Characterization of tachyzoite and bradyzoite antigens of Toxoplasma gondii recognized by immunoglobulins G, M and A in an experimental model of reactivated toxoplasmosis.

Toxoplasma gondii tachyzoite and bradyzoite antigens that are recognized during reactivated toxoplasmosis were studied in comparison with those recognized during acute and chronic infections, in murine models of toxoplasmosis. Both tachyzoite and bradyzoite antigens of the RH and KSU T. gondii strains, respectively, were resolved by sodium- dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) then probed by immunoblot (IB) (Western blot) with mice antisera elicited by different states of toxoplasmosis to allow parallel analysis of antigen recognition by immunoglobulin G, M, and A antibodies. T. gondii tachyzoite and bradyzoite antigens were well studied by IB recording some specific and commonly shared antigens. A complex array of T. gondii tachyzoite and bradyzoite antigens was revealed in the three states of toxoplasmosis. During reactivated toxoplasmosis the commonly shared tachyzoite and bradyzoite antigens were the dominantly recorded antigens. Also, antigens of tachyzoite at 48 KDa and bradyzoite at 40 KDa were recognized in reactivated toxoplasmosis by IgM and IgG, respectively, and not in other states by the same immunoglobulin. The virulent RH and avirulent KSU strains of T. gondii showed some similarities.

Residual effect of four insecticides applied for indoor control of Phlebotomus papatasi (Scopoli).

The residual effect of four known insecticides prepared in olive oil and sprayed on cement plastered walls was estimated against the Egyptian strain of Phlebotomus papatasi (Scopoli). The results showed that propoxur reduced the number of the tested sandflies to 16.5%, 24.1%, 46.4%, 53.4% and 76.7%, 75 days post treatment after an exposure time for 5, 10, 15, 20 and 30 minutes. Permethrin caused zero, 17.5%, 25.0%, 41.4% and 51.9%; malathion caused 4.3%, 10%, 26.7%, 35.9% and 49.1% and B H C caused zero, 10%, 30%, 36.3% and 48.1% for the same exposure time respectively. This indicated that propoxur had the highest residual effect and B H C had the lowest one. The results were discussed in relation to leishmaniasis control.

Some aspects of Phlebotomus papatasi (Scopoli) in greater Cairo, Egypt.

Exogenous and indigenous cases of zoonotic cutaneous leishmaniasis are reported in several Egyptian Governorates particularly those in the Nile Delta, Phlebotomus paptasi (Scopoli) is the only proven insect vector. This paper was intended to study the seasonal abundance, nocturnal activity and breeding sites as well as other relevant behaviour aiming to throw some light on this insect vector. The results showed that: (a) the seasonal activity started in April and ended in November or beginning of December. (b) female outnumbered male indoors (7.4:1) and V.V. outdoors (0.14:1). (c) blood fed females were 97.7% indoors and 29.4% outdoors. (d) the nocturnal activity ranged between 6 p.m. to 6 a.m. indoors and 8 p.m. to 6 a.m. outdoors. (e) the immature stages of Phlebotomus were successfully recovered from rodent burrows and poultry sheds.

Counter immunoelectrophoresis, a modified technique for the identification of blood meals of sandflies collected from Qualyobia Governorate, Egypt.

Specificity and sensitivity are very important when investigating the blood meals of an insect vector, particularly those having different hosts. Several techniques are used for the identification of the blood meals. Counter immunoelectrophoresis is the technique of choice. The modification was to secure save of time and least amount of materials. In this paper, a modified technique of the counter immunoelectrophoresis (CIEP) was used for the identification of the blood meal of wild Phlebotomus papatasi collected from different sites in Qualyobia Governorate. Eight antisera were used. These were human, cat, dog, rat, sheep, goat, bovine and avian. The results showed that 99.52% of 832 female P. papatasi contained human blood, 0.12% (one female) contained only avian blood and 0.36% or three females each contained mixed blood of human together with dog blood (One), rat blood (one) or avian blood (one). P. papatasi is an anthropophilic insect, but in rare cases, it is zoophilic.

The susceptibility of the Egyptian Phlebotomus papatasi to five insecticides.

Phlebotomus papatasi is the main vector of zoonotic cutaneous Leishmaniasis caused by L. major in nearly all the East Mediterranean Region. Generally speaking, control of any arthropod-borne disease should be directed against both the parasite and the vector. The present study was undertaken to establish a base line susceptibility levels of the Egyptian P. papatasi to five insecticides. These insecticides were: B H C and D D T (chlorinated hydrocarbon), permethrin (synthetic pyrethroides), malathion (Organophosphorus) and propoxur (carbamate). The results obtained revealed that the laboratory bred P. papatasi were more susceptible to the five insecticides than the wild caught ones. The insecticidal efficiency of the five insecticides based on LC50 was in the following descending order: propoxur, permethrin, BHC, DDT and malathion for laboratory bred flies and propoxur, permethrin, BHC, malathion then DDT for wild caught flies. The least LC50 was when using propoxur for both the wild caught flies (0.0014%) and laboratory bred ones (0.00043%). The least LT50 was when using propoxur for both the wild caught flies (4.8 seconds) and the laboratory bred flies (2.2 seconds).