Molecular genotyping of Echinococcus granulosus in animal and human isolates from Egypt.

Despite, Egypt is started to be considered as an emerging endemic area for cystic echinococcosis (CE), no enough data in the literature about the exact status of the genotype in both animals and humans. Therefore, the present study aims to characterize the underlying genotypes that could be responsible for the transmission cycle and for the growing infectivity. Animal isolates were collected from 47 camels and 6 pigs. Human isolates are 31 CE cases including; 21 of hepatic cases, 5 of pulmonary cases and 5 multiple-organ affection cases. Hot-Start specific PCR followed by DNA sequencing for mitochondrial 12S rRNA gene, revealed G1 genotype in one (3.2%) of 31 human isolate only. G6 genotype was detected in all the 53 (100%) animal isolates and in 30 out of 31 (96.8%) human isolate. The Egyptian G6 strain nucleotide sequence revealed 100% homology with an Argentinean reference strain 99% homology with the Kenyan G6 strain. It was concluded that G6 genotype is the predominant genotype in Egypt.

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.

Estimation of Toxoplasma gondii antibodies in patients with cardiomyopathy.

The possible involvement of Toxoplasma gondii in the pathogenesis or as a complicating factor in patients with cardiomyopathy has been investigated by the serological detection of specific antibodies by IFAT. Fifty six serum samples were collected from patients who presented with dyspnoea on effort, pericardial pains, palpitations and oedema of lower limbs. They were investigated by Echo, ECG and epidemiological history, and diagnosed as dilated, ischaemic and restrictive cardiomyopathies and myocarditis. Forty serum samples from patients with valvular lesions were examined as a control group. Twelve out of 56 samples were positive at end titre of 1:16 (21.4%). Sera with positive titres were found to occur mostly in patients with ischaemic cardiomyopathy. All samples of the control group were negative.

Investigation of Sarcocystis as a causative agent in cardiac disease.

Sera from 56 cases with cardiomyopathy and myocarditis and 40 cases with different types of valvular diseases were tested, using the indirect fluorescent antibody test (IFAT) for the detection of antibodies to Sarcocystis. None of the cases showed specific reaction where the IFAT was negative at the cut off titre 1:8 in all the cases.

Studies on flea fauna in El Fayoum Governorate, Egypt.

This paper dealt with the studies of flea fauna as collected on the rodent hosts over one year. The collected rodents (499) in a descending order of abundance in the collection were Rattus rattus, R. norvegicus, Mus musculus, Gerbillus pyramidum and Arvicanthis niloticus. The collected fleas in a descending order in the collection were X. cheopis, P. irritans, N. jasciatus, C. felis, L. segnis and E. gallinacea. The total flea index reached the maximum (0.76) in May and it was zero in December and January. The highest number of fleas was on R. norvegicus and A. niloticus and the lowest was on G. pyramidum. The highest number of rodents and their flea ectoparasites was during the Spring and the lowest was during Autumn. The medical importance of the collected fleas and the whole results were discussed.

Evaluation of a direct agglutination test and methylene blue dye test in diagnosis of cutaneous leishmaniasis.

The usefulness and sensitivity of a direct agglutination test (DAT) in the diagnosis of cutaneous leishmaniasis infection has been investigated. Trypsin treated, formalin fixed and coomassie blue stained Leishmania promastigotes were used as antigens: L. infantum, L. donovani, L. aethiopica. Although the titres of sera from patients with localized cutaneous leishmaniasis were low, sera from lepromatous, tuberculous and toxoplasmic patients gave high titres indicating cross reactivity. Comparable results were obtained when the same sera were tested using freshly prepared antigen or antigens stored for 5 months at 4 degrees C, and with addition of 0.78% 2-mercaptoethanol to the diluent.

Preliminary assessment of prevalence of toxoplasmosis in patients with chest diseases.

Frequency of Toxoplasma antibodies in chest disease patients was assessed by IFAT. An overall positivity of 20.5% was recorded which is the range of prevalences reported in Egypt. The majority (90.3%) were positive at titre 1/16 and one case of atypical pneumonia showed titre of 1/256. The implications are discussed.

Experimental concomitant toxoplasma and malaria infection in rats.

The effect of concomitant toxoplasma and malaria infection on the reticuloendothelial system was investigated in rats. This was evaluated by the level of plasmodial parasitaemia; humoral antibody response; effect on splenic weight; histopathological changes in thymus and spleen; histopathological and histochemical changes in liver. The parasitaemia appeared after 2 days in single malaria and concomitant infections. The peak was reached after 6 days with single and precedent malaria, and after 10 days with precedent toxoplasma. The clearance of parasitaemia was delayed to 30 days with concomitant infections instead of 14 days with single malaria. Higher than normal malarial antibody levels were reached with precedent toxoplasma, while the toxoplasma antibodies were lower than normal in both concomitant infections. There was a significant increase in splenic weight in both precedent malaria and toxoplasma, followed by a decrease which did not return to normal in case of precedent malaria. The thymus was packed with thymocytes in precedent malaria, while depletion in the cortex occurred in precedent toxoplasma. In the liver, there was glycogen depletion and decrease in succinic dehydrogenase activity in both concomitant infections. Choline esterase activity in precedent malaria was decreased and returned to normal on day 40 while in precedent toxoplasma the activity was normal all through the period. The alkaline phosphatase activity was decreased and returned to normal on day 40 in both concomitant infections.

Effect of Toxoplasma gondii on histopathology and histochemistry or reticuloendothelial system in experimental animals.

The effect of acute and chronic infections by Toxoplasma gondii on the spleen, thymus and liver of mice and rats, and on their antibody response has been studied. In acute infection while the splenic weight increased the thymic weight decreased. The histopathological studies demonstrated lymphocytic depletion of splenic follicles and thymic cortex. Numerous phagocytes and plasma cells were seen in the red pulp and thymic medulla. Vascular congestion and haemorrhages were marked. The liver cells showed degeneration which progressed from hydropic to fatty. The succinic dehydrogenase activity of damaged cells was decreased, while the phosphatase activity was increased. The parasites were seen in some liver cells. Marked cellular infiltration was observed around the blood vessels in the form of granulomata. The reticuloendothelial cells, Kupffer cells and phagocytes showed higher alkaline phosphatase activity. In chronic infection the thymus showed early lymphocytic depletion then returned to normal. The splenic weight was increased and the follicles were enlarged with the presence of immunoblasts in the germinal centres. The cords of the red pulp were thickened and contained numerous plasma cells. Most of the liver cells were normal with normal enzymatic activity but small foci of necrosis were seen. There was a gradual increase in antibody response in both acute and chronic infections. It was concluded from the results that acute infection mainly produced toxic effects, whereas chronic infection produced immunological responses.