Worm Burden Research Articles

Intra-specific variations in Schistosoma mansoni and their possible contribution to inconsistent virulence and diverse clinical outcomes.

Schistosoma mansoni was introduced from Africa to the Americas during the transatlantic slave trade and remains a major public health problem in parts of South America and the Caribbean. This study presents a comprehensive comparative analysis of three S. mansoni strains with different geographical origins-from Liberia, Belo Horizonte and Puerto Rico. We demonstrated significant variation in virulence and host-parasite interactions. We investigated the phenotypic characteristics of the parasite and its eggs, as well as the immunopathologic effects on laboratory mouse organ systems. Our results show significant differences in worm morphology, worm burden, egg size, and pathologic organ changes between these strains. The Puerto Rican strain showed the highest virulence, as evidenced by marked liver and spleen changes and advanced liver fibrosis indicated by increased collagen content. In contrast, the strains from Liberia and Belo Horizonte had a less pathogenic profile with less liver fibrosis. We found further variations in granuloma formation, cytokine expression and T-cell dynamics, indicating different immune responses. Our study emphasizes the importance of considering intra-specific variations of S. mansoni for the development of targeted therapies and public health strategies. The different virulence patterns, host immune responses and organ pathologies observed in these strains provide important insights for future research and could inform region-specific interventions for schistosomiasis control.

Goats are more susceptible to Haemonchus contortus infection than sheep under similar experimental settings

Due to differences in their feeding behavior, sheep and goats are often assumed to respond differently to helminth infections. The present study compared Haemonchus contortus infection profile between sheep and goats under the same experimental setting. Experimental infection was conducted using a randomized block design in four groups of intact sheep (InfSH and ConSH) and goats (InfG, and ConG). Groups InfSH and InfG (N = 7 each) received 10,000L3 of H. contortus whereas the control groups ConSH and ConG (N = 7 each) remained uninfected. Faecal egg counts and PCV were measured from Day 0 to day 56 post infection (PI). On day 56 PI, animals were humanely slaughtered and abomasal contents were recovered to measure worm burden, worm length and in utero egg count. The findings show that: (1) Haemonchus infected animals showed an increase in FEC starting from day 21 PI, (2) progressive reduction in PCV was registered from day 7 PI and continued to the end of the experiment while this remained at pre-infection levels in control groups, (3) FEC was much higher (P < 0.001) and PCV was significantly lower (P < 0.05) in infected goats than in infected sheep, (4) at necropsy, total worm burden with worm establishment rates of 63% and 28.87% were registered respectively for infected goats and sheep with significant difference (P < 0.05), (5) Female worms were significantly longer (P < 0.05) in InfG (22.8(± 1.2) compared to InfSH (20.5 ± 0.67 mm) while (6) Mean worm fecundity was 974.8 ± 239.4 and 1162.5 ± 89.4 respectively for groups InfSH and InfG with no significant difference (P = 0.07), and (7) Parasite traits such as worm burden, FEC and female worm length were well correlated in sheep whereas few such patterns were observed in goats. In conclusion, under the same experimental infection, Arsi-Bale goats are more susceptible to H. contortus infection than Arsi-Bale sheep and hence deserve special attention when they are forced to live on grazing rather than browsing.

Differences of in vitro immune responses between patent and pre-patent Litomosoides sigmodontis-infected mice are independent of the filarial antigenic stimulus used.

Lymphatic filariasis and onchocerciasis are neglected tropical diseases and cause significant public health problems in endemic countries, especially in sub-Saharan Africa. Since the human parasites are not viable in immune-competent mice, animal models have been developed, among them Litomosoides sigmodontis which permits a complete life cycle in BALB/c mice, including the development of patent infections with circulating microfilariae (Mf, the worm's offspring). To investigate the immunomodulatory properties of helminths in vitro, antigenic extracts can be prepared from different life cycle stages of the L. sigmodontis model, including adult worms, but the methods to prepare these antigens differ between research groups. This study analyzed whether different centrifugation methods during the preparation of an antigenic extract, the gender of used worms, or the different fractions (soluble or pellet) altered filarial-specific CD4+ Tcell responses. These cells were isolated from pre-patent or patent/chronic infected mice, hence those without and those with Mf, respectively. Ex vivo immune responses were compared at these two different time points of the infection as well as the parasitic parameters. Worm burden and cell infiltration were elevated in the thoracic cavity (TC) and draining mediastinal lymph nodes at the pre-patent stage. Within the TC, eosinophils were significantly up-regulated at the earlier time point of infection which was further reflected by the eosinophil-related eotaxin-1 levels. Regarding the production of cytokines by re-stimulated CD4+ T cells in the presence of different antigen preparations, cytokine levels were comparable for all used extracts. Our data show that immune responses differ between pre-patent and patent filarial infection, but not in response to the different antigenic extracts themselves.

Partial Protection of Goats against Haemonchus contortus Achieved with ADP-Ribosylation Factor 1 Encapsulated in PLGA Nanoparticles.

Haemonchus contortus (H. contortus), a nematode with global prevalence, poses a major threat to the gastrointestinal health of sheep and goats. In an effort to combat this parasite, a nanovaccine was created using a recombinant ADP-ribosylation factor 1 (ARF1) antigen encapsulated within poly lactic-co-glycolic acid (PLGA). This study aimed to assess the effectiveness of this nanovaccine in providing protection against H. contortus infection. Fifteen goats were randomly divided into three groups. The experimental group received two doses of the PLGA encapsulated rHcARF1 (rHcARF1-PLGA) nanovaccine on days 0 and 14. Fourteen days after the second immunization, both the experimental and positive control groups were challenged with 8000 infective larvae (L3) of H. contortus, while the negative control group remained unvaccinated and unchallenged. At the end of the experiment on the 63rd day, all animals were humanly euthanized. The results showed that the experimental group had significantly higher levels of sera IgG, IgA, and IgE antibodies, as well as increased concentrations of cytokines, such as IL-4, IL-9, IL-17, and TGF-β, compared to the negative control group after immunization. Following the L3 challenge, the experimental group exhibited a 47.5% reduction in mean eggs per gram of feces (EPG) and a 55.7% reduction in worm burden as compared to the positive control group. These findings indicate that the nanovaccine expressing rHcARF1 offers significant protective efficacy against H. contortus infection in goats. The results also suggest the need for more precise optimization of the antigen dose or a reassessment of the vaccination regimen. Additionally, the small sample size limits the statistical rigor and the broader applicability of the findings.

Prior Trichinella spiralis infection protects against Schistosoma mansoni induced hepatic fibrosis.

Schistosomiasis affects approximately 250 million people worldwide, with 200,000 deaths annually. It has been documented that the granulomatous response to Schistosoma mansoni (S. mansoni) oviposition is the root cause of progressive liver fibrosis in chronic infection, in 20% of the patients, and can lead to liver cirrhosis and/or liver cancer. The influence of helminths coinfection on schistosomiasis-induced liver pathological alterations remains poorly understood. Therefore, in this study, we investigated the effect of Trichinella spiralis (T. spiralis) infection on S. mansoni-induced hepatic fibrosis. Thirty adult male Balb-c mice were divided into three groups. Group 1 was left uninfected; group 2 was infected with S. mansoni cercariae and group 3 was orally infected with T. spiralis larvae, then 28 days later, this group was infected with S. mansoni cercariae. All groups were sacrificed at the end of the 8th week post infection with S. mansoni to evaluate the effect of pre-infection with T. spiralis on S. mansoni induced liver fibrosis was evaluated parasitologically (worm burden and egg count in tissues), biochemically (levels of alanine aminotransferase and aspartate aminotransferase), histopathologically (H&E and MT staining, and immunohistochemical staining for the expression of α-SMA, IL-6, IL-1β, IL-17, IL-23, TNF-α, and TGF-β). The results in the present study demonstrated marked protective effect of T. spiralis against S. mansoni induced liver pathology. We demonstrated that pre-infection with T. spirais caused marked reduction in the number of S. mansoni adult worms (3.17 ± 0.98 vs. 18 ± 2.16, P = 0.114) and egg count in both the intestine (207.2 ± 64.3 vs. 8,619.43 ± 727.52, P = 0.009) and liver tissues (279 ± 87.2 vs. 7,916.86 ± 771.34; P = 0.014). Consistently, we found significant reductions in both number (3.4 ± 1.1 vs. 11.8.3 ± 1.22; P = 0.007) and size (84 ± 11 vs. 294.3 ± 16.22; P = 0.001) of the hepatic granulomas in mice pre-infected with T. spiralis larvae compared to those infected with only S. mansoni. Furthermore, pre- infection with T. spiralis markedly reduced S. mansoni- induced hepatic fibrosis, as evidenced by decreased collagen deposition, low expression of α-SMA, and significantly reduced levels of IL-17, IL-1B, IL-6, TGF-B, IL-23, and TNF-α compared to mice infected with S. mansoni only. Our data show that pre-infection with T. spiralis effectively protected mice from severe schistosomiasis and liver fibrosis. We believe that our findings support the potential utility of helminths for the preventing and ameliorating severe pathological alterations induced by schistosomiasis.

Acute Toxicity and IN VIVO Antischistosomal Effects of Entada africana Guill &amp; Perott (Fabaceae) Methanol Stem Bark Extract in Albino Mice

The study was aimed at determining the acute toxicity and schistosomicidal effects of methanol extract (ME) of Entada africana (E. africana), in albino mice. Fresh stem bark of E. africana was shade-dried and extracted by Soxhlet extraction. Acute toxicity was carried out on 6 groups of mice (n=3) of 6-week-old, sizes 27-30g; to determine the therapeutic index, piloerection signs and possible mortality (LD50) in 24h exposure period. Cercaria from B. globosus snails were shed under a 100W bulb for 2 hours. In vivo antischistosomal assays was by used of 6-weeks old (27-30g) mice. Set I (n=10) involved investigation on schistosomules infection in the mice, 3-7 days post infection (PI). Set II (n=10) was infected and treated with E. africana ME extract, at concentrations 10-100mg/l, 35th day, PI for 5 consecutive days. Set III (n=10), were infected and treated with praziquantel– PZQ (positive control). While set IV (n=10) were infected and untreated (negative control). All were sacrificed, 75th day of PI. Data were analyzed by GraphPad® prism 8.4, version 2020. Findings revealed that E. africana ME did not generate any harmful or clinical effect within 24h, post administration; and there were no obvious reactions such as paw licking, stooling, piloerection or immediate death, except at phase II, 5000mg/kg bwt, (1⁄3) being the highest dosage. Worm burden decreased with increase in concentrations, especially at 70-100mg/l. Lower concentrations (10mg/l), had high worm population (76.00±21.28). Infected and untreated group had highest worm population (189.67±32.52). E. africana ME stem bark extract, showed antischistosomal effect and worm reduction in a dose- dependent pattern.

In vivo anti-schistosomal activity of the methanol extracts from Searsia longipes and Lannea schimperi

Schistosomiasis is a disease caused by the flat worms under the genus Schistosoma. The disease is prominent in tropical and sub tropical countries and it is manifested in two forms; the acute and the chronic form. Treatment and control of the schistosomiasis is constrained with various factors including immerging worm resistance and selective efficacy of the current recommended drug of choice. This therefore calls for the search of new approaches to offset the problems. The aim of this study was to investigate the efficacy of the methanolic extract from Searsia longipes and Lannea schimperi against Schistosoma mansoni by using animal model. Swiss albino mice were used for the efficacy testing, whereby, for each extract, 5 groups of mice were used, and each contained 5 mice. Three different doses were administered to three groups, whereas the remaining two groups were used as negative and positive control arms. Efficacies were assessed based on the reduction of the worm eggs in the faeces and organs, body weight gain, loss of liver weight, as well as reduction of worm burden. Both extracts demonstrated significant egg and worm reduction, which was directly proportional to the dose increment. At the highest dose used, Searsia longipes expressed the higher percentage egg reduction (73.33 %), whereas Lannea schimperi demonstrated the higher worm burden reduction (68.53 %). The present study provides strong evidence of the anti-schistosomal activity of the extracts from both S. longipes and L. schimperi. These findings are a significant step forward, suggesting that these plants could be a promising alternative medicine for the treatment of schistosomiasis. However, further investigations are warranted to isolate the compound responsible for this activity and to assess the sub-acute toxicity of the plant extracts. This next phase of research is crucial for advancing our understanding and potential use of these plant extracts.

Therapeutic efficacy of praziquantel loaded-chitosan nanoparticles on juvenile Schistosoma mansoni worms in murine model

Praziquantel (PZQ) is the standard treatment for schistosomiasis; however, it is poorly effective on immature and juvenile worms. The present study aimed to evaluate the therapeutic efficacy of praziquantel loaded-chitosan nanoparticles (PZQ-CSNPs) on the 25 days old juvenile Schistosoma mansoni worms compared to PZQ and chitosan nanoparticles (CSNPs). It was conducted on 60 Swiss albino mice, including 20 control and 40 experimental mice. The control groups included healthy uninfected and infected non-treated mice. The experimental groups included mice infected treated on the 25th day with 400 mg/kg PZQ, 30 mg/kg CSNPs, 100 mg/kg, and 400 mg/kg PZQ-CSNPs. The results revealed that PZQ-CSNPs (100, 400 mg/kg) gave the best results substantiated by a remarkable decrease in worm burden, egg count, granuloma count and size compared to the other treatments. Moreover, it induced severe deformations of worm morphology regarding oral and ventral suckers, tegument, spines distribution, and male gynaecophoric canal. Liver enzymes and oxidative stress markers were significantly decreased while antioxidant activities were increased compared to control and other treated groups. In conclusion, a single dose of PZQ-CSNPs had significant antischistosomal therapeutic effects during the early maturation phase.

Hepatic transcriptomic analysis reveals differential regulation of metabolic and immune pathways in three strains of chickens with distinct growth rates exposed to mixed parasite infections.

During parasite infections, the liver may prioritise immune-related pathways over its metabolic functions. Intestinal infections caused by Ascaridia galli and Heterakis gallinarum impair feed intake, nutrient absorption, and weight gain. Histomonas meleagridis, vectored by H. gallinarum, can also damage liver tissues, potentially impairing liver functions. This study examined the hepatic gene expression in three strains of chickens: Ross-308 (R), Lohmann Brown Plus (LB), and Lohmann Dual (LD), 2weeks after an experimental infection (n = 18) with both A. galli and H. gallinarum or kept as uninfected control (n = 12). Furthermore, H. gallinarum infection led to a co-infection with H. meleagridis. The mixed infections reduced feed intake and the average daily weight gain (P < 0.001). The infections also increased the plasma concentrations of alpha (1)-acid glycoprotein and the antibody titre against H. meleagridis (P = 0.049), with no strain differences (P > 0.05). For host molecular response, 1887 genes were differentially expressed in LD, while 275 and 25 genes were differentially expressed in R and LB, respectively. The up-regulated genes in R and LD were mostly related to inflammatory and adaptive immune responses, while down-regulated genes in LD were involved in metabolic pathways, including gluconeogenesis. Despite performance differences among the strains, worm burdens were similar, but hepatic molecular responses differed significantly. Moreover, there was an indication of a shift in hepatic functions towards immune-related pathways. We, therefore, conclude that the liver shifts its functions from metabolic to immune-related activities in chickens when challenged with mixed parasite species.

Evaluation of protective immune responses induced by DNA vaccines encoding Echinococcus granulosus EgM123 protein in Beagle dogs.

Echinococcus granulosus, known as cystic echinococcosis, is a prominent zoonotic parasitic disease of significant global concern. The definitive hosts serves as the primary reservoir for the transmission of echinococcosis, as well as a main factor in the prevention and control of the disease. Unfortunately, there is currently no commercially available vaccine for these hosts. Nevertheless, DNA vaccines show potential as a feasible strategy for the control and management of parasitic diseases. In this study, the EgM123 antigen was selected for its well-documented immunogenic properties to develop a DNA vaccine aimed at combating E. granulosus infection in canines. The results showed a marked increase in IgG levels in the group vaccinated with pVAX1-EgM123 DNA compared to the PBS group. Additionally, the cytokines IL-1, IFN-γ, IL-4, and IL-6 were significantly upregulated in the pVAX1-EgM123 DNA vaccine group. Furthermore, in comparison to the PBS control group, the EgM123 DNA vaccine group exhibited a notable 87.85% reduction in worm burden and a 65.00% inhibition in segment development. These findings indicate that the pVAX1-EgM123 DNA vaccine shows promising immunogenicity, successfully eliciting a targeted immune response in canines. Moreover, it significantly diminishes the worm burden and hinders the progression of tapeworms in the pVAX1-EgM123 DNA vaccine group. These findings suggest that the pVAX1-EgM123 DNA vaccine holds promise as a potential candidate vaccine for combating E. granulosus infection in dogs.

Oral Administration of Kaempferol Isolated from Baccharis Mattogrosensis Enables In Vivo Activity Against Schistosoma Mansoni.

Baccharis mattogrosensis is a species from Asteraceae which has been used in Brazilian folk medicine to treatment of several illnesses, including those caused by parasites. In the present work, the MeOH extract of aerial parts of B. mattogrosensis was subjected to chromatographic fractionation to afford three flavonoids: apigenin (1), quercetin (2), and kaempferol (3) as well as a mixture three chlorogenic acids: 3,4-O-dicaffeoylquinic (4), 3,5-O-dicaffeoylquinic (5), and 4,5-O-dicaffeoylquinic (6) acids. When tested in vitro, kaempferol (3) exhibited activity against Schistosoma mansoni with EC50=81.86 μM, whereas compounds 1, 2, 4-6 showed to be inactives. Considering this result, the effects of kaempferol (3) against S. mansoni infection using an experimental approach (in vivo assay) was tested at first time. Using a single oral dose (400 mg/kg) of kaempferol (3) to S. mansoni-infected mice reduced the worm burden by 25.5 %. Similarly, the number of eggs, which are responsible for a variety of pathologies and transmission of schistosomiasis, was decreased by 28.8 % in treated mice. Collectively, although kaempferol (3) is partially active when administered orally in a mouse model of schistosomiasis, our results suggest that this compound could be, in future studies, administered in different forms, such as nanoformulation.

Schistosomiasis in the Military-A Narrative Review.

Schistosomiasis is a parasitosis caused by trematodes of the genus Schistosoma. Humans are infected when coming into contact with freshwater containing the parasites' infective stages, which are amplified through freshwater-dwelling snails acting as intermediate hosts. Schistosomiasis has posed significant problems for troops exposed to freshwater in endemic regions ever since the Napoleonic wars. Schistosomiasis has substantial differences in clinical presentation, depending on the type of parasite, intensity of infection and reinfection, clinical form, and disease stage. It can remain undiagnosed for long periods of time, with well-known long-term morbidity and mortality risks. The diagnosis of schistosomiasis depends on its stage and relays on several tests, all with limitations in sensitivity and specificity. The diagnostic gold standard is the detection of eggs in urine, feces, or tissue biopsies, but this can raise problems in patients such as military personnel, in which the worm burden is usually low. Praziquantel is the drug of choice for schistosomiasis. Currently, there is no available commercial vaccine against any Schistosoma parasite. Avoiding freshwater exposure is the best prevention. Herein, we review the clinical presentation, diagnosis, treatment, and prevention of schistosomiasis in the military. This information may decrease the impact of schistosomiasis on this particular professional group.

Helminth co-infections have no additive detrimental impact on milk yield and milk quality compared to mono-infections in German dairy cows

BackgroundInfections with (tricho-)strongyles, Dictyocaulus viviparus or Fasciola hepatica have been shown to reduce milk production in dairy cows. However, the current published studies focused on one single helminth infection by neglecting helminth co-infections and their possible (additive) effects on host performance. Hence, for the first time, we investigated differences in the impact of patent helminth co-infections versus mono-infections on milk production parameters in individual cows.MethodsA total of 1583 dairy cows from 27 herds were included in this study. Faecal samples were examined in 2015 and 2021/2022 to determine the number of eggs/larvae per gram faeces for (tricho-)strongyles, D. viviparus, F. hepatica and rumen flukes. The cows were classified as non-infected, mono-infected and co-infected. Linear mixed models were applied to analyse the association between infection status (non-infected vs. mono-infected vs. co-infected) with milk yield, milk protein and milk fat content by including potential confounders.ResultsInfections with (tricho-)strongyles, D. viviparus, F. hepatica and rumen flukes were detected in 100%, 28.6%, 50.0% and 21.4% of herds, and 27.4%, 2.6%, 10.8% and 0.8% of faecal samples in 2015, while 100%, 0.0%, 86.7% and 60.0% of herds and 52.3%, 0.0%, 13.3% and 26.8% of faecal samples were positive in 2021/2022. Co-infections with two or more helminth taxa were detected in 74.4% of herds and 5.0% of faecal samples in 2015, and in 93.3% of herds and 21.7% of faecal samples in 2021/2022. The correlations between strongyle EPG, D. viviparus LPG and F. hepatica EPG were significantly positive in 2015. Significantly higher mean EPGs were identified in 2015 in faecal samples presenting co-infections with F. hepatica and one or two other helminth taxa than in faecal samples presenting F. hepatica mono-infections (P = 0.013). Although expected, the infection status (mono- or co-infected) had no significant impact on milk yield, milk protein and milk fat content in the linear mixed model analyses based on individual faecal examinations.ConclusionsPatent helminth co-infections had no additive detrimental impact on milk production parameters in the present study. This might be a result of presumably low worm burdens, but should be confirmed in future studies.Graphical

Rapid phenotypic and genotypic change in a laboratory schistosome population.

Genomic analysis has revealed extensive contamination among laboratory-maintained microbes including malaria parasites, Mycobacterium tuberculosis and Salmonella spp. Here, we provide direct evidence for recent contamination of a laboratory schistosome parasite population, and we investigate its genomic consequences. The Brazilian Schistosoma mansoni population SmBRE has several distinctive phenotypes, showing poor infectivity, reduced sporocysts number, low levels of cercarial shedding and low virulence in the intermediate snail host, and low worm burden and low fecundity in the vertebrate rodent host. In 2021 we observed a rapid change in SmBRE parasite phenotypes, with a~10x increase in cercarial production and ~ 4x increase in worm burden. To determine the underlying genomic cause of these changes, we sequenced pools of SmBRE adults collected during parasite maintenance between 2015 and 2023. We also sequenced another parasite population (SmLE) maintained alongside SmBRE without phenotypic changes. While SmLE allele frequencies remained stable over the eight-year period, we observed sudden changes in allele frequency across the genome in SmBRE between July 2021 and February 2023, consistent with expectations of laboratory contamination. (i) SmLE-specific alleles rose in the SmBRE population from 0 to 41-46% across the genome between September and October 2021, documenting the timing and magnitude of the contamination event. (ii) After contamination, strong selection (s=~ 0.23) drove replacement of low fitness SmBRE with high fitness SmLE alleles. (iii) Allele frequency changed rapidly across the whole genome, except for a region on chromosome 4 where SmBRE alleles remained at high frequency. We were able to detect contamination in this case because SmBRE shows distinctive phenotypes. However, this would likely have been missed with phenotypically similar parasites. These results provide a cautionary tale about the importance of tracking the identity of parasite populations, but also showcase a simple approach to monitor changes within populations using molecular profiling of pooled population samples to characterize fixed single nucleotide polymorphisms. We also show that genetic drift results in continuous change even in the absence of contamination, causing parasites maintained in different labs (or sampled from the same lab at different times) to diverge.

Evidence for a constitutive cost of host resistance on body fat growth in ewe lambs from lines selected for resistance or susceptibility to experimental infections with Haemonchus contortus

Although benefits of selection for host resistance to gastro-intestinal nematodes have long been recognized, its costs on production traits remain unclear. A main difficulty when studying those costs is to disentangle genetic effects due to selection from plastic responses induced by infection. Putative costs of host resistance have been extensively investigated in growing sheep. However, while most of those studies have relied on live weight to assess body growth, more comprehensive assessments accounting for body composition are advocated to detect trade-offs. In this study we used 90 female lambs from lines divergently selected on resistance to Haemonchus contortus that we experimentally infected (n = 60) or not (n = 30) under controlled conditions. As those conditions were defined to enable uninfected lambs to fully express their growth potential, we sought to precisely identify the effects of selection for host resistance on health traits and on growth traits. We assessed muscular and fat growth based on repeated measurements with dorsal ultrasonography for all lambs on farm, and with whole-body computed tomography (CT) scans for a subgroup of 18 infected lambs. Lambs achieved a high growth rate, including infected ones despite their high worm burden (confirmed at necropsy in the subgroup). As expected, lambs from the resistant (R) line were less infected than those from the susceptible (S) line. However, the clear pathogenic effects observed on muscular growth and voluntary feed intake were similar between lines. In contrast, a line difference in body fat was supported both by dorsal and volumetric CT measurements. Specifically, lower fat in the R line compared with the S line was observed equally in infected and uninfected groups, thus providing evidence for a constitutive cost of host resistance. Although this cost is not necessarily disadvantageous in nutrient-rich environments exposing animals to excess fat deposition, its consequences in nutrient-scarce environments may be important to promote sustainable breeding strategies for host resistance.

Evaluation of muscular apoptotic changes and myogenin gene expression in experimental trichinosis after stem cells and atorvastatin added to ivermectin treatment

Trichinosis is a common parasitic disease that affects the striated skeletal muscles, causing apoptotic and degenerative changes associated with myogenin expression in the affected myocytes. Hence, this study aimed to assess the ameliorative effects of stem cells and atorvastatin added to ivermectin on the infected myocytes during the muscular phase of murine trichinosis. 120 laboratory Swiss albino male mice were divided into 10 groups, and each group was subdivided into intestinal and muscular phases (each n = 6); uninfected control; untreated infected control; infected received ivermectin monotherapy; infected received atorvastatin monotherapy; infected received stem cells monotherapy; infected received ivermectin and atorvastatin dual therapy; infected received ivermectin and stem cells dual therapy; infected received atorvastatin and stem cells dual therapy; infected received ivermectin 0.2, atorvastatin 40, and stem cells triple therapy; and infected received ivermectin 0.1, atorvastatin 20, and stem cells triple therapy. Intestinal phase mice were sacrificed on the 5th day post-infection, while those of the muscular phase were sacrificed on the 35th day post-infection. Parasitological, histopathological, ultrastructural, histochemical, biochemical, and myogenin gene expression assessments were performed. The results revealed that mice that received ivermectin, atorvastatin, and stem cell triple therapies showed the maximum reduction in the adult worm and larvae burden, marked improvement in the underlying muscular degenerative changes (as was noticed by histopathological, ultrastructural, and histochemical Feulgen stain assessment), lower biochemical levels of serum NK-κB and tissue NO, and lower myogenin expression. Accordingly, the combination of stem cells, atorvastatin, and ivermectin affords a potential synergistic activity against trichinosis with considerable healing of the underlying degenerative sequel.

Rapid phenotypic and genotypic change in a laboratory schistosome population.

Genomic analysis has revealed extensive contamination among laboratory-maintained microbes including malaria parasites, Mycobacterium tuberculosis and Salmonella spp. Here, we provide direct evidence for recent contamination of a laboratory schistosome parasite population, and we investigate its genomic consequences. The Brazilian Schistosoma mansoni population SmBRE has several distinctive phenotypes, showing poor infectivity, reduced sporocysts number, low levels of cercarial shedding and low virulence in the intermediate snail host, and low worm burden and low fecundity in the vertebrate rodent host. In 2021 we observed a rapid change in SmBRE parasite phenotypes, with a ~10x increase in cercarial production and ~4x increase in worm burden. To determine the underlying genomic cause of these changes, we sequenced pools of SmBRE adults collected during parasite maintenance between 2015 and 2023. We also sequenced another parasite population (SmLE) maintained alongside SmBRE without phenotypic changes. While SmLE allele frequencies remained stable over the eight-year period, we observed sudden changes in allele frequency across the genome in SmBRE between July 2021 and February 2023, consistent with expectations of laboratory contamination. (i) SmLE-specific alleles rose in the SmBRE population from 0 to 41-46% across the genome between September and October 2021, documenting the timing and magnitude of the contamination event. (ii) After contamination, strong selection (s = ~0.23) drove replacement of low fitness SmBRE with high fitness SmLE alleles. (iii) Allele frequency changed rapidly across the whole genome, except for a region on chromosome 4 where SmBRE alleles remained at high frequency. We were able to detect contamination in this case because SmBRE shows distinctive phenotypes. However, this would likely have been missed with phenotypically similar parasites. These results provide a cautionary tale about the importance of tracking the identity of parasite populations, but also showcase a simple approach to monitor changes within populations using molecular profiling of pooled population samples to characterize fixed single nucleotide polymorphisms. We also show that genetic drift results in continuous change even in the absence of contamination, causing parasites maintained in different labs (or sampled from the same lab at different times) to diverge.

Efficacy assessment of miltefosine and curcumin against Clonorchis sinensis infection.

Praziquantel (PZQ) is currently the only approved drug for treating clonorchiasis, but its poor efficacy against Clonorchis sinensis larvae has highlighted the need to develop newer drugs. In this study, to address this challenge, we investigated the anti-parasitic efficacy of miltefosine (MLT), curcumin (CUR), and PZQ against C. sinensis metacercariae (CsMC), newly excysted juvenile worms (CsNEJs), and adults. Larvicidal effects of MLT and CUR surpassed those elicited by PZQ in vitro. These two drugs exerted their effect against both CsMC and CsNEJs in a dose- and time-dependent manner. To confirm the effect of these drugs in vivo, Syrian golden hamsters were orally infected with 100 CsMC and subsequently treated with MLT, CUR, or PZQ at 1 and 4 weeks post-infection (wpi). MLT and CUR reduced the worm recoveries at 1 and 4 wpi, indicating that these drugs were efficacious against both larvae and adult C. sinensis. PZQ was only efficacious against adult worms. Interestingly, both MLT and CUR showed lower levels of C. sinensis-specific IgG responses than the infection control group, implying that worm burden and bile IgG responses could be correlated. These results indicate that MLT and CUR are efficacious against both larval and adult stages of C. sinensis, thereby highlighting their potential for further development as alternative therapeutic options for clonorchiasis.

In Vivo Antischistosomicidal and Immunomodulatory Effects of Dietary Supplementation with Taraxacum officinale.

Bilharziasis is a widespread trematode parasite that poses a severe public health burden. Dandelion (Taraxacum officinale) has several pharmacological and traditional properties critical for treating several hepatic disorders. The present study was designed to assess the potential efficacy of T. officinale root (TOR) dietary supplementation with or without praziquantel (PZQ) against liver and intestinal disorders in mice infected with Schistosoma mansoni. This study was conducted on five groups; G1: uninfected control, G2: untreated S. mansoni-infected mice, G3: infected animals treated with 250 mg/kg PZQ for three alternative days, G4: infected animals were orally administered 600 mg/kg bw TOR daily for 10 days, and G5: infected animals that received both PZQ and TOR as previously described. The current findings after different treatments indicated topographical scanning electron microscopy alterations of male adult worms and a critical reduction in worm burden, ova count, granuloma diameter, hepatic and intestinal histological abnormalities, fibrosis, immunohistochemical expression of CD3+ and CD20+ cells, oxidative stress, and interleukin-10, also upregulation of interferon-gamma, and antioxidant enzymes, when compared to the infected untreated mice. The best results were obtained in mice administered PZQ+TOR together because of their antioxidant properties and ability to promote the host immune response to parasitic infection.

The potential prophylactic and therapeutic efficacy of progesterone and mifepristone on experimental trichinellosis with ultra-structural studies

Right up to now, there has not been an effective or safe therapy for trichinellosis. Thus, this study aimed to determine the efficacy of prophylactic and therapeutic regimens of progesterone and mifepristone on the intestinal and muscular phases of experimental Trichinella spiralis infection compared to albendazole. Seven distinct groups of mice were divided as follows: negative, positive, and drug control groups, as well as prophylactic and treatment groups using mifepristone and progesterone. Mice were sacrificed on the 7th and 37th days after infection. Treatment efficacy was evaluated using parasitological techniques, histopathological examination, immunohistochemical staining, and ultrastructural morphological analysis of adult worms by scanning electron microscopy. The mice groups received progesterone (300 ng/ml) and mifepristone (100 ng/ml). They demonstrated a significant improvement in intestinal and muscular inflammation and a statistically significant decline in the adult worm burden and encysted larvae (P < 0.001). Moreover, immunohistochemical staining of vascular endothelial growth factor and mucosal mast cell analyses were coincided with the obtained parasitological results. There was notable destruction and degeneration of the adult worm tegument by using both drugs. The current study pointed out that progesterone and mifepristone may provide new insights regarding the development of vaccines and drug protocols to treat trichinellosis through their combined action in reducing the inflammation, affecting the intestinal immune cell, and decreasing the adult worm burden, and larval capsule development.