Skip to Main content Skip to Navigation
Journal articles

Molecular Identification of the Human Pathogen Amphimerus sp. in the Freshwater Snail Aroapyrgus sp. in Ecuador

Abstract : Here, we report for the first time the snail intermediate host for the Amphimerus liver fluke, a foodborne trematodiasis. In Ecuador, Amphimerus of the Opisthorchiidae family, infects humans, cats, and dogs, in the tropical Pacific-coast region. Opisthorchiidae comprising also Clonorchis sinensis , Opisthorchis sp., and Metorchis sp., have complex life cycles involving a definitive and two intermediate hosts. We identified morphologically and investigated the presence and prevalence of Amphimerus cercaria and DNA in freshwater snails collected in a human-amphimeriasis endemic region in Ecuador, extracted DNA from snail tissue and emerged cercariae, performed real-time polymerase chain reaction (PCR) with the newly developed primers and probe amplifying the Amphimerus ribosomal internal transcribed spacer 2 (ITS2) region, and sequenced the amplified DNA fragment. We collected 2,800 snails, characterized four species Aroapyrgus sp., Melanoides tuberculata , Biomphalaria cousini , and Aplexa marmorata , isolated three cercariae morphotypes. Of the 640 snails analyzed by qPCR, only Aroapyrgus and one of the three cercariae resulted positive, at a 15% infection prevalence. Polymerase chain reaction revealed that the Aroapyrgus snail and cercaria-morphotype-3 corresponded to Amphimerus , but not to C. sinensis , Fasciola hepatica , or Paragonimus mexicanus . The sequence of amplified DNA product matched that of human-isolated Amphimerus . This finding constitutes the first documentation that Aroapyrgus sp. is the first intermediate host for the Amphimerus sp. that infect humans in Ecuador. The ITS2–gene PCR and sequencing analysis demonstrated a high prevalence of snail infection and proved useful for detecting the infection in snails, which findings can help the establishment of suitable control programs against transmission in any endemic region of interest.
Document type :
Journal articles
Complete list of metadata

https://hal-univ-perp.archives-ouvertes.fr/hal-03724045
Contributor : Sonja Böttger Connect in order to contact the contributor
Submitted on : Friday, July 15, 2022 - 3:09:06 PM
Last modification on : Wednesday, September 28, 2022 - 4:20:11 PM

Identifiers

Collections

Citation

Manuel Calvopiña, Carlos Bastidas-Caldes, Francisco Romero, Irina Villacrés-Granda, Jean-Pierre Pointier, et al.. Molecular Identification of the Human Pathogen Amphimerus sp. in the Freshwater Snail Aroapyrgus sp. in Ecuador. American Journal of Tropical Medicine and Hygiene, American Society of Tropical Medicine and Hygiene, 2022, 106 (1), pp.222-228. ⟨10.4269/ajtmh.21-0697⟩. ⟨hal-03724045⟩

Share

Metrics

Record views

7