Immunohistochemistry analyses of the abomasal mucosa show differences in cellular-mediated immune responses to Haemonchus contortus infection in resistant and susceptible young lambs.

Haemonchus contortus is known for its high pathogenicity in sheep, and the uncontrolled use of anthelmintics resulted in the emergence of multiple drug-resistant populations. Breeding sheep for gastrointestinal nematode resistance is a sustainable alternative to reduce dependence of anthelmintic drugs, and differences in the degree of resistance between breeds have been reported. Here we compare two sheep breeds (Santa Ines and Ile de France), concerning the differences in innate and adaptive immune response involved in the resistance against H. contortus infection. Immunohistochemical analyses of the abomasum were conducted in naïve Santa Ines (n = 14) and Ile de France (n = 12) lambs randomized into four groups: infected Santa Ines (n = 8), non-infected control Santa Ines (n = 6), infected Ile de France (n = 8), and non-infected control Ile de France (n = 4). The infected lambs were initially infected with H. contortus infective larvae at 14 days of age, and multiple infections were conducted every second day until they reached 66 days of age. There was a significant effect (P < 0.001) of the infection with increase in numbers of CD3+ T; CD79α+ B; GATA3+ Th2/ILC2; POU2F3+ tuft cells; FOXP3+ T reg; and IgE + cells in the fundus of the abomasal mucosa in both Santa Ines and Ile de France lambs. Nevertheless, the infected Santa Ines lambs presented the highest averages for CD79α+ B; GATA3+ Th2/ILC; IgE + cells; and POU2F3+ tuft cells and there was a significant association of the breed and infection status with regards to POU2F3+ tuft cells, with the highest mean in the infected Santa Ines group. The infected Santa Ines group had three lambs with high degree of resistance and five lambs that showed a moderate infection. Our results suggest a mechanism of synergistic coordination between different immune-cell types in promoting resistance of suckling lambs under H. contortus infection.

Local immune response of Canarian Majorera goats infected with Teladorsagia circumcincta.

BACKGROUND: Due to increased anthelmintic resistance, alternative methods to drugs are necessary to control gastrointestinal nematodes (GINs). Some of the most promising alternatives are based on the immune response of the host, such as the selection of genetically resistant breeds or the use of vaccines against these parasites. Given the limited information available on the immune response against GINs in goats, this study investigated the local immune response of goat kids of an indigenous Canary Islands breed (Majorera breed) experimentally infected with Teladorsagia circumcincta, one of the most pathogenic and prevalent GIN species. METHODS: For this purpose, the relationship between different parasitological (number of mature and immature worms, worm length, and number of intrauterine eggs) and immunological parameters at the local level (related to both the humoral and cellular immune response) was analyzed at early (1 week post-infection [wpi]) and late (8 wpi) stages of infection. RESULTS: Primary infection of goat kids with T. circumcincta infective larvae (L3) generated a complex immune response that could be defined as Th2 type, characterized by increased infiltration in abomasal tissues of several effector cells as well as a progressive presence of specific antibodies against parasitic antigens in the gastric mucus. Cellular responses were evidenced from 1 wpi onward, showing an increase in antigen-presenting cells and various lymphocyte subsets in the gastric mucosa. CONCLUSIONS: The complexity of the host response was evidenced by statistically significant changes in the number of all these subpopulations (MHCII+, CD4+, CD8+, γδ+, CD45R+, IgA+, and IgG+), as well as in the evolution of the relative cytokine gene expression. From a functional point of view, negative associations were observed between the number of most of the immune cells (CD4, IgA, IgG, and CD45R cells) and parameters that could be related to the fecundity of worms, a phenomenon that was especially evident when the number of IgG and CD45R cells or the specific IgA levels of the gastric mucus were compared with parasitological parameters such as the female worm length or fecal egg counts at 8 wpi.

Acute oral colchicine caused gastric mucosal injury and disturbance of associated microbiota in mice.

Colchicine (COL), an ancient and well-known drug, has been used in clinical practice for centuries. On the other hand, COL has also attracted extensive concerns for its potent toxic effects, especially gastrointestinal adverse reactions (nausea, vomiting, and diarrhea) before clinical symptoms relief. In this study, we used a rodent model to study the effects of COL on gastric mucosa and associated microbiota. The mice were exposed to various concentrations of COL (0.1, 0.5, and 2.5 mg kg-1 body weight per day) for 7 days, and the results showed that COL treatment caused severe gastric mucosal damage, accompanied by a significant decrease in gastric mucosal proinflammatory cytokines (IL-1ß, IL-6, and TNF-α). The 16S rRNA gene sequencing revealed that COL significantly perturbed the gastric microbiota composition and reduced the gastric microbiota diversity in mice. Also, we identified bacterial biomarkers associated with diarrhea, including phylum Firmicutes, class Bacilli, order Lactobacillales, family Lactobacillaceae, genu Lactobacillus, and genu Blautia, suggesting that COL-triggered adverse reactions are closely related to gastric microbial perturbations. Our findings open new paths for understanding the mechanism of COL-related adverse gastrointestinal reactions, broadening the scientific view on the interaction between drugs and host gastrointestinal microbiota.

Th17 Cells Provide Mucosal Protection against Gastric Trypanosoma cruzi Infection.

Trypanosoma cruzi is the intracellular parasite of Chagas disease, a chronic condition characterized by cardiac and gastrointestinal morbidity. Protective immunity requires CD4+ T cells, and Th1 cells and gamma interferon (IFN-γ) are important players in host defense. More recently, Th17 cells and interleukin 17A (IL-17A) have been shown to exert protective functions in systemic T. cruzi infection. However, it remains unclear whether Th17 cells and IL-17A protect in the mucosa, the initial site of parasite invasion in many human cases. We found that IL-17RA knockout (KO) mice are highly susceptible to orogastric infection, indicating an important function for this cytokine in mucosal immunity to T. cruzi. To investigate the specific role of Th17 cells for mucosal immunity, we reconstituted RAG1 KO mice with T. cruzi-specific T cell receptor transgenic Th17 cells prior to orogastric T. cruzi challenges. We found that Th17 cells provided protection against gastric mucosal T. cruzi infection, indicated by significantly lower stomach parasite burdens. In vitro macrophage infection assays revealed that protection by Th17 cells is reduced with IL-17A neutralization or reversed by loss of macrophage NADPH oxidase activity. Consistently with this, mice lacking functional NADPH oxidase were not protected by Th17 cell transfer. These data are the first report that Th17 cells protect against mucosal T. cruzi infection and identify a novel protective mechanism involving the induction of NADPH oxidase activity by IL-17A. These studies provide important insights for Chagas vaccine development and, more broadly, increase our understanding of the diverse roles of Th17 cells in host defense.

Dynamic transcriptomic changes of goat abomasal mucosa in response to Haemonchus contortus infection.

Gastrointestinal nematode (GIN) infections are one of the major constraints for grazing sheep and goat production worldwide. Genetic selection for resistant animals is a promising control strategy. Whole-transcriptome analysis via RNA-sequencing (RNA-seq) provides knowledge of the mechanisms responsible for complex traits such as resistance to GIN infections. In this study, we used RNA-seq to monitor the dynamics of the response of the abomasal mucosa of Creole goat kids infected with Haemonchus contortus by comparing resistant and susceptible genotypes. A total of 8 cannulated kids, 4 susceptible and 4 resistant to GIN, were infected twice with 10 000 L3 H. contortus. During the second infection, abomasal mucosal biopsies were collected at 0, 8, 15 and 35 days post-infection (dpi) from all kids for RNA-seq analysis. The resistant animals showed early activation of biological processes related to the immune response. The top 20 canonical pathways of differentially expressed genes for different comparison showed activation of the immune response through many relevant pathways including the Th1 response. Interestingly, our results showed a simultaneous time series activation of Th2 related genes in resistant compared to susceptible kids.

[Duodenal obstruction by Strongyloides stercoralis, an unusual complication]. / Obstrucción duodenal por Strongyloides stercoralis, una complicación inusual.

Strongyloidiasis is a neglected disease in Latin America. Gastrointestinal manifestations are nonspecific and duodenal obstruction is a rare complication. Here we present the case of a 31-year-old male from the central jungle of Peru, admitted due to a high intestinal obstruction, with duodenal ulcers and stenosis evidenced in the upper endoscopy. The histopathological report revealed presence of larvae of Strongyloides stercoralis. Clinical and endoscopic follow up were favorable with ivermectin treatment. There are near 20 reported cases of duodenal obstruction due to S. stercoralis. Additionally, infection by HTLV-1 was confirmed, being this a frequent association.

Gastric coccidiosis in Thoracocharax stellatus caused by Goussia guamaensis n. sp. (Apicomplexa: Eimeriidae) from the Amazon region.

Ninety-seven specimens of spotfin hatchetfish, Thoracocharax stellatus, an ornamental freshwater species from the Amazon basin, were captured in the basin of the Guamá River in the municipality of Belém, in northern Brazil, and analysed for coccidiosis infection. Overall, 26 of the specimens were infected by apicomplexan parasites of the genus Goussia, with unsporulated forms being found in the gastric epithelium and sporulated forms in the intestinal lumen. The spheroid oocysts (mean diameter: 13.2 ± 1.7 µm) have four elliptical sporocysts. A partial sequence of the SSU rDNA of the new species was obtained, which contained 1,121 base pairs, with 43.8% guanine + cytosine (G + C), and the bases distributed as follows: A = 28.1%, C = 18.3%, G = 25.5% and T = 28.1%. The combined analysis of the morphometric and phylogenetic evidence confirmed that the specimens represented the genus Goussia and were allocated to a new species, Goussia guamaensis n. sp., which is described here.

Obstrucción duodenal por Strongyloides stercoralis, una complicación inusual / Duodenal obstruction by Strongyloides stercoralis, an unusual complication

Resumen La estrongiloidiasis es una enfermedad desatendida en Latinoamérica. Las manifestaciones gastrointestinales son inespecíficas y la obstrucción duodenal es una complicación infrecuente. Presentamos el caso clínico de un varón de 31 años, procedente de la selva central de Perú, que ingresó por una obstrucción intestinal alta, con úlceras y una estenosis duodenal evidenciadas en la endoscopia digestiva alta. El informe histopatológico reveló la presencia de larvas de Strongyloides stercoralis. La evolución clínica y endoscópica fueron favorables con el tratamiento con ivermectina. Existen poco más de 20 casos publicados de obstrucción duodenal por S. stercoralis. Adicionalmente, se confirmó una infección por HTLV-1, asociación descrita frecuente.

Strongyloidiasis is a neglected disease in Latin America. Gastrointestinal manifestations are nonspecific and duodenal obstruction is a rare complication. Here we present the case of a 31-year-old male from the central jungle of Peru, admitted due to a high intestinal obstruction, with duodenal ulcers and stenosis evidenced in the upper endoscopy. The histopathological report revealed presence of larvae of Strongyloides stercoralis. Clinical and endoscopic follow up were favorable with ivermectin treatment. There are near 20 reported cases of duodenal obstruction due to S. stercoralis. Additionally, infection by HTLV-1 was confirmed, being this a frequent association.

Anisakiasis: The risks of seafood consumption.

CONTEXT AND AIMS: Japanese cuisine is now popular worldwide, and consumption of raw fish has thus increased at sushi bars and Japanese restaurants outside Japan. Anisakiasis, also known as herring-worm disease, is caused by ingesting larval nematodes in raw seafood and is a common illness in Japan. However, due to the rising popularity of Japanese food, gastroenterologists outside Japan need to be familiar with this disease. SUBJECTS AND METHODS AND RESULTS: We treated 158 patients presenting with acute gastrointestinal manifestations caused by anisakiasis from April 1991 to April 2000. One or more nematodes were removed endoscopically within 48 h of presentation in 44% of these patients, which resulted in prompt resolution of symptoms. Major endoscopic findings were gastric ulcer accompanied by hemorrhage, erosion, redness, and edema of the gastric mucosa in areas penetrated by larvae and other areas. CONCLUSIONS: Endoscopy was valuable for the diagnosis and treatment of anisakiasis. We recommend endoscopy in suspected cases of anisakiasis. Moreover, it is desirable to combine complementary tests such as immunological tests/IgE measurement. As the popularity of Japanese cuisine increases, reports of anisakiasis are likely to be more frequent in countries other than Japan.

Severe strongyloidiasis and systemic vasculitis: comorbidity, association or both? Case-based review.

A possible association between strongyloidiasis and systemic vasculitis is rarely reported in the literature. We report the case of a patient with severe strongyloidiasis and an angiographic finding consistent with polyarteritis nodosa. Diagnosis of strongyloidiasis was made by finding of larvae and adult parasites in samples of the upper gastrointestinal tract mucosa and stool. The patient was treated with albendazole, ivermectin and corticosteroid withdrawal. This therapy led to the resolution of symptoms, with repeated stool samples negative for S. stercoralis. However, the clinical course was complicated with pulmonary tuberculosis. Despite tuberculostatic therapy and supportive measures, a lethal outcome occurred. The report is followed by a focused review of the available literature on the association of strongyloidiasis and systemic vasculitis.

Molecular and Cellular Response to Experimental Anisakis pegreffii (Nematoda, Anisakidae) Third-Stage Larval Infection in Rats.

Background: Anisakiasis is a zoonotic disease caused by accidental ingestion of live Anisakis spp. third-stage larvae present in raw or undercooked seafood. Symptoms of this emerging infectious disease include mild-to-severe abdominal pain, nausea, and diarrhea. Some patients experience significant allergic reactions. Aims: In order to better understand the onset of anisakiasis, we aimed to: (i) histopathologically describe severe inflammatory/hemorrhagic infection site lesions in Sprague-Dawley rats experimentally infected with Anisakis pegreffii larvae; and (ii) qualitatively and quantitatively characterize the transcriptomes of affected tissues using RNA-Seq. Methodology: The experiment was performed on 35 male rats, sacrificed at 5 time points (6, 10, 18, 24, and 32 h post-infection). Gastric intubation was performed with 10 A. pegreffii larvae (N = 5 infected rats per time point) or 1.5 ml of saline (external control N = 2 rats). 16 pools, seven for muscle tissues and nine for stomach tissues, were created to obtain robust samples for estimation of gene expression changes depicting common signatures of affected versus unaffected tissues. Illumina NextSeq 500 was used for paired-end sequencing, while edgeR was used for count data and differential expression analyses. Results: In total, there were 1372 (855 up and 517 down) differentially expressed (DE) genes in the Anisakis-infected rat stomach tissues, and 1633 (1230 up and 403 down) DE genes in the muscle tissues. Elicited strong local proinflammatory reaction seems to favor the activation of the interleukin 17 signaling pathway and the development of the T helper 17-type response. The number of DE ribosomal genes in the Anisakis-infected stomach tissue suggests that A. pegreffii larvae might induce ribosomal stress in the early infection stage. However, the downstream pathways and post-infection responses require further study. Histopathology revealed severe inflammatory/hemorrhagic lesions caused by Anisakis infection in the rat stomach and muscle tissues in the first 32 h. The lesion sites showed infiltration by polymorphonuclear leukocytes (predominantly neutrophils and occasional eosinophils), and to a lesser extent, macrophages. Conclusion: Understanding the cellular and molecular mechanisms underlying host responses to Anisakis infection is important to elucidate many aspects of the onset of anisakiasis, a disease of growing public health concern.

Gongylonema Parasites of Rodents: A Key to Species and New Data on Gongylonema neoplasticum.

Specimens of the genus Gongylonema were collected from the gastric mucosa of rodents of Rattus rattus Linnaeus, 1758, and Rattus norvegicus Berkenhout, 1769, collected in urban areas in Belém, Pará, in the eastern Brazilian Amazon. The helminths were processed for analysis using light microscopy and scanning electron microscopy (SEM) techniques and presented taxonomic characteristics of the species Gongylonema neoplasticum. The SEM analyses revealed the presence of 2 developed buccal plates (1 dorsal, 1 ventral), also called interlabia, with a prominent and bifurcated ventral plaque. The occurrence of the bifurcated ventral interlabium had not yet been identified by any other author from G. neoplasticum. As a result of our extensive research on published data on Gongylonema spp., we propose a taxonomic key for species of this genus that parasitize rodents. This is the first record of G. neoplasticum in urban areas of the Brazilian Amazon.

Early and late gene expression profiles of the ovine mucosa in response to Haemonchus contortus infection employing Illumina RNA-seq technology.

We conducted herein transcriptome sequencing of the ovine abomasal tissues using the Illumina HiSeq 4000 platform to segregate early and late H. contortus-infected sheep (7 and 50days post-infected groups, respectively) from the control naive ones. A total of 548, 357 and 7 were substantially induced genes in 7days post-infection versus uninfected-control group, 50days post-infection versus 7days post-infection (7dpi), and 50days post-infection (50dpi) versus uninfected-control group, respectively. However, a total of 301, 355 and 11 were significantly repressed genes between 7dpi versus uninfected-control group, 50dpi versus 7dpi, and 50dpi versus uninfected-control group, correspondingly. This indicates that H. contortus infection induced a more potent activation of abomasal gene expression in the early stage of infection as compared to the late stage. Seven pathways were annotated by Kyoto Encyclopedia of Genes, and Genomes pathway analysis accounted for the significant percentage in early H. contortus infection. This study shows for the first time that both galectin-11 and matricellular protein osteopontin are up-regulated in abomasal tissue after chronic H. contortus infection, while galectin-4 is specifically down-regulated in the early infection. Additionally, our results showed that the induction or repression of these molecules is likely to determine the infection progression.

Characterization of Ostertagia ostertagi annexin-like proteins at different developmental stages.

Ostertagiosis remains an economically important parasitic disease in cattle in the temperate regions of the world. Repeated exposures to Ostertagia ostertagi in calves cause significant pathology in the abomasum but elicit little protective immunity. The larvae use the host's gastric glands as a niche for development, where the parasite completes its parasitic stages, while in the gastric glands, the larvae must down-regulate the host inflammatory immune responses. Annexin (ANX) A1, commonly found in most eukaryotes, is heavily involved in controlling anti-inflammatory responses by binding receptors on leukocytes. We hypothesized, therefore, that parasite proteins of the ANX family may be involved in host-parasite interactions during ostertagiosis. BLASTN search with the bovine ANXA1 identified two families of Oos-ANX like proteins (Oos-ANXL), each of which was highly conserved at the genetic level and identical at the amino acid sequence level. Oos-ANXL-1 is encoded by two transcripts and Oos-ANXL-2 by 20 transcripts. The present study characterized one Oos-ANXL, representing the most abundant Oos-ANXL, which was further defined as Oost-ANXL-2.1. Oos-ANXL-2.1 with a coding sequence of 519 bp was PCR-amplified, cloned, and expressed. Oos-ANXL-2.1 was immunolocalized to both L3 and adult, but not L4. The staining appeared to be associated with the gut and hypodermis in L3, but it was specifically localized to the hypodermis in adult worms. Western blots detected three protein bands in parasite lysates using anti-recombinant Oos-ANXL-2.1 antibody. Integrated optical density for each of the 3 Oos-ANXL-2s or the total Oos-ANXL-2s detected by Western blots (P < 0.05) was higher in adult worms than in L3 or L4. The results indicate that the production of Oos-ANXL-2s is developmentally regulated and most abundant in the adult worm. This rather large family of proteins could be a potential vaccine target against O. ostertagi infection and warrants further investigation.