Histochemical effects of some biological agents on culex pipiens larvae

The histochemical effects of the lethal concentration that kills 50% of larvae [LC[50]] of three biological agents, abamectin, Bacillus thuringiensis and spinosad on the carbohydrates [polysaccharides], proteins, nucleic acids and lipids content of the midgut and fat bodies of Culex pipiens 2[nd] instar larvae were studied. The results showed that the three tested compounds reduced the carbohydrates [polysaccharides], proteins, RNA synthesis and lipids content after 72 hours of treatment where abamectin was the most effective followed by Bacillus thuringiensis then spinosad

Use of multiplex PCR in the differential detection of Entamoeba histolytica and/or Entamoeba dispar in comparison to microscopic examination

Intestinal amoebiasis, caused by E. histolytica, is a major public health problem in developing countries. E. dispar is morphologically identical to E. histolytica, but is considered a commensal protozoan. Differential identification of E. histolytica and/or E. dispar is important for treatment and epidemiological studies of intestinal amoebiasis. To evaluate multiplex PCR in the differential detection of E. histolytica and/or E. dispar in comparison to conventional microscopic stool examination. The present study was performed on 100 individuals. They were divided into symptomatic and asymptomatic groups according to the presence or absence of symptoms and signs of intestinal amoebiasis. Stool samples were collected and subjected to microscopic examination of fresh preparations of direct wet mount and formalin diethyl ether concentrates, and of permanent preparations stained by trichrome, in addition to molecular assay using multiplex PCR. Percentage detection of Entamoeba species was highest by multiplex PCR [36%] and lowest by direct wet mount [25%]. Multiplex PCR detected E. histolytica in 25%, E. dispar in 41.7% and mixed infection in 33.3% of cases. The sensitivity of PCR was 96.4% compared with the trichrome stain [75%]. Multiplex PCR was more sensitive than the conventional microscopic techniques in the differential detection of E. histolytica and/or E. dispar, at the same time and in a single PCR round

Worm and larval burden, histopathological and ultrastructural evaluation of T spiralis vaccination using crude worms and/or larvae antigens: experimental studies

Currently, there is no vaccine for T spiralis; however, several studies have been made towards understanding the immune mechanisms that contribute to host protection against it. The aim of the present study is to evaluate the protective effect of vaccination by T spiralis adult, larval and combinea adult and larval crude antigens against trichinellosis in experimental mice. Swiss male albino mice [No. = 125] were divided mm 5 groups. Groups A, h and C were immunized by T spiralis crude larval antigen, crude worm antigen, and combined larval and worm antigens, respectively. One week after the last dose of injection, each mouse was injected orally with 150-200 larvae. Two other groups [D and E] served as infected non immunized control groups. Group E. received adjuvant and phosphate buffer saline before infection. At the 8tn day post-infection [PI], 12 mice from each group were sacrificed and the intestinal worm burden was assessed, while the muscle larval burden was evaluated at 28th day P1 in the remaining mice of each group. Intestinal and skeletal muscle specimens were prepared for histopathological study. Meanwhile, adults and larvae were examined by scanning electron microscopic [SEM] and infected muscle sections were examined by transmission electron microscope [TEM]. Combined antigen gave the highest reduction% in intestinal worm and larval muscle burdens 92% and 96%, respectively], followed by larval antigen [86% and 91%], then worm antigen [73% and 88%], compared with infected non immunized control groups. Compared with groups [A and B], group C gave significant reduction in both intestinal and muscle burdens. Histopathological examination revealed marked decrease in intestinal inflammatory infiltrates, and marked reduction of encysted larvae with mild infiltration around the degenerated larvae in mice of group C. SEM and TEM results confirmed the significant effect of the combined vaccine [Group C]. Vaccination with combined worms and larval antigens gave the most protective action against T spiralis challenge infection. The use of combined antigen in mass vaccination of reservoir animals may decrease the risk of human infection