Biochemical analysis of Hyalomma dromedarii salivary glands and gut tissues using SR-FTIR micro-spectroscopy.

Ticks are obligatory voracious blood feeders infesting diverse vertebrate hosts, that have a crucial role in the transmission of diverse pathogens that threaten human and animal health. The continuous emergence of tick-borne diseases due to combined worldwide climatic changes, human activities, and acaricide-resistant tick strains, necessitates the development of novel ameliorative tick control strategies such as vaccines. The synchrotron-based Fourier transform infrared micro-spectroscopy (SR-FTIR) is a bioanalytical microprobe capable of exploring the molecular chemistry within microstructures at a cellular or subcellular level and is considered as a nondestructive analytical approach for biological specimens. In this study, SR-FTIR analysis was able to explore a qualitative and semi-quantitative biochemical composition of gut and salivary glands of Hyalomma dromedarii (H. dromedarii) tick detecting differences in the biochemical composition of both tissues. A notable observation regarding Amide I secondary structure protein profile was the higher ratio of aggregated strands in salivary gland and beta turns in gut tissues. Regarding the lipid profile, there was a higher intensity of lipid regions in gut tissue when compared to salivary glands. This detailed information on the biochemical compositions of tick tissues could assist in selecting vaccine and/or control candidates. Altogether, these findings confirmed SR-FTIR spectroscopy as a tool for detecting differences in the biochemical composition of H. dromedarii salivary glands and gut tissues. This approach could potentially be extended to the analysis of other ticks that are vectors of important diseases such as babesiosis and theileriosis.

Acaricidal Efficacy of Biosynthesized Zinc Oxide Nanoparticles Against Hyalomma dromedarii (Acari: Ixodidae) and Their Toxic Effects on Swiss Albino Mice.

PURPOSE: The current study aimed to investigate the efficacy of zinc oxide nanoparticles (ZnO NPs) synthesized by Melia azedarach aqueous extract to control Hyalomma dromedarii tick, and to evaluate their toxic effects on Swiss albino mice. METHODS: ZnO NPs were synthesized using M. azedarach aqueous extract. UV-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive spectroscopy were used to characterize the synthesized NPs. Egg, nymph, larva, and adult immersion tests were used for bioassay of tick stages with the synthesized ZnO NP. A toxicity study was performed on Swiss albino mice after treatment with 1/10 of the oral LD50 of ZnO NPs (8437 mg/kg) for 5 successive days by oral gavage. RESULTS: The LC50 of ZnO NPs on the eggs, larvae, and nymphs was 11.6, 8.03, and 3.9 mg/ml, respectively. The reproductive performance of females treated with ZnO NPs was lower than that of untreated females. The hematological results showed an insignificant increase in the level of white blood cells with normal red blood cells, hemoglobin, in addition to normal platelet count. The biochemical analysis showed an insignificant increased level (P > 0.05) of alkaline phosphatase and alanine aminotransferase. The liver and kidney suffered few histopathological changes after oral administration of ZnO NPs. CONCLUSION: These results suggest that ZnO NPs have good acaricidal activity against eggs, larvae, and engorged nymphs of H. dromedarii. ZnO NPs minimized the number of eggs laid by engorged females and the hatchability of their eggs. ZnO NPs did not affect unfed adults. The toxicity results of the mice revealed insignificant changes in the hemogram, biochemistry, with liver and kidney suffering few histopathological changes. Future studies are needed to assess application routes (topical vs oral). Based on these findings, ZnO NPs may be incorporated in the control of camel tick H. dromedarii.

Acaricidal activity of Artemisia herba-alba and Melia azedarach oil nanoemulsion against Hyalomma dromedarii and their toxicity on Swiss albino mice.

Biopesticides such as essential oils (EOs) are considered an improvement for integrated pest control as they appear to be less toxic to the environment than chemical acaricides. The current study aimed to evaluate the acaricidal activity of Artemisia herba-alba and Melia azedarach oil loaded nano-emulsion as alternatives for chemical acaricides against the camel tick Hyalomma dromedarii, besides evaluating their toxic effect on Swiss albino mice. Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) were used for the characterization of loaded nano-emulsions.The immersion test was used for the bioassay of both loaded nanoemulsions on tick stages (egg, nymph, larva, and adult). Mortality percentages and LC50 values of each tick stage were calculated. Reproductive performance for the survived engorged females after treatment was monitored. The toxicity of both loaded nano-emulsions was evaluated on Swiss albino mice by an oral dose of 1500 mg/kg/day for five successive days. The hematological, biochemical, and histopathological changes were evaluated. TEM characterization revealed spherical droplets for A. herba-alba and M. azedarach oil loaded nano-emulsion with droplet size ranging from 62 to 69 nm and 52-91 nm, respectively. FTIR revealed the absence of extra peaks in the loaded nano-emulsions that confirmed no chemical changes existed by ultrasonication. The LC50 values of A. herba-alba and M. azedarach oil loaded nano-emulsion on embryonated eggs, larvae, engorged nymphs, and unfed adults were 0.3 and 1.1%, 0.7 and 1.7%, 0.3 and 0.4%, 4.4 and 22.2%, respectively. The egg productive index (EPI), egg number, and hatchability percentage were lower in the treated females compared with Butox 5% (deltamethrin) and control. The hematological picture and biochemical analysis revealed insignificant changes in the treatment group compared with the negative control group. The liver of the A. herba-alba and M. azedarach oil loaded nano-emulsion treated group exhibited vacuolar degeneration and infiltration of lymphocytic cells. The kidney of mice treated with A. herba-alba and M. azedarach oil loaded nano-emulsion showed hemolysis and slight degeneration of epithelial cells of tubules. It is concluded that A. herba-alba and M. azedarach oil loaded nano-emulsion have good acaricidal activity against camel tick H. dromedarii.

In vitro acaricidal activity of green synthesized nickel oxide nanoparticles against the camel tick, Hyalomma dromedarii (Ixodidae), and its toxicity on Swiss albino mice.

The green synthesized nanoparticles have been determined as a novel pesticide against arthropod pests. This study was designed to evaluate the in vitro acaricidal activity of green synthesized nickel oxide nanoparticles (NiO NPs) using aqueous extract of Melia azedarach ripened fruits against different developmental stages of the camel tick Hyalomma dromedarii in addition to their toxic effect on laboratory animals. The synthesized NiO NPs were characterized by UV-visible (UV-Vis) spectroscopy, Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The UV-Vis spectra of the NiO NPs showed an absorption peak at 307 nm. FTIR analysis showed the possible functional groups used for capping and stabilization of NiO NPs with strong bands at 3416.2 and 1626.6 cm-1. The SEM images of the NiO NPs exhibited a size ranging from 21 to 35 nm. The immersion test was used for the in vitro application of the synthesized NiO NPs on the various tick stages (egg, nymph, larva, and adult). Mortality percentages and LC50 values of each tick stage were calculated. The oviposition and hatchability of the engorged females were monitored for the survived tick after treatment. The LC50 values for NiO NPs on embryonated eggs, larvae, and engorged nymphs were 5.00, 7.15, and 1.90 mg/mL, respectively. The egg productive index (EPI), egg number, and hatchability (%) were lower in females treated with the NiO NPs than in control ticks. The toxicity of the NiO NPs on laboratory animals was also investigated using Swiss albino mice by oral dose of 500 mg/kg/day administration for five consecutive days. The hematological, biochemical, and histopathological changes were evaluated. The hematological analysis showed significant increase in the level of white blood cells (WBC) and hemoglobin (Hb). Biochemical analysis showed non-significant decrease in alkaline phosphatase (ALP) and alanine amino transferase (ALT). We concluded that NiO NPs have a significant acaricidal activity as demonstrated on eggs, larvae, engorged nymphs, and fully fed females of H. dromedarii. From a toxicological point of view further in vivo investigations are needed to determine the mechanism of toxic effect of NiO NPs.

In vitro acaricidal effect of Melia azedarach and Artemisia herba-alba extracts on Hyalomma dromedarii (Acari: Ixodidae): embryonated eggs and engorged nymphs.

The present study aimed to evaluate the in vitro efficacy of four medicinal plant extracts: petroleum ether and ethyl alcohol extracts of the ripen fruits of Melia azedarach and whole aerial parts of Artemisia herba-alba against the two inactive stages of the camel tick Hyalomma dromedarii, embryonated eggs and engorged nymphs in comparison to reference acaricide Butox®5.0 (Deltamethrin). Egg and nymphal immersion tests at four concentrations with three replicates were used. The deformity in larvae hatched from treated eggs and adults moulted from treated nymphs were observed and photographed by light microscope (LM) and scanning electron microscope (SEM). The results showed that M. azedarach and A. herba-alba extracts revealed higher significant toxic effects on embryonated eggs and engorged nymphs comparing with the reference acaricide (Butox®5.0) and control. In egg emmersion test, the LC50 of petroleum ether extracts of M. azedarach and A. herba-alba was 3.14 and 3.91%, respectively and LC50 of the respective ethyl alcohol extracts was 1.77 and 2.45%. In nymphal immersion test, LC50 of petroleum ether extracts of M. azedarach and A. herba-alba was 0.26 and 1%, respectively, and LC50 of the respective ethyl alcohol extracts was 4.17 and 8.7%. Abnormalities were observed by LM and SEM in the larvae hatched from the treated eggs as incomplete development of legs and mouth parts as well as shrinkage mainly in legs and mouthparts of adults emerged from treated nymphs. In conclusion, all extracts and petroleum ether extracts of the two plants have great potential to be developed as a novel acaricidal for controlling eggs and nymphs of H. dromedarii, respectively.