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Papers by Shereen Mossallam

Journal of the Egyptian Society of Parasitology, 2008

The present study was designed to evaluate the efficiency of two serodiagnostic tests; the direct... more The present study was designed to evaluate the efficiency of two serodiagnostic tests; the direct agglutination test (DAT) and the fast agglutination screening test (FAST) in the diagnosis of Microsporidia in experimentally infected mice and to differentiate between different species of the parasite. The swiss albino mice were divided into non infected control and infected experimental groups which were further subdivided into ten subgroups. Ten samples of microsporidial spores were isolated from ten human stools and each one was used to infect each subgroup of mice. Stool and sera were collected weekly from each subgroup from the 1st to the 4th week post infection (PI). DAT & FAST tests, using antigen prepared from the different species of microsporidial spores were used to detect antibodies in sera of different mice subgroups. The cross reactivity of microsporidial spores with the antibodies of Cyclospora cyatenensis and Cryptosporidium parvum was investigated by DAT & FAST. The r...

Veterinary Parasitology, 2015

The potential use of probiotics in controlling enteric infections has generated tremendous intere... more The potential use of probiotics in controlling enteric infections has generated tremendous interest in the last decade. The protective efficacy of seven oral doses of two newly isolated Egyptian probiotic strains; Lactobacillus acidophilus P110 (L. acidophilus) and Lactobacillus plantarum P164 (L. plantarum) versus Lactobacillus casei ATCC 7469 (L. casei) - against experimental intestinal trichinellosis - was assessed via parasitological, immunological and histopathological parameters, after verifying their in vivo safety and intestinal colonization. Parasitologically, the highest adult count reduction was observed in L. plantarum-fed infected sub-subgroup (56.98, 65.42 and 69.02%) - on the 5th, 12th and 17th days post infection (P.I.), respectively. Lesser percentage reductions were recorded in both the L. casei-fed infected sub-subgroup (36.19, 23.68 and 31.58%) and L. acidophilus-fed infected sub-subgroup (36.50, 11.8 and 7.61%) at the same intervals. On the 28th day post challenge, the highest larval count reduction was in L. plantarum-fed infected sub-subgroup (87.92%). While lower percentage yet still significant were observed in the L. casei-fed infected (74.88%) and L. acidophilus-fed infected sub-subgroups (60.98%). Immunologically, serum IFN-γ levels in the probiotic-fed non infected sub-subgroups were higher than those in the probiotic-fed infected sub-subgroups. Both showed higher levels of IFN-γ than the non probiotic-fed sub-subgroups. Histopathologically, intestinal sections of the probiotic-fed infected sub-subgroups showed amelioration of the inflammation and damage resulting from Trichinella spiralis (T. spiralis) infection. Results indicate that, through mechanical and immunological mechanisms, L. plantarum showed parasitological and histopathological protective superiority with respect to both L. casei and L. acidophilus against murineT. spiralis infection.

... Synthesis of Substituted Pyrimidinedione Derivatives as Potential Schistosomicidal Agents Man... more ... Synthesis of Substituted Pyrimidinedione Derivatives as Potential Schistosomicidal Agents Manal NS Saudi* ,1 , Amal M. Youssef 1 , Mona H. Badr 1 , Rasha Y. Elbayaa 1 , Mervat Z. El-azzouni 2 , Shereen F. Mossallam 2 , Nahed M. Baddour 3 and Maha M. Eissa 2 ...

Journal of the Egyptian Society of Parasitology, 2010

Fresh fruit juices are popular, but not always safe. For assessing the likelihood of infection wi... more Fresh fruit juices are popular, but not always safe. For assessing the likelihood of infection with newly emerging intestinal protozoa, commercial fresh orange, lemon, sugar cane, strawberry, and mango juices were screened by wet mounts, Weber's modified trichrome and modified Ziehl-Neelsen stains. Protozoa viability was done by fluorescein-diacetate/propidium-iodide staining, and infectivity was performed in Swiss albino mice. Results showed that 35.43% were contaminated with one or more of Cryptosporidia, Microsporidia, and Cyclospora, as well as Giardia spp. Strawberry was the most contaminated juice (54.28%), while orange was the slightest (22.86%). Cryptosporidia was the highest contaminant (61.29%), and Cyclospora was the least (14.52%). Microsporidia spp. was the most robust contaminant which retained its viability and infectivity in juices in which it was detected. Moderately acidic strawberry and mango juices and alkaline sugar cane juice pose a possible threat, due to ...

Journal of the Egyptian Society of Parasitology, 2007

The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel ... more The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel (PZQ) as a therapeutic control was evaluated. Swiss Albino mice were divided into infected non-treated control, PZQ-treated group given a single dose of 500 mg/kg four weeks post infection (PI), and infected mice treated with single, double, and triple doses of 5 mg/kg CLS per dose, one week apart starting from the 4th week PI. All animals were perfused for adults count. Parts of livers and intestines were examined for granulomata number and sizes. Pathological changes in hepatic parenchyma by H&E and Masson trichrome stains were also examined. Results revealed that a single treatment with PZQ caused a significant percentage reduction (%R) of worm load (92.68%), mean egg count in liver and intestine (91.20 & 94.01% respectively), and mean size of liver granulomata was reduced (92.06%). Regarding CLS, the worm burden was reduced proportionally with number of doses given; 87.80, 96.34 & 97...

Journal of Parasitic Diseases, 2014

Leishmaniasis is one of the neglected infectious diseases included in the World Health Organizati... more Leishmaniasis is one of the neglected infectious diseases included in the World Health Organization's list of the top guns of antimicrobial resistance. Miltefosine is the first and the only available oral effective therapy for leishmaniasis. For fear of its potential resistance, identification of alternative, effective and safe drugs is urgently needed. Therefore, in view of azithromycin promising activity against a number of Leishmania species, this work was carried out to evaluate the efficacy of oral azithromycin alone versus its combination with miltefosine against experimental Old World Cutaneous leishmaniasis thus, can provide another alternative oral therapy or for the first time an oral combination therapy for leishmaniasis. The experiment were carried out on Swiss strain albino mice which were treated either with miltefosine for 20 days, Azithromycin for 20 days or both drugs in combination therapy for shorter duration of 10 days. Efficacy of azithromycin mono and combination therapy with miltefosine was evaluated clinically, parasitologically and by examination of the cutaneous lesions by Transmission Electron Microscopy. The current work demonstrated superior activity of oral azithromycin over oral miltefosine in the treatment of experimentally infected mice with Leishmania major (MHOM/IL/81/FEBNI). Unfortunately, oral combination therapy of azithromycin and miltefosine for short duration though, induced dramatic clinical improvement yet, relapse rapidly developed after cessation of therapy. Oral azithromycin could be a promising oral antileishmanial agent. Further research is recommended to investigate its leishmanicidal activity against other Leishmania species thus; another alternative oral therapy for leishmaniasis can be rapidly available.

Fresh fruit juices are popular, but not always safe. For assessing the likelihood of infection wi... more Fresh fruit juices are popular, but not always safe. For assessing the likelihood of infection with newly emerging intestinal protozoa, commercial fresh orange, lemon, sugar cane, strawberry, and mango juices were screened by wet mounts, Weber's modified trichrome and modified Ziehl-Neelsen stains. Protozoa viability was done by fluorescein-diacetate/propidium-iodide staining, and infectivity was performed in Swiss albino mice. Results showed that 35.43% were contaminated with one or more of Cryptosporidia, Microsporidia, and Cyclospora, as well as Giardia spp. Strawberry was the most contaminated juice (54.28%), while orange was the slightest (22.86%). Cryptosporidia was the highest contaminant (61.29%), and Cyclospora was the least (14.52%). Microsporidia spp. was the most robust contaminant which retained its viability and infectivity in juices in which it was detected. Moderately acidic strawberry and mango juices and alkaline sugar cane juice pose a possible threat, due to ...

PLOS Neglected Tropical Diseases

Extracellular vesicles (EVs) are protein-loaded nano-scaled particles that are extracellularly re... more Extracellular vesicles (EVs) are protein-loaded nano-scaled particles that are extracellularly released by eukaryotes and prokaryotes. Parasite’s EVs manipulate the immune system, making them probable next-generation vaccines. Schistosomal EVs carry different proteins of promising immunizing potentials. For evaluating the immune-protective role of Schistosoma mansoni (S. mansoni) egg-derived EVs against murine schistosomiasis, EVs were isolated from cultured S. mansoni eggs by progressive sequential cooling ultra-centrifugation technique. Isolated EVs were structurally identified using transmission electron microscope and their protein was quantified by Lowry’s technique. Experimental mice were subcutaneously immunized with three doses of 20 μg EVs (with or without alum adjuvant); every two weeks, then were challenged with S. mansoni cercariae two weeks after the last immunizing dose. Six weeks post infection, mice were sacrificed for vaccine candidate assessment. EVs protective eff...

Acta Tropica, 2017

As parasites and cancer cells share many lifestyle and behavioral resemblances, repositioning of ... more As parasites and cancer cells share many lifestyle and behavioral resemblances, repositioning of anti-cancerous agents as anti-parasitic is quite trendy, especially those sharing the same therapeutic targets. Therefore, the current study investigated the in vitro efficacy of ascending concentrations of chlorambucil (0.5-20μg/ml) against adult Schistosoma mansoni worms, over 72h. Additionally, its in vivo effects against the different developmental stages of the worm were assessed, after an oral dose of 2.5mg/kg/day for five successive days, through evaluating the worm load reduction and worms' morphological alterations and oogram changes. In addition to tissue egg count, a histopathological study of the liver was conducted. In vitro, chlorambucil demonstrated noticeable anti-schistosomal effects in the form of progressive reductions of the worms' viability in a dose dependent manner. Complete worm death was achieved at 72h incubation with 5μg/ml drug concentration. In vivo, chlorambucil induced a significant reduction in the total worm load against all developmental stages. Its highest impact was evident against the juvenile stage, where it induced 75.8% total worm load reduction, and 89.2% and 86.7% intestinal and hepatic egg counts reduction, respectively, along with ogram alterations. Besides, it induced significant shortening of both male and female worms and promoted an amelioration of hepatic histopathology. Results show that chlorambucil possesses favorable in vitro and in vivo anti-schistosomal activity. The highest in vivo efficacy was against the juvenile stage of S. mansoni, significantly superior to praziquantel, with extended potency to the adult stage. Further studies are recommended for chlorambucil target verification and to enhance its therapeutic efficacy.

BMC Infectious Diseases, 2015

Background: Schistosoma mansoni infection represents a major cause of morbidity and mortality in ... more Background: Schistosoma mansoni infection represents a major cause of morbidity and mortality in many areas of the developing world. Effective vaccines against schistosomiasis are not available and disease management relies mainly on treatment with the anthelmintic drug praziquantel. Several promising schistosomal antigens have been evaluated for vaccine efficacy such as Sm14, Sm29 and tetraspanins. However, most investigators examine these promising antigens in animal models individually rather than in properly adjuvanted antigen combinations. Methods: In the present study, we made a recombinant fusion protein comprised of the promising schistosomal antigens Sm14 and Sm29. The fusion protein, FSm14/29, was administered to Swiss albino mice either unadjuvanted or adjuvanted with polyinosinic-polycytidylic acid adjuvant, poly(I:C). Mice were challenged with S. mansoni cercariae and different parasitological/immunological parameters were assessed seven weeks post-challenge. Data were analyzed using the ANOVA test with post-hoc Tukey-Kramer test. Results: Mice pre-immunized with unadjuvanted or poly(I:C)-adjuvanted fusion protein showed reduction of adult worm burden of 44.7 and 48.4%, respectively. In addition, significant reduction of tissue egg burdens was observed in mice immunized with the fusion protein when compared with the infected saline/adjuvant negative control groups and groups immunized with the individual Sm14 and Sm29 antigens. Light microscope and scanning electron microscope (SEM) investigation of adult worms recovered from FSm14/29-immunized mice revealed appreciable morphological damage and tegumental deformities. Histopathological examination of liver sections of immunized mice demonstrated reduced granulomatous and inflammatory reactions when compared with infected unvaccinated mice or mice immunized with the individual Sm14 and Sm29 antigens. Conclusion: The findings presented in this study highlight the importance of the fusion protein FSm14/29 as a potential vaccine candidate that is worthy of further investigation.

Journal of the Egyptian Society of Parasitology, 2009

This study evaluated the immune-potentiating effect of administrating bovine Lactoferrin (LF) to ... more This study evaluated the immune-potentiating effect of administrating bovine Lactoferrin (LF) to immunocompetent (IC) and immunosuppressed (IS) mice prior to infection with tachyzoites of T. gondii RH strain. Mice were IS with cyclophosphamide. LF was given in seven of them as oral doses on alternate days. Immunological and parasitological assessments showed that LF induced statistical significance comparable resistance against acute toxoplasmosis in IC and IS mice. This was verified by elevated splenic CD4+ T lymphocytes, reduced tachyzoites' viability and infectivity, with diminished parasite burdens. So, mice mortality declined and their survival was prolonged. This indicated that LF have prophylactic efficacy against human toxoplasmosis in risky persons with alleviating immune balance.

Journal of the Egyptian Society of Parasitology, 2007

The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel ... more The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel (PZQ) as a therapeutic control was evaluated. Swiss Albino mice were divided into infected non-treated control, PZQ-treated group given a single dose of 500 mg/kg four weeks post infection (PI), and infected mice treated with single, double, and triple doses of 5 mg/kg CLS per dose, one week apart starting from the 4th week PI. All animals were perfused for adults count. Parts of livers and intestines were examined for granulomata number and sizes. Pathological changes in hepatic parenchyma by H&E and Masson trichrome stains were also examined. Results revealed that a single treatment with PZQ caused a significant percentage reduction (%R) of worm load (92.68%), mean egg count in liver and intestine (91.20 & 94.01% respectively), and mean size of liver granulomata was reduced (92.06%). Regarding CLS, the worm burden was reduced proportionally with number of doses given; 87.80, 96.34 & 97...

Asian Pacific Journal of Tropical Biomedicine, 2013

Biomphalaria alexandrina, Schistosoma mansoni, Rotifers, Snail histopathology, Cercarial biology ... more Biomphalaria alexandrina, Schistosoma mansoni, Rotifers, Snail histopathology, Cercarial biology Objective: To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes. Methods: Susceptible laboratory-bred Biomphalaria alexandrina (B. alexandrina) snails were exposed to lab-maintained rotifers; Philodina spp., two weeks before and after being infected with Schistosoma mansoni (S. mansoni) miracidia. The consequent histopathological impact on snail tissues and cercarial biology were investigated before and after emergence from snails. Results: Contamination of B. alexandrina snails with philodina, two weeks before miracidial exposure, was found to hinder the preliminary development of S. mansoni cercariae inside the snail tissues. Furthermore, when snails were contaminated with rotifers two weeks post miracidial exposure; growth of already established cercariae was found to be retarded. The consequent influence of internalized rotifers within the snail tissue was clearly reflected on cercarial emergence, activity and infectivity along the four weeks duration of shedding. In the present study, comparison of snail histopathological findings and altered cercarial biology observed between the experimental and control groups indicated that the rotifers may have affected the levels of snail's energy reservoirs, which eventually was found to have had an adverse impact on reproduction, growth and survival of the parasite within the snail host, coupled with its performance outside the snail. Conclusions: In future biological control strategies of schistosomiasis, ritifers should be considered as a parasitic scourge of humanity.

Schistosoma mansonicauses intestinal schistosomiasis, a disease that is prevalent in several regi... more Schistosoma mansonicauses intestinal schistosomiasis, a disease that is prevalent in several regions worldwide. To date, a protective vaccine againstS. mansoniis still lacking. Several promising antigens have been discovered and evaluated for vaccine protection, such as Sm14 and Sm28GST. In this short communication, we report the successful detection of an alternatively spliced truncated form of Sm14 which was highly expressed in an Egyptian strain ofS. mansoni. This truncated Sm14 (TrSm14) protein was formerly reported to be practically non-existent and its complementary DNA (cDNA) was thought to be ‘a rare misprocessing of mRNA precursor’. Our finding demonstrates that there is inter-strain variation in theS. mansonitranscriptome and subsequently in the role/function of the expressed proteins. We expressed TrSm14 successfully inEscherichia colias a fusion protein with the schistosomal antigen Sm28GST. The fusion protein was purified using metal affinity chromatography and was found to be reactive with serum fromS. mansoni-infected patients. This suggests a possible diagnostic value for this protein in detection of anti-schistosomal antibodies. In addition, this fusion protein could offer a potential bivalent vaccine candidate againstS. mansonithat is worthy of further investigation.

Experimental Parasitology, 2014

Through increased awareness and improved diagnostics, microsporidiosis has now been identified in... more Through increased awareness and improved diagnostics, microsporidiosis has now been identified in a broader range of human populations; however current therapies are inconsistently effective. Recently, probiotics were determined as means for the control of intestinal parasitic infections through their secretory products; bacteriocins. This is the first study on the effect of bacteriocin produced by Lactobacillus acidophilus CH1 bacteriocin, with or without gold nanoparticles (Au-NPs), against intestinal microsporidiosis in immunosuppressed mice. Fecal and intestinal spore loads, besides viability, extrusion and infectivity of spores from treated animals were assessed. Results showed that the anti-microsporidial effects of bacteriocin were significantly potent. This efficiency was further potentiated upon conjugating bacteriocins with Au-NPs, as it induced a strikingly sustained reduction in fecal spore shedding after cessation of therapy by 1 week (94.26%). Furthermore, reduction in intestinal spore load was highest in bacteriocin/Au-NPs-inoculated mice (89.7%) followed by bacteriocin-inoculated group (73.5%). Spores encountered from stool of bacteriocin/Au-NPs group showed 92.4% viability, versus 93.7% in bacteriocin group. Spore extrusion and infectivity were most inhibited by exposure to bacteriocin/Au-NPs. Safety of bacteriocin/Au-NPs was also verified. Thus, considering the results of the present work, L. acidophilus CH1-derived bacteriocin can present a powerful safe therapy against intestinal microsporidiosis.

Acta Tropica, 2015

Control of schistosomiasis relies on a single drug, praziquantel (PZQ). Given the rising concerns... more Control of schistosomiasis relies on a single drug, praziquantel (PZQ). Given the rising concerns about the potential emergence of PZQ-resistant strains, it has now become necessary to search for novel therapeutics. However, the current pace for anti-schistosomal drug discovery is slow; hence, repositioning of existing approved drugs can offer a safe, rapid and cost-effective solution. The anti-malarial synthetic artemisinin-derivatives trioxolanes demonstrated anti-schistosomal efficacies against the three major species infecting humans and, unlike PZQ, showed activities against both juvenile and adult worm stages. The 1,2,4-trioxolane/OZ277 (arterolane maleate) in combination with a partner drug: piperaquine phosphate was recently developed as an anti-malarial drug and manufactured by Ranbaxy (India) as Synriam™ (SYN). Herein, the in vivo activities of SYN were investigated in a mouse model of Schistosoma mansoni (S. mansoni), compared to PZQ. We show that a single fixed dose of 240mg/kg SYN (40mg/kg arterolane and 200mg/kg piperaqine) induced significant protective effects in mice, in terms of reduction in worm and tissue egg burdens, which were evident against all schistosome developmental stages. Extensive alterations in the tegument and subtegumental tissues of SYN-exposed worms were revealed by both scanning and transmission electron microscopes. Progressive decrease in worm activity and occurrence of death were noticed in vitro upon exposure to the drug - more pronounced in the presence of haemin. This report provides the first evidence of the efficacy of a combination of 1,2,4-trioxolane and piperaquine against S. mansoni in mice. Being effective against young stages, SYN could be used to prevent early Schistosoma infection.

Alexandria Journal of …, 2012

Background: Leishmaniasis is one of the neglected diseases included in the World Health Organizat... more Background: Leishmaniasis is one of the neglected diseases included in the World Health Organization's list of the top guns of antimicrobial resistance. Miltefosine (MIL) was the first successful oral agent used against visceral leishmaniasis in India. As regards cutaneous leishmaniasis (CL), multiple experimental and clinical studies have investigated its efficacy in treatment of New World CL, while only few trials have focused on Old World CL. Therefore, this work was designed to study the efficacy of MIL in experimental Old World CL caused by Leishmania major (MHOM/IL/81/FEBNI), one of the causative species of CL in the Middle East. Results: Groups of infected mice were given MIL orally, at a dose of 20 mg/kg/day for 20 days. Results showed that untreated infected mice suffered from autoamputation of the inoculated footpads. While, those treated with MIL showed complete clinical cure, significant reduction of parasite burden and improvement of the histopathological changes of the cutaneous lesions. The drug causes evident ultrastructural morphological alterations of L. major amastigote form. One month posttreatment, no clinical sings of relapse were observed, and parasite density continued to decrease significantly. Conclusion: The present study revealed activity of MIL against experimental Old World CL in the mouse model caused by L. major (MHOM/IL/81/FEBNI), one of the causative species of CL in the Middle East.

Experimental Parasitology, 2014

h i g h l i g h t s Combination of Sm14 and Sm29 antigens was tested in S. mansoni infection mode... more h i g h l i g h t s Combination of Sm14 and Sm29 antigens was tested in S. mansoni infection model. Significant reduction of S. mansoni adult worms and tissue egg burden was attained. Reduced liver histopathology and granuloma size was also achieved. Combining antigens is a realistic approach for vaccine development against S. mansoni.

Journal of the Egyptian Society of Parasitology, 2008

The present study was designed to evaluate the efficiency of two serodiagnostic tests; the direct... more The present study was designed to evaluate the efficiency of two serodiagnostic tests; the direct agglutination test (DAT) and the fast agglutination screening test (FAST) in the diagnosis of Microsporidia in experimentally infected mice and to differentiate between different species of the parasite. The swiss albino mice were divided into non infected control and infected experimental groups which were further subdivided into ten subgroups. Ten samples of microsporidial spores were isolated from ten human stools and each one was used to infect each subgroup of mice. Stool and sera were collected weekly from each subgroup from the 1st to the 4th week post infection (PI). DAT & FAST tests, using antigen prepared from the different species of microsporidial spores were used to detect antibodies in sera of different mice subgroups. The cross reactivity of microsporidial spores with the antibodies of Cyclospora cyatenensis and Cryptosporidium parvum was investigated by DAT & FAST. The r...

Veterinary Parasitology, 2015

The potential use of probiotics in controlling enteric infections has generated tremendous intere... more The potential use of probiotics in controlling enteric infections has generated tremendous interest in the last decade. The protective efficacy of seven oral doses of two newly isolated Egyptian probiotic strains; Lactobacillus acidophilus P110 (L. acidophilus) and Lactobacillus plantarum P164 (L. plantarum) versus Lactobacillus casei ATCC 7469 (L. casei) - against experimental intestinal trichinellosis - was assessed via parasitological, immunological and histopathological parameters, after verifying their in vivo safety and intestinal colonization. Parasitologically, the highest adult count reduction was observed in L. plantarum-fed infected sub-subgroup (56.98, 65.42 and 69.02%) - on the 5th, 12th and 17th days post infection (P.I.), respectively. Lesser percentage reductions were recorded in both the L. casei-fed infected sub-subgroup (36.19, 23.68 and 31.58%) and L. acidophilus-fed infected sub-subgroup (36.50, 11.8 and 7.61%) at the same intervals. On the 28th day post challenge, the highest larval count reduction was in L. plantarum-fed infected sub-subgroup (87.92%). While lower percentage yet still significant were observed in the L. casei-fed infected (74.88%) and L. acidophilus-fed infected sub-subgroups (60.98%). Immunologically, serum IFN-γ levels in the probiotic-fed non infected sub-subgroups were higher than those in the probiotic-fed infected sub-subgroups. Both showed higher levels of IFN-γ than the non probiotic-fed sub-subgroups. Histopathologically, intestinal sections of the probiotic-fed infected sub-subgroups showed amelioration of the inflammation and damage resulting from Trichinella spiralis (T. spiralis) infection. Results indicate that, through mechanical and immunological mechanisms, L. plantarum showed parasitological and histopathological protective superiority with respect to both L. casei and L. acidophilus against murineT. spiralis infection.

... Synthesis of Substituted Pyrimidinedione Derivatives as Potential Schistosomicidal Agents Man... more ... Synthesis of Substituted Pyrimidinedione Derivatives as Potential Schistosomicidal Agents Manal NS Saudi* ,1 , Amal M. Youssef 1 , Mona H. Badr 1 , Rasha Y. Elbayaa 1 , Mervat Z. El-azzouni 2 , Shereen F. Mossallam 2 , Nahed M. Baddour 3 and Maha M. Eissa 2 ...

Journal of the Egyptian Society of Parasitology, 2010

Fresh fruit juices are popular, but not always safe. For assessing the likelihood of infection wi... more Fresh fruit juices are popular, but not always safe. For assessing the likelihood of infection with newly emerging intestinal protozoa, commercial fresh orange, lemon, sugar cane, strawberry, and mango juices were screened by wet mounts, Weber's modified trichrome and modified Ziehl-Neelsen stains. Protozoa viability was done by fluorescein-diacetate/propidium-iodide staining, and infectivity was performed in Swiss albino mice. Results showed that 35.43% were contaminated with one or more of Cryptosporidia, Microsporidia, and Cyclospora, as well as Giardia spp. Strawberry was the most contaminated juice (54.28%), while orange was the slightest (22.86%). Cryptosporidia was the highest contaminant (61.29%), and Cyclospora was the least (14.52%). Microsporidia spp. was the most robust contaminant which retained its viability and infectivity in juices in which it was detected. Moderately acidic strawberry and mango juices and alkaline sugar cane juice pose a possible threat, due to ...

Journal of the Egyptian Society of Parasitology, 2007

The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel ... more The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel (PZQ) as a therapeutic control was evaluated. Swiss Albino mice were divided into infected non-treated control, PZQ-treated group given a single dose of 500 mg/kg four weeks post infection (PI), and infected mice treated with single, double, and triple doses of 5 mg/kg CLS per dose, one week apart starting from the 4th week PI. All animals were perfused for adults count. Parts of livers and intestines were examined for granulomata number and sizes. Pathological changes in hepatic parenchyma by H&E and Masson trichrome stains were also examined. Results revealed that a single treatment with PZQ caused a significant percentage reduction (%R) of worm load (92.68%), mean egg count in liver and intestine (91.20 & 94.01% respectively), and mean size of liver granulomata was reduced (92.06%). Regarding CLS, the worm burden was reduced proportionally with number of doses given; 87.80, 96.34 & 97...

Journal of Parasitic Diseases, 2014

Leishmaniasis is one of the neglected infectious diseases included in the World Health Organizati... more Leishmaniasis is one of the neglected infectious diseases included in the World Health Organization's list of the top guns of antimicrobial resistance. Miltefosine is the first and the only available oral effective therapy for leishmaniasis. For fear of its potential resistance, identification of alternative, effective and safe drugs is urgently needed. Therefore, in view of azithromycin promising activity against a number of Leishmania species, this work was carried out to evaluate the efficacy of oral azithromycin alone versus its combination with miltefosine against experimental Old World Cutaneous leishmaniasis thus, can provide another alternative oral therapy or for the first time an oral combination therapy for leishmaniasis. The experiment were carried out on Swiss strain albino mice which were treated either with miltefosine for 20 days, Azithromycin for 20 days or both drugs in combination therapy for shorter duration of 10 days. Efficacy of azithromycin mono and combination therapy with miltefosine was evaluated clinically, parasitologically and by examination of the cutaneous lesions by Transmission Electron Microscopy. The current work demonstrated superior activity of oral azithromycin over oral miltefosine in the treatment of experimentally infected mice with Leishmania major (MHOM/IL/81/FEBNI). Unfortunately, oral combination therapy of azithromycin and miltefosine for short duration though, induced dramatic clinical improvement yet, relapse rapidly developed after cessation of therapy. Oral azithromycin could be a promising oral antileishmanial agent. Further research is recommended to investigate its leishmanicidal activity against other Leishmania species thus; another alternative oral therapy for leishmaniasis can be rapidly available.

Fresh fruit juices are popular, but not always safe. For assessing the likelihood of infection wi... more Fresh fruit juices are popular, but not always safe. For assessing the likelihood of infection with newly emerging intestinal protozoa, commercial fresh orange, lemon, sugar cane, strawberry, and mango juices were screened by wet mounts, Weber's modified trichrome and modified Ziehl-Neelsen stains. Protozoa viability was done by fluorescein-diacetate/propidium-iodide staining, and infectivity was performed in Swiss albino mice. Results showed that 35.43% were contaminated with one or more of Cryptosporidia, Microsporidia, and Cyclospora, as well as Giardia spp. Strawberry was the most contaminated juice (54.28%), while orange was the slightest (22.86%). Cryptosporidia was the highest contaminant (61.29%), and Cyclospora was the least (14.52%). Microsporidia spp. was the most robust contaminant which retained its viability and infectivity in juices in which it was detected. Moderately acidic strawberry and mango juices and alkaline sugar cane juice pose a possible threat, due to ...

PLOS Neglected Tropical Diseases

Extracellular vesicles (EVs) are protein-loaded nano-scaled particles that are extracellularly re... more Extracellular vesicles (EVs) are protein-loaded nano-scaled particles that are extracellularly released by eukaryotes and prokaryotes. Parasite’s EVs manipulate the immune system, making them probable next-generation vaccines. Schistosomal EVs carry different proteins of promising immunizing potentials. For evaluating the immune-protective role of Schistosoma mansoni (S. mansoni) egg-derived EVs against murine schistosomiasis, EVs were isolated from cultured S. mansoni eggs by progressive sequential cooling ultra-centrifugation technique. Isolated EVs were structurally identified using transmission electron microscope and their protein was quantified by Lowry’s technique. Experimental mice were subcutaneously immunized with three doses of 20 μg EVs (with or without alum adjuvant); every two weeks, then were challenged with S. mansoni cercariae two weeks after the last immunizing dose. Six weeks post infection, mice were sacrificed for vaccine candidate assessment. EVs protective eff...

Acta Tropica, 2017

As parasites and cancer cells share many lifestyle and behavioral resemblances, repositioning of ... more As parasites and cancer cells share many lifestyle and behavioral resemblances, repositioning of anti-cancerous agents as anti-parasitic is quite trendy, especially those sharing the same therapeutic targets. Therefore, the current study investigated the in vitro efficacy of ascending concentrations of chlorambucil (0.5-20μg/ml) against adult Schistosoma mansoni worms, over 72h. Additionally, its in vivo effects against the different developmental stages of the worm were assessed, after an oral dose of 2.5mg/kg/day for five successive days, through evaluating the worm load reduction and worms' morphological alterations and oogram changes. In addition to tissue egg count, a histopathological study of the liver was conducted. In vitro, chlorambucil demonstrated noticeable anti-schistosomal effects in the form of progressive reductions of the worms' viability in a dose dependent manner. Complete worm death was achieved at 72h incubation with 5μg/ml drug concentration. In vivo, chlorambucil induced a significant reduction in the total worm load against all developmental stages. Its highest impact was evident against the juvenile stage, where it induced 75.8% total worm load reduction, and 89.2% and 86.7% intestinal and hepatic egg counts reduction, respectively, along with ogram alterations. Besides, it induced significant shortening of both male and female worms and promoted an amelioration of hepatic histopathology. Results show that chlorambucil possesses favorable in vitro and in vivo anti-schistosomal activity. The highest in vivo efficacy was against the juvenile stage of S. mansoni, significantly superior to praziquantel, with extended potency to the adult stage. Further studies are recommended for chlorambucil target verification and to enhance its therapeutic efficacy.

BMC Infectious Diseases, 2015

Background: Schistosoma mansoni infection represents a major cause of morbidity and mortality in ... more Background: Schistosoma mansoni infection represents a major cause of morbidity and mortality in many areas of the developing world. Effective vaccines against schistosomiasis are not available and disease management relies mainly on treatment with the anthelmintic drug praziquantel. Several promising schistosomal antigens have been evaluated for vaccine efficacy such as Sm14, Sm29 and tetraspanins. However, most investigators examine these promising antigens in animal models individually rather than in properly adjuvanted antigen combinations. Methods: In the present study, we made a recombinant fusion protein comprised of the promising schistosomal antigens Sm14 and Sm29. The fusion protein, FSm14/29, was administered to Swiss albino mice either unadjuvanted or adjuvanted with polyinosinic-polycytidylic acid adjuvant, poly(I:C). Mice were challenged with S. mansoni cercariae and different parasitological/immunological parameters were assessed seven weeks post-challenge. Data were analyzed using the ANOVA test with post-hoc Tukey-Kramer test. Results: Mice pre-immunized with unadjuvanted or poly(I:C)-adjuvanted fusion protein showed reduction of adult worm burden of 44.7 and 48.4%, respectively. In addition, significant reduction of tissue egg burdens was observed in mice immunized with the fusion protein when compared with the infected saline/adjuvant negative control groups and groups immunized with the individual Sm14 and Sm29 antigens. Light microscope and scanning electron microscope (SEM) investigation of adult worms recovered from FSm14/29-immunized mice revealed appreciable morphological damage and tegumental deformities. Histopathological examination of liver sections of immunized mice demonstrated reduced granulomatous and inflammatory reactions when compared with infected unvaccinated mice or mice immunized with the individual Sm14 and Sm29 antigens. Conclusion: The findings presented in this study highlight the importance of the fusion protein FSm14/29 as a potential vaccine candidate that is worthy of further investigation.

Journal of the Egyptian Society of Parasitology, 2009

This study evaluated the immune-potentiating effect of administrating bovine Lactoferrin (LF) to ... more This study evaluated the immune-potentiating effect of administrating bovine Lactoferrin (LF) to immunocompetent (IC) and immunosuppressed (IS) mice prior to infection with tachyzoites of T. gondii RH strain. Mice were IS with cyclophosphamide. LF was given in seven of them as oral doses on alternate days. Immunological and parasitological assessments showed that LF induced statistical significance comparable resistance against acute toxoplasmosis in IC and IS mice. This was verified by elevated splenic CD4+ T lymphocytes, reduced tachyzoites' viability and infectivity, with diminished parasite burdens. So, mice mortality declined and their survival was prolonged. This indicated that LF have prophylactic efficacy against human toxoplasmosis in risky persons with alleviating immune balance.

Journal of the Egyptian Society of Parasitology, 2007

The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel ... more The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel (PZQ) as a therapeutic control was evaluated. Swiss Albino mice were divided into infected non-treated control, PZQ-treated group given a single dose of 500 mg/kg four weeks post infection (PI), and infected mice treated with single, double, and triple doses of 5 mg/kg CLS per dose, one week apart starting from the 4th week PI. All animals were perfused for adults count. Parts of livers and intestines were examined for granulomata number and sizes. Pathological changes in hepatic parenchyma by H&E and Masson trichrome stains were also examined. Results revealed that a single treatment with PZQ caused a significant percentage reduction (%R) of worm load (92.68%), mean egg count in liver and intestine (91.20 & 94.01% respectively), and mean size of liver granulomata was reduced (92.06%). Regarding CLS, the worm burden was reduced proportionally with number of doses given; 87.80, 96.34 & 97...

Asian Pacific Journal of Tropical Biomedicine, 2013

Biomphalaria alexandrina, Schistosoma mansoni, Rotifers, Snail histopathology, Cercarial biology ... more Biomphalaria alexandrina, Schistosoma mansoni, Rotifers, Snail histopathology, Cercarial biology Objective: To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes. Methods: Susceptible laboratory-bred Biomphalaria alexandrina (B. alexandrina) snails were exposed to lab-maintained rotifers; Philodina spp., two weeks before and after being infected with Schistosoma mansoni (S. mansoni) miracidia. The consequent histopathological impact on snail tissues and cercarial biology were investigated before and after emergence from snails. Results: Contamination of B. alexandrina snails with philodina, two weeks before miracidial exposure, was found to hinder the preliminary development of S. mansoni cercariae inside the snail tissues. Furthermore, when snails were contaminated with rotifers two weeks post miracidial exposure; growth of already established cercariae was found to be retarded. The consequent influence of internalized rotifers within the snail tissue was clearly reflected on cercarial emergence, activity and infectivity along the four weeks duration of shedding. In the present study, comparison of snail histopathological findings and altered cercarial biology observed between the experimental and control groups indicated that the rotifers may have affected the levels of snail's energy reservoirs, which eventually was found to have had an adverse impact on reproduction, growth and survival of the parasite within the snail host, coupled with its performance outside the snail. Conclusions: In future biological control strategies of schistosomiasis, ritifers should be considered as a parasitic scourge of humanity.

Schistosoma mansonicauses intestinal schistosomiasis, a disease that is prevalent in several regi... more Schistosoma mansonicauses intestinal schistosomiasis, a disease that is prevalent in several regions worldwide. To date, a protective vaccine againstS. mansoniis still lacking. Several promising antigens have been discovered and evaluated for vaccine protection, such as Sm14 and Sm28GST. In this short communication, we report the successful detection of an alternatively spliced truncated form of Sm14 which was highly expressed in an Egyptian strain ofS. mansoni. This truncated Sm14 (TrSm14) protein was formerly reported to be practically non-existent and its complementary DNA (cDNA) was thought to be ‘a rare misprocessing of mRNA precursor’. Our finding demonstrates that there is inter-strain variation in theS. mansonitranscriptome and subsequently in the role/function of the expressed proteins. We expressed TrSm14 successfully inEscherichia colias a fusion protein with the schistosomal antigen Sm28GST. The fusion protein was purified using metal affinity chromatography and was found to be reactive with serum fromS. mansoni-infected patients. This suggests a possible diagnostic value for this protein in detection of anti-schistosomal antibodies. In addition, this fusion protein could offer a potential bivalent vaccine candidate againstS. mansonithat is worthy of further investigation.

Experimental Parasitology, 2014

Through increased awareness and improved diagnostics, microsporidiosis has now been identified in... more Through increased awareness and improved diagnostics, microsporidiosis has now been identified in a broader range of human populations; however current therapies are inconsistently effective. Recently, probiotics were determined as means for the control of intestinal parasitic infections through their secretory products; bacteriocins. This is the first study on the effect of bacteriocin produced by Lactobacillus acidophilus CH1 bacteriocin, with or without gold nanoparticles (Au-NPs), against intestinal microsporidiosis in immunosuppressed mice. Fecal and intestinal spore loads, besides viability, extrusion and infectivity of spores from treated animals were assessed. Results showed that the anti-microsporidial effects of bacteriocin were significantly potent. This efficiency was further potentiated upon conjugating bacteriocins with Au-NPs, as it induced a strikingly sustained reduction in fecal spore shedding after cessation of therapy by 1 week (94.26%). Furthermore, reduction in intestinal spore load was highest in bacteriocin/Au-NPs-inoculated mice (89.7%) followed by bacteriocin-inoculated group (73.5%). Spores encountered from stool of bacteriocin/Au-NPs group showed 92.4% viability, versus 93.7% in bacteriocin group. Spore extrusion and infectivity were most inhibited by exposure to bacteriocin/Au-NPs. Safety of bacteriocin/Au-NPs was also verified. Thus, considering the results of the present work, L. acidophilus CH1-derived bacteriocin can present a powerful safe therapy against intestinal microsporidiosis.

Acta Tropica, 2015

Control of schistosomiasis relies on a single drug, praziquantel (PZQ). Given the rising concerns... more Control of schistosomiasis relies on a single drug, praziquantel (PZQ). Given the rising concerns about the potential emergence of PZQ-resistant strains, it has now become necessary to search for novel therapeutics. However, the current pace for anti-schistosomal drug discovery is slow; hence, repositioning of existing approved drugs can offer a safe, rapid and cost-effective solution. The anti-malarial synthetic artemisinin-derivatives trioxolanes demonstrated anti-schistosomal efficacies against the three major species infecting humans and, unlike PZQ, showed activities against both juvenile and adult worm stages. The 1,2,4-trioxolane/OZ277 (arterolane maleate) in combination with a partner drug: piperaquine phosphate was recently developed as an anti-malarial drug and manufactured by Ranbaxy (India) as Synriam™ (SYN). Herein, the in vivo activities of SYN were investigated in a mouse model of Schistosoma mansoni (S. mansoni), compared to PZQ. We show that a single fixed dose of 240mg/kg SYN (40mg/kg arterolane and 200mg/kg piperaqine) induced significant protective effects in mice, in terms of reduction in worm and tissue egg burdens, which were evident against all schistosome developmental stages. Extensive alterations in the tegument and subtegumental tissues of SYN-exposed worms were revealed by both scanning and transmission electron microscopes. Progressive decrease in worm activity and occurrence of death were noticed in vitro upon exposure to the drug - more pronounced in the presence of haemin. This report provides the first evidence of the efficacy of a combination of 1,2,4-trioxolane and piperaquine against S. mansoni in mice. Being effective against young stages, SYN could be used to prevent early Schistosoma infection.

Alexandria Journal of …, 2012

Background: Leishmaniasis is one of the neglected diseases included in the World Health Organizat... more Background: Leishmaniasis is one of the neglected diseases included in the World Health Organization's list of the top guns of antimicrobial resistance. Miltefosine (MIL) was the first successful oral agent used against visceral leishmaniasis in India. As regards cutaneous leishmaniasis (CL), multiple experimental and clinical studies have investigated its efficacy in treatment of New World CL, while only few trials have focused on Old World CL. Therefore, this work was designed to study the efficacy of MIL in experimental Old World CL caused by Leishmania major (MHOM/IL/81/FEBNI), one of the causative species of CL in the Middle East. Results: Groups of infected mice were given MIL orally, at a dose of 20 mg/kg/day for 20 days. Results showed that untreated infected mice suffered from autoamputation of the inoculated footpads. While, those treated with MIL showed complete clinical cure, significant reduction of parasite burden and improvement of the histopathological changes of the cutaneous lesions. The drug causes evident ultrastructural morphological alterations of L. major amastigote form. One month posttreatment, no clinical sings of relapse were observed, and parasite density continued to decrease significantly. Conclusion: The present study revealed activity of MIL against experimental Old World CL in the mouse model caused by L. major (MHOM/IL/81/FEBNI), one of the causative species of CL in the Middle East.

Experimental Parasitology, 2014

h i g h l i g h t s Combination of Sm14 and Sm29 antigens was tested in S. mansoni infection mode... more h i g h l i g h t s Combination of Sm14 and Sm29 antigens was tested in S. mansoni infection model. Significant reduction of S. mansoni adult worms and tissue egg burden was attained. Reduced liver histopathology and granuloma size was also achieved. Combining antigens is a realistic approach for vaccine development against S. mansoni.