Antiprotozoal potential of Salvadora persica against three virulent subtypes of Blastocystis sp.

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 heat-treated aqueous extracts of S. persica at minimal concentration of 2.5 µl/ml compared to parasites' growth controls (P < 0.05). Maximal antiprotozoal effect was reached at a concentration of 20 µl/ml of S. persica aqueous extract. Means of growth inhibition effect obtained with untreated and heat-treated extracts at 40 µl/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 heat-stable 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.

Subtyping of Blastocystis sp. isolated from symptomatic and asymptomatic individuals in Makkah, Saudi Arabia.

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.

IMPORTED MALARIA TO MAKKAH DISTRICT, SAUDI ARABIA: IS THERE ANY RISK OF LOCAL TRANSMISSION?

In Makkah, Saudi Arabia, there is an impending risk of imported malaria. This risk comes from the fact that millions of people, in majority from tropical and subtropical countries where malaria is endemic, visit the country to perform Hajj and Umrah every year. Moreover, millions of expatriates from endemic countries come to Makkah for work. Likewise, many Saudi citizens travel to endemic areas overseas for business and pleasure. We performed a retrospective analysis of all reported malaria cases in Makkah region, Saudi Arabia for years 2014 and 2015. In addition, sorting of mosquito populations in Makkah region was undertaken. Based on national data regarding reported malaria cases, 235 malaria cases were recorded in years 2014 and 2015. Of the reported cases 232 were non-Saudi and only 3 cases were Saudi. Those recorded Saudi cases were just returning from a travel to an endemic area. Most of the cases (79.6%) were P. falciprum and the remaining was P. vivax. Infected male represent 62% and female represent 38%. Age of the majority of reported cases (71.5%) lie between 31 and 50 years. Most of reported cases were from Chad, Pakistan, Nigeria and Sudan. Sorting of mosquito populations revealed the absence of malaria vectors in Makkah District.

Pattern of malignant solid tumors and lymphomas in children in the east delta of Egypt: A five-year study.

Worldwide, the incidence and mortality rates of childhood cancers differ. The study of incidence patterns and survival rates in childhood malignancies is important in aiding in the planning of treatment centers and in obtaining further information with regard to the etiology. Few studies have investigated the survival in cases of childhood solid tumors in Egypt. The aim of the current study was to evaluate the patterns, frequency and outcome of solid tumors and lymphomas in children admitted to and followed up at the Pediatric Oncology Department of Zagazig University Hospital (Zagazig, Egypt) over a duration of 5 years (January 2004 to December 2008). A retrospective study was conducted, which included 155 children with solid tumors and lymphomas. The medical records were reviewed and the relevant data collected, in particular, those concerning demographic, clinical, histopathological, laboratory and imaging data as well as the treatment plans and outcomes. The mean age of patients was 5.6±3.04 years at diagnosis. The patients comprised 94 males and 61 females. Non-Hodgkin lymphoma (NHL) was the most common tumor type, followed by neuroblastoma (31.0 and 29.0%, respectively). When patients were stratified in terms of age (<5, ≥5 but <10, and ≥10 years), the <5-years-of-age group exhibited the greatest number of patients. Fever, pallor and pain were the most frequent initial clinical presentations among the patients and stage II was the most common stage (39.1%) followed by stage IV, III and I (35.0, 20.3 and 5.6% respectively). The overall 5-year survival rate in the study group was 66.7%. The survival rate was significantly higher in patients with Wilm's tumor and Hodgkin lymphoma, followed by NHL (92.0, 88.0 and 72.0%, respectively; P<0.001), while the mortality rate was significantly higher in patients with neuroblastoma (P<0.001). In conclusion, NHL and neuroblastoma were the most common tumors; the survival rates were higher in patients with Wilm's tumor and Hodgkin lymphoma and lower in patients with neuroblastoma. A larger multicenter study is required to further investigate the conclusions drawn from this study.

Vaccination with Toxoplasma lysate antigen and CpG oligodeoxynucleotides: comparison of immune responses in intranasal versus intramuscular administrations.

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.

Effect of a novel benzimidazole derivative in experimental Schistosoma mansoni infection.

Currently, praziquantel is the only drug of choice for treatment of schistosomiasis. Reports of praziquantel resistance raise concerns about future control of the disease. Therefore, the search for new schistosomicidal drugs is eminent. In this study, the effect of a novel benzimidazole-derived compound (compound BTP-Iso) was assessed in mice harboring adult Schistosoma mansoni (Egyptian strain). Mice were treated 42 days p.i. with compound BTP-Iso using two treatment regimens (200 or 300 mg/kg). In both regimens, there were significant reductions in the number of recovered S. mansoni worms especially females and in immature ova, in addition to a significant reduction in the number and size of hepatic granulomata. A dose of 300 mg/kg resulted in a significant decrease in intestinal and hepatic tissue egg loads. Effect on schistosomes was confirmed by scanning electron microscopy, where adult worms recovered from mice treated with 200 mg/kg of compound BTP-Iso revealed tegumental alternations, characterised by swelling of tegumental ridges, bleb formation, and mild erosion in male worms; however in females, there were extensive erosion and destruction of the tegumental surface. These promising results may encourage future use of compound BTP-Iso in the treatment of schistosomiasis. However, more research is needed to detect the effect of compound BTP-Iso on early developmental stages of S. mansoni and on other species of human schistosomes.

In vivo effect of single oral dose of artemether against early juvenile stages of Schistosoma mansoni Egyptian strain.

The current treatment and control of schistosomiasis, rely on a single drug, praziquantel, although, it has minor activity against juvenile stages of the parasite. Studies have shown that artemether (ART) exhibits effects against juveniles of Schistosoma mansoni Liberian and Puerto Rican strains, Schistosoma japonicum and Schistosoma haematobium. Aiming to assess the in vivo activity of single oral dose of ART against early juvenile stages of S. mansoni Egyptian strain, this study was established. Mice were treated with ART (400 mg/kg) at two time points evenly spaced over the period of larval development (7 and 21 days post-infection; pi), and a third treatment point (day 49 pi) was included to elucidate when susceptibility decreases. Administration of ART on day 7 pi reduced the total worm burden by 85.94%. The greatest reductions were seen when treatment was given on day 21 pi, with total and female worm burden reductions of 91.52% and 90.57%, respectively, and cessation of oviposition. Similar dose given on day 49 pi reduced total worm burden by 55.17% and female worm burden by 66.51%. Moreover, it induced significant reduction in the tissue egg load and significant alterations in the oogram pattern with decreased immature eggs and increased dead eggs. Antipathological activities were evident in significant reductions in granulomata count and diameter. In conclusion, ART exhibits major in vivo schistosomicidal effects against the early larval migratory stages of S. mansoni Egyptian strain, mainly the 21-day old schistosomula, hence preventing disease progression and morbidity.

The role of B-cells in immunity against adult Strongyloides venezuelensis.

BACKGROUND: Strongyloides venezuelensis has been used as a tool and model for strongyloidiasis research. Elimination of S. venezuelensis adult worms from mice has been particularly associated with proliferation and activation of intestinal mast cells and eosinophils. To date, the role of B-cells in the protective mechanism against adult Strongyloides infection in experimental animals has not been reported in the literature. Therefore, the present study was carried to investigate the role of B-lymphocytes in immunity against adult S. venezuelensis infection using mice with a targeted deletion of the JH locus. METHODS: JHD knockout mice with its wild-type Balb/c mice were infected by intra-duodenal implantation of adult S. venezuelensis. Fecal egg count, intestinal worm recovery, mucosal mast cells and eosinophils were counted. RESULTS: At day 11 post infection, parasites in wild-type mice stopped egg laying, while in JHD knockout mice parasites continued to excrete eggs until the end of the observation period, day 107. The higher number of parasite eggs expelled in the feces of JHD knockout infected mice was a consequence of higher worm burdens, which established in the small intestine of these animals. On the other hand worm fecundity was comparable in both groups of mice. Both B-cell-deficient mice and wild-type mice, showed an influx of mucosal mast cells and eosinophils. The absolute numbers in JHD knockout mice were lower than those seen in wild-type mice at day 11, but not to a level of significance. JHD knockout mice could not recover from infection despite the recruitment of both types of cells. CONCLUSION: Our findings highlight a role of B cells in mucosal immunity against invasion of adult S. venezuelensis and in its expulsion. Therefore, we conclude that B-cells together with mucosal mast cells and eosinophils, contribute to immunity against adult S. venezuelensis by mechanism(s) to be investigated.

First insight into the effect of single oral dose therapy with artemisinin-naphthoquine phosphate combination in a mouse model of Schistosoma mansoni infection.

Praziquantel is the current drug of choice against schistosomiasis. The dependency on praziquantel exclusively is problematic, given the spread of the disease and the threat of drug resistance. This study investigates an alternative antischistosomal drug using the compound naphthoquine phosphate tablet, which is a novel single oral dose antimalarial drug, containing a combination of naphthoquine phosphate and artemisinin. In the present study, the therapeutic efficacies of different artemisinin-naphthoquine phosphate combination-dosing protocols were evaluated in experimentally infected mice harbouring juvenile or adult stages of Schistosoma mansoni (Egyptian strain). The study shows that the oral administration of artemisinin-naphthoquine phosphate combination in a single dose of 400 mg/kg on day 7 p.i. resulted in a significant worm burden reduction of 95.07%. When used at a dose of 600 mg/kg on day 21 p.i., all female worms were killed before depositing eggs, resulting in complete absence of eggs in hepatic and intestinal tissues. The same dose given on day 42 p.i. reduced total and female worm burdens by 93.36% and 94.17%, respectively. In addition, artemisinin-naphthoquine phosphate combination induced significant reductions of 80.18% and 76.73% in the hepatic and intestinal tissue egg loads, respectively. Artemisinin-naphthoquine phosphate combination also induced significant alterations in the oogram pattern with elevated levels of dead eggs. Antipathological activities were evident in the amelioration of hepatic granulomata. Our findings hold promise for the development of a novel antischistosomal drug using an artemisinin-naphthoquine phosphate combination. Further in vitro and in vivo studies should be launched to elucidate the possible mechanism/s of action and to study the effect of artemisinin-naphthoquine phosphate combination on other human schistosomes.

Effect of Mirazid in Schistosoma japonicum-infected mice: parasitological and pathological assessment.

Conflicting reports are found in the literature about the antischistosomal efficacy of Mirazid (MZ), which is a special formulation of myrrh obtained from the stem of the plant Commiphora molmol. This initiated the present study to assess this drug for the first time in experimental schistosomiasis japonicum. Mice were divided into four groups: infected untreated control (I); infected treated with MZ, 500 mg/kg (II); infected treated with MZ, 250 mg/kg (III); and infected treated with praziquantel (PZQ), 200 mg/kg (IV). The drugs were given 7 weeks post-infection for five successive days. All animals were killed 3 weeks posttreatment. Results showed no signs of antibilharzial activity of MZ. Total worms, total tissue egg load, egg developmental stages, and granuloma area were not affected by any of the MZ treatment regimens as compared to the infected untreated group (P > 0.05 for all variables). These results were in contrast to those obtained in PZQ-treated animals in which 82.82 % total worm reduction, 94.62 % egg reduction, and 86.35 % granuloma area reduction were observed. Also, it significantly increased the percentage of dead ova and decreased the percentage of mature ova with complete absence of immature ones in comparison with the control group (P < 0.01 for all variables). In conclusion, the results of the current study raise serious doubts about the antischistosomal activity of MZ.

Prevalence of genital tract infection with Entamoeba gingivalis among copper T 380A intrauterine device users in Egypt.

BACKGROUND: This study was performed to study the prevalence and potential pathogenicity of E. gingivalis in the genital tracts of intrauterine contraceptive device (IUD) users. STUDY DESIGN: A prospective study conducted at the Obstetrics and Gynecology Department and Fertility Care Unit, Mansoura University Hospital, Egypt. The study was carried out on 87 IUD users and 87 nonusers. The copper T 380A IUD was removed from each woman and washed with phosphate-buffered saline (PBS) pH 7.4; the IUD wash was centrifuged. The sediment was resuspended in 2 ml PBS and divided into two portions. One portion was used for preparation of direct and iron hematoxylin-stained smears. Direct smears and stained smears were examined for detailed morphology. The second portion of the sediment was used for DNA extraction and subsequent PCR amplification targeting the small subunit ribosomal RNA of E. gingivalis. RESULTS: The parasite was found in 12.64% of IUD users and in 6.9% of non users (p>.3). It was found that 90.9% of those harboring E. gingivalis in their genital tract had the parasite in their oral cavity. The percentage of genital infection in IUD users increased with low level of education, rural areas, insertion in primary health-care center and among those not washing hands before checking the strings. In the infected cases, vaginal discharge was more common (81.8%) than in noninfected cases (32.9%), such difference was statistically significant (p<.05). Also, excessive vaginal discharge is more common than backache and menorrhagia in the infected cases. CONCLUSION: Higher incidence of E. gingivalis infection in IUD users is related to oral cavity infection, residence, the facility where they inserted their IUD and washing hands attitude before checking the strings. We recommend treatment of gingival infection, proper counseling and medical education on oral and genital tract hygiene for IUD users.

Past and present situation of human fascioliasis in Dakahlia Governorate, Egypt.

Zoonotic fascioliasis is a problem not only in Dakahlia Governorate, but also in other Egyptian Governorates. This work was conducted in ten centers at Dakahlia Governorate, Egypt. Three thousand cases were randomly selected annually from each center representing five rural and five urban areas. Cases were examined for Fasciola infection by stool examination using, direct smear, formol ether sedimentation and Kato-Katz technique. Infection was higher in rural areas than urban areas. Female /male ratio was 1.5:1. Children between five and ten years old represent the highest infected group. The prevalence of infection was more among illiterate compared to educated individuals examined. Remarkable reduction in the prevalence rate was recorded in the last year of study compared to previous years, which is a good index of excellent control measures conducted by the Egyptian governorate to overcome parasitic infections.

Prevalence of low positive anti-HCV antibodies in blood donors: Schistosoma mansoni co-infection and possible role of autoantibodies.

Patients infected with schistosoma frequently show a high seroprevalence of anti-hepatitis C virus (anti-HCV) antibodies. The aim of this study was to find the underlying reason for this phenomenon, and to examine a possible involvement of autoantibodies. Out of 2,400 Egyptian blood donors, 192 (8%) were anti-HCV positive by ELISA. They were 133 males and 59 females with age ranging from 27 to 48 years. According to optical density ratio (ODR) of anti-HCV antibodies, 96 cases were low positive (LP) with ODR (1-2) designated as group I, and 96 were high positive (HP) with ODR (> or =2) (group II). Both groups were examined for quantitative HCV core antigen (HCVcAg), liver function (Albumin, ALT, AST) and anti-Schistosoma mansoni(anti-Sm) IgG. Group I cases were HCVcAg negative with normal liver function tests, and 44 of them were anti-Sm positive. Ninety cases (93.75%) of group II were HCVcAg positive with markedly affected liver function tests and 72 cases were anti-Sm positive. All group I cases were examined for autoimmune markers (ANA, AMA, SMA and LKM). In group I, 33 (75%) of anti-Sm positive cases were positive for one or more of the autoimmune markers examined, while none of anti-Sm negative was positive for any marker with significant difference between the two groups (P < 0.0001). Our results primarily on blood donors indicate that LP anti-HCV frequently represents false-positive reactivity with a possible role of Sm-induced autoantibodies in this phenomenon.

Protective effect of vaccination with Toxoplasma lysate antigen and CpG as an adjuvant against Toxoplasma gondii in susceptible C57BL/6 mice.

Infection with the intracellular protozoan parasite Toxoplasma gondii causes serious public health problems to both humans and livestock and of great economic impact worldwide. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote Th1 responses, an adjuvant activity that is desirable for vaccination against intracellular pathogens. We investigated the feasibility of using CpG as an adjuvant combined with Toxoplasma lysate antigen (TLA) as a vaccine against toxoplasmosis. Genetically susceptible C57BL/6 mice were vaccinated with TLA with or without CpG ODN as an adjuvant and then challenged with 85 cysts of the moderately virulent RRA (Beverley) strain of T. gondii. Prior to challenge infection, immunization with TLA plus CpG ODN directed cellular and humoral immunity toward a Th1 pattern, characterized by enhanced INF gamma production by splenic cells in response to TLA, and enhanced production of toxoplasma-specific IgG and IgG (2a) antibodies. Consequently, CpG/TLA-treated mice showed prolonged survival and 64% reduction in brain parasite burden compared to non-CpG/TLA treated group. Our results suggest that CpG ODN would provide a stable and effective adjuvant for use in vaccination against toxoplasmosis.

Establishment of Schistosoma japonicum calpain-specific mouse T cell hybridomas and identification of a T cell epitope that stimulates IFNgamma production.

Calpain is a calcium-dependent cystein protease, and the homologues of schistosome are known as one of vaccine candidate molecules against schistosomiasis. Here, we established two IL-2 producing T cell hybridoma cell lines specific for Schistosoma japonicum calpain, to identify T cell epitope(s) on the molecule. Overlapping 15mer oligopeptides of calpain were synthesized and tested for their stimulatory abilities to the hybridomas. As a result, epitopes recognized by the two hybridoma lines were the same: EQLKIYAQRC. Spleen cells from calpain multiple antigenic peptide (MAP)-immunized BALB/c mice produced IFNgamma upon stimulation with MAP or soluble worm antigen preparation (SWAP). The identification of the T cell epitope to stimulate Th1 response will contribute to the proper design of synthetic vaccines, evaluation of their protective potentials and elucidation of protective mechanisms in murine experimental schistosomiasis.

Reliability of hepatitis C virus core antigen assay for detection of viremia in HCV genotypes 1, 2, 3, and 4 infected blood donors: a collaborative study between Japan, Egypt, and Uzbekistan.

Nucleic acid amplification-based methods are used for confirmation of viremia in antibody to hepatitis C virus (anti-HCV)-positive patients. However, this technology is labor intensive, time consuming, requires complex laboratory conditions, and expensive. The aim of this study was to evaluate the sensitivity and specificity of the HCV core antigen (HCVcAg) assay as an alternative approach for confirmation of viremia in HCV-infected subjects with HCV genotype 1-4. Two hundred forty-six asymptomatic HCV RNA- positive donors were enrolled in this study, consisting of 122 blood donors from Egypt (116 with genotype 4, 4 with genotype 1, and 2 with 1 + 4 genotypes), 109 from Japan (85 with genotype 1, and 24 with genotype 2), and 15 from Uzbekistan (all with genotype 3). A total of 234 (95.1%) of 246 RNA-positive specimens were detected by the HCVcAg assay; the sensitivity of HCVcAg assay consisted 93.4, 100, 100, and 94.8% for genotypes 1, 2, 3, and 4, respectively in comparison with RT-PCR assay. The specificity of the assay was confirmed in the absence of the false-positive results among 53 anti-HCV-negative, but anti-Schistosoma mansoni (anti-Sm) positive donors from Egypt. A positive correlation between HCVcAg and HCV RNA concentration levels (r = 0.671, P < 0.05) was observed among specimens with HCV genotype 4. The mean HCVcAg level was significantly lower in specimens with genotype 4 (2,935 fmol/L) comparing to genotypes 1, 2, and 3 (5,034, 4,962, and 4,740 fmol/L, respectively). No specific mutation was found in the core-encoding region of the studied specimens. In conclusion, HCVcAg is shown to be specific, sensitive, and informative qualitative index for HCV viremia in asymptomatic carriers.

Intraepithelial infiltration of eosinophils and their contribution to the elimination of adult intestinal nematode, Strongyloides venezuelensis in mice.

Eosinophils were examined for the capacity of attacking Strongyloides venezuelensis adult worms in the intestinal mucosa by using interleukin (IL)-5 transgenic mice. In IL-5 transgenic mice, most of the subcutaneously inoculated infective larvae were killed during migration, and only a few worms could reach the small intestine. When the same number of adult worms were surgically implanted in the small intestine of IL-5 transgenic and control mice, fecal egg output as well as the number of adult worms recovered from the intestine was significantly lower in IL-5 transgenic mice. In the intestinal mucosa of IL-5 transgenic mice, large number of eosinophils was present in the lamina propria even before adult worm implantation. The number of eosinophils increased significantly as early as 24 h after implantation and tripled by day 3, whereas mucosal eosinophilia remained low in wild-type mice. Most notably, eosinophils infiltrated into the intestinal epithelium and surrounded adult worms in IL-5 transgenic mice, which was never seen in wild-type control mice. However, IL-5 transgenic mice required the same period as normal mice to completely expel implanted adult worms. The amount of specific IgA as well as total IgA in the stool was high in IL-5 transgenic mice before adult worm implantation, and dropped rapidly after adult worm implantation. The present study suggests that eosinophils are capable of attacking adult nematodes in the intestinal epithelia, probably in conjunction with secretory IgA, although they are not enough for the complete worm expulsion.

Strongyloides venezuelensis: longitudinal distribution of adult worms in the host intestine is influenced by mucosal sulfated carbohydrates.

Mechanisms for the longitudinal distribution of parasitic females of Strongyloides venezuelensis in the host intestine were investigated in mice. Adult worms were mostly recovered from the anterior-most one-third of the small intestine throughout the infection after infective larvae inoculation. Surgically implanted adult worms established well in the small intestinal mucosa, either in the duodenum or in the ileum, whereas a few worms could establish in the large intestine. Implanted worms in the small intestine remained where they were implanted until expelled. Mucosal mast cells were induced in the whole small intestine after the worm implantation. In the large intestine, a considerable number of adult worms settled in the mucosa of mutant mice, whose goblet cell mucins were undersulfated because of a mutation in sulfate-activating enzymes. In these mice, the degree of sulfation of goblet cell mucins in the large intestine was significantly reduced to the level of normal small intestine goblet cell mucins. Our results suggest that sulfated glycoconjugates, either from mucosal mast cells or goblet cells, have important effects on the longitudinal distribution of parasitic females of S. venezuelensis.