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Papers by RAAFAT MOHAMED

Egypt, Arab Republic of - MIDDLE EAST AND NORTH AFRICA- P145699- Strengthening Social Safety Net Project - Procurement Plan

Journal of Parasitic Diseases, 2020

Blastocystis sp. is a group of anaerobic protozoa parasitizing the gastrointestinal tract of huma... more Blastocystis sp. is a group of anaerobic protozoa parasitizing the gastrointestinal tract of humans and a broad variety of animals. Evidences of Blastocystis parasites resistance development to antiprotozoal drugs urge the exploration of new therapeutics. Antiprotozoal potential of Salvadora persica, a medicinal plant traditionally used for oral hygiene, was evaluated in vitro against Blastocystis sp. human isolates. Until now, no study has described the effect of S. persica extracts on this parasitic protozoa. Blastocystis sp. positive stool samples collected from patients with gastrointestinal complaints and asymptomatic individuals diagnosed by microscopy were furthermore cultured in vitro and characterized by PCR and multiplex-PCR using sequence-tagged-site primers to determine their subtypes. Out of 21 Blastocystis sp. isolates, five were determined as ST1, 14 as ST3, and two as ST5 subtypes. Antiprotozoal activity of untreated and heat-treated S. persica roots aqueous extracts was evaluated in vitro by serial dilutions on three Blastocystis sp. subtypes; ST1, ST3, and ST5 isolated from symptomatic patients. A significant killing activity was observed with both, untreated and heattreated aqueous extracts of S. persica at minimal concentration of 2.5 ll/ml compared to parasites' growth controls (P \ 0.05). Maximal antiprotozoal effect was reached at a concentration of 20 ll/ml of S. persica aqueous extract. Means of growth inhibition effect obtained with untreated and heat-treated extracts at 40 ll/ml against the three subtypes of Blastocystis sp. were 80% (SD 2.3) and 82% (SD 1.1), respectively. No significant difference was observed in the inhibitory effect of S. persica extracts between the three Blastocystis sp. subtypes. Aqueous extract of S. persica roots contains therefore heatstable components with significant antiprotozoal activity against Blastocystis sp. subtypes ST1, ST3, and ST5 in vitro. Further investigations are required to determine and characterize the active antiprotozoal components of S. persica roots and their evaluation in vivo.

International Journal of Zoological Research, 2017

Background and Objective: A zoonotic Trypanosoma evansi (T. evansi ) has the widest range and geo... more Background and Objective: A zoonotic Trypanosoma evansi (T. evansi ) has the widest range and geographical distribution attributed to the mechanical transmission by many vectors. Inducible nitric oxide synthase (iNOS) activation by interleukin-17 (IL-17) were expressed in mice experimentally infected with T. evansi in addition to detection of serum level of IL-17 for better understanding the roles of iNOS and IL-17 in controlling this protozoan infection. Materials and Methods: Infected group (I) mice were injected with 4.5×10 5 trypomastigotes intraperitoneally, subdivided into I-3, I-5, I-10 and I-20 subgroups (10 mice, each), then sacrificed at 3, 5, 10 and 20 days post infection (p.i.), respectively, whereas control group mice (C) were injected with saline, subdivided into C-3, C-5, C-10 and C-20 subgroups (6 mice, each) and sacrificed along the parallel infected subgroup one. Results: iNOS was immunohistochemically detected with more expression in brain and the IL-17 revealed more in spleen than liver or brain, also its serum level increased significantly with progression of the infection. There was a negative correlation between parasitemia and either iNOS or IL-17. Conclusion: Trypanosoma evansi infection caused increasing both IL-17 and iNOS expression which both were coinciding with a low number of trypomastigotes referring strongly to their roles in limiting the infection.

International Journal of TROPICAL DISEASE & Health, 2019

This work was carried out in collaboration between all authors. Author RAB designed the study and... more This work was carried out in collaboration between all authors. Author RAB designed the study and wrote the first draft of the manuscript. Author RTM performed parasites culture, DNA extraction and genotyping experiments, while authors OAA, SMH and AES performed in vitro susceptibility assays and statistical analysis. Finally author MAEB wrote the protocol, shared in molecular experiments and manuscript writing. All authors read and approved the final manuscript.

Parasites & Vectors, 2017

Background: Blastocystis is a group of cosmopolitan gastrointestinal parasite of humans and a wid... more Background: Blastocystis is a group of cosmopolitan gastrointestinal parasite of humans and a wide variety of animals. These anaerobic protozoans include more than 17 specific small-subunit ribosomal RNA subtypes, of which nine are found in humans with a variable geographical distribution. Until now, no study has described the Blastocystis subtypes present in Saudi Arabia. Methods: In total, 1,262 faecal samples were collected from patients with gastrointestinal complaints and asymptomatic individuals visiting two major hospitals. All samples were analysed by F1/R1 diagnostic PCR, microscopy and culture methods. The subtypes of Blastocystis sp. isolates were determined by the sequenced-tagged site (STS)-based method. Results: One-hundred-thirty-three positive cases were detected by F1/R1 diagnostic PCR, of which 122 were also positive by the culture method and 83 by direct microscopy. The sensitivities of direct microscopy and the culture method were 62% and 92%, respectively. Subtype (ST3) was the most prevalent (80.5%), followed by ST1 (14.5%) and ST2 (5%). ST4, ST5, ST6 and ST7 were not detected in this study. ST3 infections were significantly predominant (P < 0.05) among symptomatic patients. Conclusions: To our knowledge, this study provides the first run-through information on Blastocystis sp. epidemiology in Makkah city, revealing a rather moderate prevalence of 10.5% and the presence of three subtypes, ST1, ST2, and ST3. ST3 was the most predominant, particularly among symptomatic patients.

First Record of Indigenous Furuncular Myiasis Due to Cordylobia anthropophaga in Unusual Ecologic Niche, Makkah, Saudi Arabia

International Journal of TROPICAL DISEASE & Health, 2016

Department of Parasitology, Faculty of Medicine, Assiut University, Egypt. Department of Laborato... more Department of Parasitology, Faculty of Medicine, Assiut University, Egypt. Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah 7607, Saudi Arabia. Department of Animal Hygiene and Zoonoses, Faculty of Veterinary Medicine, Assiut University, Egypt. Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah 7607, Saudi Arabia. Department of Medical Parasitology, Faculty of Medicine, El-Minia University, Egypt. Clinical Laboratory Diagnosis, Animal Medicine, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt.

Application of adult worm and lung-stage antigens to immunize against Schistosoma mansoni using cytokines as adjuvants

Journal of the Egyptian Society of Parasitology, 2006

Different Schistosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) t... more Different Schistosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) together with different cytokine adjuvants (Interferon-gamma and Interleukin-4) were used to immunize mice against. S. mansoni. Immunization program was directed towards the production of an intense immune response together with balanced T-helper1 and T-helper2 immune responses. The goal of immunization was not only to protect from infection but also to modulate the pathology inflicted by the parasite. Parameters like adult load, egg counts, anti-Schistosoma antibody titers and liver pathology were used to evaluate the different immunization scheme. SLAP antigen has proven to be a better antigen not only in protection but also in pathology modulation. SLAP plus IFN-gamma as an adjuvant was the best immunization regimen with almost 50% protection and a remarkable resolving of parasite pathology. Unexpectedly, IL-4 had a weak but observed adjuvant protective effect. The results is a step in...

The miniature pig: a unique experimental model for Schistosoma japonicum infection

Parasitology International, 2004

As part of a search for good animal models for human schistosomiasis, two miniature pigs of the C... more As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17-20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum infection.

Parasitology Research, 2014

Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on ... more Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on earth and highly prevalent in most warm-blooded vertebrates. There are no drugs that target the chronic cyst stage of this infection; therefore, development of an effective vaccine would be an important advance in disease control. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote T-helper 1 (Th1) responses, an adjuvant activity that is desirable for vaccination against intracellular pathogen. In this study, we compare the immune responses of Toxoplasma susceptible C57BL/6 mice following intranasal and intramuscular vaccination with Toxoplasma lysate antigen (TLA) with or without CpG ODN as adjuvant. Immunized and control non-immunized mice were challenged with 85 cyst of the moderately virulent Beverley strain of T. gondii. Intranasal vaccination gave significantly a higher protection compared to other groups as indicated by prolonged survival and significantly reduced brain cyst burden (P< 0.01). Intranasal vaccination stimulated cellular immunity towards Th1 response characterized by significant INF-γ production (P<0.01). Furthermore, fecal IgA antibody levels as an indicator of mucosal immune responses were significantly higher (P<0.05) in intranasal vaccinated group before the challenge compared to all other groups. Intranasal vaccination was not able to upgrade the Th1 humoral arm. In contrast, intramuscular vaccination enhanced humoral immunity towards a type Th1 pattern characterized by a significant increase of specific IgG and Ig2a. Our results suggest that intranasal administration of CpG/TLA would provide a stable, pronounced, and effective vaccine against toxoplasmosis through stimulation of Th1 cellular immunity and mucosal IgA.

The Journal of Immunology, Dec 15, 1999

Parasitology International, 1998

In order to investigate the host immune response and to analyze the kinetics of Thl and Th2 cytok... more In order to investigate the host immune response and to analyze the kinetics of Thl and Th2 cytokine response in Schis~osomajaponi~~~ infection, C57BU6 mice were infected with 50 cercariae of a zoophilic Taiwan strain of S. juponicum and sacrificed 3 to 12 weeks later. The cytokine mRNA expressions were detected with the reverse transcription-polymerase chain reaction and the cytokine protein productions were measured by the enzyme-linked immunosorbent assay. Six cytokines: IFN-y, IL2, R-4, R-5, IL-lo, and TNF-a were evaluated. The results showed that IFN-7 mRNA level increased significantly at 3-4 wk postinfection, and started to decrease at 5 wk, reaching the preinfection level at 6 wk. The IL-4 and IL-IO mRNA levels, however, began to rise at 7 wk and reached the peak at 8 and 9 wk, then declined at 9 and 12 wk. respectively. The TNF-a response was similar to IL-IO pattern The study on cytokine protein production showed that IFN-7 is the major immune response before the egg laying. On the other hand, Th2 cytokine IL-4 is the major response after the egg laying when the production of TIN-7 is suppressed. These findings indicated that the Thl response is involved in the early stage of infection (3-5 wk), while the Th2 response and TNF-a production are the major phenomena associated with the acute stage of infection (7-12 wk)

Parasitology International, 1998

Third-stage larva of the bot-fly Gasterolthilus hoemorrtthidalis obtairled fr'ont thc stomach of-... more Third-stage larva of the bot-fly Gasterolthilus hoemorrtthidalis obtairled fr'ont thc stomach of-Egyptian equines were strrdiecl tracroscopically and by light microscope; apd for the first time by the scanning electrc.rtt nticroscope with particular reference to the anterior cephalic iegion and the nevrll, discovered sensory array of the mouth hooks, Tlre clcsign ot'thit array was cotttl.riu'c<l rvith that of larvae ol Gosterophiltts intestinalis and Gasterophilrts nasalls anrl ',vas ftrurtd to bc diffcrcnt tttairtly irr thc shape of the sensilla and the number of the angled ptates and that these fine criteria rnay be usecl to differentiate other larvac. Irr atltlitiort, ltrore dctailed clescription rvas added to the cephalic ancl caudal regions rvltich are ol'intl;ortant taxonomic value. GasteropSiline larvae are of vetcrinary anrl rttcdical irtlportance, rvitlt some httmatt creeping cutaneous nryiasis, ophtltalrnorrryiasis artd ottc reccttt rccord of intestinal myiasis.

For schistosonriasis, the development of long-lasting protective immunity through rraccination ma... more For schistosonriasis, the development of long-lasting protective immunity through rraccination may be the real solution to control the ciisease spread. The cegument which is the parasite outer coverinq serves as an interface between the host immune system and the parasite. Thus, antigens associated with the tegument have been a major focus for either vaccine development or immunodiagnostic reagents for schistosomiasis. In the present study pooled sera collected from Schistosome mansoni chronically infected patients was purified over a column made of 7-days schistosomula NP40 extract , then used to immunoscreen )" gt|l cDNA library of 7-days schistosomula , a number of cDNA clones were identified after three rounds of -.--immunoscreening and plaques purification. The isolated plaques were amplified rvith polymerase chain reaction (PCR) using I gtl I fonvard and reverse primers. The PCR products were cloned in PCRTNII plasmiC vector. Ail isolated clones were sequenced, the identified clone -s was found to encocie an alpha tubulin like gene. The

Sensitivity and specificity of vvet mount, culture and PCR in diagnosing Trichomonas vaginalis i... more Sensitivity and specificity of vvet mount, culture and PCR in diagnosing Trichomonas vaginalis infection in females attending the Running title: Sensitivity and specificity of T. vaginalis diagnostic methods Abstract Background and Objectives: Trichomoniasis affects approximately 180 million women worldwide. It cau have an atypical or even asyrnptomatic course. Therefore, to accurately diagnose this disease, microbiological investigation is necessary. The aim of

Different Sc:histosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) ... more Different Sc:histosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) together with ditferent cytokine adjuvants (lnterferon-gamma and Interleukin-4) were used to immunize mice against. S. nttutsoni.

Proteins that arc secretcd by or anchored on the surfacc of intramammalian stage of Schistosoma n... more Proteins that arc secretcd by or anchored on the surfacc of intramammalian stage of Schistosoma ntansoni are exposed to host tissucs and thus present potcnthl condldatc moleculcs for the developmcnt of nerv vaccine.

Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on ... more Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on earth and highly prevalent in most warm-blooded vertebrates. There are no drugs that target the chronic cyst stage of this infection; therefore, development of an effective vaccine would be an important advance in disease control. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote T-helper 1 (Th1) responses, an adjuvant activity that is desirable for vaccination against intracellular pathogen. In this study, we compare the immune responses of Toxoplasma susceptible C57BL/6 mice following intranasal and intramuscular vaccination with Toxoplasma lysate antigen (TLA) with or without CpG ODN as adjuvant. Immunized and control non-immunized mice were challenged with 85 cyst of the moderately virulent Beverley strain of T. gondii. Intranasal vaccination gave significantly a higher protection compared to other groups as indicated by prolonged survival and significantly reduced brain cyst burden (P< 0.01). Intranasal vaccination stimulated cellular immunity towards Th1 response characterized by significant INF-γ production (P<0.01). Furthermore, fecal IgA antibody levels as an indicator of mucosal immune responses were significantly higher (P<0.05) in intranasal vaccinated group before the challenge compared to all other groups. Intranasal vaccination was not able to upgrade the Th1 humoral arm. In contrast, intramus-cular vaccination enhanced humoral immunity towards a type Th1 pattern characterized by a significant increase of specific IgG and Ig2a. Our results suggest that intranasal administration of CpG/TLA would provide a stable, pronounced, and effective vaccine against toxoplasmosis through stimulation of Th1 cellular immunity and mucosal IgA.

As part of a search for good animal models for human schistosomiasis, two miniature pigs of the C... more As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17 – 20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum infection.

Egypt, Arab Republic of - MIDDLE EAST AND NORTH AFRICA- P145699- Strengthening Social Safety Net Project - Procurement Plan

Journal of Parasitic Diseases, 2020

Blastocystis sp. is a group of anaerobic protozoa parasitizing the gastrointestinal tract of huma... more Blastocystis sp. is a group of anaerobic protozoa parasitizing the gastrointestinal tract of humans and a broad variety of animals. Evidences of Blastocystis parasites resistance development to antiprotozoal drugs urge the exploration of new therapeutics. Antiprotozoal potential of Salvadora persica, a medicinal plant traditionally used for oral hygiene, was evaluated in vitro against Blastocystis sp. human isolates. Until now, no study has described the effect of S. persica extracts on this parasitic protozoa. Blastocystis sp. positive stool samples collected from patients with gastrointestinal complaints and asymptomatic individuals diagnosed by microscopy were furthermore cultured in vitro and characterized by PCR and multiplex-PCR using sequence-tagged-site primers to determine their subtypes. Out of 21 Blastocystis sp. isolates, five were determined as ST1, 14 as ST3, and two as ST5 subtypes. Antiprotozoal activity of untreated and heat-treated S. persica roots aqueous extracts was evaluated in vitro by serial dilutions on three Blastocystis sp. subtypes; ST1, ST3, and ST5 isolated from symptomatic patients. A significant killing activity was observed with both, untreated and heattreated aqueous extracts of S. persica at minimal concentration of 2.5 ll/ml compared to parasites' growth controls (P \ 0.05). Maximal antiprotozoal effect was reached at a concentration of 20 ll/ml of S. persica aqueous extract. Means of growth inhibition effect obtained with untreated and heat-treated extracts at 40 ll/ml against the three subtypes of Blastocystis sp. were 80% (SD 2.3) and 82% (SD 1.1), respectively. No significant difference was observed in the inhibitory effect of S. persica extracts between the three Blastocystis sp. subtypes. Aqueous extract of S. persica roots contains therefore heatstable components with significant antiprotozoal activity against Blastocystis sp. subtypes ST1, ST3, and ST5 in vitro. Further investigations are required to determine and characterize the active antiprotozoal components of S. persica roots and their evaluation in vivo.

International Journal of Zoological Research, 2017

Background and Objective: A zoonotic Trypanosoma evansi (T. evansi ) has the widest range and geo... more Background and Objective: A zoonotic Trypanosoma evansi (T. evansi ) has the widest range and geographical distribution attributed to the mechanical transmission by many vectors. Inducible nitric oxide synthase (iNOS) activation by interleukin-17 (IL-17) were expressed in mice experimentally infected with T. evansi in addition to detection of serum level of IL-17 for better understanding the roles of iNOS and IL-17 in controlling this protozoan infection. Materials and Methods: Infected group (I) mice were injected with 4.5×10 5 trypomastigotes intraperitoneally, subdivided into I-3, I-5, I-10 and I-20 subgroups (10 mice, each), then sacrificed at 3, 5, 10 and 20 days post infection (p.i.), respectively, whereas control group mice (C) were injected with saline, subdivided into C-3, C-5, C-10 and C-20 subgroups (6 mice, each) and sacrificed along the parallel infected subgroup one. Results: iNOS was immunohistochemically detected with more expression in brain and the IL-17 revealed more in spleen than liver or brain, also its serum level increased significantly with progression of the infection. There was a negative correlation between parasitemia and either iNOS or IL-17. Conclusion: Trypanosoma evansi infection caused increasing both IL-17 and iNOS expression which both were coinciding with a low number of trypomastigotes referring strongly to their roles in limiting the infection.

International Journal of TROPICAL DISEASE & Health, 2019

This work was carried out in collaboration between all authors. Author RAB designed the study and... more This work was carried out in collaboration between all authors. Author RAB designed the study and wrote the first draft of the manuscript. Author RTM performed parasites culture, DNA extraction and genotyping experiments, while authors OAA, SMH and AES performed in vitro susceptibility assays and statistical analysis. Finally author MAEB wrote the protocol, shared in molecular experiments and manuscript writing. All authors read and approved the final manuscript.

Parasites & Vectors, 2017

Background: Blastocystis is a group of cosmopolitan gastrointestinal parasite of humans and a wid... more Background: Blastocystis is a group of cosmopolitan gastrointestinal parasite of humans and a wide variety of animals. These anaerobic protozoans include more than 17 specific small-subunit ribosomal RNA subtypes, of which nine are found in humans with a variable geographical distribution. Until now, no study has described the Blastocystis subtypes present in Saudi Arabia. Methods: In total, 1,262 faecal samples were collected from patients with gastrointestinal complaints and asymptomatic individuals visiting two major hospitals. All samples were analysed by F1/R1 diagnostic PCR, microscopy and culture methods. The subtypes of Blastocystis sp. isolates were determined by the sequenced-tagged site (STS)-based method. Results: One-hundred-thirty-three positive cases were detected by F1/R1 diagnostic PCR, of which 122 were also positive by the culture method and 83 by direct microscopy. The sensitivities of direct microscopy and the culture method were 62% and 92%, respectively. Subtype (ST3) was the most prevalent (80.5%), followed by ST1 (14.5%) and ST2 (5%). ST4, ST5, ST6 and ST7 were not detected in this study. ST3 infections were significantly predominant (P < 0.05) among symptomatic patients. Conclusions: To our knowledge, this study provides the first run-through information on Blastocystis sp. epidemiology in Makkah city, revealing a rather moderate prevalence of 10.5% and the presence of three subtypes, ST1, ST2, and ST3. ST3 was the most predominant, particularly among symptomatic patients.

First Record of Indigenous Furuncular Myiasis Due to Cordylobia anthropophaga in Unusual Ecologic Niche, Makkah, Saudi Arabia

International Journal of TROPICAL DISEASE & Health, 2016

Department of Parasitology, Faculty of Medicine, Assiut University, Egypt. Department of Laborato... more Department of Parasitology, Faculty of Medicine, Assiut University, Egypt. Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah 7607, Saudi Arabia. Department of Animal Hygiene and Zoonoses, Faculty of Veterinary Medicine, Assiut University, Egypt. Department of Medical Parasitology, Faculty of Medicine, Umm Al-Qura University, Makkah 7607, Saudi Arabia. Department of Medical Parasitology, Faculty of Medicine, El-Minia University, Egypt. Clinical Laboratory Diagnosis, Animal Medicine, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt.

Application of adult worm and lung-stage antigens to immunize against Schistosoma mansoni using cytokines as adjuvants

Journal of the Egyptian Society of Parasitology, 2006

Different Schistosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) t... more Different Schistosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) together with different cytokine adjuvants (Interferon-gamma and Interleukin-4) were used to immunize mice against. S. mansoni. Immunization program was directed towards the production of an intense immune response together with balanced T-helper1 and T-helper2 immune responses. The goal of immunization was not only to protect from infection but also to modulate the pathology inflicted by the parasite. Parameters like adult load, egg counts, anti-Schistosoma antibody titers and liver pathology were used to evaluate the different immunization scheme. SLAP antigen has proven to be a better antigen not only in protection but also in pathology modulation. SLAP plus IFN-gamma as an adjuvant was the best immunization regimen with almost 50% protection and a remarkable resolving of parasite pathology. Unexpectedly, IL-4 had a weak but observed adjuvant protective effect. The results is a step in...

The miniature pig: a unique experimental model for Schistosoma japonicum infection

Parasitology International, 2004

As part of a search for good animal models for human schistosomiasis, two miniature pigs of the C... more As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17-20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum infection.

Parasitology Research, 2014

Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on ... more Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on earth and highly prevalent in most warm-blooded vertebrates. There are no drugs that target the chronic cyst stage of this infection; therefore, development of an effective vaccine would be an important advance in disease control. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote T-helper 1 (Th1) responses, an adjuvant activity that is desirable for vaccination against intracellular pathogen. In this study, we compare the immune responses of Toxoplasma susceptible C57BL/6 mice following intranasal and intramuscular vaccination with Toxoplasma lysate antigen (TLA) with or without CpG ODN as adjuvant. Immunized and control non-immunized mice were challenged with 85 cyst of the moderately virulent Beverley strain of T. gondii. Intranasal vaccination gave significantly a higher protection compared to other groups as indicated by prolonged survival and significantly reduced brain cyst burden (P< 0.01). Intranasal vaccination stimulated cellular immunity towards Th1 response characterized by significant INF-γ production (P<0.01). Furthermore, fecal IgA antibody levels as an indicator of mucosal immune responses were significantly higher (P<0.05) in intranasal vaccinated group before the challenge compared to all other groups. Intranasal vaccination was not able to upgrade the Th1 humoral arm. In contrast, intramuscular vaccination enhanced humoral immunity towards a type Th1 pattern characterized by a significant increase of specific IgG and Ig2a. Our results suggest that intranasal administration of CpG/TLA would provide a stable, pronounced, and effective vaccine against toxoplasmosis through stimulation of Th1 cellular immunity and mucosal IgA.

The Journal of Immunology, Dec 15, 1999

Parasitology International, 1998

In order to investigate the host immune response and to analyze the kinetics of Thl and Th2 cytok... more In order to investigate the host immune response and to analyze the kinetics of Thl and Th2 cytokine response in Schis~osomajaponi~~~ infection, C57BU6 mice were infected with 50 cercariae of a zoophilic Taiwan strain of S. juponicum and sacrificed 3 to 12 weeks later. The cytokine mRNA expressions were detected with the reverse transcription-polymerase chain reaction and the cytokine protein productions were measured by the enzyme-linked immunosorbent assay. Six cytokines: IFN-y, IL2, R-4, R-5, IL-lo, and TNF-a were evaluated. The results showed that IFN-7 mRNA level increased significantly at 3-4 wk postinfection, and started to decrease at 5 wk, reaching the preinfection level at 6 wk. The IL-4 and IL-IO mRNA levels, however, began to rise at 7 wk and reached the peak at 8 and 9 wk, then declined at 9 and 12 wk. respectively. The TNF-a response was similar to IL-IO pattern The study on cytokine protein production showed that IFN-7 is the major immune response before the egg laying. On the other hand, Th2 cytokine IL-4 is the major response after the egg laying when the production of TIN-7 is suppressed. These findings indicated that the Thl response is involved in the early stage of infection (3-5 wk), while the Th2 response and TNF-a production are the major phenomena associated with the acute stage of infection (7-12 wk)

Parasitology International, 1998

Third-stage larva of the bot-fly Gasterolthilus hoemorrtthidalis obtairled fr'ont thc stomach of-... more Third-stage larva of the bot-fly Gasterolthilus hoemorrtthidalis obtairled fr'ont thc stomach of-Egyptian equines were strrdiecl tracroscopically and by light microscope; apd for the first time by the scanning electrc.rtt nticroscope with particular reference to the anterior cephalic iegion and the nevrll, discovered sensory array of the mouth hooks, Tlre clcsign ot'thit array was cotttl.riu'c<l rvith that of larvae ol Gosterophiltts intestinalis and Gasterophilrts nasalls anrl ',vas ftrurtd to bc diffcrcnt tttairtly irr thc shape of the sensilla and the number of the angled ptates and that these fine criteria rnay be usecl to differentiate other larvac. Irr atltlitiort, ltrore dctailed clescription rvas added to the cephalic ancl caudal regions rvltich are ol'intl;ortant taxonomic value. GasteropSiline larvae are of vetcrinary anrl rttcdical irtlportance, rvitlt some httmatt creeping cutaneous nryiasis, ophtltalrnorrryiasis artd ottc reccttt rccord of intestinal myiasis.

For schistosonriasis, the development of long-lasting protective immunity through rraccination ma... more For schistosonriasis, the development of long-lasting protective immunity through rraccination may be the real solution to control the ciisease spread. The cegument which is the parasite outer coverinq serves as an interface between the host immune system and the parasite. Thus, antigens associated with the tegument have been a major focus for either vaccine development or immunodiagnostic reagents for schistosomiasis. In the present study pooled sera collected from Schistosome mansoni chronically infected patients was purified over a column made of 7-days schistosomula NP40 extract , then used to immunoscreen )" gt|l cDNA library of 7-days schistosomula , a number of cDNA clones were identified after three rounds of -.--immunoscreening and plaques purification. The isolated plaques were amplified rvith polymerase chain reaction (PCR) using I gtl I fonvard and reverse primers. The PCR products were cloned in PCRTNII plasmiC vector. Ail isolated clones were sequenced, the identified clone -s was found to encocie an alpha tubulin like gene. The

Sensitivity and specificity of vvet mount, culture and PCR in diagnosing Trichomonas vaginalis i... more Sensitivity and specificity of vvet mount, culture and PCR in diagnosing Trichomonas vaginalis infection in females attending the Running title: Sensitivity and specificity of T. vaginalis diagnostic methods Abstract Background and Objectives: Trichomoniasis affects approximately 180 million women worldwide. It cau have an atypical or even asyrnptomatic course. Therefore, to accurately diagnose this disease, microbiological investigation is necessary. The aim of

Different Sc:histosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) ... more Different Sc:histosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) together with ditferent cytokine adjuvants (lnterferon-gamma and Interleukin-4) were used to immunize mice against. S. nttutsoni.

Proteins that arc secretcd by or anchored on the surfacc of intramammalian stage of Schistosoma n... more Proteins that arc secretcd by or anchored on the surfacc of intramammalian stage of Schistosoma ntansoni are exposed to host tissucs and thus present potcnthl condldatc moleculcs for the developmcnt of nerv vaccine.

Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on ... more Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on earth and highly prevalent in most warm-blooded vertebrates. There are no drugs that target the chronic cyst stage of this infection; therefore, development of an effective vaccine would be an important advance in disease control. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote T-helper 1 (Th1) responses, an adjuvant activity that is desirable for vaccination against intracellular pathogen. In this study, we compare the immune responses of Toxoplasma susceptible C57BL/6 mice following intranasal and intramuscular vaccination with Toxoplasma lysate antigen (TLA) with or without CpG ODN as adjuvant. Immunized and control non-immunized mice were challenged with 85 cyst of the moderately virulent Beverley strain of T. gondii. Intranasal vaccination gave significantly a higher protection compared to other groups as indicated by prolonged survival and significantly reduced brain cyst burden (P< 0.01). Intranasal vaccination stimulated cellular immunity towards Th1 response characterized by significant INF-γ production (P<0.01). Furthermore, fecal IgA antibody levels as an indicator of mucosal immune responses were significantly higher (P<0.05) in intranasal vaccinated group before the challenge compared to all other groups. Intranasal vaccination was not able to upgrade the Th1 humoral arm. In contrast, intramus-cular vaccination enhanced humoral immunity towards a type Th1 pattern characterized by a significant increase of specific IgG and Ig2a. Our results suggest that intranasal administration of CpG/TLA would provide a stable, pronounced, and effective vaccine against toxoplasmosis through stimulation of Th1 cellular immunity and mucosal IgA.

As part of a search for good animal models for human schistosomiasis, two miniature pigs of the C... more As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17 – 20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum infection.