An ex vivo system for investigation of Plasmodium berghei invasion of the salivary gland of Anopheles stephensi mosquitoes.

Plasmodium sporozoites associated with the midgut and in the hemolymph of mosquitoes differ from sporozoites in the secretory cavities and ducts of the insects' salivary glands in their transcriptome, proteome, motility, and infectivity. Using an ex vivo Anopheles stephensi salivary gland culture system incorporating simple microfluidics and transgenic Plasmodium berghei with the fluorescent protein gene mCherry under the transcriptional control of the Pbuis4 promoter whose expression served as a proxy for parasite maturation, we observed rapid parasite maturation in the absence of salivary gland invasion. While in vivo Pbuis4::mCherry expression was only detectable in sporozoites within the salivary glands (mature parasites) as expected, the simple exposure of P. berghei sporozoites to dissected salivary glands led to rapid parasite maturation as indicated by mCherry expression. These results suggest that previous efforts to develop ex vivo and in vitro systems for investigating sporozoite interactions with mosquito salivary glands have likely been unsuccessful in part because the maturation of sporozoites leads to a loss in the ability to invade salivary glands.

Comparative fine structure of eggs of autogenous and anautogenous Culex pipiens (Diptera: Culicidae).

Culex (Cx.) pipiens is the potential vector human filariasis in Egypt. However, autogenous Cx. pipiens may be less efficient vector of Wuchereria (W.) bancrofti in endemic areas of Egypt compared to anautogenous counterparts. In this study, an attempt was made to differentiate eggs of autogenous and anautogenous Cx. pipiens using scanning electron micrographs. The results indicated that eggs of both species appear to be similar to great extent in surface morphology. Eggs of both forms are black and elongate-oval. Width is greatest at the anterior end. The posterior end is pointed. The micropylar disc is apparent with distinct edge. Exochorionic bridges are angular. Size of both eggs represented by length and width are comparable. In both eggs, length is greater than width. However, eggs of both forms can be distinguished from each other by the exochorionic bridges being longer and thinner in the autogenous eggs than in the anautogenous eggs.

Histopathological changes in liver of mice after experimental envenomation with Androctonus amoreuxi scorpion venom.

A total of 78 adult male Albino mice were divided into thirteen groups (6 mice in each). One served as a control group and the other twelve groups were venom treated groups. The mice of treated groups were injected with 0.1 ml saline solution in which a particular amount of scorpion venom. The first 6 groups were subcutaneously injected with 1/2 LD50 (0.05 microg/g body weight), while the other 6 groups were injected with 1/4 LD 50 (0.025 microg/g body weight) by the same route. The animals from each group were anesthetized with ethyl ether and sacrificed at different time intervals (3, 6, 9, 12 hrs, 4 & 7days post toxin administration). The microscopic examination of liver tissue obtained from envenomed animals showed variable histopathological changes being severely increased with the time interval of envenoming. The most obvious changes in the liver were acute cellular swelling, hydropic degeneration, congestion of central veins and portal blood vessels. Besides, extramedullary hematopoiesis and invaginations in nuclei of hepatic cells, with formation of intranuclear cytoplasmic inclusions were observed.

Clinicopathological investigations on mice envenomed with scorpion venom (Androctonus amoreuxi).

The present study assessed the toxicity of Androctonus amoreuxi crude venom on blood and biochemical serum parameters of mice. Adult male Albino mice were divided into three groups, in the control group mice were injected S.C. with saline solution. The second group and the third were injected with the venom S.C. in mice in the following doses 1/4 and 1/2 dose of LD50 respectively. Blood and serum samples were taken after 3 hours, 6 hours, 9 hours, 12 hours, 4 days and 7 days. Hematocrit (Ht), red blood cells (RBC) count, hemoglobin, MCV, MCH & MCHC were performed. Serum biochemical parameters, the levels of total proteins, albumin, globulin, glucose, cholesterol, triglycerides, ALT, AST, ALP, creatinine, uric acid and urea were measured. RBCs, Hob, PCV, MCV, MCH & MCHC showed significant increase, and increase in total protein, albumin and globulin within the experiment. Glucose and cholesterol levels were significantly increase from the beginning. Triglycerides showed significant decrease after 6 hours. Liver enzymes and kidney functions revealed significant changes post-injection.

Studies on rodents role as reservoir hosts of leishmaniasis with specical reference to their ectoparasites in Suez Governorate.

The distribution of rodents was studied in three different habitats. Seven rodent species were identified: Rattus norvegicus, R. alexandrinus, R. frugivorous, Mus musculus, Acomys russatus, Meriones sacramenti and Gerbillus pyramidum. The species distribution varied with the habitat type. The highest density of rodents was in July and August and the lowest one was in January. However, some species were collected all the year round. The rodents were investigated for the endo- and ecto-parasites. No Leishmania parasites were found. The ectoparasites were: Xenopsylla cheopis, Leptopsylla segnis and Ctenocephalides felis, Polyplax spinulos, Hyalomma dromedarii (nymph) and Echinolaelaps echidninus and Hemolaelaps glassgowi. Ecto-parasites were on rodents all year-round in domestic habitat and peridomestic habitats. In wild one, ecto-parasites activity was from March to December. The rodents' role as reservoir for L. major was experimentally studied. Rodents inoculated with L. major together with hamster and BALB-c mice developed cutaneous lesions. The active lesions, the rodents' ecological habitats and the presence of insect-vector may pave the way to an epidemic zoonotic leishmaniasis role.

Ecology, biology and susceptibility of Phlebotomus papatasi to Leishmania experimental infection in Suez Governorate.

Zoonotic cutaneous leishmaniasis (ZCL) is endemic in Sinai Peninsula. The sand fly and reservoirs were investigated in Suez G., since new settlements and land reclamation programs are ongoing. The results showed that Phlebotomus papatasi reached its highest density in September. The successfully colonized P. papatasi facilitated its biology and competence study. An autogenous trait was proven within P. papatasi population indicating its ability to survive and breed during adverse conditions. The vector competence was carried out under laboratory condition through feeding on lesion of a L. major experimentally infected hamster and by membrane feeding technique. Both hamsters and BALB-c mice inoculated with L. major developed ZCL lesions.