Autochthonous Transmission of Angiostrongylus Cantonensis in a Domestic Rabbit (Oryctolagus Cuniculus) in Hawai`i: Detection in Multiple Tissues Using AcanITS1 and AcanR3990 PCR Assays

Background: Hawaii is the hotspot for rat lungworm disease (angiostrongyliasis) caused by the nematode Angiostrongylus cantonensis in the USA. In humans, PCR of the CSF is typically used for diagnosis, however, collection of CSF requires hospitalization. Here, we evaluate the efficacy of two different PCR tests to detect A.cantonensis DNA in multiple tissues including blood from a rabbit presumably infected by eating contaminated lettuce. Methods: Two different PCR assays (AcanR3990, and AcanITS1) were used comparatively to test DNA extracted from slug and rabbit tissues. Assays were conducted using established protocols and were run in triplicate, with negative (dH20) controls included throughout. Results: A juvenile Parmarian martensi (semi-slug) found in local lettuce tested positive for the presence of Angiostrongylus cantonensis DNA. A family and their two domestic rabbits (Oryctolagus cuniculus) consumed this lettuce twice within the five days preceding testing. One rabbit exhibited symptoms consistent with eosinophilic meningitis 3-6 days after being fed the lettuce. Appropriate veterinary treatment was ineffective and the rabbit was subsequently euthanized. This study comparatively applies two different PCR assays to detect A. cantonensis DNA in the peripheral blood, cerebrospinal fluid, brain, heart, and lung tissue of this rabbit, and provides data implicating parasite transmission via contaminated home-grown lettuce. Six of the nine brain DNA samples, as well as the CSF sample, tested positive in replicate or triplicate for A. cantonensis DNA with both PCR assays. The AcanR3990 assay also detected A. cantonensis DNA from the lung, heart septum, all nine samples from the brain, and blood products (plasma, EDTA-treated whole blood, and buffy coat/red blood cells) in replicate or triplicate.

Ultrastructural aspects of the intestinal cells surface of Angiostrongylus cantonensis by using of transmission electron microscopy

Summary The rat lungworm Angiostrongylus cantonensis is a zoonotic parasite and the main cause of eosinophilic meningitis in the world. Its main source of nutrients originates from the degradation of host hemoglobin in blood-feeding helminths, such as A. cantonensis. The purpose of this study was to analyze the ultrastructure of the intestinal cells by using of transmission electron microscopy (TEM). A. cantonensis worms obtained from Rattus norvegicus (norway rats) from endemic area were used for TEM. The ultrastructural analysis was performed using fragments cut from the middle part of the worms, and the TEM study revealed the cells with microvilli and nuclei containing areas of loose and condensed chromatin and the presence of macrovesicles and microvesicles of digestion and it was observed in this study that intestinal epithelium is look like a syncytium. The ultrastructural aspects of the intestinal cells surface of A. Cantonensis the indicate that the intestinal epithelium is a multinucleate mosaic or syncytium.

Up-Regulated Galectin-1 in Angiostrongylus Cantonensis L5 Reduces Body Fat and Increases Oxidative Stress Tolerance

Background: Angiostrongylus cantonensis L5, parasitizing in human cerebrospinal fluid, leads to eosinophilic meningitis, which is attributed to tissue inflammatory responses caused primarily by high percentage of eosinophils. Eosinophils are also involved in helminthic killing, using the peroxidative oxidation and hydrogen peroxide (H2O2) generated by dismutation of superoxide produced during respiratory burst. In contrast, helminthic worms have evolved to attenuate eosinophil-mediated tissue inflammatory responses for their survival. In previous study, we have demonstrated the extracellular function of Acan-Gal-1 in inducing the apoptosis of macrophages. And here, the intracellular functions of Acan-Gal-1 were investigated with the aim to further reveal the mechanism of A. cantonensis L5 worms surviving in the central nervous system of human from inflammatory responses. Methods: Bioinformatics were used to analyse the structural characterisation of Acan-Gal-1; qRT-PCR and microinjection were performed to detect the expression patterns of Acan-gal-1; microinjection was performed to construct transgenic worms; oxidative stress assay and Oil Red O fat staining were used to determine the functions of Acan-Gal-1.Results: The results showed that Acan-Gal-1 was expressed ubiquitously and mainly localized in cuticle, and it was up-regulated in both L5 and adult worm. N2 worms expressing pCe-Acan-gal-1::Acan-gal-1::rfp, with lipid deposition reduced, were significantly resistant to oxidative stress. lec-1 mutant worms, with lipid deposition increased, showed susceptible to oxidative stress, and this phenotype could be rescued by expressing pCe-Acan-gal-1::Acan-gal-1::rfp. And fat-6;fat-7 double-mutant worms expressing pCe-Acan-gal-1::Acan-gal-1::rfp showed no significant changes in oxidative stress tolerance.Conclusion: In C. elegans worms, up-regulated Acan-Gal-1 plays a defensive role against damage due to oxidative stress for worm survival through reducing fat deposition. And this might indicate the mechanism of A. cantonensis L5 worms, with Acan-Gal-1 up-regulated, surviving in the central nervous system of human from immune attack of Eosinophil.

Changes in Hepatic Metabolism of Rattus norvegicus Infected to Angiostrongylus cantonensis (Nematoda) and Exposed to Glyphosate-Based Herbicide

Helminth infection associated with exposure to pesticides has received little attention regarding its effect on the human population and on farm and wild animals. The aim of this study was to evaluate the effects a glyphosate-based herbicide on the hepatic and glycemic metabolism of Rattus norvegicus (Wistar) infected by Angiostrongylus cantonensis. Experimental groups were orally infected with 50 L3 larvae of A. cantonensis and exposed to the herbicide after and before the infection. Biochemical serum analyses were carried out to determine the levels of Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Total Bilirubin (TB), total protein, albumin, urea, creatinine, uric acid, glucose and hepatic glycogen. All exposed groups showed an increase in the concentration of glycogen, AST, ALT and TB, the last ones suggesting liver tissue damage. Exposure to the herbicide caused hyperalbuminemia as an antioxidant response to the herbicide. These findings contribute to a better understanding of how glyphosate-based herbicides can change the hepatic metabolism the vertebrate and to influence the parasite-host relationship.