Publications by authors named "Wesam S Meshrif"

7 Publications

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Fitness cost of malathion resistance in Egyptian Culex pipiens populations.

Med Vet Entomol 2022 Mar 31. Epub 2022 Mar 31.

Zoology Department, Faculty of Science, Tanta University, Tanta, Egypt.

The extensive use of insecticides in agriculture and public health has resulted in the rapid development of insecticide resistance in mosquito populations. Therefore, in this study, we aimed to evaluate insecticide resistance costs on the fitness of Culex pipiens. Two Cx. pipiens field populations (Beheira malathion-resistant and Gharbia malathion-susceptible) were compared to the reference (sensitive) population. The biochemical composition and expression of four genes relevant to insecticide resistance were estimated in third instar larvae. Adult survival, female fecundity and egg hatchability were also determined. As per our findings, it was found that the total protein and carbohydrate contents in Beheira malathion-resistant larvae were significantly lower than that in the reference larvae. Beheira malathion-resistant larvae had higher phenoloxidase (PO) specific activity than the reference population. In terms of the relevant genes, only cytochrome P450 (CYP6F1) expression showed elevated levels in the Gharbia malathion-susceptible population compared to the Beheira malathion-resistant population. In esterases (Estα and Estβ) and glutathione S-transferase, the tested populations did not show any significant differences. Compared to the reference mosquito population, Gharbia malathion-susceptible Cx. pipiens males exhibited significantly longer median survival. Female fecundity and hatchability showed nonsignificant differences among the populations tested. In conclusion, malathion resistance can induce lower protein and carbohydrate contents, but higher PO activity in larvae.
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http://dx.doi.org/10.1111/mve.12572DOI Listing
March 2022

Drosophila melanogaster as a low-cost and valuable model for studying type 2 diabetes.

J Exp Zool A Ecol Integr Physiol 2022 Jun 21;337(5):457-466. Epub 2022 Feb 21.

Department of Zoology, Faculty of Science, Tanta University, Tanta, Egypt.

Drosophila melanogaster has been used as the most successful invertebrate model for studying metabolic diseases such as type 2 diabetes (T2D). We induced T2D by feeding Drosophila larvae on a high-sugar diet (HSD). The glucose and trehalose, glycogen, lipid, triglyceride, and protein levels were determined in HSD-fed larvae. Moreover, larval food intake, water content, size, and weight in addition to the development until pupation were observed. Levels of Drosophila insulin-like peptides (DILPs 2, 3, and 5), as well as adipokinetic hormone (AKH), were also determined in HSD-fed larvae by quantitative real-time polymerase chain reaction. The results demonstrated that HSD could induce elevated levels of glucose, trehalose, glycogen, and proteins in larvae. The larvae consumed less food intake and were smaller, lighter, and less developed on HSD than those on the control diet. Moreover, the water content of larvae fed HSD was similar to that fed the control diet. HSD induced higher expression of DILP3 and AKH, confirming hyperglycemia with insulin resistance. In sum, Drosophila offers an appropriate model for quick and inexpensive in vivo experimentation on human metabolic diseases.
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http://dx.doi.org/10.1002/jez.2580DOI Listing
June 2022

Reduced fitness of the mosquito Culex pipiens (Diptera: Culicidae) after feeding on a blood meal with hepatitis C virus.

J Invertebr Pathol 2022 03 24;189:107719. Epub 2022 Jan 24.

Department of Zoology, Faculty of Science, Tanta University, Tanta 31527, Egypt.

Hepatitis C virus (HCV) is a blood-borne virus. Given that mosquitoes can take blood meals from HCV patients, we aimed to test whether HCV in the blood meal can induce alterations in the biology of Culex pipiens. To address this aim, Cx. pipiens females were fed HCV-negative blood from healthy individuals or HCV-positive fresh blood samples harvested from viremic HCV patients. Replication of HCV in mosquitoes was confirmed by negative strand-specific RT-PCR and sequencing of RNA extracted from the mosquito bodies 7 days post-feeding. In addition, several parameters that determine the fitness of the mosquitoes were measured. Virus acquisition was associated with alterations in the architecture of the gut microvilli and the immune response, indicated by an increase in phenol oxidase activity. Interestingly, the mosquitoes that were fed the HCV-positive blood meal showed shorter median longevity (8 days) and laid fewer eggs than the control mosquitoes. Furthermore, the offspring of females fed the HCV-positive blood meal demonstrated a lower emergence rate than the controls. In sum, the results indicate that feeding on HCV by Cx. pipiens decreases fitness, which may, in turn, affect its potential as a vector.
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http://dx.doi.org/10.1016/j.jip.2022.107719DOI Listing
March 2022

Insecticidal activity of some synthesized 1,3,4-oxadiazole derivatives grafted on chitosan and polymethylmethacrylate against the cotton leafworm Spodoptera littoralis.

Int J Biol Macromol 2021 Jun 17;180:539-546. Epub 2021 Mar 17.

Zoology Department, Faculty of Science, Tanta University, Tanta, Egypt. Electronic address:

To combat insect pests and vectors that are responsible for high losses in food and lives, insecticide discovery is of top priority. This study aimed to synthesize, characterize and investigate the insecticidal activity of 1,3,4-oxadiazole derivatives grafted on chitosan (CS) and modified polymethyl methacrylate (PMMA). 5-(pyridin-3-yl)-1,3,4-oxadiazole-2-thiol and 5-(pyridin-4-yl)-1,3,4-oxadiazole-2-thiol were respectively reacted with ethylchloroacetate and methyl-2-choloroacetoacetate. The resulted esters were grafted with CS and modified-PMMA. The products were characterized using FT-IR, H NMR, TGA, and XRD techniques. Four CS grafted ones were able to show good insecticidal activity against the cotton leafworm Spodoptera littoralis. Furthermore, the safety of these compounds was tested using MTT assay on a human cell line (WI-38). The results indicated that compounds 2a, 2b, 6a, and 6d are considered insecticide candidates to S. littoralis fourth-instar larvae. Cytotoxicity of 2b and 6d indicated that they are the least toxic to humans. It is concluded that both compounds may represent promising insecticide candidates.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.03.050DOI Listing
June 2021

WITHDRAWN: Reduced fitness of the mosquito Culex pipiens (Diptera: Culicidae) after feeding on a blood meal with hepatitis C virus.

J Invertebr Pathol 2021 Jan 28:107522. Epub 2021 Jan 28.

Department of Zoology, Faculty of Science, Tanta University, Tanta 31527, Egypt.

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http://dx.doi.org/10.1016/j.jip.2020.107522DOI Listing
January 2021

Genetic variation among Drosophila melanogaster isofemale lines influences encapsulation ability of the parasitoid Asobara tabida.

Authors:
Wesam S Meshrif

J Egypt Soc Parasitol 2013 Apr;43(1):1-15

Department of Zoology, Faculty of Science, Tanta University, Tanta 31527, Egypt.

One of the most important factors which affect the outcome of the host-parasite interactions is the genetic variation in particular those of the host. The aim of this study was to test the effect of variation within Drosophila melanogaster population on the encapsulation ability against the parasitoid Asobara tabida. To this end, nine isofemale lines of D. melanogaster which represent different levels of encapsulation ability were used. The encapsulation ability and its related parameters such as infestation, avoidance, and parasitism success and super-parasitism rates were assessed following oviposition. Larval weight, protein contents and phenoloxidase in extremes and intermediate lines, were investigated. The variation among D. melanogaster lines influenced encapsulation, avoidance, parasitism and superparasitism rates. Upon emergence, low success of the parasitoid associated with high mortality rates were observed in the representative lines. Although parasitized larvae may suffer from weight loss, they could survive based on mounting effective immune response. Parasitism of A. tabida in the Drosophila larvae induced high phenoloxidsae activity, particularily in the resistant ones refelecting their immune competency. In sum, the variation in encapsulation ability among isofemale lines demonstrates high underlying genetic variation. The data might help to design successful biological control programs and to facilitate interpretation of a similar interaction of other host-parasite model systems.
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http://dx.doi.org/10.12816/0006362DOI Listing
April 2013

Interactions of Spodoptera littoralis haemocytes following injection with the entomopathogenic fungi: Beauveria bassiana and Nomuraea rileyi.

J Egypt Soc Parasitol 2011 Dec;41(3):699-714

Department of Zoology, Faculty of Science, Tanta University, Tanta, Egypt.

This study compared the cellular interactions of Spodopteralittoralis haemocytes with two virulence-different entomopathogenic fungi: Beauveriabassiana and Nomuraearileyi. Using light and transmission microscopy, five types of haemocytes namely, prohaemocytes (PRs), plasmatocytes (PLs), granulocytes (GRs), spherule cells (SPs) and oenocytoids (OEs) were identified in the 6th instar larvae. PRs and PLs were found in the haemopoietic tissue. Intra-haemocoelic injection of blastospores induced ultrastructural alterations in the cytoplasm and nuclei of circulating haemocytes of treated larvae. Different responses were observed in the populations of haemocyte types following injection with the tested fungi. The most important changes were the decrease of the numers of GRs accompanied with increase in SPs at 12-48h following injection with B. bassiana, whereas, a decrease of PLs with a commitment increase inSPs and OEs were observed at most time intervals after injection with N. rileyi. Both fungi provoked a decrease of the total number of haemocytes at 48h followed by an increase at 72h post-injection. In vivo assay showed that the GRs and PLs actively phagocytised fungal blastospores. There was a time-dependent decrease and increase in the phagocytosis activity after injection of B. bassiana and N. Rileyi, respectively. In B. bassiana-injected insects, the numbers nodules increased significantly at 6-48h in comparison with the controls post-injection. In N. rileyi-injected insects, nodules increased significantly only at 72h post-injection. No cellular encapsulation was observed in any of the examined insects.
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December 2011
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