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 HI4]. The LC[50] value of methomyl for both field and the 12[th] generation [F12] of the selected strain was 1.789 ppm and 8.925 ppm respectively. The LC[50] 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 and 2.395ppm respectively. The specific activity of trypsin enzyme in control susceptible colony was 20.806 +/- 0.452[micromol/min/mg protein; but at F4 and F8 for malathion and methomyl treated larvae were 10.810 +/- 0.860 and 15.616 +/- 0.408 [micromol/min/mg protein, respectively. Trypsin activity of F12 in treated larvae with B.t.H14 was 2.097 +/- 0.587micromol/min/mg protein. Aminopeptidase specific activity for susceptible control larvae was 173.05 +/- 1.3111micromol/min/mg protein. This activity decreased to 145.15 +/- 4.12, 152.497 +/- 6.775 and 102.04 +/- 3.58 [a]micromol/min/mg protein after larval [F12] treatment with methomyl, malathion and B.t H14 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. al-exandrinus [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 "e0" and 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 preva1ence 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 current spatial patterns, but also predicting its distribution under expected future developmental and environmental changes

Biochemical fingerprints of salviary gland for some ticks species in Egypt by SDS-polyacrylamide gel electrophoresis

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 persicus, Hyalomma antolicum excavatum, H. an antolicum, H. dromedarii, H. impeltatum and Rhipicephalus sanguineus]. The 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. antolicum 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 7.1 12 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 and 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

Bionomics of ticks collected from Sinai peninsula: 2-abundance, attachment sites, and density estimators of ticks infesting arabian camels

In this study, ten camels were examined monthly. A total of 5468 adult ticks of six species and subspecies of genus Hyalomma; H. dromedarii, H. Impeltatum, H. A excavatum, H. A. anatolicum, H. schulzei and H. marginatum rufipes in addition to 115 Hyalomma nymphs species were collected. Of these, the first four types represented about 96.2% of the total collection. The infestation rate was higher during the period from March to November. The large number of the adult ticks was concentrated on tail, brisket, anus and udder which totaled 68.2%. Attachment sites of males and females were not significantly correlated in most species. Nymphs were localized in few sites; whereas 91.6% of the total nymphs were attached to hump, neck, head [ear] and side. H. Dromedarii, H. Impeltatum and H a. excavatum were found on most of the body sites, tail, brisket, udder and anus totaling 79.9%. Males exceeded females in all sites and were on neck and legs. Females were the only stage collected from udder. Both sex of H. a. anatolicum were collected from tail. H. Schulzei and H. m rufipes were concentrated in brisket, udder, anus and tail

Observations on the structure and histololgy of the female genital system of the cattle tick Boophilus annulatus [SAY]

Female genital system of Boophilus annulatus was examined grossly on the day of drop-off from the host and grossly and microscopically on the 4th day. It consisted of an ovary, two oviducts, a common oviduct, a connecting tube, a seminal receptacle, a vagina divided into cervical and vestibular parts, two accessory glands and gene's organ. The ovary oocytes underwent an excessive growth during four days after drop-off from the host. Oocytes accumulated eosinophilic material during growth and underwent histological changes similar to those seen in other ixodid ticks

Outdoor resting and nectar feeding behaviour of some mosquito species in two villages in Egypt

Mosquito samples resting on different host plants were collected from 2 localities in Egypt, Kafr Tohoria Village, Qalyoubia Governorate, and El-Abttal Village, Ismailia Governorate. Collected mosquitos were identified, classified according to their feeding stage and tested for carbohydrate feeding. Results indicated that Cx. pipiens represented 96% and above of collected species in the 2 localities. The available plants and crops showed different attraction levels for resting female mosquitos. Most of the collected females were empty. Mosquitos may be attracted to certain plants due to the presence of some phagostimulant chemicals rather than the presence of the sugars

Haemoglobinometry as a method to determine the blood meal size of two argasid tick specties

A standardized clinical method for measuring hemoglobin was applied to measure the quantity of blood ingested by Argas persicus and A. hermanni feeding on chicken and pigeons, respectively. The blood fed ticks were added to a reagent that converted all hemoglobin to hemoglobincyanide [HiCN], which can be read spectrophotometrically. The validity of this method was established by comparing hemoglobin determination with the size of blood meals measured by weight. Linear relationships with high correlation coefficients were obtained for nymphs, males and females of A. persicus and A. hermanni, showing that both gravimetric [weighing] and HiCN methods gave similar estimates of ingested blood

Mites [acari] infesting commensal rats in Suez canal zone, Egypt

Mites are arthropods distinguished from ticks by usually being microscopical in size and have a hypostome unarmed with tooth- like anchoring processes. They are group in a number of suborders, each with super-families and families including many genera of medical and economic importance. In this paper, commensal rodents [Rattus norvegicus, R. r. alexandrinus and R. r. frugivorous] were surveyed in the Suez Canal Zone for their acari ectoparasites. 4 species of mites were recovered. In descending order of mite indices, they were Eulaelaps stabularis [4.83 on 6 rats], Laelaps nuttalli [3.11 on 27 rats], Ornithonyssus bacoti [1.66 on 9 rats] and Dermanyssus gallinae [0.66 on 24 rats]. The overall mite indices in the 3 governorates were 3.66 in Suez, 2.82 in Ismailia and zero in Port Said. The medical and economic importance of the mites were discussed

Laelaps Sinai sp nov [laelapinae, laelapidae], a parasite of gerbillus pyramium in El-Arish, north Sinai, Egypt

Laelaps sinai sp. nov. collected from gerbils in El-Arish, Northern Sinai Peninsula, is studied. A detailed description of the female is given. Eight microscopic drawings of gnathostoma and idiosoma are shown. The taxonomic position of the species is discussed

seasonal abundance of gerbillus pyramidum and their flea ectoparasites in Al Arish, North Sinai governorate, Egypt

The seasonal abundance and the flea ectoparasites of Gerbillus pyramidum were studied. The results showed that the jerboa was more common in summer [jerboa index 0.43] and least common in winter [jerboa index 0.35]. The overall male to female ratio was 4.2: 1. The flea ectoparasites were more common in autumn [flea index 10.5] and least common in summer [flea index 6.8]. The overall flea index was 8.75 and the majority of fleas [90.9%] was collected on male jerboa. The collected fleas in a descending order of abundance and flea index were: Xenopsylla cheopis [3.1], X. ramesis [2.7], Stenoponia tripectinata [1.4], Nosopsylla sinaiensis [0.9], Hopkinsipsylla occulta [0.6], and Pulex irritans [0.01]

Leishmania major in meriones sacramenti thomas 1922 in Nakhel, North Sinai Egypt

Leishmania major is a protozoal parasite of desert and savanna rodents, the vectors being mainly Phlebotomus [Phlebotomus] papatasi and very closely related species. Man is an incidental host, in whom usually it causes zoonotic cutaneous leishmaniasis. In this paper, spot light survey was carried out in Nakhel to identify the role of animal reservoir[s] where a sudden outbreak occurred in Nakhel center. The trapped rodents were M. musculus, Meriones sacramenti and Gerbillus pyramidum. Three isolates were obtained from the ear and/or spleen of three M. sacramenti. Isoenzyme characterization of the isolates using five enzymes showed the isolates to be identical with the L. major reference strain. The results were discussed on the light of the work previously done in Sinai Peninsula

Distribution and host relationship of ticks [ixodoidea] infesting domestic animals and rodents in Sinai peninsula

Geographical distribution of ticks infesting farm animals in Sinai Peninsula revealed the presence of 12 tick species; namely, Hyalomma dromedarii, H. impeltatum, H. ananatolicum, H. anexcavatum, H. marginatum rufipes, H. M. turanicum, H. schulzei, Rhipicephalus sanguineus, R. turanicus, Boophilus annulatus, Ornithodoros erraticus and Argas persicus. The distribution map of those species is given. The areas of Sinai could be arranged as regards the number of tick species in the following descending order: Beer Lehfin and St. Catherine [9 spp.], Kosaimah and Nuweibah [8 spp.], Arish and Godirate [7 spp.], Firan [6 spp.], Beer El-Abd, Zowaid, Rafah, Quntara, Wadi- Hadra and El-Tur [5 spp.], Abu Redis, and Hammam Pharon [4 spp.]

Susceptibility of three tick hyalomma spp from north Sinai governorate to certain pesticide groups

Three species of Hyalomma tick, [H. anatolicum, H, dromedarii and H. impeltatum] were collected from camels in North Sinai .The susceptibility of adult females and males of each species to four different groups of insecticides [BHC, Fenitrothion, Permethrin and Baygon] were determined. The results of Lc50 values showed that BHC was the most effective compound against adult males and female of H. impeltatum, whereas the superior efficiency against H. anatolicum and H. dromedarii occurred by Baygon and Permethrin respectively on both males and females. Also the results indicated that the adult males of all tested species of ticks were more susceptible to all the tested insecticides than the adult females

role of rodents as reservoirs for some diseases in new reclaimed areas in north Sinai

In a trial to determine the role of Sinai rodents as reservoirs to rickettsial diseases, the IFA technique was used to detect the presence of R. typhi and spotted fever group in blood of some commensal and wild rodent species collected in Sinai during the last five years [1985-1989]. Out of 277 Rattus spp. collected in El Arish [47.3%] were positive to R. typhi and only [5.9%] of 35 Mus musculus were positive to R. typhi As for GerbiIlus spp. only [1.5%] of 206 animals were positive for R. typhi. The positive cases of spotted fever group were [34.6%] in Rattus spp. and [18.8%] in Gerbillus spp. With the presence of ticks and fleas in Sinai, the potentiality for rickettsial disease transmission exists. Such disease impose serious impacts on manpower in Sinai especially with the ambicious development plans ongoing presently

review and distribution map of rodents in Sinai, Egypt

Sinai is living reconstruction and development in all fields. On the other hand, rodents have a time honoured public health place in the history of science and followed man wherever he goes. Hence, a review and distribution map of rodents of medical and veterinary importance were given