. duodenalis assemblage E genotype for both TPI and beta-giardin genes. The genetic analysis of these two loci revealed the presence of different haplotypes among the farms included in the survey and high homology with homologous genes from cattle and sheep. Altogether, the data presented here provide additional information to the prevalence and genetic characterization of Giardia isolates. The absence of assemblages A and B in this study suggests that zoonotic transmission of Giardia from goats could be of low epidemiological significance, although these findings should be validated in studies including other geographical areas, age groups and larger number of samples.

The free-living amoebae of the genus Acanthamoeba include non-pathogenic and pathogenic species and has been recently classified into 15 different genotypes, T1-T15. In this study, a survey was conducted in order to determine the presence and pathogenic potential of free-living amoebae of Acanthamoeba genus in freshwater sources associated with human activities in the Nile Delta region, Egypt. Identification of Acanthamoeba was based on the morphology of cyst and trophozoite forms and PCR amplification with a genus specific primer pair. The pathogenic potential of Acanthamoeba isolates was characterized using temperature and osmotolerance assays and PCR reactions with two primer pairs specific to Acanthamoeba pathogenesis. Isolates genotypes were also determined after ribosomal DNA sequencing. These data revealed that isolates belong to T1, T2, T3, T4 and T7 genotypes. As expected, T4 isolates exhibited the most pathogenic traits and were osmotolerant, temperature tolerant and expressed extracellular serine proteases. This is the first report presenting environmental distribution of Acanthamoeba genotypes in Egypt.

Unlabelled: The Uruguayan Registry of Glomerulopathies began its activity in 1974 and since 1985 is a national registry. The aim of this report is to analyze the incidence and the variations in frequencies of the histological diagnosis and clinical presentation during the 1980-2003 period., Patients and Methods: From the 2,058 patients with renal biopsy in the whole period, we analyzed the histological diagnosis and the following data has been collected when the patients were registered: age, gender, clinical syndrome, proteinuria, hematuria, serum creatinine, blood pressure and time from the first symptom. Four periods of registry entry were considered: 1980-1989, 1990-1994, 1995-1999 and 2000-2003. Chi-square and Student test for independent samples were used to evaluate the differences among the variables frequencies in the four periods., Results: The incidence of registered glomerulopathies per million population (pmp) increased from 13 (1980-1989) to 43 (2000-2003). In the 2000-2003 period, the incidences pmp were: primary glomerulopathy (PG), 25.3 and secondary glomerulopathy, 14.2. The highest incidences pmp were: focal and segmental glomeruloesclerosis (FSGS) 6.4; vasculitis 5.4; lupus nephritis 4.6; minimal change disease (MCD) 4.6; IgA nephropathy (IgAN) 4.5; and membranous nephropathy (MN) 4.0. The most frequent PG were the FSGS (29.3%) and the MCID (19.6%). The FSGS frequency decreased from 36.3% in 1995-1999 to 19.1% in 2000-2003. The IgAN frequency increased from 5.2% in 1980-1989 to 17.5% in 2000-2003. Nephrotic syndrome was the most frequent clinical presentation; its frequency was over 30% in the four periods. Asymptomatic urinary abnormality frequency increased from 14.0% in 1980-1989 to 22.7% in 2000-2003. The frequency of serum creatinine under 1.5 mg/dl, increased from 42.2% in 1980-1989 to 67.2% in 2000-2003 (p = 0.001). The frequency of serum creatinine over 6.0 mg/dl, decreased from 19.3% in 1990-1994 to 7.2% in 2000-2003. The percentage of patients referred since the first month of the apparent onset of the disease increased from 24.0% in 1980-1989 to 40.1% in 2000-2003 (p < 0.001)., Conclusions: In Uruguay, the incidence of glomerulopathies with histological diagnosis has increased and the frequency of the different types has changed. Several indicators seem to show that the reference of patients to the nephrologist tended to be earlier in the last years.