BACKGROUND: Angiostrongylus cantonensis (rat lungworm) is recognised as the leading cause of human eosinophilic meningitis, a serious condition observed when nematode larvae migrate through the CNS. Canine Neural Angiostrongyliasis (CNA) is the analogous disease in dogs. Both humans and dogs are accidental hosts, and a rapid diagnosis is warranted. A highly sensitive PCR based assay is available but often not readily accessible in many jurisdictions. An alternative DNA amplification assay that would further improve accessibility is needed. This study aimed to assess the diagnostic utility of a newly designed LAMP assay to detect DNA of globally distributed and invasive A. cantonensis and Angiostrongylus mackerrasae, the other neurotropic Angiostrongylus species, which is native to Australia. METHODOLOGY/PRINCIPAL FINDINGS: Cerebrospinal fluid (CSF) from dogs with a presumptive diagnosis of A. cantonensis infection (2020-2022) were received for confirmatory laboratory testing and processed for DNA isolation and ultrasensitive Angiostrongylus qPCR targeting AcanR3390. A newly designed LAMP assay targeting the same gene target was directly compared to the reference ultrasensitive qPCR in a diagnostic laboratory setting to determine the presence of A. cantonensis DNA to diagnose CNA. The LAMP assay (Angie-LAMP) allowed the sensitive detection of A. cantonensis DNA from archived DNA specimens (Kappa = 0.81, 95%CI 0.69-0.92; n = 93) and rapid single-step lysis of archived CSF samples (Kappa = 0.77, 95%CI 0.59-0.94; n = 52). Only A. cantonensis DNA was detected in canine CSF samples, and co-infection with A. mackerrasae using amplicon deep sequencing (ITS-2 rDNA) was not demonstrated. Both SYD.1 and AC13 haplotypes were detected using sequencing of partial cox1. CONCLUSIONS/SIGNIFICANCE: The Angie-LAMP assay is a useful molecular tool for detecting Angiostrongylus DNA in canine CSF and performs comparably to a laboratory Angiostrongylus qPCR. Adaptation of single-step sample lysis improved potential applicability for diagnosis of angiostrongyliasis in a clinical setting for dogs and by extension, to humans.
- MeSH
- Angiostrongylus cantonensis * genetika MeSH
- Angiostrongylus * genetika MeSH
- hlemýždi genetika MeSH
- infekce hlísticemi řádu Strongylida * diagnóza veterinární MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- meningitida * diagnóza veterinární MeSH
- psi MeSH
- ribozomální DNA MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Naive use of molecular data may lead to ambiguous conclusions, especially within the context of "cryptic" species. Here, we integrated molecular and morphometric data to evaluate phylogenetic relationships in the widespread terrestrial micro-snail genus, Euconulus. We analyzed mitochondrial (16S + COII) and nuclear (ITS1 + ITS2) sequence across 94 populations from Europe, Asia and North America within the nominate species E. alderi, E. fulvus and E. polygyratus, and used the southeastern USA E. chersinus, E. dentatus, and E. trochulus as comparative outgroups. Phylogeny was reconstructed using four different reconstruction methods to identify robust, well-supported topological features. We then performed discriminant analysis on shell measurements between these genetically-identified species-level clades. These analyses provided evidence for a biologically valid North American "cryptic" species within E. alderi. However, while highly supported polyphyletic structure was also observed within E. fulvus, disagreement in placement of individuals between mtDNA and nDNA clades, lack of morphological differences, and presence of potential hybrids imply that these lineages do not rise to the threshold as biologically valid cryptic species, and rather appear to simply represent a complex of geographically structured populations within a single species. These results caution that entering into a cryptic species hypothesis should not be undertaken lightly, and should be optimally supported along multiple lines of evidence. Generally, post-hoc analyses of macro-scale features should be conducted to attempt identification of previously ignored diagnostic traits. If such traits cannot be found, i.e. in the case of potentially "fully cryptic" species, additional criteria should be met to propound a cryptic species hypothesis, including the agreement in tree topology among both mtDNA and nDNA, and little (or no) evidence of hybridization based on a critical analysis of sequence chromatograms. Even when the above conditions are satisfied, it only implies that the cryptic species hypothesis is plausible, but should optimally be subjected to further careful examination.
- MeSH
- analýza hlavních komponent MeSH
- buněčné jádro genetika MeSH
- fylogeneze MeSH
- hlemýždi klasifikace genetika MeSH
- pravděpodobnostní funkce MeSH
- respirační komplex IV klasifikace genetika MeSH
- RNA ribozomální 16S klasifikace genetika MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- sekvenční seřazení MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH