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The genetic variation of Angiostrongylus cantonensis in the People’s Republic of China

BACKGROUND: The People’s Republic of China (P.R. China) is the presumptive home range of the rat lungworm Angiostrongylus cantonensis, a major aetiological agent of human eosinophilic meningitis. We present a study of the genetic variation of A. cantonensis in P.R. China. Our aim was to deepen the c...

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Autores principales: Lv, Shan, Zhang, Yi, Steinmann, Peter, Utzinger, Jürg, Zhou, Xiao-Nong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579933/
https://www.ncbi.nlm.nih.gov/pubmed/28859686
http://dx.doi.org/10.1186/s40249-017-0341-z
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author Lv, Shan
Zhang, Yi
Steinmann, Peter
Utzinger, Jürg
Zhou, Xiao-Nong
author_facet Lv, Shan
Zhang, Yi
Steinmann, Peter
Utzinger, Jürg
Zhou, Xiao-Nong
author_sort Lv, Shan
collection PubMed
description BACKGROUND: The People’s Republic of China (P.R. China) is the presumptive home range of the rat lungworm Angiostrongylus cantonensis, a major aetiological agent of human eosinophilic meningitis. We present a study of the genetic variation of A. cantonensis in P.R. China. Our aim was to deepen the current knowledge pertaining to its origin and global spread from a molecular perspective. METHODS: Adult A. cantonensis were collected in the frame of a national survey and identified based on morphological criteria. Polymerase chain reaction (PCR) was employed to amplify the target DNA sequences (cytochrome c oxidase subunit I (cox1), nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1) and internal transcribed spacer (ITS)). The PCR product of cox1 was directly submitted to sequencing, while clone sequencing was used for nad1 and ITS. The identity of the samples was verified by comparing the sequences to those of accepted A. cantonensis specimens. The specific composition of substitutions in each gene was analysed, and the genotypes were compared based on the complete cox1, nad1 and ITS genes. RESULTS: We characterised the complete mitochondrial genes cox1 and nad1 of 130 specimens and obtained 357 nuclear sequences containing two complete ITS (ITS1 and ITS2) and 5.8S rRNA of the same samples. All specimens were genetically confirmed as A. cantonensis. Two major groups (i.e. I and II) were identified according to the phylogeny of cox1 sequences. Group I could be further categorised into six distinct clades. Almost half of the specimens (47.7%) belong to the clade Ia and 22.3% to the group II. The former was widely distributed across the study region. A variable number of repeat units in three microsatellites was observed, resulting in considerable length variation in ITS. Intragenomic variation of ITS sequences was found in a large proportion of the samples. Genotyping showed a striking difference between mitochondrial DNA and ITS. CONCLUSIONS: Our results demonstrate that A. cantonensis is the only rat lungworm species in P.R. China and shows high genetic diversity. Results of diversity and genotyping of A. cantonensis can be impacted by the sequencing strategy and biomarker. Although ITS may be a valuable marker for interspecific identification, it is not suitable for studying the intraspecific variation of A. cantonensis due to its high intragenomic variation and current challenges for direct sequencing. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40249-017-0341-z) contains supplementary material, which is available to authorized users.
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spelling pubmed-55799332017-09-07 The genetic variation of Angiostrongylus cantonensis in the People’s Republic of China Lv, Shan Zhang, Yi Steinmann, Peter Utzinger, Jürg Zhou, Xiao-Nong Infect Dis Poverty Research Article BACKGROUND: The People’s Republic of China (P.R. China) is the presumptive home range of the rat lungworm Angiostrongylus cantonensis, a major aetiological agent of human eosinophilic meningitis. We present a study of the genetic variation of A. cantonensis in P.R. China. Our aim was to deepen the current knowledge pertaining to its origin and global spread from a molecular perspective. METHODS: Adult A. cantonensis were collected in the frame of a national survey and identified based on morphological criteria. Polymerase chain reaction (PCR) was employed to amplify the target DNA sequences (cytochrome c oxidase subunit I (cox1), nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1) and internal transcribed spacer (ITS)). The PCR product of cox1 was directly submitted to sequencing, while clone sequencing was used for nad1 and ITS. The identity of the samples was verified by comparing the sequences to those of accepted A. cantonensis specimens. The specific composition of substitutions in each gene was analysed, and the genotypes were compared based on the complete cox1, nad1 and ITS genes. RESULTS: We characterised the complete mitochondrial genes cox1 and nad1 of 130 specimens and obtained 357 nuclear sequences containing two complete ITS (ITS1 and ITS2) and 5.8S rRNA of the same samples. All specimens were genetically confirmed as A. cantonensis. Two major groups (i.e. I and II) were identified according to the phylogeny of cox1 sequences. Group I could be further categorised into six distinct clades. Almost half of the specimens (47.7%) belong to the clade Ia and 22.3% to the group II. The former was widely distributed across the study region. A variable number of repeat units in three microsatellites was observed, resulting in considerable length variation in ITS. Intragenomic variation of ITS sequences was found in a large proportion of the samples. Genotyping showed a striking difference between mitochondrial DNA and ITS. CONCLUSIONS: Our results demonstrate that A. cantonensis is the only rat lungworm species in P.R. China and shows high genetic diversity. Results of diversity and genotyping of A. cantonensis can be impacted by the sequencing strategy and biomarker. Although ITS may be a valuable marker for interspecific identification, it is not suitable for studying the intraspecific variation of A. cantonensis due to its high intragenomic variation and current challenges for direct sequencing. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40249-017-0341-z) contains supplementary material, which is available to authorized users. BioMed Central 2017-09-01 /pmc/articles/PMC5579933/ /pubmed/28859686 http://dx.doi.org/10.1186/s40249-017-0341-z Text en © The Author(s). 2017 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Lv, Shan
Zhang, Yi
Steinmann, Peter
Utzinger, Jürg
Zhou, Xiao-Nong
The genetic variation of Angiostrongylus cantonensis in the People’s Republic of China
title The genetic variation of Angiostrongylus cantonensis in the People’s Republic of China
title_full The genetic variation of Angiostrongylus cantonensis in the People’s Republic of China
title_fullStr The genetic variation of Angiostrongylus cantonensis in the People’s Republic of China
title_full_unstemmed The genetic variation of Angiostrongylus cantonensis in the People’s Republic of China
title_short The genetic variation of Angiostrongylus cantonensis in the People’s Republic of China
title_sort genetic variation of angiostrongylus cantonensis in the people’s republic of china
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579933/
https://www.ncbi.nlm.nih.gov/pubmed/28859686
http://dx.doi.org/10.1186/s40249-017-0341-z
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