Intestinal spore-forming protozoa among patients suffering from chronic renal failure.

Cryptosporidium parvum, Isospora belli, Cyclospora cayetanensis and Microsporidia are four intestinal spore-forming protozoa that cause diarrhoea in immuno-competent individuals and immuno-suppressed patients. Fresh stool samples were obtained from 120 patients suffering from CRF and attending the Dialysis Unit of Zagazig University Hospital. Also, stool samples were obtained from 40 immuno-competent individuals complaining of diarrhoea (control group). The stool samples were examined by direct smear and formol-ether concentration methods then stained by Giemsa, Modified Ziehl Neelsen (MZN) and Aniline carbol methyl violet stains. The four intestinal spore-forming protozoa were detected in 40/120 (33.3%) of patients with CRF and in 2/40 (5.0%) of the control group with a statistically highly significant difference (P < 0.001). C. parvum, Microsporidia, C. cayetanensis and I. belli were detected in 18/120 (15%), 10/120 (8.3%), 9/120 (7.5%) and 3/120 (2.5%), respectively. The four protozoa were found as mixed infections with other pathogens or as single infections confirming their role alone as a cause of diarrhoea. MZN stain was the most efficient simple, and not expensive.

Specific anti-Toxoplasma antibodies in relation to infection and reinfection using different infective stages.

The possibility of rat re-infection with different Toxoplasma gondii stages was studied in this work. Two groups of rats were infected with either intra-peritoneal injection of 1000 trophozoites of virulent Toxoplasma strain or 1000 oocysts through oral routes. IgA, IgM and IgG were detected 15, 30, 60 and 120 days post infections. IgA and IgM appeared as early as 15 days post infection but declined afterwards. IgA antibody response was more prominent with oocyst infection and IgM was more prominent with tachyzoite infection with insignificant statistical difference. On the other hand, IgG started to increase 60 days post infection, then increased gradually till the end of the experiment (120 days). The primary orally infected rats were either re-infected orally with oocysts or intra-peritoneal trophozoites and re-examined after 15 and 120 days for the same immunological parameters. Those rats which primary infected with intra-peritoneal trophozoites were re-examined after oral infection with oocysts or injection of trophozoites intra-peritoneal. The level of IgA and IgM in one rat of group A and 2 rats of group B were significantly increased and this occurred in presence of anti-Toxoplasma IgG from the primary infection. In this study, the rats were lab-bred so, the factors affect the immune system could be under control, also strain variability was excluded as the infection was only by one strain, and as the IgG level was high, these rats were presumed to be immune from the primary infection. So, the rats which became positive after challenge most probably re-infected.

P 53 suppressor gene and cathepsin D expression in correlation with cellular and humoral immunity in cutaneous leishmaniasis.

A total of fifteen clinically and parasitologically proven adult cases of cutaneous leishmaniasis were studied for the demonstration of premalignant factor(s). The levels of antibodies against Leishmania parasite were measured with the indirect haemagglutination test (IHAT) and evaluated with the results of lymphoblast transformation test (LTT), a tumour suppressor gene (P53) and an asportic proteinase enzyme (Cathepsin D). Three patients (females) refused to be biopsied. The results showed a direct correlation between elevation of IHAT in 7/12 patients (Titers 1/128 to 1/512) and elevation of LTT in 7/12 patients (82 to 90%). On the other hand, two males with low (?) seropositive IHAT (1/64) and low LTT (20 & 40%) gave positive P53 antibody and moderate (1) and marked (1) degrees Cathepsin D. So, it is concluded that cutaneous leishmaniasis infection particularly chronic one favours the premalignant changes in the granulomatous lesions.