Effects of TNF-α and IL-10-819 T>C single nucleotide polymorphisms on urogenital schistosomiasis in preschool children in Zimbabwe.

BACKGROUND: Knowledge gaps exist between host genetic factors and susceptibility to schistosomiasis. OBJECTIVE: This study determined cytokine levels and single nucleotide polymorphisms of tumour necrosis factor (TNF)-α (rs1800629) and interleukin (IL)-10 (rs1800871) and their possible impact on susceptibility to schistosomiasis in preschool-age children in the Madziva area of Shamva district, Mashonaland Central province, Zimbabwe. METHODS: Urogenital schistosomiasis was diagnosed using the urine filtration method, while a sandwich enzyme-linked immunosorbent assay was used for cytokine level determination. The survey was done in August 2015 and reinfection levels post treatment were assessed at 3, 6 and 12 months. Amplification refractory mutation system polymerase chain reaction with visualisation on 2% agarose gel electrophoresis was used for genotyping. RESULTS: Schistosomiasis prevalence was found to be 10.5% (59/563). Reinfections were detected in only six children at 3 months and only one was reinfected at 12 months. There were no significant differences in TNF-α-308 G/A allele or genotype frequencies between the Schistosoma haematobium infected participants (p = 0.360) and uninfected participants (p = 0.279). However, no children with the IL-10-819 TT genotype had schistosomiasis. The TNF-α GG genotype corresponded with significantly lower TNF-α levels when compared with the GA or AA genotypes (p < 0.001), and TNF-α levels were significantly lower in infected children compared to uninfected children (p < 0.001). CONCLUSION: Higher TNF-α levels and lower IL-10 levels are potentially protective against schistosomiasis infection. The IL-10-819 TT genotype is potentially protective against infection through its association with lower IL-10 levels.

The gut microbiome but not the resistome is associated with urogenital schistosomiasis in preschool-aged children.

Helminth parasites have been shown to have systemic effects in the host. Using shotgun metagenomic sequencing, we characterise the gut microbiome and resistome of 113 Zimbabwean preschool-aged children (1-5 years). We test the hypothesis that infection with the human helminth parasite, Schistosoma haematobium, is associated with changes in gut microbial and antimicrobial resistance gene abundance/diversity. Here, we show that bacteria phyla Bacteroidetes, Firmicutes, Proteobacteria, and fungi phyla Ascomycota, Microsporidia, Zoopagomycota dominate the microbiome. The abundance of Proteobacteria, Ascomycota, and Basidiomycota differ between schistosome-infected versus uninfected children. Specifically, infection is associated with increases in Pseudomonas, Stenotrophomonas, Derxia, Thalassospira, Aspergillus, Tricholoma, and Periglandula, with a decrease in Azospirillum. We find 262 AMR genes, from 12 functional drug classes, but no association with individual-specific data. To our knowledge, we describe a novel metagenomic dataset of Zimbabwean preschool-aged children, indicating an association between urogenital schistosome infection and changes in the gut microbiome.

Inflammation during Schistosoma haematobium infection and anti-allergy in pre-school-aged children living in a rural endemic area in Zimbabwe.

BACKGROUND: Allergies and autoimmune disorders are less prevalent in areas where parasitic infections are abundant. The relationship between schistosomiasis, Chitinase 3-Like 1 protein (YKL-40), an inflammatory marker, and antinuclear antibodies (ANA), an allergy marker, was investigated in pre-school-aged children (1-5 years old) living in an area endemic to Schistosoma haematobium infection. METHODS: Cross-sectional study including 145 participants, 66 females and 79 males. S. haematobium infection was diagnosed using the urine filtration technique. Levels of YKL-40 and antinuclear antibodies concentrations were determined using enzyme-linked immunosorbent assay. RESULTS: The prevalence of S. haematobium infection was 21.4 % (n = 31) with 114 not infected, 18 with light and 13 with moderate infections. YKL-40 levels were higher in the S. haematobium-infected group than in the uninfected group (P = 0.038). However, S. haematobium infection intensity did not correlate with YKL-40 levels. ANA levels were significantly higher in uninfected children than in infected children (P = 0.028). There was a significant inverse relationship between ANA levels and schistosome infection intensity (r = -0.225, P = 0.016). The correlation between ANA levels and YKL-40 levels was not significant. CONCLUSION: Inflammatory marker in pre-school-aged children living in an area endemic for schistosomiasis indicate YKL-40 as a possible biomarker of S. haematobium infection in pre-school-aged children, warranting further investigations in a longitudinal study.  The study gives an insight into allergy as ANA levels were higher in schistosome-uninfected than infected participants, further studies on allergies are needed.

CONTEXTE: Les allergies et les troubles auto-immunes sont moins répandus dans les régions où les infections parasitaires sont abondantes. La relation entre la schistosomiase, la protéine Chitinase 3-Like 1 (YKL-40), un marqueur antiinflammatoire, et les anticorps antinucléaires (AAN), un marqueur d'allergie, a été étudiée chez des enfants d'âge préscolaire (1 à 5 ans) vivant dans une zone endémique pour l'infection à Schistosoma haematobium. MÉTHODES: Etude transversale portant sur 145 participants, 66 de sexe féminin et 79 de sexe masculin. L'infection à S. haematobium a été diagnostiquée à l'aide de la technique de filtration de l'urine. Les niveaux de YKL-40 et les concentrations d'AAN ont été déterminés en utilisant un dosage immunoenzymatique . RÉSULTATS: La prévalence de l'infection à S. haematobium était de 21,4% (n = 31) avec 114 non infectés, 18 avec des infections légères et 13 avec des infections modérées. Les niveaux de YKL-40 étaient plus élevés dans le groupe infecté par S. haematobium que dans le groupe non infecté (p = 0,038). Cependant, l'intensité de l'infection à S. haematobium ne corrélait pas avec les niveaux de YKL-40. Les niveaux d'AAN étaient significativement plus élevés chez les enfants non infectés que chez les infectés (p = 0,028). Il y avait une relation inverse significative entre les niveaux d'AAN et l'intensité de l'infection schistosomique (r = -0,225, p = 0,016). La corrélation entre les niveaux d'AAN et les niveaux de YKL-40 n'était pas significative. CONCLUSION: Les marqueurs d'inflammation et les marqueurs d'allergie chez les enfants d'âge préscolaire vivant dans une zone endémique pour la schistosomiase indiquent YKL-40 comme biomarqueur possible de l'infection par S. haematobium chez les enfants d'âge préscolaire, ce qui justifie des investigations supplémentaires dans une étude longitudinale. Comme les niveaux d'AAN étaient plus élevés chez les participants non infectés que chez ceux infectés par le schistosome, d'autres études sur les allergies sont nécessaires.

Elevation of C-reactive protein, P-selectin and Resistin as potential inflammatory biomarkers of urogenital Schistosomiasis exposure in preschool children.

BACKGROUND: Schistosomiasis is known to induce inflammatory immune responses. C-reactive protein (CRP), resistin and P-selectin are serological inflammatory markers that rise during the acute stages of infection. Here, we propose such inflammatory biomarkers have a potential for use in urogenital schistosomiasis diagnostic screening for exposure and infection in preschool-aged children. METHODS: As part of a larger study on urogenital schistosomiasis, 299 preschool children aged 1-5 years were included in this cross-sectional study. Parasitological diagnosis was conducted using urine filtration for Schistosoma haemtobium infection, and Kato Katz for S. mansoni infection. Serum levels of P-selectin, resistin, CRP, and antibodies against S. haematobium cercarial antigen preparation (CAP) and soluble worm antigen preparation (SWAP) were measured by ELISA. RESULTS: Of the 299 participants, 14% were egg positive for S. haematobium. Serology showed 46 and 9% of the participants to have been exposed to S. haematobium cercarial antigens and adult worm antigens, respectively. Levels of P-selectin were significantly higher in participants infected with S. haematobium (egg-positive) than in uninfected participants (p = 0.001). Levels of P-selectin were also higher in those exposed to cercarial antigen than in unexposed participants (p = 0.019). There was a positive correlation between P-selectin and infection intensity (r = 0.172; p = 0.002), as well as with IgM responses to CAP and SWAP (r = 0.183; p = 0.001); (r = 0.333; p < 0.0001) respectively. CRP significantly correlated with IgM responses to CAP (r = 0.133; p = 0.029) while resistin correlated with IgM responses to CAP and SWAP (r = 0.127; p = 0.016); (r = 0.197; p = 0.0004). CRP levels were higher in those exposed to cercarial and adult worm antigens than unexposed participants (p = 0.035); (p = 0.002) respectively, while resistin was higher in participants exposed to cercarial antigen than unexposed participants (p = 0.024). CONCLUSION: In this preschool population, P-selectin is significantly associated with urogenital schistosome infection and intensity; hence a potential biomarker for infection diagnosis and disease monitoring. The inflammatory biomarkers (P-selectin, Resistin and CRP) were significantly higher in participants exposed to cercarial antigens than unexposed individuals indicating an underlying inflammatory environment.

Dynamics of paediatric urogenital schistosome infection, morbidity and treatment: a longitudinal study among preschool children in Zimbabwe.

BACKGROUND: Recent research has shown that in schistosome-endemic areas preschool-aged children (PSAC), that is, ≤5 years, are at risk of infection. However, there exists a knowledge gap on the dynamics of infection and morbidity in this age group. In this study, we determined the incidence and dynamics of the first urogenital schistosome infections, morbidity and treatment in PSAC. METHODS: Children (6 months to 5 years) were recruited and followed up for 12 months. Baseline demographics, anthropometric and parasitology data were collected from 1502 children. Urinary morbidity was assessed by haematuria and growth-related morbidity was assessed using standard WHO anthropometric indices. Children negative for Schistosoma haematobium infection were followed up quarterly to determine infection and morbidity incidence. RESULTS: At baseline, the prevalence of S haematobium infection and microhaematuria was 8.5% and 8.6%, respectively. Based on different anthropometric indices, 2.2%-8.2% of children were malnourished, 10.1% underweight and 18.0% stunted. The fraction of morbidity attributable to schistosome infection was 92% for microhaematuria, 38% for stunting and malnutrition at 9%-34%, depending on indices used. S haematobium-positive children were at greater odds of presenting with microhaematuria (adjusted OR (AOR)=25.6; 95% CI 14.5 to 45.1) and stunting (AOR=1.7; 95% CI 1.1 to 2.7). Annual incidence of S haematobium infection and microhaematuria was 17.4% and 20.4%, respectively. Microhaematuria occurred within 3 months of first infection and resolved in a significant number of children, 12 weeks post-praziquantel treatment, from 42.3% to 10.3%; P<0.001. CONCLUSION: We demonstrated for the first time the incidence of schistosome infection in PSAC, along with microhaematuria, which appears within 3 months of first infection and resolves after praziquantel treatment. A proportion of stunting and malnutrition is attributable to S haematobium infection. The study adds scientific evidence to the calls for inclusion of PSAC in schistosome control programmes.

Multiple cellular effects of leaf extracts from Parinari curatellifolia.

BACKGROUND: Parinari curatellifolia is a prominent plant in folk medicine in Sub-Saharan Africa. The plant decoctions are used to treat various ailments, including the treatment of cancer, pneumonia, fever, microbial infections and anti-inflammation. The aims of the study were to investigate the effects of P. curatellifolia leaf extracts on cell inflammatory and proliferative activity. METHODS: Parinari curatellifolia fresh leaves were collected from Centenary in Mashonaland Central Province of Zimbabwe. Plant extracts were prepared using methanol, water, acetone and ethanol. Firstly, the effects of the extracts were determined on xanthine oxidase activity. Kinetic constants were determined for the extracts that showed inhibitory effects. Then the effects of Parinari curatellifolia water extract on LPS, menadione and hydrogen peroxide-activated nitric oxide production in RAW 264.7 cells was determined by quantifying the amount of nitrites formed. Finally, the effects of P. curatellifolia on the proliferation of Jurkat-T cells as well as its modulation of cisplatin-induced cell- cytotoxicity was investigated on a Jurkat human T-cell lymphoma cell line. RESULTS: There was significant XO inhibitory activity by the ethanol and methanol extracts at 15.6 µg/ml and 3.9 µg/ml respectively. The IC50 determination for allopurinol, ethanol extract and methanol extract were 0.43 µg/ml, 1.38 µg/ml and 2.19 µg/ml respectively. The kinetic results showed that the ethanol and methanol extracts were allosteric inhibitors of XO. The water extract of P. curatellifolia inhibited NO production in RAW cells when LPS was used as an activator. P. curatellifolia and cisplatin showed dose-dependent cytotoxicity on Jurkat-T cells. Isolated DNA from the cells showed that there was DNA cleavage on cells exposed to P. curatellifolia indicating that apoptosis may be a mechanism by which P. curatellifolia exerts its cytotoxicity on Jurkat-T cells. CONCLUSIONS: These results scientifically support the use of P. curatellifolia leaf extracts in the management of pain, inflammatory and neoplastic conditions. P. curatellifolia thus has multiple biological effects, thus, validating its use in traditional medical uses.

Inhibition of hematopoietic prostaglandin D2 synthase (H-PGDS) by an alkaloid extract from Combretum molle.

BACKGROUND: Hematopoietic prostaglandin D2 synthase (H-PGDS, GST Sigma) is a member of the glutathione S-transferase super family of enzymes that catalyses the conjugation of electrophilic substances with reduced glutathione. The enzyme catalyses the conversion of PGH2 to PGD2 which mediates inflammatory responses. The inhibition of H-PGDS is of importance in alleviating damage to tissues due to unwarranted synthesis of PGD2. Combretum molle has been used in African ethno medicinal practices and has been shown to reduce fever and pain. The effect of C. molle alkaloid extract on H-PGDS was thus, investigated. METHODS: H-PGDS was expressed in Escherichia coli XL1-Blue cells and purified using nickel immobilized metal affinity chromatography. The effect of C. molle alkaloid extract on H-PGDS activity was determined with 1-chloro-2, 4-dinitrobenzene (CDNB) as substrate. The effect of C. molle alkaloid extract with time on H-PGDS was determined. The mechanism of inhibition was then investigated using CDNB and glutathione (GSH) as substrates. RESULTS: A specific activity of 24 µmol/mg/min was obtained after H-PGDS had been purified. The alkaloid extract exhibited a 70% inhibition on H-PGDS with an IC50 of 13.7 µg/ml. C. molle alkaloid extract showed an uncompetitive inhibition of H-PGDS with Ki = 41 µg/ml towards GSH, and non-competitive inhibition towards CDNB with Ki = 7.7 µg/ml and Ki' = 9.2 µg/ml. CONCLUSION: The data shows that C. molle alkaloid extract is a potent inhibitor of H-PGDS. This study thus supports the traditional use of the plant for inflammation.