Digestive enzyme as benchmark for insecticide resistance development in Culex pipiens larvae to chemical and bacteriologic insecticides.

This work monitored changes in some digestive enzymes (trypsin and aminopeptidase) associated with the building up of resistance in Cx. pipiens larvae to two chemical insecticides (methomyl and/or malathion) and one biological insecticide (Bacillus thuringiensis-H14 or B.t H 14). The LC50 value of methomyl for both field- and the 12th generation (F12) of the selected strain was 1.789 ppm and 8.925 ppm respectively. The LC50 value of malathion for both field and the F12 of the selected strain was 0.082 ppm and 0.156 ppm respectively, and those of B.t H14 of field strain and the F12 was 2.550ppm & 2.395ppm respectively. The specific activity of trypsin enzyme in control susceptible colony was 20.806 +/- 0.452micromol/min/mg protein; but at F4 and F8 for malathion and methomyl treated larvae were 10.810 +/- 0.860 & 15.616+/-0.408 micromol/min/mg protein, respectively. Trypsin activity of F12 in treated larvae with B.t.H14 was 2.097 +/- 0.587 microiol/min/mg protein. Aminopeptidase specific activity for susceptible control larvae was 173.05 +/- 1.3111 micromol/min/mg protein. This activity decreased to 145.15 +/- 4.12, 152.497 +/- 6.775 & 102.04 +/- 3.58a micromol/min/mg protein after larval (F 12) treatment with methomyl, malathion and B.t H 14 respectively.

Zoonotic helminthes of commensal rodents in Talkha Center, Dakahlia Governorate.

Commensal rodents were trapped alive from different areas near garbage, canal edges, farm animals and the likes in Talkha Center over one year. A total of 135 rodents were collected, their species and index were Rattus norvegicus (0.11), R. r. frugivorous (0.13), R. r. alexandrinus (0.16) and Mus musculus (0.5). The zoonotic helminthes were trematodes (10 species), cestodes (4 species), and nematodes (10 species). The results were discussed on light of other works.

Ectoparasites of commensal rodents in Talkha Center, Dakahlia Governorate, Egypt.

The ecto-parasites infesting commensally rodents were collected from the different localities in Talkha Center (Dakahlia Governorate) from April 2006 to March 2007. The seasonal abundance of rodent number and rat index was 52 (0.58) in spring, 27 (0.3) in summer, 39 (0.22) in autumn and 17 (0.05) in winter. From 135 rodent species and rat index was Rattus norvegicus N=33 (0.24), R. r. frugivorous N=39 (0.29); R. r. alexandrinus N=48 (0.36) and Mus musculus N=15 (0.11). From 388 ecto-parasite infested rodent collected number and ecto index was fleas N= 114 (0.84 flea/rat), Lice N=93 (0.69 lice/rat), Mites N = 165 (1.2 mite/rat) and larva of ticks N=16 (0.12 tick/rat). No doubt, rodents and their ectoparasites played a serious role in spreading and transmission of zoonotic diseases to human and animal.

Spectral and landscape characterization of filarious and non-filarious villages in Egypt.

Filarial disease is endemic in Egypt in some villages of Nile Delta governorates where it is transmitted by Culex pipiens female. GIS functions are used to identify environmental indicators of high-risk village as indicated by mosquito density, human infection rate, vector species composition, mean life expectancy "e(o)" & environmental variables (geology, hydrology, soil types, etc) as well as meteorological factors (temperature, RH and rainfall) in relation to filaria transmission risk. Remote-sensing technology was used to distinguish between the two studied villages as high and non-infected, as defined by microfilarial prevalence. The results indicate that filaria transmission risk is higher at an area characterized by highly productive aquifers, silt clay soil, receiving little amount of rain with low relative humidity (RH). The results indicate that the most important landscape elements associated with prevalence are water and different vegetation. This work showed that the integration between GIS and remote sensing technologies to analyze and identify the environmental factors, associated with the disease, did not only allow mapping icurrent spatial patterns, but also predicting its distribution under expected future developmental and environmental changes.

Biochemical fingerprints of salivary gland for some ticks species in Egypt by SDS-polyacrylamide gel electrophresis.

SDS-PAGE gel electrophoresis as a sensitive method is used for simultaneously comparing the total protein extracted from salivary glands in some ticks species (Argas percsicus, Hyalomm antolicum excavatum, H. an. antolicum, H. dromedarii, H. impeltatum and Rhipicephalus sanguineus). Results of A. persicus were characterized by 4 bands with molecular weights ranging from 82.76 to 16.076 KD. On the other hand, H. an. excavatum females were characterized by 6 bands with molecular weights ranging from 103.74 to 6.216 KD. H. an. antolicun males were characterized by 5 bands with molecular weights ranging from 79.183 to 2.092 KD. R. sanguineus was characterized by 4 and 8 bands with molecular weights ranging from 88.864 to 6.216 KD and 126.69 to 7.112 KD for male and female respectively. Female H. impeltatum was characterized by 8 bands with a range of molecular weights from 106.96 to 7.829 KD. H. dromedarii was characterized by 4 & 7 bands with ranges of molecular weights from 88.147 to 4.602 KD and 110.20 to 2.630 KD for male and female respectively.