Potential relation ibetween the appearance of biomphalaria alexandrina- biomphalaria glabrata hybrid in the irrigation system and the evolution of resistance to praziquntel lyeatment in Egypt

In the last decade, partial resistance to Praziquantel [PZQ] in treatment of schistosomiasis appeared in some villages in Egypt. This happened following the invasion of the irrigation system by hybrid snails of the indigenous, vector snail Biomphalaria alexandrina and the introduced Biomphalaria glabrata. The objective of this study was to investigate if the distribution of the hybrid snails in the irrigation system represents a factor, between others, which is related to the appearance of [PZQ] resistance. Therefore, three groups of mice were infected with Schistosoma mansoni cercariae obtained from infected B. alexandrina, B.glabrata and hybrid snails. Six weeks later, the animals were treated with.the usual curative dose of PZQ [500mg/kg body weight for two consecutive days] and sacrificed two weeks post-treatment. The results showed that worms reduction in the group infected with cercariae from hybrid snails was significantly less than that in the other two groups 86.1% versus 95.1% and 92.8%, respectively. The number of dead ova in the same group was also less, being 81.5% versus 97.5%, and 95.1% respectively. The numbers of ova/g liver was 56.6%, in the same group while 64.2 and 70.9 in the other two groups. The reduction in numbers of ova/g intestine was 81.9% in this group versus 86.1% and 88.4% in the other two groups.The present results give indication that the appearance of PZQ resistance against schistosomiasis in Egypt may return at least partially to the wide distribution of the hybrid Biomphalaria snails in this country

Fascioliasis and bacterobilia in experimentally and naturally infected animals

Fascioliasis is a well known veterinary problem in sheep raising countries and is to date an important human disease. In Africa, the highest prevalence was recorded in Egypt especially in communities living in the Nile Delta. This study investigated the relationship between fascioliasis and presence of the pathogenic bacteria, and its effect on the liver and gall bladder. Six sheep were orally infected with 150 Fasciola metacercariae. Four months later, the sheep were slaughtered and number of worms, number of ova/gm feces and number of ova/mi bile solutions were estimated. Blood and bile samples from the infected sheep and 4 control non-infected sheep were collected for liver enzymes estimation and bile culture for microbiological pathogens. Meanwhile, 6 control non-infected and 14 naturally infected samples [blood and bile] from sheep and cattle were collected from the slaughter house at El-Warrak, Imbaba. Worm burden, number of ova/mi bile, liver enzymes and bile culture were estimated in the naturally infected and control non-infected cattle and sheep. Changes in liver and gall bladder tissues of all animals were examined by transmission electron microscope. In experimentally infected sheep, numbers of worm burden, ova/gm stool and ova/nil bile were 48+4.3, 473+89 and 4439+632 respectively and their bacteriological bile cultures revealed Eseherichia Coli only in 4 sheep. In the naturally infected sheep and cattle, worm burden was 107+6.2 and number of ova/mI bile was 9 176+870 and the bacteriological bile culture revealed E. co/i [50%], Klebsiella pneumonia [3 0%], Pseudomonas [8%], Proteus [5%], and 7% of bile cultures were with no growth. There was a significant increase in serum level of GPT, GOT and GGT and ALP in infected sheep and cattle when compared with uninfected control. Transmission electron microscopic examination revealed significant damage indicated by the appearance of collagen bundles, swollen mitochondria and fragmented condensed nuclear chromatin, especially on the irregular nuclear membrane when compared with uninfected control. This study is of value in endemic areas, where possibility of bacterial co-infection with Fasciola is a common occurrence