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Zoonoses and Public Health Jun 2024Angiostrongylus cantonensis, commonly known as the rat lungworm, is a metastrongyloid nematode found primarily not only in tropical and subtropical regions but also in...
BACKGROUND
Angiostrongylus cantonensis, commonly known as the rat lungworm, is a metastrongyloid nematode found primarily not only in tropical and subtropical regions but also in temperate areas and considered the leading cause of eosinophilic meningitis in humans. Synanthropic rodents such as Rattus norvegicus and Rattus rattus are the most frequent definitive hosts of this parasite.
METHODS AND RESULTS
The presence of this parasite was detected in the pulmonary arteries of three specimens of R. norvegicus in the city of Buenos Aires representing the species' southernmost known record in natural hosts. Species confirmation was achieved through partial sequences of 18S and COI genes. By comparing the COI gene sequences with those available in GenBank through the construction of a haplotype network, we obtained that the analysed specimen presents high similarity with those reported in Japan and Southeast Asia.
CONCLUSIONS
All infected rats were captured in an area surrounding a port with significant import and export activity, suggesting that A. cantonensis may have been introduced through commercial ships. Specifically, the parasite was detected in a neighbourhood with vulnerable socio-economic conditions and in a nature reserve, which exhibit biotic and abiotic characteristics conducive to sustaining high-density rat populations, scattered waste, areas of spontaneous vegetation, debris accumulation and flooded areas or lagoons offering suitable habitats for intermediate hosts such as snails. Thus, the close proximity of the port to these sites creates a favourable ecological context for the establishment of A. cantonensis. This study shows the need to conduct research to detect A. cantonensis in non-endemic areas but with the characteristics that promote its arrival and development of its life cycle in order to implement control measures to prevent expansion of this parasite and its transmission to humans and other animals.
PubMed: 38937928
DOI: 10.1111/zph.13163 -
Tropical Medicine and Infectious Disease May 2024, a zoonotic parasite, can invade the human central nervous system (CNS) and cause acute eosinophilic meningitis or eosinophilic meningoencephalitis. Mice infected with...
, a zoonotic parasite, can invade the human central nervous system (CNS) and cause acute eosinophilic meningitis or eosinophilic meningoencephalitis. Mice infected with show elevated levels of pro-inflammatory cytokines, plasminogen activators, and matrix metalloproteinase-9, resulting in disruption of the blood-brain barrier (BBB) and immune cell infiltration into the CNS. Caveolin-1 (Cav-1) regulates the permeability of the BBB, which affects immune cells and cerebrospinal fluid. This intricate interaction ultimately fuels the progression of brain damage and edema. This study aims to investigate the regulatory role of Cav-1 in the pathogenesis of meningoencephalitis induced by infection. We investigated pathological alterations by triphenyl-tetrazolium chloride, brain water content, BBB permeability, Western blot analysis, and gelatin zymography in BALB/c mice after . The study evaluates the critical role of Cav-1 regulation through the TLR4/MyD88 signaling pathway, modulates tight junction proteins, influences BBB permeability, and contributes to brain damage in -induced meningoencephalitis.
PubMed: 38922036
DOI: 10.3390/tropicalmed9060124 -
Molecules (Basel, Switzerland) May 2024, the invasive snail, is a host of the parasitic nematode , which has adverse effects on the agriculture system and human health. This work evaluated the molluscicidal...
, the invasive snail, is a host of the parasitic nematode , which has adverse effects on the agriculture system and human health. This work evaluated the molluscicidal activity of petroleum ether extracts (PEEs) from three species of against the snail . Pcp (PEE of ) showed the most effective molluscicide activity. Sixty-one compounds were identified by GC-MS and the main components were terpenoids and fatty acids. The half-lethal concentration (LC) of Pcp at 24 h (0.27 mg/mL) and 48 h (0.19 mg/mL) was used to evaluate the biochemical alterations in snail tissue. These sublethal concentrations caused the levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity to increase, while acetylcholinesterase (AChE) activity decreased. Also, under LC treatment, several histological changes were observed in the hepatopancreas and foot of the snail compared with the control group. Moreover, the toxic test in rice demonstrated that Pcp has low toxicity. These results suggest that Pcp could be developed as an effective molluscicide for control.
Topics: Animals; Molluscacides; Plant Extracts; Snails; Plant Leaves
PubMed: 38893362
DOI: 10.3390/molecules29112487 -
Parasitology Research Jun 2024Rat lungworm disease or neuroangiostrongyliasis is a cerebral parasitic infection that affects humans and animals alike. Its clinical signs and symptoms can range from...
Rat lungworm disease or neuroangiostrongyliasis is a cerebral parasitic infection that affects humans and animals alike. Its clinical signs and symptoms can range from mild self-resolving to serious life-threatening conditions. Studies suggest therapeutic interventions during the early stages of infection to be more effective than in later stages. However, early diagnosis of infection is usually problematic without the knowledge of exposure and/or detection of the parasite's DNA or antibody against the parasite in the cerebrospinal fluid. This requires a lumbar puncture, which is an invasive procedure that generally requires hospitalization. This study evaluates an affordable and less invasive alternative to detect parasitic DNA by PCR from the peripheral blood of potentially infected animals. Blood samples from 58 animals (55 dogs and 3 cats) with clinical suspicion of infection were submitted to our lab between February 2019 and August 2022 by local, licensed veterinarians. DNA was extracted from whole blood, plasma, serum, and/or packed cells using the Qiagen DNeasy Blood & Tissue Kit as per the manufacturer's protocol. All 58 animals were tested by real-time PCR using the AcanITS1 assay and 32 of these animals (31dogs; 1 cat) were also tested using the AcanR3990 assay. The PCR results for both assays were classified into strongly positive > positive > weakly positive > negative, and equivocal for ambiguous results, based on the strength of the signal. The percent infection detected using the AcanITS1 and AcanR3990 assays was 12.72% (7/55) and 20.68% (6/29), respectively. The overall percent infection detected was 34.37% (11/32), with only two animals testing positive by both assays. The three cats involved in this study tested negative by both assays. These results are promising and warrant further investigations to increase sensitivity including variables that might affect detection in the blood, such as parasite load, and laboratory methodologies.
Topics: Animals; Angiostrongylus cantonensis; Strongylida Infections; Real-Time Polymerase Chain Reaction; Cats; Cat Diseases; Dogs; Dog Diseases; Sensitivity and Specificity; DNA, Helminth
PubMed: 38862687
DOI: 10.1007/s00436-024-08251-9 -
Current Research in Parasitology &... 2024Rats, being synanthropic, are hosts to agents of zoonotic diseases that pose a threat to human and domestic animal health. The nematode parasite , commonly known as the...
Rats, being synanthropic, are hosts to agents of zoonotic diseases that pose a threat to human and domestic animal health. The nematode parasite , commonly known as the rat lungworm, is no exception; it can cause potentially fatal neural disease in humans, dogs and other species. The distribution of (haplotypes SYD.1 and Ac13) and its close relative, is not well understood in Australia. We investigated the prevalence of in rats in Sydney, Australia, primarily faecal qPCR, and identified the species and haplotypes using partial 1 sequencing. We found a moderate prevalence of infection (29%; 95% CI: 16.1-46.6%) in black () and brown () rats around public parks and residential areas. This study demonstrates that Sydney's urban rat population is a reservoir for . Modelling infection status as a function of rat species, sex, tibia length (as a proxy for age), and health index (a measure of weight by size) revealed that older rats are statistically more likely to be infected ( = 5.331, = 0.021). We observed a dominant presence of the SYD.1 haplotype, for which the implications are not yet known. No was detected, leading us to suspect it may have a more restricted host- and geographical range. Overall, this study illustrates the presence and potential risk of infection in Sydney. Public education regarding transmission routes and preventative measures is crucial to safeguard human and animal health.
PubMed: 38845789
DOI: 10.1016/j.crpvbd.2024.100179 -
Journal of Microbiology, Immunology,... May 2024Co-therapy with albendazole and steroid is commonly used in patients with eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis infections. However,...
Curative effects and mechanisms of AG1296 and LY294002 co-therapy in Angiostrongylus cantonensis-induced neurovascular unit dysfunction and eosinophilic meningoencephalitis.
BACKGROUND
Co-therapy with albendazole and steroid is commonly used in patients with eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis infections. However, anthelminthics often worsen symptoms, possibly due to the inflammatory reaction to antigens released by dying worms. Therefore, the present study was to investigate the curative effects and probable mechanisms of the platelet-derived growth factor receptor-beta (PDGFR-β) inhibitor AG1296 (AG) and the phosphoinositide 3-kinase inhibitor (PI3K) LY294002 (LY) in A. cantonensis-induced neurovascular unit dysfunction and eosinophilic meningoencephalitis.
METHODS
Western blots were used to detect matrix protein degradation and the expressions of PDGFR-β/PI3K signaling pathway. The co-localization of PDGFR-β and vascular smooth muscle cells (VSMCs), and metalloproteinase-9 (MMP-9) and VSMCs on the blood vessels were measured by confocal laser scanning immunofluorescence microscopy. Sandwich enzyme-linked immunosorbent assays were used to test S100B, interleukin (IL)-6, and transforming growth factor beta in the cerebrospinal fluid to determine their possible roles in mouse resistance to A. cantonensis.
RESULTS
The results showed that AG and LY cotherapy decreased the MMP-9 activity and inflammatory reaction. Furthermore, S100B, IL-6 and eosinophil counts were reduced by inhibitor treatment. The localization of PDGFR-β and MMP-9 was observed in VSMCs. Furthermore, we showed that the degradation of the neurovascular matrix and blood-brain barrier permeability were reduced in the mouse brain.
CONCLUSIONS
These findings demonstrate the potential of PDGFR-β inhibitor AG and PI3K inhibitor LY co-therapy as anti-A. cantonensis drug candidates through improved neurovascular unit dysfunction and reduced inflammatory response.
PubMed: 38839542
DOI: 10.1016/j.jmii.2024.05.012 -
Food and Waterborne Parasitology Jun 2024and are known human pathogens responsible for eosinophilic angiostrongyliasis and abdominal angiostrongyliasis, respectively. Humans are accidental hosts, where... (Review)
Review
and are known human pathogens responsible for eosinophilic angiostrongyliasis and abdominal angiostrongyliasis, respectively. Humans are accidental hosts, where infection occurs through the consumption of the infective larva stage 3 in intermediate or paratenic hosts. The proven method for abdominal angiostrongyliasis diagnosis is the histological examination through tissue biopsy, while the diagnosis of eosinophilic angiostrongyliasis is the detection of larva in the cerebrospinal fluid. As there is molecular evidence of cryptic species within and lineages, along with morphological similarities within both lineages, accurate species identification and disease diagnosis may be challenging. Moreover, species within the lineages share similar intermediate and definitive hosts and geographic distribution. For example, both and (a closely related species in lineage) overlap in their geographic distribution in Southeast Asia. Additionally, variations in the molecular makeup of and lineages may impact the pathogenicity, infectivity, and disease severity of angiostrongyliasis. Understanding of the genetic diversity of both lineages is a cornerstone for improved diagnosis and disease intervention, especially in a changing global environment. To shed light and provide insights into the genetic diversity of the lineages causing human angiostrongyliasis, we aim to present an up-to-date review of the studies conducted and genetic markers used for and lineages. The implications for accurate molecular identification and diagnosis of human angiostrongyliasis are also discussed.
PubMed: 38827346
DOI: 10.1016/j.fawpar.2024.e00230 -
PLoS Neglected Tropical Diseases May 2024Angiostrongylus cantonensis is a parasite that mainly infects the heart and pulmonary arteries of rats and causes human eosinophilic meningitis or meningoencephalitis in...
Inflammatory and immunopathological differences in brains of permissive and non-permissive hosts with Angiostrongylus cantonensis infection can be identified using 18F/FDG/PET-imaging.
BACKGROUND
Angiostrongylus cantonensis is a parasite that mainly infects the heart and pulmonary arteries of rats and causes human eosinophilic meningitis or meningoencephalitis in certain geographical areas. Current diagnostic methods include detection of the parasite in cerebrospinal fluid (CSF) and eosinophilic immune examination after lumbar puncture, which may be risky and produce false-positive results. 18F- Fluorodeoxyglucose (FDG), a Positron emission tomography (PET) tracer, has been used to assess different pathological or inflammatory changes in the brains of patients. In this study, we hypothesized that A. cantonensis infection-induced inflammatory and immunomodulatory factors of eosinophils result in localized pathological changes in the brains of non-permissive hosts, which could be analyzed using in vivo 18F-FDG PET imaging.
METHODOLOGY/FINDINGS
Non-permissive host ICR mice and permissive host SD rats were infected with A. cantonensis, and the effects of the resulting inflammation on 18F-FDG uptake were characterized using PET imaging. We also quantitatively measured the distributed uptake values of different brain regions to build an evaluated imaging model of localized neuropathological damage caused by eosinophilic inflammation. Our results showed that the uptake of 18F-FDG increased in the cerebellum, brainstem, and limbic system of mice at three weeks post-infection, whereas the uptake in the rat brain was not significant. Immunohistochemical staining and western blotting revealed that Iba-1, a microglia-specific marker, significantly increased in the hippocampus and its surrounding area in mice after three weeks of infection, and then became pronounced after four weeks of infection; while YM-1, an eosinophilic chemotactic factor, in the hippocampus and midbrain, increased significantly from two weeks post-infection, sharply escalated after three weeks of infection, and peaked after four weeks of infection. Cytometric bead array (CBA) analysis revealed that the expression of TNF in the serum of mice increased concomitantly with the prolongation of infection duration. Furthermore, IFN-γ and IL-4 in rat serum were significantly higher than in mouse serum at two weeks post-infection, indicating significantly different immune responses in the brains of rats and mice. We suggest that 18F-FDG uptake in the host brain may be attributed to the accumulation of large numbers of immune cells, especially the metabolic burst of activated eosinophils, which are attracted to and induced by activated microglia in the brain.
CONCLUSIONS
An in vivo 18F-FDG/PET imaging model can be used to evaluate live neuroinflammatory pathological changes in the brains of A. cantonensis-infected mice and rats.
Topics: Animals; Angiostrongylus cantonensis; Fluorodeoxyglucose F18; Strongylida Infections; Brain; Mice; Positron-Emission Tomography; Rats; Rats, Sprague-Dawley; Eosinophils; Inflammation; Male; Disease Models, Animal; Lectins; Female; beta-N-Acetylhexosaminidases
PubMed: 38805557
DOI: 10.1371/journal.pntd.0012188 -
Tropical Medicine and Infectious Disease May 2024The purpose of this study is to clarify the role of IL-33 in the immune response to angiostrongyliasis, especially in terms of antibody production and isotype switching....
The purpose of this study is to clarify the role of IL-33 in the immune response to angiostrongyliasis, especially in terms of antibody production and isotype switching. In our experiment, C57BL/6 mice were each infected with 35 infectious larvae and were divided into groups that received an intraperitoneal injection of IL-33, anti-IL-33 monoclonal antibody (mAb), or anti-ST2 mAb 3 days post-infection (dpi) and were subsequently administered booster shots at 5-day intervals with the same dose. Serum samples from each group were collected weekly for ELISA assays. The levels of total IgG, IgG1, and IgG3 were significantly increased in -infected mice that were treated with IL-33, and the levels decreased significantly in infected groups treated with anti-IL-33 or anti-ST2 mAb. These results suggest that IL-33 may play a critical role in the pathogenesis of human angiostrongyliasis and could be useful for understanding protective immunity against this parasitic infection.
PubMed: 38787044
DOI: 10.3390/tropicalmed9050111