Detection of hepatitis E virus genotype 3 in an Algerian mouse (Mus spretus) in Portugal

Virus monitoring in small mammals is central to the design of epidemiological control strategies for rodent-borne zoonotic viruses. Synanthropic small mammals are versatile and may be potential carriers of several microbial agents. In the present work, a total of 330 fecal samples of small mammals were collected at two sites in the North of Portugal and screened for zoonotic hepatitis E virus (HEV, species Paslahepevirus balayani). Synanthropic small mammal samples (n = 40) were collected in a city park of Porto and belonged to the species Algerian mouse (Mus spretus) (n = 26) and to the greater white-toothed shrew (Crocidura russula) (n = 14). Furthermore, additional samples were collected in the Northeast region of Portugal and included Algerian mouse (n = 48), greater white-toothed shrew (n = 47), wood mouse (Apodemus sylvaticus) (n = 43), southwestern water vole (Arvicola sapidus) (n = 52), Cabrera's vole (Microtus cabrerae) (n = 49) and Lusitanian pine vole (Microtus lusitanicus) (n = 51). A nested RT-PCR targeting a part of open reading frame (ORF) 2 region of the HEV genome was used followed by sequencing and phylogenetic analysis. HEV RNA was detected in one fecal sample (0.3%; 95% confidence interval, CI: 0.01-1.68) from a synanthropic Algerian mouse that was genotyped as HEV-3, subgenotype 3e. This is the first study reporting the detection of HEV-3 in a synanthropic rodent, the Algerian mouse. The identified HEV isolate is probably the outcome of either a spill-over infection from domestic pigs or wild boars, or the result of passive viral transit through the intestinal tract. This finding reinforces the importance in the surveillance of novel potential hosts for HEV with a particular emphasis on synanthropic animals.

Reactive oxygen species in biological media are they friend or foe? Major In vivo and In vitro sensing challenges

The role of Reactive Oxygen Species (ROS) on biological media has been shifting over the years, as the knowledge on the complex mechanism that lies in underneath their production and overall results has been growing. It has been known for some time that these species are associated with a number of health conditions. However, they also participate in the immunoactivation cascade process, and can have an active role in theranostics. Macrophages, for example, react to the presence of pathogens through ROS production, potentially allowing the development of new therapeutic strategies. However, their short lifetime and limited spatial distribution of ROS have been limiting factors to the development and understanding of this phenomenon. Even though, ROS have shown successful theranostic applications, e.g., photodynamic therapy, their wide applicability has been hampered by the lack of effective tools for monitoring these processes in real time. Thus the development of innovative sensing strategies for in vivo monitoring of the balance between ROS concentration and the resultant immune response is of the utmost relevance. Such knowledge could lead to major breakthroughs towards the development of more effective treatments for neurodegenerative diseases. Within this review we will present the current understanding on the interaction mechanisms of ROS with biological systems and their overall effect. Additionally, the most promising sensing tools developed so far, for both in vivo and in vitro tracking will be presented along with their main limitations and advantages. This review focuses on the four main ROS that have been studied these are: singlet oxygen species, hydrogen peroxide, hydroxyl radical and superoxide anion.

A Systematic Review of Hepatitis E Virus Detection in Camels

Hepatitis E virus (HEV) represents a major cause of acute hepatitis and is considered an emerging public health problem around the world. In the Middle East's and Africa's arid regions, where camels frequently interact with human populations and camel-derived food products are a component of the food chain, camel-borne zoonotic HEV infection is a potential threat. To date, no review paper has been published on HEV in camels. As such, the purpose of the current work is to provide a scientific review of the identification of HEV genotypes seven and eight in camels worldwide to have a better understanding of the current status of this topic and to identify gaps in the current knowledge. Searches were carried out in the electronic databases PubMed, Mendeley, Web of Science, and Scopus, including studies published until 31 December 2022 (n = 435). Once the databases were checked for duplicate papers (n = 307), the exclusion criteria were applied to remove any research that was not relevant (n = 118). As a result, only 10 papers were found to be eligible for the study. Additionally, in eight of the ten studies, the rates of HEV infection were found to be between 0.6% and 2.2% in both stool and serum samples. Furthermore, four studies detected HEV genotype seven in dromedary camels, and two studies have shown HEV genotype eight in Bactrian camels. Interestingly, these genotypes were recently reported in camels from the Middle East and China, where one human infection with HEV genotype seven has been associated with the consumption of contaminated camel meat and milk. In conclusion, more research will be needed to determine the prevalence of HEV infection in camels around the world as well as the risk of foodborne transmission of contaminated camel products. As camels are utility animals in several countries, HEV in these animals may pose a potential risk to public health.

A Systematic Review and Meta-Analysis on Hepatitis E Virus Detection in Farmed Ruminants

Swine are widely recognized as the main reservoir of zoonotic HEV; however, a growing body of data on the HEV prevalence in farmed ruminants of different species also points to a potential route for HEV transmission through ruminants and ruminant products and by-products. Definite information on the zoonotic potential of ruminants is still absent or unclear, compelling the necessity for increasing knowledge on this. The aim of the current study was to analyze the state-of-the-art in this research topic and provide a summary of HEV detection and characterization in farmed ruminants. A total of 1567 papers were retrieved from four search databases that resulted in 35 eligible papers after application of exclusion/inclusion criteria. Studies on HEV in farmed ruminants were mainly based on the detection of HEV RNA and were reported in Africa (n = 1), America (n = 3), Asia (n = 18) and Europe (n = 13), and focused on a variety of ruminants species, namely cow, goat, sheep, deer, buffalo and yak. The overall pooled prevalence of HEV was 0.02% (0.01-0.03, 95% CI). The subgroup pooled prevalence of HEV RNA was 0.01% (0.00-0.02, 95% CI) in cow milk, stool, serum, liver, intestinal, bile, blood, spleen and rectal swab samples; 0.09% (0.02-0.18, 95% CI) in goat serum, bile, stool, milk, liver, rectal swab and blood samples; 0.01% (0.00-0.04, 95% CI) in sheep stool, serum, milk, blood and liver samples. Most of the HEV genotypes found in farmed ruminants belonged to the zoonotic HEV-3 (subtypes 3a, 3c) and HEV-4 (subtype 4d, 4h), with Rocahepevirus also found. The wide HEV circulation observed in different farmed ruminants raises concerns for the possibility of HEV transmission through products from infected ruminants and alerts for the potential zoonotic route for HEV in ruminant products, such as meat and dairy products. Also, contact exposure to infected farmed animals could be a risk factor. Further research should be conducted in order to understand the circulation of HEV in these animals and its zoonotic potential, as there is currently a lack of data on this topic.

Detection of hepatitis E virus in milk: Current evidence for viral excretion in a wide range of mammalian hosts

Infection with hepatitis E virus (HEV) is common in both developing and industrialized nations. Genotypes 3 and 4 are increasingly being reported, particularly in high-income countries where the precise extent of HEV transmission via food is currently unclear. Recently, HEV has been found to be excreted in milk; however, data on the potential milk-borne transmission is still lacking or conflicting and warrants further research on the topic. As such, the aim of the present study was to review the current scientific knowledge and to summarize the existing studies in which HEV has been detected in milk. Exhaustive searches were carried out in Mendeley, PubMed, Scopus and Web of Science. A total of 157 papers were retrieved from the four electronic databases. After removing duplicate articles from the databases (n = 30), exclusion criteria identified unrelated research (n = 115). This allowed the identification of 12 eligible papers. To date, studies on HEV detection in milk were mostly from China (n = 5), followed by Egypt (n = 2), Germany (n = 1), Belgium and Holland (n = 1), Turkey (n = 1), Czech Republic (n = 1) and Spain (n = 1) and were focused on a variety of animals (cow, goat, donkey, buffalo, sheep and camel) and humans. Four out of the 12 eligible studies did not find any evidence of HEV in milk. Moreover, 3 out of the 12 studies detected low rates of HEV (0.2-1.8%) and two were based on a low sample size (n = 1 and n = 4). Interestingly, one study showed very high detection rates and also detected HEV genotype 1 in an animal milk sample, an unusual finding since it only occurs in humans, deserving further studies for confirmation and characterization. Two studies detected high prevalence of HEV genotype 4 in bovine samples from China, with one showing indication of the presence of infectious HEV in milk. To date, there is still a small amount of available data on the HEV presence in milk, posing important questions regarding both animal and human health. Thus, further efforts on this potentially underestimated zoonotic route for HEV should be given, warranting further studies on the topic.

Turn-on, photostable, nontoxic and specific, iron(II) sensor

The pressing need to develop a specific analytical sensor that can identify and quantify Fe(II) without a cytotoxic response was the major motivation drive in this work. The turn-on fluorescent sensor here described can successfully detect Fe(II) and discriminate this ion from other analytes that commonly act as interferents in biological media. Moreover, this reduced fluoresceinamine-based sensor has a high photostability and high dissociation constant, which is an indication that the complex obtained between reduced fluoresceinamine (RFL) and Fe(II) is highly stable. This fluorescence-based sensor has a binding mechanism of 1:1 and a positive cooperativity was found between analyte and sensor. The detection, quantification and sensitivity parameters of the sensor were determined: 21.6 ± 0.1 μM; 65.6 ± 0.1 μM and 48 ± 3 (×10⁷) μM, respectively. To evaluate a possible cytotoxicity effect an erythrocyte assay was performed and the obtained data were evaluated considering CdTe Quantum Dots (QDs) passivated with mercaptoacetic acid has experimental control. According to the resulting data RFL is not cytotoxic even when used in high concentrations, 660 mM. On the other hand QDs are quite different. Indeed it was proven that these heavy metal-based nanoparticles are responsible for 40% erytrocytes hemolysis in concentrations of 600 mM.

Non-Newtonian Thermosensitive Nanofluid Based on Carbon Dots Functionalized with Ionic Liquids

Non-Newtonian nanofluids present outstanding features in terms of energy transfer and conductivity with high application in numerous areas. In this work, non-Newtonian nanofluids based on carbon dots (Cdots) functionalized with ionic liquids (ILs) are developed. The nanofluids are produced using a simple, single-step method where the raw materials for the Cdots synthesis are glucose and waste biomass (chitin from crab shells). The use of ILs as both reaction media and functionalization molecules allows for the development of a new class of nanofluids, where the ILs on the Cdots surface represent the base-fluid. Here, the well-known benign IL 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) and a novel home-made IL (1-tosylate-3-methyl-imidazolium triflate) [Tmi][Trif] are used. The nanofluids obtained from both substrates show, apart from high conductivity and viscosity, light absorption, and good wettability, an appealing thermal sensitivity behavior. This thermal sensitivity is preserved even when applied as thin films on glass slides and can be boosted using the surface plasmon resonance effect. The results reported demonstrate that the new Cdots/IL-based nanofluids constitute a versatile and cost-effective route for achieving high-performance thermosensitive non-Newtonian sustainable nanofluids with tremendous potential for the energy coatings sector and heat transfer film systems.

Biosensor for label-free DNA quantification based on functionalized LPGs

A label-free fiber optic biosensor based on a long period grating (LPG) and a basic optical interrogation scheme using off the shelf components is used for the detection of in-situ DNA hybridization. A new methodology is proposed for the determination of the spectral position of the LPG mode resonance. The experimental limit of detection obtained for the DNA was 62±2nM and the limit of quantification was 209±7nM. The sample specificity was experimentally demonstrated using DNA targets with different base mismatches relatively to the probe and was found that the system has a single base mismatch selectivity.

Optical fiber sensor for Hg(II) based on carbon dots

An optical fiber sensor for Hg(II) in aqueous solution based on sol-gel immobilized carbon dots nanoparticles functionalized with PEG(200) and N-acetyl-L-cysteine is described. This sol-gel method generated a thin (about 750 nm), homogenous and smooth (roughness of 2.7±0.7 Å) film that immobilizes the carbon dots and allows reversible sensing of Hg(II) in aqueous solution. A fast (less than 10 s), reversible and stable (the fluorescence intensity measurements oscillate less than 1% after several calibration cycles) sensor system was obtained. The sensor allow the detection of submicron molar concentrations of Hg(II) in aqueous solution. The fluorescence intensity of the immobilized carbon dots is quenched by the presence of Hg(II) with a Stern-Volmer constant (pH=6.8) of 5.3×10(5) M(-1).