Fatty acids contents in biomphalaria Alexandrina during the course of infection with schistosoma mansoni

The study examined the effects of larval trematode infection on the neutral lipid and phospholipid content of Biomphalaria alexandrina infected with Schistosoma mansoni. Uninfected snails were used as matched controls. As determined by qualitative high-performance silica gel thin-layer chromatography [HPTLC], the major neutral lipids present in the whole bodies and digestive gland-gonad complexes in both infected and uninfected snail populations were free sterols, free fatty acids, and triacylglycerols, and the major polar lipids were phosphatidylcho-line and phosphatidyl ethanolamine. Quantitative analysis by HPTLC with visible and UV scanning reflectance densitometry showed the snail's digestive gland lipid level was found to be almost halved in 20 days post infection; a more then 80% reduction being visible after the subsequent 40 and 60 days

The relationship between genetic variability and the susceptibility of Biomphalaria alexandrina snails to Schistosoma mansoni infection

In the present study, Biomphalaria snails collected from five Egyptian governorates (Giza, Fayoum, Kafr El-Sheikh, Ismailia and Damietta), as well as reference control Biomphalaria alexandrina snails from the Schistosome Biological Supply Center (SBSC) (Theodor Bilharz Research Institute, Egypt), were subjected to species-specific polymerase chain reaction (PCR) assays to identify the collected species. All of the collected snails were found to be B. alexandrina and there was no evidence of the presence of Biomphalaria glabrata. Randomly amplified polymorphic DNA (RAPD)-PCR assays showed different fingerprints with varying numbers of bands for the first generation (F1) of B. alexandrina snail populations (SBSC, Giza, Fayoum, Kafr El-Sheikh, Ismailia and Damietta). The primer OPA-1 produced the highest level of polymorphism and amplified the greatest number of specific bands. The estimated similarity coefficients among the B. alexandrina populations based on the RAPD-PCR profiles ranged from 0.56 (between SBSC and Ismailia snails) to 0.72 (between Ismailia and Kafr El-Sheikh snails). Experimental infection of the F1 of progeny from the collected snails with Schistosoma mansoni (SBSC strain) showed variable susceptibility rates ranging from 15% in the Fayoum snail group to 50.3% in SBSC snails. A negative correlation was observed between the infection rates in the different snail groups and the distances separating their corresponding governorates from the parasite source. The infection rates of the snail groups and their similarity coefficients with SBSC B. alexandrina snails were positively correlated. The variations in the rates of infection of different B. alexandrina groups with S. mansoni, as well as the differences in the similarity coefficients among these snails, are dependent not only on the geographical distribution of the snails and the parasite, but also on the genetic variability of the snails. Introduction of this variability into endemic areas may reduce the ability of the parasite to infect local hosts and consequently reduce schistosomiasis epidemiology.

Molluscicidal effect of three monoterpenes oils on schistosomiasis and fascioliasis vector snails in Egypt

Thymol, Linalool and Eugenol showed considerable molluscicidal effect against Biomphalaria alexandrina, Bulinus trancatus and Lymneae natalensis. The thymol was the potent one at least LC 50 and LC 90 followed by euganol then linalool. L. natalensis were mole sensitive to these compounds followed by B. truncatus and then B. alexandrina. The LC 50 and LC 90 of thymol were 22 and 34 ppm against B. alexandrina, 20 and 30 ppm for B. truncatus and 1 8 and 29 ppm for L. natalensis. These values were higher with Eugenol, 28 and 48 ppm for B. alexnadrina, 24 and 44 ppm for B. truncatus and 22 and 40 ppm for L. natalensis. Linalool showed highest values of LC 50 and LC 90 against B. alexandrina, 34 and 56 ppm, against B. truncatus 30 and 52 ppm and for L. natalensis 28 and 48 ppm, respectively. Maintaining of B. alexandrina at LC 10 of Thymol for one week induced an inhibitory effect in the level of some enzymes [AchE, SDH]. It led to increase in the activity of other enzymes [ACP, ALP and G-6-PD]. Acetylcholine-sterase activity [AchE] of treated B. alexandrina was significantly reduced by 45.9% when compared to control. The results showed a significant decrease in succinate dehydrogenase activity [SDH] by 46.4% together with a concomitant increase in glucose-6-phosphate dehydrogenase activity level [G-6-PD] by 47.5% in comparison with control. The activities of acid phosphatase and alkaline phosphatase enzymes were found to be higher in the treated snails than in control ones. The percentage increases were 47.2% and 73.2% respectively. The results also showed an elevation in the hemolymph glucose content of treated snails by 51.9% while the tissue glycogen content was reduced by 48.1%. The infection of B. alexandrina with S. mansoni miracidia was greatly reduced by thymol LC 10 [sublethal dose]. The infection rate reduction was 43.1%. The treated snails' prepatent period was prolonged [34.2 +/- 3.3 days] compared to control [28.4 +/- 1.2 days]. A highly significant reduction of total cercarial production per snail occurred in experimental snails as compared to control

Effect of the pesticides carbofuran [Carbamate] and Profenophos [Organophosphorus] on Biomphalaria alexandrina and on its infection with Schistosoma mansoni miracidia

Carbofuran [carbamate pesticide] and Profenophos [organophosphorus pesticide] showed molluscicidal effect on Biomphalaria alexandrina snails, with the LC[50] 1.42 ppm and 1.29 ppm, respectively Maintaining Biomphalaria alexandrina at sublethal concentrations of these compounds [0.5, 0.75, and 1.0 ppm] reduced the snail survival rate and net reproductive rate [R[0]] [E L[x]M[x]] compared with the control snail group. The percentage reduction in R[0] was 86.9, 90.8, and 93.9 for the tested concentrations of Carbofuran and 86.8, 82.9 and 88.5 for the tested concentrations of Profenophos, respectively. The susceptibility of Biomphalaria snails to infection with Schistosoma mansoni miracidia and further infectivity of this parasite were also reduced. Increasing the pesticide concentration increased the magnitude of reduction reaching 80.7% and 89.3% for the two pesticides, respectively. Pesticide may be considered one of the factors contributing in the disappearance of snail vectors on reaching water bodies as residues from pesticidal activities and consequently hindering schistosomiasis transmission

Immune dysfunction in Egyptian children with Down syndrome

Children with Down syndrome [DS] have an increased rate of infection and it has been proposed that this is secondary to derangements of the immune system. Multiple immunologic disturbances were commonly observed in individuals with DS including abnormal proportions of peripheral lymphocytes subsets, cellular dysfunction and others. The present study was conducted on 20 children with Down syndrome. Sex distribution was 9 males to 11 females [1: 1.2] with age ranging from 1 month to 11 years [average 25.9 +/- 31.7 months]. Control group of 15 healthy children matched for age and sex were included. Karyotype by a standard technique, evaluation of the immune system by flow cytometry and estimation of serum cytokines [interleukin-1 Beta [IL-1Beta], interleukln-2 [lL-2] and tumour necrosis factor alpha [TNF-alpha]] were carried out. A Significant decrease of the absolute number of circulating lymphocytes, a marked significant decrease of B-lymphocytes and drarratic modifications of the T-cell subsets were observed. T-cell subpopulation studies revealed marked decrease in CD4+ subpopulation has been documented with inverted CD4/CD8 ratio, whereas CD8+ cells increased significantly in percentage. A derangement of cells bearing markers associated with natural killing [NK] activity such as CD19+ and CD56+ was observed. Among the most important alterations are the presence of a high number of CD56+ lymphocytes and significantly high percent of CD56+ CD8+ T cells. Regarding cytokine production, it was found that serum IL-2 levels were significantly decreased in DS children compared to the control group and its production was correlated inversely with age. On the other hand; lL-1Beta and TNF-alpha levels in DS Children showed no significant difference compared to normal subjects. We concluded that thymic alterations and molecular abnormalities due to gene over-expression of loci located on Chromosome 21 could be involved. On the other hand, the increased percent of CD56+ CD8+ T cells; as potent antitumour immunity; is emphasizing how rare are solid tumours in DS patients

Effects of double infection with Echinostoma liei and Schistosoma mansoni on hemoglobin content and circulating hemocytes in the hemolymph of the host snail Biomphalaria Alexandria

Three groups of hemocyte cells were identified in the hemolymph of B. alexandrina snails. These are granulocytes, hyalinocytes and undifferentiated [round] cells. Granulocytes are most common. Exposure of B. alexandrina to S. mansoni and E. Liei miracidia significantly increased the number of circulating hemocytes in one-week post miracidial exposure. Meanwhile, the increase in cell number counted at two and three weeks post exposure was not statistically significant. The percentage of hemocyte categories were changed in the exposed groups of snails one week and two-weeks post exposure. In one week post exposure group, snails had significantly higher percentages of undifferentiated cells than controls. While, in two weeks post miracidial exposure group, the percentage of granulocytes significantly increased. Infection of B. alexandrina with S. mansoni and E. liei significantly reduced the hemoglobin content in their hemolymph during first-, second and third weeks post miracidial exposure

Effect of infection with fasciola gigantica on protein, lipid contact and some enzymes of the intermediate host snail lymneae natalensis

Total protein and lipid contents were estimated in hemolymph of Lymnaea natalensis snails infected with Fasciola gigantica. There was significant reduction in total protein content, while the lipid content in infected snails showed a significant elevation. Also, there was a significant increase in the activity of hexokinase [HK] by 48.9% and glucose phosphate isomerase [GPI] by 40% and a decrease in lactate dehydrogenase [LDH] by 53.7% in infected snails when compared to control snail group