Emerging and re-emerging viral diseases

Emerging infectious diseases can be defined as infections that have either newly appeared in a population, or existed, but are rapidly increasing in incidence or geographical range. Even thought there was considerable development regarding prevention, control and elimination of some of the infectious diseases through proper use of hygiene and sanitation practices in addition to development of anti- biotics (bacteria) and vaccination, some infectious diseases remained as the leading causes of morbidity and mortality worldwide. There are many factors involved in the emergence of new infectious diseases or the re-emergence of “old” infectious diseases. Increasing global epidemiological surveillance, improving public health systems, education and research into new antibiotics and new vaccines will allow us to effectively combat the constantly renewed threat of infectious diseases. This review summarizes the work on aspects of virus emergence

Removal of Carbofuran Pesticide from Aqueous Solution by Adsorption onto Animal Bone Meal as New Low Cost Adsorbent

The objective of this study is to investigate the Carbofuran pesticide adsorption from aqueous solution using animal bone meal as an alternative low cost adsorbent. The effects of various experimental factors; adsorbent dose, initial Carbofuran concentration, contact time, solution pH and particle size of adsorbent were studied by using the batch technique. The results showed that Carbofuran adsorption equilibrium was rapidly attained after 70 min of contact time. A maximum of 98.3% removal of the Carbofuran pesticide was observed by 25 mg of Animal Bone Meal (ABM). Langmuir and Freundlich isotherm models were applied for the analysis of equilibrium adsorption data obtained. The maximum monolayer adsorption capacity was 18.5 mg/g. The characteristic results; dimensionless separation factor, R L , and the adsorption intensity, n, showed that animal bone meal can be employed as an alternative to commercial adsorbents in the removal of Carbofuran pesticide from aqueous solution.Keywords: Animal Bone Meal, Carbofuran, Adsorption Isotherms, Water treatment

Effect of phenolic compounds extracted from turmeric (Curcuma longa L.) and ginger (Zingiber officinale) on cutaneous wound healing in wistar rats

Turmeric and ginger, widely used rhizomes in culinary arts, have several beneficial biological activities, such as hypoglycemic, hepato-protective, antimicrobial, and antioxidant properties. This work investigated the effects of three phenolic extracts isolated from turmeric and ginger rhizomes on anti-inflammatory and healing properties using the solid–liquid extraction method. Wistar rats were used as a biological model. The anti-inflammatory activity was evaluated on induced edema in the rat’s hind paw using carrageenan (1%). Paw volume was measured at 0 min, 45 min, 3 h, and 5 h. Treatment with turmeric and ginger extracts, administered at a dose of 100 mg/kg, revealed a reduction in edema volume by 98.8%, 94.8%, and 98.3% using an aqueous extract of turmeric, ethanolic extract of turmeric, and methanolic extract of ginger, respectively. The healing activity parameters of induced burns on the rat’s dorsal region in nine groups (7 rats each) were monitored daily throughout the experiment’s duration. Results showed that the application of creams composed of petroleum jelly dispersing turmeric and ginger extracts to wounds at a dose of 100 mg/kg g induced complete healing after 19 days while the negative control was only 60% cured. On day 14, the aqueous, ethanolic, and methanolic turmeric extracts nearly resulted in complete tissue repair by 95.26%, 98.34%, and 87.39%, respectively. According to the chromatographic analysis (Sephadex G50 column), there is a variation in the molecular weight distribution of phenolic compounds (polymers, oligomers, and monomers) in the three studied extracts, which has a differential effect on the anti-inflammatory and wound healing activities of the extracts.info:eu-repo/semantics/publishedVersio

Investigation of monocrystalline silicon surface texturization by image processing program

One of the main issues in the photovoltaic industry of silicon solar cells is the optical losses via reflection. To overcome this issue, texturization (chemical etching) remains the most commonly used method to produce a random pyramid structure to reduce reflection and thus increase photocurrent generation. Because of the anisotropic etching property of alkaline solution, square-based upright pyramids are formed, i.e., the difference in etching rates between (100) and (111) planes. In this paper, the following etching solutions were studied: 4/10, 6/6, and 10/4 (KOH weight percentage/IPA volume percentage).The optical, morphological, and electric characterizations using UV-Vis spectroscopy, electron scanning microscopy (SEM), and quasi-steady-state photoconductance (QSSPC) device are performed. Also, the standard weighted reflectance (SWR) was calculated. The pyramid size distribution generated using KOH-IPA solutions was investigated using an image processing program (ImageJ) via SEM images. The calculation of the height of the pyramids reveals that the typical pyramid size ranges from 3 to 9 m, with large pyramids of small proportions. Furthermore, when the pyramids are distributed in a mixture of tiny and medium pyramids in precise proportions, the reflectivity is at its lowest, and as the number of large pyramids rises, the reflectivity increases

Antibacterial activity of Lactic acid bacteria strains Isolated from Marine Algae against Pathogenic Bacteria

This work aims at evaluating the antibacterial activity of 14 lactic acid bacteria (LAB) strains isolated from two species of marine algae (Sargassum muticum and Ulva lactuca) against six pathogenic bacteria, including Escherichia coli ATCC 10536, Staphylococcus aureus ATCC 9144, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 33019, Bacillus sp. CIP 104717, and Salmonella sp. LAB inhibitory capacity was assessed by using agar well diffusion test. Results showed that significant inhibitory zones of 30.33, 23.33, 13, 12, 9, and 8 mm were obtained against E. coli, B. subtilis, B. cereus, Bacillus sp., Salmonella sp. and S. aureus, respectively. These findings underscore the potential use of marine LAB for producing antibacterial substances, suggesting their applications in biotechnological processes targeting food spoilage and human infections

Effect of powdered rosemary (Rosmarinus officinalis) essential oil and phenolic compounds on broiler chickens zootechnical parameters

This work aims at exploiting the essential oil (EO) and phenolic compounds (PC) of rosemary (Rosmarinus officinalis) in a formulation containing leaf powder stabilized with chitin (1%, w/w) to improve chicken meat and investigate their effect on qualitatively and quantitatively broiler chickens’ growth performances. To such a purpose, chicks, at 1 day of age, were distributed in pens on ground divided into four batches. The two control batches were fed with conventional feed, but the positive control contained flavomycin (0.5 g/kg) as growth factor. The two treated batches received a conventional feed supplemented with two doses of 20 and 50 g/kg of the developed formulation. Essential oil and phenolic compound contents in powdered leaves were, respectively, 1.20 and 22.86% in ethanolic extract. 1,8-Cineole (46.88%), followed by camphor (19.20%), α-pinene (9.56%), L.α.-terpineol (5.91%) and β-pinene (4.40%) were the main compounds of the used EO. The two batches of treated chicks showed a significant improvement in body weight (281.88 and 283.75 g, respectively), a decrease in feed conversion and a reduction in mortality (8%), when compared to the control batches. In addition, the elaborated formulation induced catalase activity used as an indicator of cellular antioxidant activity modulation

Wound-healing potentiation in mice treated with phenolic extracts of Moringa oleifera leaves planted at different climatic areas

For years, Moringa oleifera has been known for possessing wound-healing properties. This study aimed to investigate the effect of two extracts: aqueous extract (AE) and ethanolic extract (EE) of Moringa oleifera leaves planted at two regions (Mssisi and Lamta) in Morocco for their anti-inflammatory and healing properties, for which mice were used as a biological model. Inflammation was monitored by assessing forepaw volume of mice, measured at 0 min, 1 h, 3 h, and 5 h, after its induction by carrageenan. Hind paw of mice were treated with extracts of M. oleifera, at a dose of 50 mg/kg, obtained from Mssisi region. This resulted in reduction of edema by 99.2% with EE and by 91.8% with AE, compared to controls and the phenolic extract of M. oleifera planted at Lamta region. Regarding healing of burns induced on rat’s dorsal region; results showed that application of Moringa-based ointment for 14 days, at a dose of 50 mg/kg on wounds, resulted in total healing, compared to controls (negative control: more than 22 days, and positive control: 22 days). M. oleifera extracts resulted in nearly complete tissue repair of 98.26% and 95.34% with EE and AE, respectively.info:eu-repo/semantics/publishedVersio

Phylodynamics and Human-Mediated Dispersal of a Zoonotic Virus

Understanding the role of humans in the dispersal of predominately animal pathogens is essential for their control. We used newly developed Bayesian phylogeographic methods to unravel the dynamics and determinants of the spread of dog rabies virus (RABV) in North Africa. Each of the countries studied exhibited largely disconnected spatial dynamics with major geo-political boundaries acting as barriers to gene flow. Road distances proved to be better predictors of the movement of dog RABV than accessibility or raw geographical distance, with occasional long distance and rapid spread within each of these countries. Using simulations that bridge phylodynamics and spatial epidemiology, we demonstrate that the contemporary viral distribution extends beyond that expected for RABV transmission in African dog populations. These results are strongly supportive of human-mediated dispersal, and demonstrate how an integrated phylogeographic approach will turn viral genetic data into a powerful asset for characterizing, predicting, and potentially controlling the spatial spread of pathogens

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century