Eosinophils mediate SIgA production triggered by TLR2 and TLR4 to control Ascaris suum infection in mice.

Human ascariasis is the most prevalent but neglected tropical disease in the world, affecting approximately 450 million people. The initial phase of Ascaris infection is marked by larval migration from the host's organs, causing mechanical injuries followed by an intense local inflammatory response, which is characterized mainly by neutrophil and eosinophil infiltration, especially in the lungs. During the pulmonary phase, the lesions induced by larval migration and excessive immune responses contribute to tissue remodeling marked by fibrosis and lung dysfunction. In this study, we investigated the relationship between SIgA levels and eosinophils. We found that TLR2 and TLR4 signaling induces eosinophils and promotes SIgA production during Ascaris suum infection. Therefore, control of parasite burden during the pulmonary phase of ascariasis involves eosinophil influx and subsequent promotion of SIgA levels. In addition, we also demonstrate that eosinophils also participate in the process of tissue remodeling after lung injury caused by larval migration, contributing to pulmonary fibrosis and dysfunction in re-infected mice. In conclusion, we postulate that eosinophils play a central role in mediating host innate and humoral immune responses by controlling parasite burden, tissue inflammation, and remodeling during Ascaris suum infection. Furthermore, we suggest that the use of probiotics can induce eosinophilia and SIgA production and contribute to controlling parasite burden and morbidity of helminthic diseases with pulmonary cycles.

Lectin-Mediated Bacterial Modulation by the Intestinal Nematode Ascaris suum.

Ascariasis is a global health problem for humans and animals. Adult Ascaris nematodes are long-lived in the host intestine where they interact with host cells as well as members of the microbiota resulting in chronic infections. Nematode interactions with host cells and the microbial environment are prominently mediated by parasite-secreted proteins and peptides possessing immunomodulatory and antimicrobial activities. Previously, we discovered the C-type lectin protein AsCTL-42 in the secreted products of adult Ascaris worms. Here we tested recombinant AsCTL-42 for its ability to interact with bacterial and host cells. We found that AsCTL-42 lacks bactericidal activity but neutralized bacterial cells without killing them. Treatment of bacterial cells with AsCTL-42 reduced invasion of intestinal epithelial cells by Salmonella. Furthermore, AsCTL-42 interacted with host myeloid C-type lectin receptors. Thus, AsCTL-42 is a parasite protein involved in the triad relationship between Ascaris, host cells, and the microbiota.

2-Methyl-pentanoyl-carnitine (2-MPC): a urine biomarker for patent Ascaris lumbricoides infection.

Infections with intestinal worms, such as Ascaris lumbricoides, affect hundreds of millions of people in all tropical and subtropical regions of the world. Through large-scale deworming programs, World Health Organization aims to reduce moderate-to-heavy intensity infections below 1%. Current diagnosis and monitoring of these control programs are solely based on the detection of worm eggs in stool. Here we describe how metabolome analysis was used to identify the A. lumbricoides-specific urine biomarker 2-methyl pentanoyl carnitine (2-MPC). This biomarker was found to be 85.7% accurate in determining infection and 90.5% accurate in determining a moderate-to-heavy infection. Our results also demonstrate that there is a correlation between 2-MPC levels in urine and A. lumbricoides DNA detected in stool. Furthermore, the levels of 2-MPC in urine were shown to rapidly and strongly decrease upon administration of a standard treatment (single oral dose of 400 mg albendazole). In an Ascaris suum infection model in pigs, it was found that, although 2-MPC levels were much lower compared to humans, there was a significant association between urinary 2-MPC levels and both worm counts (p = 0.023) and the number of eggs per gram (epg) counts (p < 0.001). This report demonstrates that urinary 2-MPC can be considered an A. lumbricoides-specific biomarker that can be used to monitor infection intensity.

Oxfendazole kinetics in pigs: In vivo assessment of its pattern of accumulation in Ascaris suum.

Ascaris suum is a widespread parasitic nematode that causes infection in pigs with high prevalence rates. Oxfendazole (OFZ) is effective against A. suum when used at a single high oral dose of 30 mg/kg. The aim of this study was to assess the pattern of distribution/accumulation of OFZ and its metabolites, in bloodstream (plasma), mucosal tissue and contents from small and large intestine and adult specimens of A. suum collected from infected and treated pigs. The activity of glutathione-S-transferases (GSTs) in A. suum was also investigated. Infected pigs were orally treated with OFZ (30 mg/kg) and sacrificed at 0, 3, 6 and 12 h after treatment. Samples of blood, mucosa and contents from both small and large intestine as well as adult worms were obtained and processed for quantification of OFZ/metabolites by HPLC. OFZ was the main analyte measured in all of the evaluated matrixes. The highest drug concentrations were determined in small (AUC0-t 718.7 ±â€¯283.5 µg h/g) and large (399.6 ±â€¯110.5 µg h/g) intestinal content. Concentrations ranging from 1.35 to 2.60 µg/g (OFZ) were measured in adult A. suum. GSTs activity was higher after exposure to OFZ both in vivo and ex vivo. The data obtained here suggest that the pattern of OFZ accumulation in A. suum would be more related to the concentration achieved in the fluid and mucosa of the small intestine than in other tissues/fluids. It is expected that increments in the amount of drug attained in the tissues/fluids of parasite location will correlate with increased drug concentration within the target parasite, and therefore with the resultant treatment efficacy. The results are particularly relevant considering the potential of OFZ to be used for soil transmitted helminths (STH) control programs and the advantages of pigs as a model to assess drug treatment to be implemented in humans.

Shared expression of mucin12 in Ascaris lumbricoides and the human small intestine.

This study focuses on the host-parasite relationship of human Ascaris lumbricoides, which is a parasite of the small intestine and is also one of the commonest parasites worldwide. As part of this investigation, we examined the host-parasite relationship assuming that there is a common antigenicity, shared protein between A. lumbricoides and human small intestinal mucosa, using molecular techniques. We obtained three DNA clones from human colon cDNA library by screening for anti-A. lumbricoides polyclonal antibodies. The transmembrane mucin12 gene was identified after sequencing analysis of these clones. Specific signals of immunostaining with polyclonal anti-mucin12 antibodies were observed in the mucous secretory organs, epidermis, and intestinal canal of A. lumbricoides. These signals disappeared when immunohistochemistry was performed using pre-absorbed polyclonal antibodies with a specific peptide. These results suggest that mucin12 is localized in the mucous secretory organs in the epidermis of A. lumbricoides. Furthermore, we examined the site of mucin12 localization in the host; specific mucin12 signals were observed on the mucosal epithelia present around intestinal crypts and villi of the small intestine. Therefore, we suggest that mucin12 is a protein that shows common antigenicity in both A. lumbricoides and its host. It is presumed that adult A. lumbricoides live in their preferred environment, which is the small intestine, by secreting mucin12 to avoid being attacked by the host immune system.

Bifidobacterium animalis subspecies lactis modulates the local immune response and glucose uptake in the small intestine of juvenile pigs infected with the parasitic nematode Ascaris suum.

An evaluation of a localized intestinal allergic type-2 response concomitant with consumption of probiotic bacteria is not well documented. This study investigated the effect of feeding probiotic Bifidobacterium animalis subspecies lactis (Bb12) or a placebo in weaned pigs that were also inoculated with Ascaris suum (A. suum) eggs to induce a strong Th2-dependent allergic type 2 immune response. Sections of jejunal mucosa were mounted in Ussing chambers to determine changes in permeability and glucose absorption, intestine and liver samples were collected for analysis of type-2 related gene expression, jejunum examined histologically, and sera and intestinal fluid were assayed for parasite antigen specific antibody. The prototypical parasite-induced secretory response to histamine and reduced absorption of glucose in the jejunum were attenuated by feeding Bb12 without a change in mucosal resistance. Parasite antigen-specific IgA response in the serum and IgG1 and IgG2 response in the ileal fluid were significantly increased in A. suum-infected pigs treated with Bb12 compared to infected pigs given the placebo. Ascaris suum-induced eosinophilia in the small intestinal mucosa was inhibited by Bb12 treatment without affecting the normal expulsion of A. suum 4th stage larvae (L4) or the morphometry of the intestine. Expression of genes associated with Th1/Th2 cells, Treg cells, mast cells, and physiological function in the intestine were modulated in A. suum infected-pigs treated with Bb12. These results suggested that Bb12 can alter local immune responses and improve intestinal function during a nematode infection by reducing components of a strong allergenic type-2 response in the pig without compromising normal parasite expulsion.

Cognitive Performance and Iron Status are Negatively Associated with Hookworm Infection in Cambodian Schoolchildren.

Soil-transmitted helminth (STH) infection has been associated with lower cognitive performance of schoolchildren. To identify pathways through which STH infection might affect school performance, baseline data from a large rice-fortification trial in Cambodian schoolchildren were used to investigate associations between STH infection, micronutrient status, anemia, and cognitive performance. Complete data on anthropometry, cognitive performance, and micronutrient status were available for 1,760 schoolchildren, 6-16 years of age. STH infection was identified using Kato-Katz, whereas cognitive performance was assessed using Raven's Colored Progressive Matrices (RCPM), block design, and picture completion. STH infection was found in 18% of the children; almost exclusively hookwork infection. After adjusting for age and gender, raw cognitive test scores were significantly lower in hookworm-infected children (-0.65; -0.78; -2.03 points for picture completion, RCPM, and block design, respectively; P < 0.05 for all). Hookworm infection was associated with iron status (total body iron), but not with vitamin A and zinc status, nor with inflammation or anthropometry. Body iron was negatively associated with increased intensity of hookworm infection (R = 0.22, P < 0.001). Hookworm infection in Cambodian schoolchildren was associated with lower cognitive performance, an effect most likely mediated through lower body iron. Interventions that are more effective against hookworm infection are needed to contribute to better health and improvement of cognitive performance.

Differential changes in expression of intestinal antimicrobial peptide genes during Ascaris lumbricoides infection in Zambian adults do not respond to helminth eradication.

BACKGROUND: Intestinal helminthiasis modulates immune responses to vaccines and environmental allergens. To explore the impact on intestinal host defense, we assessed expression of antimicrobial peptide genes, together with T cell subset markers and cytokines, in patients with ascariasis before and after treatment. METHODS: Case patients (n = 27) and control subjects (n = 44) underwent enteroscopy for collection of jejunal biopsy specimens, which were used in quantitative, real-time reverse-transcription polymerase chain reaction for a range of host defense genes; blood samples were also analyzed simultaneously. RESULTS: The level of gene expression (mRNA) of HD5, hBD1, and LL-37 was lower in case patients than in control subjects, and the level of expression of HD6 was increased. However, after successful eradication, there was no trend to values seen in control subjects. Helminthiasis was associated with increased intestinal expression of the Th1 genes T-bet and interferon-γ. In peripheral blood mononuclear cells (PBMCs), a mixed profile of T cell markers and cytokines was increased. Ascaris-induced down-regulation of HD5 was observed in individuals with higher RORγt expression in PBMCs, but we found no evidence that this was mediated by circulating interleukin-22. CONCLUSIONS: Human ascariasis was associated with changes in antimicrobial peptide gene expression and immunological markers. Such changes may have implications for susceptibility to infectious disease and responsiveness to oral vaccines in tropical populations.

Localized multigene expression patterns support an evolving Th1/Th2-like paradigm in response to infections with Toxoplasma gondii and Ascaris suum.

Human infectious diseases have been studied in pigs because the two species have common microbial, parasitic, and zoonotic organisms, but there has been no systematic evaluation of cytokine gene expression in response to infectious agents in porcine species. In this study, pigs were inoculated with two clinically and economically important parasites, Toxoplasma gondii and Ascaris suum, and gene expression in 11 different tissues for 20 different swine Th1/Th2-related cytokines, cytokine receptors, and markers of immune activation were evaluated by real-time PCR. A generalized Th1-like pattern of gene expression was evident in pigs infected with T. gondii, along with an increased anti-inflammatory gene expression pattern during the recovery phase of the infection. In contrast, an elevated Th2-like pattern was expressed during the period of expulsion of A. suum fourth-stage larvae from the small intestine of pigs, along with low-level Th1-like and anti-inflammatory cytokine gene expression. Prototypical immune and physiological markers of infection were observed in bronchial alveolar lavage cells, small intestinal smooth muscle, and epithelial cells. This study validated the use of a robust quantitative gene expression assay to detect immune and inflammatory markers at multiple host tissue sites, enhanced the definition of two important swine diseases, and supported the use of swine as an experimental model for the study of immunity to infectious agents relevant to humans.

Serum malondialdehyde level in patients infected with Ascaris lumbricoides.

AIM: The aim of the study was to investigate the changes of serum malondialdehyde level, i.e; the oxidative stress hypothesis in patients infected with Ascaris lumbricoides. METHODS: Serum malondialdehyde activity was measured in 43 patients who were positive for intestinal parasite of Ascaris lumbricoides. Scores were obtained for the positives and their age-and sex-matched 60 Ascaris lumbricoides negative healthy controls. RESULTS: The difference between malondialdehyde levels of patients infected with Ascaris lumbricoides and control group was statistically significant both for females (P<0.05) and for males (P<0.05). In the patient and control groups, no correlation was found between age and malondialdehyde levels (P>0.05) both in females and in males. In addition, no significant correlation could be found between malondialdehyde levels of both females and males for patients and control groups (P>0.05). CONCLUSION: Malondialdehyde levels clearly increase in patients infected with Ascaris lumbricoides.

Selective alterations in mast cell subsets and eosinophil infiltration in two complementary types of intestinal inflammation: ascariasis and Crohn's disease.

OBJECTIVE: Numbers of mast cells (MCs) of different subpopulations and the extent of eosinophil infiltration were compared in Crohn's disease and ascariasis. These two types of intestinal inflammation are complementary with regard to T cell response (TH1 versus TH2), prevalence and environmental factors. METHODS: Histochemical, immunohistochemical and ultrastructural tools were applied to biopsies of morphologically uninvolved colon, ileum and duodenum from Crohn's and ascariasis patients, as well as resection margins and tissues from an experimental porcine ascariasis model. MC subsets were defined by their dye-binding properties, and their chymase content was analysed using biochemical tools. RESULTS: The TH2 (IgE-mediated) response in ascariasis was characterised by a dramatic increase in mucosal- type MCs (MMCs) and eosinophils in both the mucosa and the deeper layers of the intestinal wall and a simultaneous decrease of connective tissue-type MCs (CTMCs). Uninvolved intestine of Crohn's patients showed moderate proliferation of CTMCs in the deeper layers of the intestinal wall, but a significant decrease of the MMCs, associated with moderate eosinophilia in all layers of the gut. Similar changes were present in the uninvolved duodenum of Crohn's patients. Comparable amounts of chymase could be extracted from mucosal and submucosal duodenum, with similar proportions of its two principal isoforms in each. CONCLUSIONS: Our results indicate that T cell responses (TH1 or TH2) are associated with different MC subsets in intestinal inflammation. Changes remote from the focus of inflammation point to the systemic nature of the different MC responses.

Increase in serum beta-carotene following dark green leafy vegetable supplementation in Mebendazole-treated school children in Bangladesh.

OBJECTIVE: To study the effect of consumption of dark green leafy vegetables (DGLV) and sweet pumpkin on serum beta-carotene and retinol concentrations in children treated for Ascaris lumbricoides. DESIGN: Experimental study with a randomised design. SUBJECTS: A total of 110 primary school children aged 8-12 y in northwestern Bangladesh. INTERVENTIONS: All children were de-wormed and 2 weeks later randomly assigned to one of three groups to receive for 6 days per week, for 6 weeks, one complete meal containing either: (1) 4.4 mg beta-carotene from DGLV (n=37, after 18 dropouts); (2) 1.5 mg beta-carotene from sweet pumpkin (n=36, 18 dropouts); or (3) vegetables containing virtually no beta-carotene (control) (n = 37, 18 dropouts). RESULTS: Significant increases (P < 0.001) in mean serum beta-carotene concentrations were seen in all three study groups, with a statistically higher increase (micromol/l) in the DGLV group (0.44; 95% confidence interval (CI) 0.32, 0.55) compared to the control group (0.20; 95% CI 0.14, 0.26; P = 0.002). The increase in serum retinol (micromol/l) was statistically significant (P=0.04) only in the DGLV group (mean 0.066; 95% CI 0.002, 0.13), but this increase was not different from the increase in the control group. CONCLUSION: In children successfully treated for Ascaris lumbricoides, a substantial increase in serum beta-carotene was seen after feeding with a moderately high cumulative dose of DGLV for 6 weeks.

Relationship of childhood protein-energy malnutrition and parasite infections in an urban African setting.

A clear understanding of protein-energy malnutrition (PEM), parasite infection and their interactions is essential in formulating health and development policies. We studied the prevalence of PEM indicators and the prevalence and/or intensity of infection in 558 Zairian children aged 4 months to 10 years. Multivariate analyses were used to estimate relationships between PEM indicators and parasitic infection. Stunting was found in 40.3% of children, wasting in 4.9% and kwashiorkor in 5.1%. The risk of stunting was significantly higher in children with Ascaris lumbricoides. The risk of wasting was higher in children with A. lumbricoides or Trichuris trichiura, whereas the risk of kwashiorkor was high with T. trichiura but very reduced in those with A. lumbricoides. Plasmodium infection was not related to nutritional indicators. These relationships highlight important interactions, both synergistic and antagonistic, between nutrition and parasites in central Africa.

Effect of intestinal helminthiasis on intestinal permeability of early primary schoolchildren.

Intestinal permeability of 246 early primary schoolchildren at 2 schools (106 of whom were infected with intestinal helminths) was assessed by using the lactulose/mannitol differential absorption test. The ratio of the urinary recoveries of lactulose and mannitol was determined after oral administration of a standard solution of the 2 sugars. Assessment of intestinal permeability was repeated on 100 infected children after treatment and on a cohort of 68 uninfected children. Infected and uninfected groups were compared with respect to baseline lactulose/mannitol ratio (L/M1) and change in lactulose/mannitol ratio between assessments (delta L/M). The correlations between baseline intensity of infection and L/M1, and between fall in intensity and delta L/M, were evaluated. Based on a crude index of socioeconomic status, each child was assigned to one of 3 socioeconomic groups; all but 3 children belonged to either groups 2 or 3. Trichuris trichiura and Ascaris lumbricoides were the 2 predominant infections; the hookworm infection rate was relatively low. The results suggested that helminthiasis exerted only a marginal effect on intestinal permeability, the impact of which in children from lower socioeconomic backgrounds was negligible in comparison with the cumulative effects of other factors.

Inhibitory activity of soluble material from sheep eosinophils for sheep complement.

Soluble material from frozen and thawed sheep eosinophils and sonicated extracts of eosinophils or their granules inhibited the alternative activation pathway dependent action of sheep complement for human erythrocytes sensitized by sheep antibody. Sephadex G-50 fractions of the sonicated eosinophil and granule extracts showed that inhibitory activity was associated with the void volume fraction, the fraction possessing the eosinophil peroxidase activity.

Vitamin A absorption in children with ascariasis.

The effect of Ascaris lumbricoides infection on retinol absorption was investigated in young children from a slum area of Dhaka City, Bangladesh. Twenty-four children aged 4-10 years were screened and in every case eggs of either Ascaris, Trichuris or hookworm were isolated from the stool. The average serum retinol was 0.91 (SD 0.35) mumol/l and sixteen children had levels below 1.05 mumol/l. This compared with a serum retinol concentration of 1.70 (SD 0.52) mumol/l in five reference children from a more privileged social background. An oral dose of retinol (41.8 mumol) was given to ten children in whom the concentration of Ascaris eggs in the stool varied. Less than 1% of the supplement could be recovered in the stools collected over the following 48 h. Ascaris worms were isolated from the stool and assayed for retinol content. In no case was retinol detected in the worms. These findings do not support the contention that infection with Ascaris predisposes to malabsorption of vitamin A.

[Alpha-amylase release by pancreatic acini isolated from guinea pigs infected with invasive eggs of Ascaris suum]. / Uwalnianie alfa-amylazy przez komórki pecherzykowe izolowane z trzustek swinek morskich zarazonych inwazyjnymi jajami Ascaris suum.

The studies were carried out on dispersed acini prepared from pancreas of guinea pigs infected with 5000 invasive eggs of Ascaris suum. The basal amylase secretion and that stimulated with acetylcholine and carbachol or blocked with atropine was determined. The basal secretion of amylase was significantly higher in pancreatic acini isolated from infected animals. The stimulation by acetylcholine and carbachol of these acini was weaker than in the control group. These results suggest that cholinergic stimulation of pancreatic amylase secretion was changed during larval ascariasis.

Influence of intestinal parasitism on lactose absorption in well-nourished African children.

Hydrogen breath tests were performed in Gabon (Central Africa) after a loading dose of lactose in 67 well-nourished African children (50 with intestinal parasites and 17 unparasitized) and in 18 unparasitized young adults. All had normal nutritional status, and none had diarrhea or digestive symptoms. Parasites that were found included Ascaris lumbricoides in 76% of the parasitized children, Trichuris trichiura in 58%, Giardia in 24%, Entamoeba histolytica in 20%, Schistosoma intercalatum in 16%, and Necator Americanus in 14%. A similar proportion of parasitized (64%) or unparasitized (62.8%) subjects were lactose malabsorbers. Giardia infection was associated with a higher, but not significantly different, proportion of lactose intolerance (10 of 12, 83.3%). The presence of infection with A. lumbricoides or T. trichiura did not increase the percentage of lactose malabsorption. These data indicate that a decrease of lactase activity in well-nourished African children is not related to the presence or the importance of Ascaris or other intestinal parasites if the nutritional status is normal.

Absorption of carbohydrate from rice in Ascaris lumbricoides infected Burmese village children.

With the objective of determining the relationship between ascariasis and carbohydrate absorption from rice, breath hydrogen tests (BHT's) were performed in two study populations of Burmese village children. Using a rice test meal, breath hydrogen peaks greater than 10 ppm above baseline within 4 hours (indicating rice malabsorption) were seen in 24 out of 55 (44 per cent) Ascaris lumbricoides infected children and 3 out of 18 (17 per cent) non-infected children (age 18-59 months). In another ascaris endemic village 139 children (age 36-108 months) underwent a rice meal BHT. Seventy children had been regularly dewormed for 2 years (single dose levamisole 50 mg every 3 months) whilst 69 children had been dewormed once in 2 years, 6 weeks before breath testing. Regularly dewormed children showed a lower prevalence of rice malabsorption (33 per cent) compared to the control group (54 per cent) (P < 0.05). These findings suggest that malabsorption of carbohydrate from rice can occur during Ascaris lumbricoides infection in children.

[Experience with the use of nemocide (pyrantel pamoate) in nematodiases]. / Opyt primeneniia nemotsida (pirantelia pamoata) pri nematodozakh.

The clinical efficacy of and tolerance to the nemocide pyranthel pamoate produced by "IPCA" (India) and applied to nematodiasis treatment have been investigated. A high efficacy of the drug (94.4-100%) for ascariasis, enterobiasis and ancylostomiasis treatment has been established. The drug is well tolerated by adults and induces slight short-term alterations of hepatic functional activity in 5-10-year-old children.