Silver nanoparticles as a therapeutic agent in experimental cyclosporiasis.

Cyclosporiasis is an emerging worldwide infection caused by an obligate intracellular protozoan parasite, Cyclospora cayetanensis. In immunocompetent patients, it is mainly manifested by self-limited diarrhea, which is persistent and may be fatal in immunocompromised patients. The standard treatment for cyclosporiasis is a combination of two antibiotics, trimethoprim and sulfamethoxazole. Gastrointestinal, haematologic and renal side effects were reported with this combination. Moreover, sulfa allergy, foetal anomalies and recurrence were recorded with no alternative drug treatment option. In this study, silver nanoparticles were chemically synthesized to be evaluated for the first time for their anti-cyclospora effects in both immunocompetent and immunosuppressed experimental mice in comparison to the standard treatment. The effect of silver nanoparticles was assessed through studying stool oocyst load, oocyst viability, ultrastructural changes in oocysts, and estimation of serum gamma interferon. Toxic effect of the therapeutic agents was evaluated by measuring liver enzymes, urea and creatinine in mouse sera. Results showed that silver nanoparticles had promising anti-cyclospora potentials. The animals that received these nanoparticles showed a statistically significant decrease in the oocyst burden and number of viable oocysts in stool and a statistically significant increase in serum gamma interferon in comparison to the corresponding group receiving the standard treatment and to the infected non-treated control group. Scanning electron microscopic examination revealed mutilated oocysts with irregularities, poring and perforations. Biochemical results showed no evidence of toxicity of silver nanoparticles, as the sera of the mice showed a statistically non-significant decrease in liver enzymes in immunocompetent subgroups, and a statistically significant decrease in immunosuppressed subgroups. Furthermore, a statistically non-significant decrease in urea and creatinine was recorded in all subgroups. Thus, silver nanoparticles proved their effectiveness against Cyclospora infection, and this will draw the attention to its use as an alternative to the standard therapy.

Synthesis of some new benzothiazole derivatives as potential antimicrobial and antiparasitic agents.

Several thiazolidinonyl benzothiazoles 8a-b and thiazolinylbenzothiazoles 9a-j were synthesized by the reaction of 2-(N-substituted thiocarbamoyl hydrazino) benzothiazoles 7a-d with chloroacetic acid or phenacyl bromide respectively. The intermediate compounds 7a-d were prepared in a good yield by the reaction of 2-hydrazinobenzothiazole (6) with phenylisothiocyanates. Synthesis of hydrazones 10a-c were performed by the reaction of 6 with the corresponding aldehydes. Trials to cyclize the obtained hydrazones 10a-c into the corresponding triazolo derivatives 11a-c were unsuccessful. Addition of 4-morphylino carbonyl chloride to compound 6 yielded the corresponding 2-acid hydrazide derivative 12. Some of the prepared compounds were screened for their anti-parasitic activity. Most of them showed reasonable antinematodal or schistosomicidal activity. In addition, antimicrobial screening of all of the prepared new compounds was performed against Staphylococcus aeurus ATCC 6538, Escherichia coli ATCC 8735 and Candida albicans ATCC 10321 but non of them was active.

Diagnosis of toxoplasmosis in immunosuppressed mice using the polymerase chain reaction (PCR) and the enzyme linked immuno-sorbent assay (ELISA) techniques.

In the present study, Toxoplasma infection with the virulent and avirulent strains in both immunocompetent and immunosuppressed mice was diagnosed using the MDS ELISA for detection of CA in sera and the PCR for demonstration of DNA in livers, brains and mononuclear cells of blood. Both techniques proved to be convenient, especially in immunosuppressed mice.

A study on patients with eosinophilia of suspected parasitic origin.

A study of 53 patients with eosinophilia of suspected parasitic origin was conducted. Investigations done for each case included, stool and urine examinations, absolute eosinophilic count and countercurrent immunoelectrophoresis (CIEP) using crude antigens of Fasciola hepatica, Schistosoma mansoni worms, Trichinella spiralis and Toxocara canis larvae, and hydatid fluid. Stool examination revealed six cases with Fasciola eggs, two with Ascaris lumbricoides and one with S. mansoni eggs. The eosinophilic count ranged from 682 to 10560 cell/mm3. 26 cases showed mild eosinophilia, 24 moderate and three marked eosinophilia. Out of the 53 cases examined by the CIEPT, 30 were positive with Fasciola antigen. Their eosinophilic count ranged from 770 to 10560 cell/mm3. Six cases were positive with hydatid antigen and had an eosinophilic count ranging from 825 to 2970 cell/mm3. Only one case was positive with S. mansoni antigen and its eosinophilic count was 935 cell/mm3. 16 cases were negative with the different antigens used and their eosinophilic count ranged from 682 to 2200 cell/mm3.