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Parasites & Vectors Feb 2024The closely related Angiostrongylus cantonensis and Angiostrongylus malaysiensis have been reported to coexist in Thailand and share similar hosts and life cycles....
BACKGROUND
The closely related Angiostrongylus cantonensis and Angiostrongylus malaysiensis have been reported to coexist in Thailand and share similar hosts and life cycles. Recently, in an angiostrongyliasis outbreak in Thailand, both A. cantonensis and A. malaysiensis were found in the cerebrospinal fluid of affected patients. Morphological similarities, overlapping distribution, shared hosts and habitats, and the close genetics of the two Angiostrongylus species can complicate accurate species identification. Addressing these challenges, this study aims to evaluate whether a correlation between the morphological and genetic identities of A. cantonensis and A. malaysiensis can improve species identification accuracy.
METHODS
Angiostrongylus spp. specimens from five zoogeographical regions in Thailand were subjected to morphological and molecular identification using the mitochondrial cytochrome b gene and the nuclear internal transcribed spacer 2 region (ITS2). The morphological characters for males and females were then validated using the species identity obtained from the nuclear ITS2 region.
RESULTS
The results revealed that morphological misidentifications between these two closely related species are common due to overlapping morphological characters. Although certain male traits such as body length and width aided species differentiation, female traits were found to be less reliable. Furthermore, hybrid forms (8.2%) were revealed through the ITS2 results, which can further complicate morphological identification. Mito-nuclear discordance was also present in 1.9% of the Angiostrongylus specimens from Thailand, suggesting a complex historical interbreeding between the species.
CONCLUSIONS
Based on our findings, we suggest that nuclear ITS2 is a reliable marker for species identification of A. cantonensis and A. malaysiensis, especially in regions where both species coexist. Additionally, the scope and consequences of hybridization between the two closely related Angiostrongylus species should be further investigated in Thailand.
Topics: Humans; Animals; Male; Female; Angiostrongylus; Angiostrongylus cantonensis; Phylogeny; Phenotype; Strongylida Infections
PubMed: 38326886
DOI: 10.1186/s13071-024-06140-9 -
Pathogens (Basel, Switzerland) Dec 2023is a nematode parasite that resides in the pulmonary arteries of rodents, serving as its definitive hosts. The life cycle involves several species of non-marine...
is a nematode parasite that resides in the pulmonary arteries of rodents, serving as its definitive hosts. The life cycle involves several species of non-marine gastropods as intermediate hosts, and the African giant snail is considered one of the most important around the world. Experimental data concerning . infection in the African giant snail remains notably limited. This helminth causes eosinophilic meningitis or meningoencephalitis in humans, representing an emergent zoonosis in Brazil. Understanding the host-parasite relationship through the application of new tools is crucial, given the complex interaction between zoonosis and the intricate mechanisms involving wild/human hosts, parasite adaptation, and dispersion. The objective of this study was to employ SEM as a novel methodology to understand the structural organization of the host tissue, particularly the granuloma formation. This sheds light on the complex balance between and . Nine three-month-old snails were randomly selected and exposed for 24 h to a concentration of 2000 L1/dose of . A necropsy was performed 37 days after the infection, and the samples were examined using light and scanning electron microscopy (SEM). The histopathological results revealed third-stage larvae of . associated with granulomas distributed throughout the head-foot mass, mantle, and kidney. Scanning electron microscopy of the histological section surface showed that the granuloma is surrounded by a cluster of spherical particles, which are distributed in the region bordering the larvae. This reveal details of the nematode structure, demonstrating how this methodology can enhance our understanding of the role of granulomas in molluscan tissue. The structural characteristics of granuloma formation in . suggest it as an excellent invertebrate host for . . This relationship appears to provide protection to the parasite against the host's immune defense system while isolating the snail's tissue from potential exposure to nematode antigens.
PubMed: 38251341
DOI: 10.3390/pathogens13010034 -
Pathogens (Basel, Switzerland) Dec 2023When the zoonotic parasite of rodents that can cause human neuroangiostrongyliasis, i.e., is found in its natural definitive hosts, it is usually reported in isolation,...
When the zoonotic parasite of rodents that can cause human neuroangiostrongyliasis, i.e., is found in its natural definitive hosts, it is usually reported in isolation, as if the rat lungworm were the only component of its parasite community. In this study, we report the coinfections found in rats naturally infected by in urban populations of and in Valencia, Spain. In addition to the rat lungworms, which were found in 14 of the 125 rats studied (a prevalence of 11.20%), 18 other parasite species (intestinal and tissular protists, microsporidia and helminths) were found, some of them with high burdens. Fourteen of these nineteen species found are potential zoonotic parasites, namely , , spp., , , , spp., larvae, , , , , and . The total predominance of coinfected rats as well as their high parasite loads seem to indicate a trend towards parasite tolerance.
PubMed: 38251336
DOI: 10.3390/pathogens13010028 -
Ecology and Evolution Jan 2024The Golden apple snail, , is one of the world's 100 worst invasive alien species that is best known for its damage to wetland agriculture. It also acts as an...
The Golden apple snail, , is one of the world's 100 worst invasive alien species that is best known for its damage to wetland agriculture. It also acts as an intermediate host of some zoonotic parasites such as , posing threats to human public health and safety. Despite is being an important agricultural pest, the genetic information and population expansion history of this snail remains poorly understood in China. In this study, we analyzed the genetic variation and population genetics of populations in seven regions of China based on molecular markers of three mitochondrial (mt) genes. A total of 15 haplotypes were recognized based on single mt , , and , and eight haplotypes were identified using the concatenated genes. High haplotype diversity, moderate nucleotide diversity, low gene flow, and high rates of gene differentiation among the seven populations were detected. Shanghai and Yunnan populations showed higher genetic flow and very low genetic differentiation. The results of Tajima's , Fu's , and mismatch distribution showed that did not experience population expansion in China. Genetic distance based on haplotypes suggested that gene was more conserved than gene within . The phylogenetic analyses showed there may be two geographical lineages in the Chinese mainland. The present study may provide a new genetic marker to analyze , and results support more evidence for studying the genetic distribution of in China and contribute to a deeper understanding of its population genetics and evolutionary biology.
PubMed: 38239339
DOI: 10.1002/ece3.10836 -
Journal of Helminthology Jan 2024(Issel, 1874) is a species of terrestrial slug that occurs in southeast China and the Pacific Basin and is the only species of its genus that occurs beyond the Oriental...
(Issel, 1874) is a species of terrestrial slug that occurs in southeast China and the Pacific Basin and is the only species of its genus that occurs beyond the Oriental region and to the east of Wallace's line in the Australian region, where it has probably been introduced. In this study, we report for the first time as an intermediate host for (Chen, 1935) based on histological and molecular analyses of slugs from Tuamasaga, Samoa, deposited at the Medical Malacological Collection (Fiocruz-CMM). DNA was obtained from the deparafinized tissues scraped from specimen slides. Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) targeted to the () region were carried out using the restriction enzyme I. The RFLP profile observed for our larval specimen of was identical to the profile previously established for , demonstrating that can be naturally infected with and is likely to be an intermediate host for this parasitic nematode species in the field. The potential for geographical range expansion of in the Pacific Basin, its small size, and the general role of veronicellids as crop pests and hosts of nematodes, indicate the significance of as an invasive species in the Pacific Basin. Our work also highlights the importance of biological collections for investigating the environmental impact of invasive species on agriculture, public health, and biodiversity conservation.
Topics: Animals; Angiostrongylus cantonensis; Australia; Mollusca; Nematoda; Gastropoda; Introduced Species; Angiostrongylus; Strongylida Infections
PubMed: 38225903
DOI: 10.1017/S0022149X23000809 -
Frontiers in Veterinary Science 2023A 1,5-year-old male Maltipoo was presented to the emergency service for dyspnea, weakness, and cough. An echocardiographic examination showed evidence of pulmonary...
A 1,5-year-old male Maltipoo was presented to the emergency service for dyspnea, weakness, and cough. An echocardiographic examination showed evidence of pulmonary hypertension with a McConnell sign. Lung ultrasound, including color Doppler, was performed and identified two distinct populations of lung consolidation. Color Doppler analysis of the first type of consolidation showed the absence of blood flow within regions of the consolidation and flow amputation. These findings were consistent with the "" reported in human medicine and prompted consideration of pulmonary thromboembolism as a differential diagnosis. In the second type of consolidation, color Doppler identified blood flow within the pulmonary vessels of the consolidated lung, forming a "branching tree-like" pattern that followed the anatomical course of the pulmonary vasculature. These findings suggested that blood flow was preserved within the pulmonary vasculature of the consolidated lung and prompted consideration of inflammatory causes of pulmonary pathology. On recheck 6 days later, recanalization of the first type of consolidation was identified with color Doppler. The case was followed serially once a month for 5 months with LUS, which showed continued improvement. Based on a positive fecal Baermann test, a final diagnosis of was made. New or Unique information Provided-this is the first report of color Doppler LUS being used to characterize and help differentiate the cause of lung consolidation in dogs.
PubMed: 38152596
DOI: 10.3389/fvets.2023.1275929 -
One Health (Amsterdam, Netherlands) Dec 2023This study investigated the influence of stress on release of larvae from a snail host, . We subjected 140 infected, wild-caught to three stress-inducing treatments...
This study investigated the influence of stress on release of larvae from a snail host, . We subjected 140 infected, wild-caught to three stress-inducing treatments (heat, molluscicide, physical disturbance) and an unstressed control treatment for 24 h, after which larval presence and abundance in the slime were quantified by qPCR targeting the ITS1 region of the parasite's DNA, and compared among treatments. The significance of stress and host infection load on larval release was determined by generalized linear mixed models and permutation tests. The results indicated that stress significantly increased the probability of larval presence in slime and the number of larvae released, and highly infected snails were also more likely to release larvae. Among stressed snails, 13.3% released larvae into slime, the number of larvae present in the slime ranging from 45.5 to 4216. Unstressed controls released no larvae. This study offers a partial explanation for conflicting results from prior studies regarding presence in snail slime and sheds light on the broader One Health implications. Stress-induced larval release highlights the potential role of slime as a medium for pathogen transmission to accidental, paratenic, definitive and other intermediate hosts. These findings emphasize the importance of considering stress-mediated interactions in host-parasite systems and their implications for zoonotic disease emergence. As stressors continue to escalate because of anthropogenic activities and climate change, understanding the role of stress in pathogen shedding and transmission becomes increasingly important for safeguarding human and wildlife health within the One Health framework.
PubMed: 38116454
DOI: 10.1016/j.onehlt.2023.100658 -
American Journal of Veterinary Research Feb 2024This study determined the in vitro efficacy of 6 common anthelmintics (eprinomectin, ivermectin, milbemycin oxime, moxidectin, selamectin, and fenbendazole) on motility...
OBJECTIVE
This study determined the in vitro efficacy of 6 common anthelmintics (eprinomectin, ivermectin, milbemycin oxime, moxidectin, selamectin, and fenbendazole) on motility (viability) of infectious third-stage larvae (L3) of Crenosoma vulpis, Angiostrongylus vasorum, and Aelurostrongylus abstrusus, which are important causes of canine and feline cardiopulmonary disease.
SAMPLES
First-stage larvae (L1) from C vulpis, An vasorum, and Ae abstrusus.
PROCEDURES
Naïve Limax maximus slugs were fed 1,000 to 2,000 L1 and held at 16 °C for at least 4 weeks to produce live L3. Approximately 50 to 100 L3/well were subsequently incubated in culture media alone or media containing 6 separate test anthelmintics at 4 concentrations, to bracket expected in vivo drug plasma levels in anthelmintic-treated dogs and cats. Drug effects on L3 motility (viability) were analyzed by multilevel logistic models, generating dose-response relationships. Experiments were completed 1-9/2019.
RESULTS
Drug concentration estimates corresponding to a 50% larval mortality rate identified that C vulpis was the most sensitive species to the anthelmintics tested. Ae abstrusus was most susceptible to moxidectin and selamectin, while An vasorum was insusceptible to all anthelmintics tested, except for selamectin at high drug concentrations.
CLINICAL RELEVANCE
The in vitro anthelmintic response to antiparasitic agents may guide and improve disease therapy and prevention. Considering the observed lack of efficacy against L3, monthly anthelmintic treatment for protection against An vasorum infection in dogs would primarily rely on the anthelmintic's adulticidal activity. Maximal preventive control for An vasorum would, therefore, require at least 1 treatment administered a minimum of 1 week after the end of the transmission season.
Topics: Animals; Cats; Dogs; Angiostrongylus; Cat Diseases; Larva; Dog Diseases; Metastrongyloidea; Anthelmintics; Ivermectin; Macrolides
PubMed: 38109845
DOI: 10.2460/ajvr.23.06.0123 -
International Journal For Parasitology Mar 2024In recent years, Angiostrongylus vasorum, Crenosoma vulpis, Eucoleus aerophilus (syn. Capillaria aerophila) and Eucoleus boehmi (syn. Capillaria boehmi), commonly...
A Taq-Man-based multiplex quantitative PCR for the simultaneous detection and quantification of Angiostrongylus vasorum, Crenosoma vulpis, and species of respiratory capillarids in canids.
In recent years, Angiostrongylus vasorum, Crenosoma vulpis, Eucoleus aerophilus (syn. Capillaria aerophila) and Eucoleus boehmi (syn. Capillaria boehmi), commonly referred to as canine lungworms, have gained a growing interest worldwide as the result of their geographical expansion. Each of these nematode species differs considerably in its biology and pathogenicity. Despite their impact on dogs' health, these parasites are often underdiagnosed owing to diagnostic challenges. Here, we describe the development and validation of a Taq-Man-based multiplex quantitative PCR (qPCR) for the simultaneous detection of the main species of canine lungworms in faeces of infected dogs. Using 10-fold serial dilutions of synthetic gene block fragments containing individual sequence targets of each lungworm species, the analytical sensitivity of the assay ascertained was 1.84 ng/μl for A. vasorum, 3.08 ng/μl for C. vulpis and 0.79 ng/μl for Eucoleus spp. The sensitivity of the assays and their ability to detect mixed species infections were compared with microscopy-based techniques (faecal floatation and Baermann technique) applied to faecal samples submitted for lungworm testing through an accredited diagnostic laboratory at the Institute of Parasitology, University of Zurich, Switzerland, and from community dogs as part of a research project on canine endoparasites in Cambodia. The multiplex qPCR displayed high diagnostic sensitivity (42/46, 91.3%; 95% Confidence Interval (CI): 79.1-97.1%) and a diagnostic specificity of 100% (45/45, 95% CI: 90.6-100%), and was able to detect 42.9% additional mixed lungworm species infections compared with microscopy-based methods. Kappa statistics showed substantial agreement between the qPCRs and microscopy for mixed infections (κ = 0.72, 95% CI: 0.4-1) and Eucoleus spp. (κ = 0.65, 95% CI: 0.45-0.85) and almost perfect agreement for C. vulpis (κ = 0.85, 95% CI: 0.63-1) and A. vasorum (κ = 0.92, 95% CI: 0.84-1). This multiplex qPCR enables timely, accurate, and sensitive diagnosis of canine lungworm species in faecal samples and can be used to monitor the geographical distribution and emergence of these parasitic species, globally.
Topics: Animals; Dogs; Angiostrongylus; Dog Diseases; Metastrongyloidea; Feces; Polymerase Chain Reaction; Strongylida Infections
PubMed: 38097033
DOI: 10.1016/j.ijpara.2023.12.001 -
The American Journal of Case Reports Dec 2023BACKGROUND Angiostrongylus cantonensis, also known as the rat lungworm, is the most common parasitic cause of human eosinophilic meningitis. A. cantonensis infection is...
BACKGROUND Angiostrongylus cantonensis, also known as the rat lungworm, is the most common parasitic cause of human eosinophilic meningitis. A. cantonensis infection is an emergent disease causing permanent neurological injury or even death when not diagnosed and treated promptly. Usually, human infection occurs through ingestion of food contaminated by intermediated hosts or the third stage larvae of A. cantonensis. Indicators for diagnosis include clinical signs of meningitis; contact history, such as that from eating raw or improperly cooked intermediated hosts or contaminated vegetables; and cerebrospinal fluid (CSF) eosinophilia. However, diagnosis is now primarily defined through polymerase chain reaction (PCR) assay of CSF or serum. CASE REPORT A 66-year-old homeless man with unclear exposure history presented with fever and conscious change. The initial hemogram showed eosinophilia without neutrophilic leukocytosis. Non-contrast computed tomography (CT) and magnetic resonance imaging (MRI) of the head revealed no evidence of stroke. A lumbar puncture was performed and showed eosinophilic meningitis. The patient was ultimately diagnosed through PCR and sequencing for A. cantonensis infection, and dexamethasone treatment was started immediately. Although his general condition improved after dexamethasone treatment, his mental status did not improve completely. CONCLUSIONS Our report highlights the importance of applying molecular techniques in diagnosis of angiostrongylosis, especially in individuals who have unknown contact history.
Topics: Aged; Animals; Humans; Male; Angiostrongylus cantonensis; Dexamethasone; Eosinophilia; Leukocytosis; Meningitis
PubMed: 38044596
DOI: 10.12659/AJCR.941925