Experimental trichinosis: parasitological, electrophysiological and biochemical studies

Trichinosis is a parasitic infection affecting the gut and the muscles causing mild gastrointestinal symptoms followed by periorbital oedema, muscle pains, fever and eosinophilia. The infection evokes functional disturbances in physiological effector systems. Furthermore, several biochemical changes are associated with the infection. Therefore, this work was carried out to study the electrophysiological changes in intestine, striated and cardiac muscles by electromyography [EMG] and to assess the biochemical changes through measurement of serum cholinesterase and intestinal myeloperoxidase activity [MPO] in both light and heavy infected experimental animals by Trichinella spiralis [T. spiralis]. Electrophysiological results showed increased contractility of the smooth muscle layers of the intestine only early in the infection, whereas both striated and cardiac muscles showed increase in the contractility with the progress of infection in both light and heavy infection. Significant myocardial dysfunction in the form of bradycardia, in addition to major histopathological changes in the heart occurred from the beginning of the infection and increased till the end of the study. Biochemical study showed gradual increase in serum cholinesterase, while, the intestinal MPO showed increase only in the early stage of the infection. It was noticed that all changes were more pronounced in the heavily infected group than the lightly infected one

comparative efficacy study of praziquantel and albendazole treatment in experimental schistosomiasis

The currently used drug for chemotherapeutic control of schistosomiasis is praziquantel [PZQ]. Albendazole is a broad spectrum antiparasitic drug that showed trematocidal activity. The present study aimed at testing the effect of albendazole on experimental schistosomiasis mansoni infection using PZQ as therapeutic control. Swiss strain albino mice were infected with Schistosoma mansoni [S. mansoni] cercariae. Drugs were given orally on the 45[th] day post infection [PI] for 2 successive days. Mice were sacrificed on the 47[th] day PI and subjected to parasitological and scanning electron microscopic [SEM] studies. Albendazole caused a significant reduction in worm load and those recovered were shorter as measured by the camera lucida. By SEM, perfused S. mansoni albendazole treated worms showed surface tegumental changes. Albendazole is a promising drug for treatment of schistosomiasis

Effect of topical agents on cercariae of schistosoma mansoni

The present work was planed to evaluate the effect of free N, N- diethyl-m- toluamide [DEET], controlled release DEET and white precipitate ointment on the viability of cercariae of S. mansoni in vitro. They were also topically applied to mice to study their efficiency in preventing cercarial skin penetration. Free DEET and controlled release DEET formula caused immobilization and death of cercariae within 20 and 5 min, respectively. The number of adults detected after the application of free DEET and white precipitate ointment to mice skin prior to infection were significantly lower than the control group. When controlled release DEET was applied, no adults could be detected, indicating the failure of cercariae to enter through the skin. This was confirmed by histopathological study of the liver which was free of granuloma. Scanning electron microscopy revealed tegumental changes in cercariae exposed to both free DEET and controlled released DEET. So, topical application of any of the three chemicals was found to be effective in controlling S. mansoni infection. The best was with controlled release DEET

Vaccination trial against experimental trichinellosis using autoclaved trichinella spiralis larvae vaccine [ATSLV]

The autoclaved Trichinella spiralis larvae vaccine [ATSLV] was tested and showed unpredictable effect on the immune system of mice experimentally infected with T. spiralis. The vaccine was given with Bacillus Calmette-Guerin [BCG] as an adjuvant at different durations and by different routes of administration. The best result was achieved by given the vaccine twice intradermally with two-week interval as evidenced by a significant reduction in adult and larval count, as well as reproductive capacity index. Histopathologically, there was a significant reduction in the number of the encysted larvae, which showed degeneration and hyalinization of the cyst wall accompanied by early pericystic fibrosis

Further studies an antoclaved cercarial vaccine against Schistosomasis: Safety, longevity and stability

This study was performed to adjust the dose and to assess vaccine safety, longevity and stability as well as the possibility of transplacental transmission of immune response from pregnant mice to their offspring. The results showed that two doses of the lowest most effective concentration of autoclaved cercarial vaccine [ACV] that achieved the high percentage reduction of worm burden were safe as demonstrated by the absence of any local or systemic side effects, normal blood picture and normal liver and kidney function tests. ACV is stable when kept either at 4C for 6 months or at-35C for up to 12 months and it offers a considerable duration of longevity. The offspring of vaccinated mothers did not show any signs of protection against challenge infection

In-pouch TV culture system in diagnosis of trichomonas vaginalis infection

A newly simplified culture method, the In-Pouch TV culture system, the wet mount [WM] examination and the acridine orange stain were compared with the Oxoid culture as a standard technique in the diagnosis of trichomoniasis. Out of 70 symptomatic cases enrolled in this study, 28 specimens were positive by all methods. Among these positive specimens, 21 were positive by the Oxoid culture [75%] and 24 [85.7%] with sensitivity of 85.7% by the In-Pouch system. Both wet mount preparation and acridine orange stain had less sensitivity than the In-Pouch system [61.9%] and detected 15[53.6%] and 16 [57.1%] of the cases respectively. The In-Pouch system has been proved to be easier in the transport and culture technique than the ordinary culture method. It alleviates the need to enter the culture, thus prevents contamination. Its cost is comparable to the ordinary culture tube. Therefore, it is recommended to use the In-Pouch culture system as a method of diagnosing trichomoniasis

Studies on experimental mixed infection of schistosoma haematobium and schistosoma mansoni

Swiss albino mice have been infected with S. hematobium and challenged four weeks later with S. mansoni. Parasitological, pathological and ultrastructural studies were done. The results revealed cross mating between the two species. A reduction in S. mansoni worm load, egg count, hepatic granuloma number and size was noticed. The presence of heterologous immunity was suggested

Differential study of two strains of Toxoplasma gondii

This study aimed to differentiate between the virulent and avirulent strains of T. gondii by studying morphometric measurement using CIAS, determination of the relative DNA content and extract, SDS poly acrylamide gel electrophoresis and isoenzyme on cellulose acetate gel. Identifying these differences may be useful in studying different disease types and in pathogenic mechanisms. Besides, the presence of common proteins between them may be of value for diagnostic purposes and for formulation of vaccines

Frequency of entamoeba gingivalis among periodontal patients under chemotherapy

The present study was carried out to investigate the frequency of Entamoeba gingivalis in the gingival crevices of dental patients with advanced periodontitis compared to normal subjects. The effect of metronidazole on this protozoa was also investigated in patients receiving chemotherapeutic agents. Histological sections were studied to determine the location of E. gingivalis in the gingival tissue. The results revealed that in patients with periodontitis E. gingivalis was found to be 64% before treatment and 26% after metronidazole treatment with a decrease of 38%. In cases under chemotherapeutic agents the percentage was 58%, while it was only 34% in the control group. Histological sections revealed that E. gingivalis was not observed within the gingival epithelium, but was observed within plaque or cellular debris adjacent to sulcular epithelium

Frequency of entamoeba gingivalis among periodontitis and patient under chemotherapy

This study was carried out to investigate the frequency of E. gingivalis in the gingival crevices of patients with periodontitis compared with normal subjects. Flagyl therapy was tried in cases with periodontitis. Also, the frequency of this amoeba was investigated in patients receiving chemotherapy to be compared with normal subjects. The results revealed that higher frequency was observed in patients with periodontitis and flagyl therapy reduced this frequency. Cases under chemotherapy showed higher frequency than the normal control. Histopathological sections from the gingiva of periodontitis patients did not show any amoeba invading the tissue

protective role of fasciola tegument antigen against trichinella spiralis infection

Fasciola gigantica tegument antigen was prepared to be used for induction of immunity against Trichinella spiralis in albino mice. The results of the study showed that the antigen was more effective when administered in a dose of 3 ug than in a dose of 30 ug. This was evidenced by the reduction in adult count 72%, adult length 61.4%, larval count 78.7%, length of muscle larvae 32.2%, and the significant reduction in reproductive capacity index

Maternal transfer of resistance to schistosoma mansoni in offspring born to trichinella-infected mice

This study was performed to investigate the presence of maternal transfer of resistance to S. mansoni in mice born to Trichinella-infected mothers T. spiralis-born mice were infected with S. mansoni cercariae. Parasitological study was done at eight and twelve weeks post-schistosomal infection. There was a significant reduction in the number of schistosomes [44.4%], in the liver egg count [38.9%] and in the intestinal egg count [50.46%]. Histopathologically, there was a reduction in the number and size of granulomata at the different time intervals as well as acceleration in the inflammatory reaction

Heterophyids: experimental chemotherapy and immunotherapy

Heavy infections with the tiny flukes heterophyids can cause intestinal pain and mucous diarrhea, thus the study of praziquantel [Pzq] and the new drug cyclosporin A [CsA] as antiparasitic drugs, were undertaken in this work, as well as the effect of matecercarial and adult antigens as immunizing agents. To assess the result of the work, the number and length of the recovered heterophyids were studied. Description of the surface by SEM was carried out for the groups; treated by cyclosporin A and immunized by adult heterophyid antigen [third fraction] which gave the highest percentage reduction

Cyclosporine A in experimental trichinosis scanning electron microscopic study

The surface morphology of adult and larvae of Trichinella spiralis after cyclosporin A treatment was studied by scanning electron microscopy [SEM] of fixed, dried and metal coated specimens. The earliest topographic changes revealed in adults after the drug treatment were in form of disorganization of the cuticle, especially between the hypodermal pores which appeared somewhat thickened and irregular. Other changes were in the form of bullae formation covering the whole width of the adult surface. Other specimens showed wrinkling of the outer layer that was seen later to peel off. In few worms, layer outer was damaged, releasing some of the internal organs. Smoothening of the cuticle with obliteration of the grooves between the cuticular ridges were observed as the earliest surface larval changes, ulcer formation which was deeply seated was seen in patchy areas in some specimens. The interaction between the parasite surface and the drug is of significant importance, as this can throw light on the possibilities of its mode of action

Cyclosporine A in experimental trichinosis: parasitological study

During the last few years, antiparasitic effects has been related to the immunosuppressant cyclosporin A [CsA]. This work was planned to study the effect of this drug against different aspects of experimental trichinosis. The work included three experiments. The first experiment was to study the effect of [CsA] on infection when administered to mice at different durations i.e. post infection as well as before and on the same day of infection. It proved to be most effective when given on the same day of infection as evidenced by the significant reduction in adult count, length of female, larval count and index of reproductive capacity [RCI]. However, the effect though still significant, diminished when the drug was given pre- and post- infection. The second experiment was to study the effect of [CsA] on infectivity of the T. spiralis larvae treated either in vivo or in vitro. The results showed that the drug has marked effect in that part of the study as shown by the reduction in all parameters of assessment .The third experiment demonstrated the challenge that followed [CsA] treated primary compared to that of non treated one. Results showed significant reduction in all values. These results evoke ideas for further designs of other treatment and control stratigies for the disease