Dietary Chitosan Nanoparticles: Potential Role in Modulation of Rainbow Trout (Oncorhynchus mykiss) Antibacterial Defense and Intestinal Immunity against Enteric Redmouth Disease

Bio-nanotechnology employing bio-sourced nanomaterial is an emerging avenue serving the field of fish medicine. Marine-sourced chitosan nanoparticles (CSNPs) is a well-known antimicrobial and immunomodulatory reagent with low or no harm side effects on fish or their human consumers. In this study, in vitro skin mucus and serum antibacterial activity assays along with intestinal histology, histochemical, and gene expression analyses were performed to evaluate the impact of dietary CSNPs (5 g kg⁻¹ dry feed) on rainbow trout resistance against ‘enteric redmouth’ disease. Two treatment conditions were included; short-term prophylactic-regimen for 21 days before the bacterial challenge, and long-term therapeutic-regimen for 21 days before the challenge and extended for 28 days after the challenge. Our results revealed higher antibacterial defense ability and positive intestinal histochemical and molecular traits of rainbow trout after dietary CSNPs. The prophylactic-regimen improved trout health while the therapeutic regimen improved their disease resistance and lowered their morbidity. Therefore, it is anticipated that CSNPs is an effective antibacterial and immunomodulatory fish feed supplement against the infectious threats. However, the CSNPs seem to be more effective in the therapeutic application rather than being used for short-term prophylactic applications.     

Potentialities and soil impact analysis of rock phosphorus fertilization of perennial and annual legume crops

ABSTRACT

The objective of this study is to evaluate the impacts of the direct use of natural rock phosphates on two forage legumes, Vicia sativa, and Medicago sativa. Crops were grown in pots containing two P deficient soils and fertilized with Tunisian rock phosphate (TRP) or chemical triple superphosphate (TSP). TRP amendment significantly increased shoot dry yield (+53% to +162%), P-content, protein content, and chlorophyll content mainly at the rate of 150 kg P ha^?1. No significant effects were observed on mycorrhization and antioxidant enzyme activities. However, TSP negatively affected the frequency of root mycorrhization and stimulated antioxidant enzyme activities. TRP amendment induced an increase in fluorescein diacetate activity, alkaline phosphatase activity, and species richness. The stimulation involved mainly Actinobacteria, Proteobacteria, and Firmicutes with higher stimulation of Actinobacteria in the case of vetch. The present work indicated a better P-use efficiency of vetch. It suggested also that at least a part of the enhancement observed in plant-growth parameters following TRP fertilization is driven by changes in the structure of rhizosphere microbial communities. Nevertheless, the correlation between changes in microbial composition and phosphorus uses efficiency needs to be investigated further.     

Farmers' knowledge,perceptions, and farm-level management practices of citrus pests and diseases in Morocco

Journal of Plant Diseases and Protection - This paper documents pest management practices adopted by citrus farmers in two of the citrus-growing regions in Morocco. The survey data propose possible...     

Wheat Gluten Polymer Structures: The Impact of Genotype,Environment, and Processing on Their Functionality in Various Applications

For a number of applications, gluten protein polymer structures are of the highest importance in determining end‐use properties. The present article focuses on gluten protein structures in the wheat grain, genotype‐ and environment‐related changes, protein structures in various applications, and their impact on quality. Protein structures in mature wheat grain or flour are strongly related to end‐use properties, although influenced by genetic and environment interactions. Nitrogen availability during wheat development and genetically determined plant development rhythm are the most important parameters determining the gluten protein polymer structure, although temperature during plant development interacts with the impact of the mentioned parameters. Glutenin subunits are the main proteins incorporated in the gluten protein polymer in extracted wheat flour. During dough mixing, gliadins are also incorporated through disulfide‐sulfhydryl exchange reactions. Gluten protein polymer size and complexity in the mature grain and changes during dough formation are important for breadmaking quality. When using the gluten proteins to produce plastics, additional proteins are incorporated in the polymer through disulfide‐sulfhydryl exchange, sulfhydryl oxidation, β‐eliminations with lanthionine formation, and isopeptide formation. In promising materials, the protein polymer structure is changed toward β‐sheet structures of both intermolecular and extended type and a hexagonal close‐packed structure is found. Increased understanding of gluten protein polymer structures is extremely important to improve functionality and end‐use quality of wheat‐ and gluten‐based products.     

Impact of sanitary landfill on air quality in Baghdad

Hydrogen sulfide, NH₃ and CH₄ are pollutant gases known to be generated from the fermentation of organic matter in solid waste. This work was conducted in a completed sanitary landfill in Baghdad to investigate the possible effect of gases generated and emitted from this landfill on the ambient air quality of the area. Pollutant gases were monitored twice a week for a 14 mo period using continuous monitoring type instruments. Results indicate that concentrations of H₂S, NH₃, and CH₄ occasionally reach relatively high levels. The air quality of the area is not substantially deteriorated.     

Variation of Agro-morphological Characters in Moroccan Barley Landraces Under Near Optimal and Drought Conditions

In many areas of North Africa, barley is often the only possible rainfed crop. In these regions water deficit is the primary constraint affecting crop production. Twenty barley landraces collected from different localities in south Morocco and four modern varieties were characterized in two field experiments, one under well-irrigated and one under limited-irrigated conditions. Nine agro-morphological characters were evaluated: Plant height, tiller number per plant, number of grains per spike, number of spikes per plant, spike weight, spike length, plant weight (PW), number of internodes of rachis (NIR), and length of the last internode of rachis. The correlation coefficients among characters were nearly the same in the well- and limited-irrigated experiment. Under limited-irrigated conditions, plant growth was significantly decreased as measured by all characters except NIR, which was unaffected. The percentage of reduction, ranging from 80.08% to 5.82%, was recorded on PW and NIR, respectively. The injury index ranging from 4.02 to 0.06 was recorded on PW and NIR, respectively. Using discriminant analysis the genotypes were arranged in three, clearly separated groups that varied in their tolerance to drought stress.     

The Effects of Season and Site of Catch on Morphometric Characteristics,Mineral Content,and Fatty Acids of Sardines (Sardina pilchardus) Caught on the Algerian Coast

The variation of morphometrics, mineral content, and fatty acid composition of sardines was determined in relation to season and site of catch in the Mediterranean Sea. Sardines were caught in two regions of the Algerian coast: Mostaganem and Béni-Saf. In both sites, the contents of phosphorus (223 and 211 mg 100 g^?1) and sodium (95 and 10 mg 100 g^?1) were higher in June than in February. Total lipid content was related to the season, being low in winter (2.9%) and high in summer (11.3%). The fatty acid composition shows a high content of polyunsaturated fatty acids (PUFA) dominated by n-3 fatty acids eicosapentaenoic acid (EPA C20:5 n-3; 10%) and docosahexaenoic acid (DHA C22:6n-3; 25%). However, the content of n-6 fatty acids was relatively low both in winter (3.4%) and summer (4.7%). The saturated fatty acid (SFA) content was appreciable in sardines, which range from 34% to 37% according to season. This is in agreement with the literature related to the Mediterranean sardine.     

Phylogeny of Egyptian isolates of <Emphasis Type="Italic">Cucumber mosaic virus</Emphasis> (CMV) and <Emphasis Type="Italic">Tomato mosaic virus</Emphasis> (ToMV) infecting <Emphasis Type="Italic">Solanum lycopersicum</Emphasis>

Four Cucumber mosaic virus (CMV) (CMV-HM 1–4) and nine Tomato mosaic virus (ToMV) (ToMV AH 1–9) isolates detected in tomato samples collected from different governorates in Egypt during 2014, were here characterized. According to the coat protein gene sequence and to the complete nucleotide sequence of total genomic RNA1, RNA2 and RNA3 of CMV-HM3 the new Egyptian isolates are related to members of the CMV subgroup IB. The nine ToMV Egyptian isolates were characterized by sequence analysis of the coat protein and the movement protein genes. All isolates were grouped within the same branch and showed high relatedness to all considered isolates (98–99%). Complete nucleotide sequence of total genomic RNA of ToMV AH4 isolate was obtained and its comparison showed a closer degree of relatedness to isolate 99–1 from the USA (99%). To our knowledge, this is the first report of CMV isolates from subgroup IB in Egypt and the first full length sequencing of an ToMV Egyptian isolate.     

Synthesis,Characterization and Biological Evaluation of Triclosan Grafted onto Cellulosic Fibers

With the increased risk of disease transmissions and cross-infection caused by microorganisms, the control of microbial infections becomes a very important issue in modern societies. Moreover, with the emergence of antibio-resistant bacterial strains, it is necessary to control the bacterial growth. One of ways to limit the bacterial proliferation is to develop antimicrobial surfaces. The present work describes the synthesis process of a direct linking of propargyled Triclosan to a modified Kraft Pulp. Propargylated Triclosan, and azidated Kraft Pulp were linked in the presence of Cu(I) catalyst, a type of Huisgen’s 1,3-dipolar azide-alkyne cycloaddition reaction, leading to the formation of Triclosan linked to kraft Pulp fibers. The modified Kraft Pulp fibers are characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). This novel material has been investigated for its antibacterial properties against Escherichia coli, Staphylococcus aureus, Bacillus cereus and Pseudomonas aeruginosa. The developed material showed an important antibacterial activity. Although Triclosan is covalently grafted onto Kraft Pulp, its antibacterial properties are maintained.     

In vitro assessment of the antimicrobial efficacy of chitosan nanoparticles against major fish pathogens and their cytotoxicity to fish cell lines

Nanotechnology is an emerging avenue employed in disease prevention and treatment. This study evaluated the antimicrobial efficacy of chitosan nanoparticles (CSNPs) against major bacterial and oomycete fish pathogens in comparison with chitosan suspension. Initially, the minimum inhibitory concentrations (MIC, MIC₉₀) were determined and the per cent inhibition of bacterial growth was calculated. Subsequently, the minimum bactericidal concentrations (MBCs) were determined. The time-dependent disruptions of CSNP-treated pathogens were observed via transmission electron microscopy (TEM), and the effect of CSNPs on the viability of two fish cell lines was assessed. No antimicrobial effect was observed with chitosan, while CSNPs (105 nm) exhibited a dose-dependent and species-specific antimicrobial properties. They were bactericidal against seven bacterial isolates recording MBC values from 1 to 7 mg/ml, bacteriostatic against four further isolates recording MIC values from 0.125 to 5 mg/ml and fungistatic against oomycetes recording MIC₉₀ values of 3 and 4 mg/ml. TEM micrographs showed the attachment of CSNPs to the pathogenic cell membranes disrupting their integrity. No significant cytotoxicity was observed using 1 mg/ml CSNPs, while low dose-dependent cytotoxicity was elicited by the higher doses. Therefore, it is anticipated that CSNPs are able to compete and reduce using antibiotics in aquaculture.