Background: Lumpy skin disease (LSD), a disease of cattle and buffaloes, has recently become widely prevalent in Egypt. The aim of this study was to ascertain the potential role of Rhipicephalus (Boophilus) annulatus ticks in the transmission of this disease. Samples collected from suspected lumpy skin disease virus (LSDV) infected cows that had previously been vaccinated with the Romanian sheep pox virus (SPPV) in various Egyptian governorates were obtained between May to November over two consecutive years, namely 2018 and 2019. Ticks were morphologically identified and the partial cytochrome oxidase subunit I gene (COI) were sequenced, revealing that they were closely related to R. (Boophilus) annulatus. The G-protein-coupled chemokine receptor (GPCR) gene of the LSDV was used to test hard ticks. Results: Two positive samples from Kafr El-Sheikh province and one positive sample from Al-Behera province were reported. BLAST analysis revealed that the positive samples were closely related to the Kazakhstani Kubash/KAZ/16 strain (accession number MN642592). Phylogenetic analysis revealed that the GPCR gene of the LSDV recently circulating in Egypt belongs to a global cluster of field LSDV with a nucleotide identity of 98–100%. LSDV isolation was successfully performed four days after inoculation using 9 to 11-day-old embryonated chicken eggs showing characteristic focal white pock lesions dispersed on the choriallantoic membrane after three blind passages. Intracytoplasmic inclusion bodies, cell rupture, vacuoles in cells, and virus particles ovoid in shape were demonstrated by electron microscopy. Conclusion: In this study the role of hard ticks in the transmission of the LSDV to susceptible animals in Egypt was revealed and confirmed by various methods.

Foot-and-mouth Disease (FMD) is a highly contagious viral disease affecting all hoof-cloven animals. Serotypes A, O and SAT 2 of the foot-and-mouth disease virus (FMDV) are circulating in Egypt. The present study aimed to identify and molecularly characterize the FMDV strains circulating in Northern Egypt during an epidemic that struck the nation in 2022. RNA was extracted from the epithelial specimens, vesicular fluid from affected cattle. The samples were screened using real-time reverse-transcription polymerase chain reaction (RT-PCR) targeting the RNA-dependent RNA polymerase (RdRp) gene. Positive samples underwent individual serotype-specific amplification using primers designed for VP1 of O, A, and SAT 2 serotypes. Subsequently, direct sequencing was performed on the positive samples. The real-time RT-PCR detected positive samples from epithelial and vesicular fluid samples, but not in the blood of infected animals. Out of the 16 samples, seven tested positive for FMDV serotype A. Of these seven positive samples, six were categorized as serotype A-African topotype-G-IV, and these positive samples were isolated in BHK-21 cells, yielding an overt cytopathic effect caused by the virus. In conclusion, it is necessary to sustain continuous surveillance of the evolution of circulating FMDV strains to facilitate the assessment and aid in the selection of vaccine strains for the effective control of FMDV in Egypt.

Despite intensive control efforts, Foot and mouth disease (FMD) outbreaks continue to occur regularly in Egypt and resulting in dramatic economic losses to the livestock industry. During 2018 and 2022, FMD was clinically suspected among previously vaccinated cattle in Beheira and Kafr El-Sheikh provinces, Egypt. FMDV RNA was detected in 18 (45%) out of 40 epithelial tissue samples using real-time RT-PCR based on a pan-FMDV primers set. The 2018 outbreak isolates (n = 8) included the FMDV serotypes A and SAT2, whereas all isolates (n = 10) from the 2022 outbreak belonged to the FMDV serotype A. Four selected isolates, designated FMDV/SAT2/EGY/ Beheira/2018, FMDV/A/EGY/Kafr El-Sheikh/2018, FMDV/A/EGY/Kafr El-Sheikh/2022 and FMDV/A/EGY/ Behiera/2022, were characterized on the basis of partial VP1 gene sequence analysis. The FMDV/SAT2/EGY/ Beheira/2018 strain was clustered within the Lib-12 lineage of the topotype VII and shared 79.2-98.4% nucleotide identity with other Egyptian SAT2 strains available in Genbank database. On the other hand, the three FMDV serotype A sequences shared 74.4-99.1% nucleotide identity with each other. Also, they were phylogenetically classified within two distinct topotypes. The FMDV/A/Egy/Kafr El-Sheikh/2018 strain was grouped within the Asian topotype, meanwhile the FMDV/A/EGY/Kafr El-Sheikh/2022 and FMDV/A/EGY/Behiera/2022 strains were grouped together within the genotype IV of the African topotype. Interestingly, the deduced amino acid sequences of the four strains displayed numerous variations in comparison to the vaccine strains currently used in Egypt. In addition, most of these variations were present in prominent antigenic positions in the VP1 protein. These findings raise a crucial need to validate the protective potential of the vaccine strains against the newly emerging FMDV field strains and to update the vaccination strategy accordingly.

Heavy metal contamination in freshwater ecosystems poses persistent threats to aquatic organisms and public health. This study evaluates the transgenerational toxicity of cadmium chloride and copper sulfate on Culex pipiens, focusing on development, reproduction, and midgut histopathology over two successive generations. Larval bioassays showed cadmium chloride to be more toxic than copper sulfate, with early instars exhibiting higher sensitivity (LC₅₀ = 8.66 μg/L for Cd; 175.63 μg/L for Cu). Both metals significantly delayed larval and pupal development, reduced fecundity, and decreased egg hatchability in a dose-dependent manner. Histopathological examination revealed midgut epithelial degeneration, vacuolation, and brush border loss, with copper sulfate inducing more severe cytotoxicity. These findings confirm that sublethal, chronic metal exposure can impair physiological and reproductive traits across generations. Moreover, this study highlights the utility of mosquitoes as sensitive bioindicators of aquatic pollution, and underscores the long-term ecological implications of heavy metal contamination on vector dynamics and disease transmission.

Spodoptera frugiperda (fall armyworm) is a highly destructive agricultural pest with a remarkable ability to develop resistance to insecticides, posing a severe threat to global food security. Understanding the physiological and molecular responses of this species to insecticide exposure is crucial for improving resistance monitoring and developing effective management strategies. In this study, the toxicity and the associated biochemical, molecular, and genotoxic responses of third-instar S. frugiperda larvae were investigated following exposure to four commonly used insecticides: emamectin benzoate, indoxacarb, methomyl, and a binary mixture of acetamiprid + bifenthrin. Toxicity bioassays showed that emamectin benzoate was the most potent insecticide (LC ₅₀ = 0.188 ppm/L), whereas the binary mixture exhibited the highest resistance coefficient (RC = 12.86) relative to the recommended field dose. Biochemical analyses conducted over a seven-day exposure period, significant metabolic alterations were observed. Reduced acetylcholinesterase (AChE) and carboxylesterase (CarE) activities suggested neurotoxic stress, Whereas elevated glutathione S-transferase (GST) and peroxidase (POD) activities reflected enhanced detoxification and oxidative stress responses. Gene expression analyses revealed significant upregulation of SFCYP1, SFCYP2, SFCYP4, SFCYP5, SFRYR, and EF1α, while SFCYP3 was consistently downregulated, indicating activation of detoxification and stress-related pathways. Genotoxic effects were assessed using the comet assay, which demonstrated significant DNAdamage in hemocytes of treated larvae. This damage was characterized by increased tail length, tail DNApercentage, and tail moment, particularly in individuals exposed to emamectin benzoate. Collectively, these findings indicate that sublethal insecticides exposure not only disrupts enzymatic homeostasis but also induces genotoxic stress. These findings demonstrate that S. frugiperda exhibits complex adaptive physiological and molecular responses that may contribute to resistance development under sustained insecticide selection pressure. Overall, the results provide integrated biochemical and molecular insights that can support future investigation into insecticide response mechanisms and improve resistance monitoring strategies for this economically important pest.

Root-knot nematodes ( Meloidogyne spp. ) are among the most destructive pathogens affecting tomato production worldwide, leading to severe yield losses and compromised plant health. This study evaluated the efficacy of six organic acids—benzoic, salicylic, citric, lactic, malic, and acetic acids—applied at three concentrations each, in managing Meloidogyne incognita infection in tomato cultivar “023.”Among all treatments, salicylic acid (SA) exhibited the strongest nematicidal activity, achieving 100% juvenile mortality within 72 hours and the highest inhibition of egg hatchability, even at the lowest concentration (0.01%). Benzoic and malic acid followed, showing strong nematocidal effects with moderate suppression of egg hatching, while citric and lactic acids displayed intermediate efficacy. Acetic acid was the least effective. Under greenhouse conditions, Salicylic acid alleviated nematode-induced growth loss through a significant reduction in root galling, egg masses, larvae, and egg counts, resulting in marked improvements in shoot and root biomass compared to the infected untreated control and other treatments. Citric and benzoic acids moderately improved plant growth, especially in root development, whereas lactic and acetic acids had minimal effects. At the molecular level, salicylic acid markedly upregulated the expression of peroxidase (POD) and polyphenol oxidase (PPO) genes, peaking at day 4 and remaining elevated through day 8. Citric, benzoic, and malic acids caused moderate induction, while lactic and acetic acids induced weak or transient expression. The expression pattern suggests dynamic and transient defense activation in response to organic acid treatments. Computational insights obtained through molecular docking simulations predicted that salicylic and benzoic acids may interfere with essential biological processes in Meloidogyne incognita . Both compounds exhibited the highest binding affinities toward several key pathogenicity-related proteins, including NAD(P)H oxidase, putative aspartyl protease, cytochrome c oxidase subunit 1, prefoldin-2, venom allergen-like protein Mi-vap-2, and protein disulfide-isomerase, complementing their in vivo nematicidal effects. Overall, salicylic acid at 0.01% emerged as the most potent and eco-friendly alternative for managing root-knot nematodes in tomato plants, combining strong nematicidal activity, enhanced plant defense responses, and molecular-level evidence of protein inhibition.