Sanguinarine: an alkaloid with promising in vitro and in vivo antiparasitic activity against different developmental stages of Schistosoma mansoni and in silico pharmacokinetic properties (ADMET)

The objective of the study was to evaluate the in vitro and in vivo schistosomicidal activity of sanguinarine (SA) on Schistosoma mansoni and its in silico pharmacokinetic parameters. ADMET parameters and oral bioavailability were evaluated using the PkCSM and SwissADME platforms, respectively. The activity of SA in vitro, at the concentrations of 1.0-25 µM, was analyzed through the parameters of motility, mortality, and cell viability of the worms at intervals of 3-24 h. Mice were infected with cercariae and treated by gavage with SA (5 mg/kg/day, in a single dose or two doses of 2.5 mg/kg every 12 h for 5 consecutive days) on the 1st (skin schistosomula), 14th (pulmonary schistosomula), 28th (young worms), and 45th (adult worms) days after infection. In vitro and in vivo praziquantel was the control. In vitro, SA showed schistosomicidal activity against schistosomula, young worms, and couples; with total mortality and reduced cell viability at low concentrations and incubation time. In a single dose of 5 mg/kg/day, SA reduces the total worm load by 47.6%, 54%, 55.2%, and 27.1%, and female worms at 52.0%, 39.1%, 52.7%, and 20.2%, respectively, results which are similar to the 2.5 mg/kg/day dose. SA reduced the load of eggs in the liver, and in histopathological and histomorphometric analyses, there was a reduction in the number and volume of hepatic granulomas, which exhibited less inflammatory infiltrate. SA has promising in vitro and in vivo schistosomicidal activity against different developmental stages of S. mansoni, in addition to reducing granulomatous liver lesions. Furthermore, in silico, SA showed good predictive pharmacokinetic ADMET profiles.

Respiratory allergy symptoms and cytokine profiles in the presence of anti-Ascaris antibody in Giardia lamblia-infected children

Anti-Ascaris lumbricoides (Asc) IgE and IgG can immunomodulate the allergy; however, the influence of these isotypes has not been investigated in the giardiasis and allergy. Therefore, the frequency of respiratory allergy (RA) symptoms in Giardia lamblia-infected children, with or without anti-Asc IgE, IgG1, or IgG4 and Th1, Th2/Treg, and Th17 cytokine production, was evaluated. We performed a case-control study with children aged 2-10 years old selected by questionnaire and stool exams to form the groups: infected or uninfected with RA (G-RA, n = 55; nG-RA, n = 43); infected and uninfected without RA (G-nRA, n = 59; nG-nRA, n = 54). We performed blood leukocyte counts and in vitro culture. Cytokine levels in the supernatants (CBA), serum total IgE and anti-Asc IgE (ImmunoCAP), IgG1, IgG4, and total IgA (ELISA) were measured. Infection was not associated with allergy. Infected children showed increased levels of anti-Asc IgG1, IL-2, IFN-γ, IL-4, and IL-10. There was a lower frequency of allergy-related symptoms in anti-Asc IgG1-positive children than IgG1-negative (OR = 0.38; CI = 0.17-0.90, p = 0.027) and few eosinophils in G-RA than in G-nRA and more in G-nRA than in nG-nRA, whereas TNF-α levels were higher in the G-RA than in the nG-nRA group. For infected and positive anti-Asc IgG1, there was higher TNF-α and IL-10 production than G/-IgG1. IL-10 levels were lower in nG/ + IgG1 than in infected or non-infected, and both were negative for anti-Asc IgG1. Th1/Th2/IL-10 profiles were stimulated in the infected patients, and in those with circulating anti-Asc IgG1, the TNF-α production was strengthened with a lower risk for respiratory allergy symptoms.

Schistosoma mansoni infection decreases IL-33-mRNA expression and increases CXCL9 and CXCL10 production by peripheral blood cells

Schistosoma mansoni infections, particularly egg antigens, induce Th2-dominant granulomatous responses accompanied by remarkable immunoregulatory mechanisms that avoid intense fibrosis. Interleukin (IL)-33 is a cytokine that stimulates the early activation of Th2 responses, and its soluble ST2 receptor (sST2) avoids granulomatous response, as well as CXCL9 and CXCL10 chemokines that have antifibrotic activity. However, in schistosomiasis, these molecules have not been suitably studied. Therefore, this study aimed to measure IL-33 and sST2 RNA, cytokines, and chemokines in peripheral blood cultures from individuals living in schistosomiasis-endemic areas. Peripheral blood cells from individuals with S. mansoni (n = 34) and non-infected individuals (n = 31) were cultured under mitogen stimulation. Supernatant chemokines and cytokines were evaluated using a cytometric bead array, and IL-33 and sST2 mRNA expression was measured using qPCR. Infected individuals showed higher levels of CXCL8, CXCL9, CXCL10, IFN-γ, TNF-α, IL-6, IL-2, IL-4, and IL-10; there was a lower expression of IL-33 mRNA and similar expression of sST2mRNA in infected than non-infected individuals. In conclusion, for the first time, we demonstrated lower IL-33mRNA expression and high levels of the antifibrotic chemokines CXCL9 and CXCL10 in schistosomiasis mansoni, which could control exacerbations of the disease in individuals from endemic areas.

Urban schistosomiasis: An ecological study describing a new challenge to the control of this neglected tropical disease

Background

Social and environmental vulnerabilities contribute to the persistence and increase of Schistosomiasis, which has been a public health problem in Brazil and worldwide. In this study, we aimed to monitor the entry, installation, and maintenance of schistosomiasis transmission in an urban area on the Brazilian coast over two decades (2000-2010/2010-2020).

Methods

This population-based cross-sectional study was conducted in Porto de Galinhas, state of Pernambuco, Brazil, to investigate the dynamics of schistosomiasis transmission in the urban area. Through 3 malacological and parasitological surveys and using geoprocessing technologies, schistosomiasis transmission foci (STF), as well as cases of the disease were identified and quantified. Statistical and geoprocessing tools were used to analyse the data.

Findings

Overall, the number of STF decreased from 15 (2000) to 11 (2010) and then to 9 (2020). Although the infection ratio of snails in 2000 has decreased from 16·1% to 5·8% in 2010, we observed an increase to 7·2% in 2020. Additionally, 6,499 individuals were analysed (2012 in 2000; 2459 in 2010, and 2028 in 2020) and the prevalence of human infection has decreased over years, from 32·5% (2000), 16·6% (2010) to 8·8% (2020). The disorderly urbanization process was directly related to the spatial distribution of STF and schistosomiasis cases, causing a new scenario where people became infected by walking on unpaved and flooded streets.

Interpretation

Although we observed a decreasing in schistosomiasis cases and STF, this NTD became a health problem related to urbanization in the study area. The challenge to overcome this new sort of transmission will require a greater understanding of the disorderly migration, spatial occupation, and degradation of the environment.

Funding

National Council for Scientific and Technological Development (CNPq), Ministry of Science, Technology, Innovations and Communications, Brazil.

Schistosoma mansoni infection is associated with decreased risk of respiratory allergy symptoms and low production of CCL2

OBJECTIVES

We measured the production of cytokines, chemokines and antibodies involved in allergic responses and sCD23 levels during Schistosoma mansoni infection.

METHODS

Individuals (n = 164) were selected using the ISAAC questionnaire and parasitological exams. The subjects were divided as follows: those infected individuals with allergy-related symptoms (A-I), those with allergy-related symptoms only (A-NI); those only infected (NA-I); and those non-infected individuals without allergy-related symptoms (NA-NI). We used supernatants from cell culture (mitogenic stimulation) to measure cytokine and chemokine levels using cytometric bead arrays. Serum levels of anti-Ascaris lumbricoides (Asc) and anti-Blomia tropicalis IgE were measured using ImmunoCAP, and sCD23 was measured using ELISA.

RESULTS

Schistosoma mansoni infection was associated with a lower risk of allergy-related symptoms. In A-I, there were higher levels of TNF-α, IL-10, IL-6, IFN-γ and CXCL8 than in NA-NI group, with TNF-α and IL-6 also at higher levels compared to A-NI group. Levels of IL-6, CXCL8, total and anti-Asc IgE, as well as the numbers of eosinophils, were higher in NA-I than in NA-NI, and the antibodies were also lower in A-NI than in NA-I group. In AI and NA-I, there was less production of CCL2 than in NA-NI. There were no differences in the levels of IL-2, IL-4, IL-17, CCL5, sCD23 and anti-Blomia IgE.

CONCLUSIONS

Patients with allergy-related symptoms and infected (simultaneously) had higher levels of IL-10; due to the infection, there was increased production of IL-6 and CXCL8 and less CCL2. These data may characterize deviation to Th1 or attenuation of the Th2 response in allergy sufferers in areas endemic for schistosomiasis.

Multiple Introductions Followed by Ongoing Community Spread of SARS-CoV-2 at One of the Largest Metropolitan Areas of Northeast Brazil

Multiple epicenters of the SARS-CoV-2 pandemic have emerged since the first pneumonia cases in Wuhan, China, such as Italy, USA, and Brazil. Brazil is the third-most affected country worldwide, but genomic sequences of SARS-CoV-2 strains are mostly restricted to states from the Southeast region. Pernambuco state, located in the Northeast region, is the sixth most affected Brazilian state, but very few genomic sequences from the strains circulating in this region are available. We sequenced 101 strains of SARS-CoV-2 from patients presenting Covid-19 symptoms that reside in Pernambuco. Phylogenetic reconstructions revealed that all genomes belong to the B lineage and most of the samples (88%) were classified as lineage B.1.1. We detected multiple viral introductions from abroad (likely from Europe) as well as six local B.1.1 clades composed by Pernambuco only strains. Local clades comprise sequences from the capital city (Recife) and other country-side cities, corroborating the community spread between different municipalities of the state. These findings demonstrate that different from Southeastern Brazilian states where the epidemics were majorly driven by one dominant lineage (B.1.1.28 or B.1.1.33), the early epidemic phase at the Pernambuco state was driven by multiple B.1.1 lineages seeded through both national and international traveling.

Extract of Ascaris suum induces TGF-β and early production of IgG1 in experimental autoimmune hepatitis

In experimental autoimmune hepatitis (EAH) of Th1 profile, an extract of adult Ascaris suum worms (ASC) was previously found to deviate the immune response to a Th2/IL-10 pattern. Here, the effects of treatment with ASC on production of TGF-β and the anti-Ascaris isotypes IgG1 and IgG2a in EAH were evaluated. EAH was induced in BALB/c mice, intravenously with concanavalin A. Two hours later, these animals received ASC (EAH+ASC group) or PBS vehicle (EAH group). IgG1 and IgG2a were evaluated 8 h, 24 h and 7 d after induction. TGF-β was measured in a splenocyte culture at this last time. The isotype levels in the EAH group were low throughout the kinetics. In the EAH+ASC group, there was significant production of IgG1 at 24 h and 7 d, but of IgG2a only at 7 d. There was statistically greater production of TGF-β in the EAH+ASC group. The higher levels of IgG1 and TGF-β in this group suggest that an additional Th1 response control route exists in EAH, which needs to be investigated.

Urban transmission of schistosomiasis: new epidemiological situation in the forest area of Pernambuco

Introduction:

Schistosomiasis is considered an endemic disease in Vitória de Santo Antão, Pernambuco, a district which has presented both high incidence and prevalence of it for decades. Poor environmental conditions lead to contamination of water sources in rural areas, which are used by the population during daily activities, resulting in typical transmission. Recently, there has been evidence of vector snails in urban areas, which could set a new model for schistosomiasis transmission in this district.

Objective:

To identify the new epidemiological situation for the urban transmission of schistosomiasis in Vitória de Santo Antão, Pernambuco.

Methods:

A malacological survey was conducted in all water sources in the city limits to investigate schistosomiasis vector snails (Biomphalaria spp.). The collected snails were examined for taxonomic identification and Schistosoma mansoni infection. All breeding sites were georeferenced to build risk maps through the TrackMaker PRO program and ArcGIS software.

Results:

We identified 22 Biomphalaria straminea breeding sites and collected 1,704 snails. One of these breeding sites was identified as a source of transmission and seven as potential sources of transmission. The designed maps identified two risk areas of urban transmission of schistosomiasis and expansion areas for breeding sites, establishing an increased risk of transmission to the population.

Conclusion:

This study verified the existence of a new epidemiological situation in which the possibility of the urban transmission of the disease was confirmed.

Gestation and breastfeeding in schistosomotic mothers differently modulate the immune response of adult offspring to postnatal Schistosoma mansoni infection

Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4⁺FoxP3⁺T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4⁺FoxP3⁺T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-g, but lower levels of IL-4 and CD4⁺FoxP3⁺T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.

[Presence of Cryptosporidium spp in children with acute diarrhea in a public daycare center in Recife, State of Pernambuco]

The objective of the present study was to analyze the frequency of oocysts of Cryptosporidium spp in fecal samples from children aged one to fourteen years at a public daycare center located in a needy community in the city of Recife, Pernambuco. The investigation was carried out between June 28, 2006, and April 3, 2007, and involved 182 children. Among the samples analyzed, 59 (32.4%) were positive regarding the presence of oocysts of Cryptosporidium spp, and the age group most affected was between three and five years (54.2%). The high frequency of samples positive for Cryptosporidium spp obtained in this study confirms that daycare centers are an environment that favors such occurrences, because of the direct contact between children or between children and staff. The most important infection route for Cryptosporidium spp is person-to-person transmission, which is well illustrated in daycare centers. Immaturity, deficiencies of the immune system and inadequate hygiene habits are factors that also contribute towards this type of infection.