{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T16:17:43Z","timestamp":1778084263161,"version":"3.51.4"},"reference-count":68,"publisher":"American Society of Tropical Medicine and Hygiene","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,5,6]]},"abstract":"<jats:title>ABSTRACT.<\/jats:title>\n                  <jats:p>\n                    <jats:italic>Strongyloides stercoralis<\/jats:italic>\n                    (\n                    <jats:italic>S. stercoralis<\/jats:italic>\n                    ), the etiological agent of strongyloidiasis, is a medically important intestinal nematode that can cause life-threatening disseminated infections, particularly in immunocompromised individuals. Despite its clinical significance, limited information is available on the genetic diversity, population structure, and phylogenetic relationships of this parasite, especially in endemic regions. Therefore, generating molecular data from different geographic areas is essential for better understanding transmission patterns and epidemiology. In the present study, the intraspecies genetic diversity of\n                    <jats:italic>S. stercoralis<\/jats:italic>\n                    isolates obtained from humans in endemic regions of Iran was investigated by using mitochondrial and nuclear genetic markers. Fecal samples were collected from infected individuals in four provinces of Iran and examined using standard parasitological methods. Molecular analysis was performed through polymerase chain reaction amplification of the mitochondrial cytochrome c oxidase subunit 1 (\n                    <jats:italic>Cox<\/jats:italic>\n                    1) gene and the nuclear 18S recombinant DNA [rDNA] hypervariable regions (HVR I and IV). The obtained sequences were analyzed and aligned using Chromas (Technelysium Pty Ltd, Brisbane, Australia), BioEdit (Tom Hall, North California State University, NC), and CLC Genomics Workbench 11 (QIAGEN Sciences Inc., Germantown, MD), compared with reference sequences from GenBank, and phylogenetic trees were constructed using MEGA version 7.0 (MEGA Software GmbH, Dortmund, Germany). Haplotype networks were visualized with PopART version 1.7 (University of Otago, Dunedin, New Zealand). Analysis of 40 human isolates revealed 13\n                    <jats:italic>Cox<\/jats:italic>\n                    1 haplotypes, of which 11 were newly identified in the present study. Notably, one haplotype clustered closely with dog-derived isolates from Japan and Cambodia. Isolates from Hormozgan Province formed distinct clades compared with other regions. Furthermore, 18S rDNA analysis revealed shared HVR-I and HVR-IV haplotypes between human and canine isolates, suggesting zoonotic transmission. Overall, the findings reveal considerable genetic diversity and regional differentiation of\n                    <jats:italic>S. stercoralis<\/jats:italic>\n                    in Iran, highlighting the need for broader multigene studies to clarify transmission dynamics and support effective control strategies.\n                  <\/jats:p>","DOI":"10.4269\/ajtmh.25-0554","type":"journal-article","created":{"date-parts":[[2026,3,3]],"date-time":"2026-03-03T17:01:38Z","timestamp":1772557298000},"page":"923-929","source":"Crossref","is-referenced-by-count":0,"title":["Diversity of Strongyloides stercoralis Isolates from Humans in Iran"],"prefix":"10.4269","volume":"114","author":[{"given":"Zohreh","family":"Fakhrieh-Kashan","sequence":"first","affiliation":[{"name":"Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Meysam","family":"Sharifdini","sequence":"additional","affiliation":[{"name":"Department of Medical Parasitology and Mycology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Farzaneh","family":"Zahabiun","sequence":"additional","affiliation":[{"name":"Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eshrat Beigom","family":"Kia","sequence":"additional","affiliation":[{"name":"Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran;"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"2795","reference":[{"key":"b1","series-title":"Trans R Soc Trop Med Hyg","first-page":"967","article-title":"Strongyloidiasis\u2013The most neglected of the neglected tropical diseases?","volume":"103","author":"Olsen","year":"2009"},{"key":"b2","series-title":"PLoS Negl Trop Dis","first-page":"e2288","article-title":"Strongyloides stercoralis: Global distribution and risk factors","volume":"7","author":"Sch\u00e4r","year":"2013"},{"key":"b3","series-title":"PLoS Negl Trop Dis","first-page":"e0008505","article-title":"The global progress of soil-transmitted helminthiases control in 2020 and World Health Organization targets for 2030","volume":"14","author":"Montresor","year":"2020"},{"key":"b4","series-title":"Parasitol Res","first-page":"891","article-title":"The roundworm Strongyloides stercoralis in children, dogs, and soil inside and outside a segregated settlement in Eastern Slovakia: Frequent but hardly detectable parasite","volume":"116","author":"\u0160trkolcov\u00e1","year":"2017"},{"key":"b5","series-title":"Oxford Med Case Rep","first-page":"83","article-title":"Pulmonary strongyloidiasis following renal transplantation without travel to an endemic area","volume":"2014","author":"Agarwala","year":"2014"},{"key":"b6","series-title":"Am J Case Rep","first-page":"339","article-title":"Strongyloides stercoralis infection among human immunodeficiency virus (HIV)-infected patients in the United States of America: A case report and review of literature","volume":"18","author":"Vazquez Gillamet","year":"2017"},{"key":"b7","series-title":"Parasitol Today","first-page":"335","article-title":"Strongyloides fuelleborni kellyi: Infection and disease in humans","volume":"8","author":"Ashford","year":"1992"},{"key":"b8","series-title":"Trans R Soc Trop Med Hyg","first-page":"454","article-title":"Strongyloidiasis: A neglected tropical disease","volume":"108","author":"Grove","year":"2014"},{"key":"b9","series-title":"Curr Opin Infect Dis","first-page":"458","article-title":"Screening, prevention, and treatment for hyperinfection syndrome and disseminated infections caused by Strongyloides stercoralis","volume":"25","author":"Mejia","year":"2012"},{"key":"b10","series-title":"Parasitol Int","first-page":"102155","article-title":"Molecular diagnosis of Strongyloides infections","volume":"79","author":"Sato","year":"2020"},{"key":"b11","series-title":"Am J Trop Med Hyg","first-page":"1285","article-title":"Comparison of nested polymerase chain reaction and real-time polymerase chain reaction with parasitological methods for detection of Strongyloides stercoralis in human fecal samples","volume":"93","author":"Sharifdini","year":"2015"},{"key":"b12","series-title":"PLoS Negl Trop Dis","first-page":"e0005752","article-title":"Different but overlapping populations of Strongyloides stercoralis in dogs and humans\u2014Dogs as a possible source for zoonotic strongyloidiasis","volume":"11","author":"Jaleta","year":"2017"},{"key":"b13","series-title":"Iran J Public Health","first-page":"16","article-title":"A DNA-based identification of Strongyloides stercoralis isolates from Iran","volume":"36","author":"Nilforoushan","year":"2007"},{"key":"b14","series-title":"Int J Parasitol","first-page":"527","article-title":"Molecular prospecting for cryptic species of nematodes: Mitochondrial DNA versus internal transcribed spacer","volume":"32","author":"Blouin","year":"2002"},{"key":"b15","series-title":"Parasitol Int","first-page":"407","article-title":"Molecular identification of the causative agent of human strongyloidiasis acquired in Tanzania: Dispersal and diversity of Strongyloides spp. and their hosts","volume":"59","author":"Hasegawa","year":"2010"},{"key":"b16","series-title":"Parasitol Res","first-page":"869","article-title":"Hyper-variable regions in 18S rDNA of Strongyloides spp. as markers for species-specific diagnosis","volume":"104","author":"Hasegawa","year":"2009"},{"key":"b17","series-title":"Sci Rep","first-page":"4844","article-title":"A possible origin population of pathogenic intestinal nematodes, Strongyloides stercoralis, unveiled by molecular phylogeny","volume":"7","author":"Nagayasu","year":"2017"},{"key":"b18","series-title":"Iran J Parasitol","first-page":"155","article-title":"An analysis of clinical characteristics of Strongyloides stercoralis in 70 indigenous patients in Iran","volume":"9","author":"Sharifdini","year":"2014"},{"key":"b19","series-title":"Ann Parasitol","first-page":"333\u2013339","article-title":"Critical diagnosis of complicated strongyloidiasis with nested PCR and high resolution melting analysis (HRM)","volume":"65","author":"Fakhrieh-Kashan","year":"2019"},{"key":"b20","series-title":"Parasitol Res","first-page":"663","article-title":"Strongyloides stercoralis hyperinfection syndrome in HIV+\/AIDS patients in Iran","volume":"101","author":"Meamar","year":"2007"},{"key":"b21","series-title":"Parasit Vectors","first-page":"21","article-title":"Strongyloides stercoralis genotyping in a human population in southwestern Iran","volume":"17","author":"Beiromvand","year":"2024"},{"key":"b22","series-title":"Iran J Parasitol","first-page":"29","article-title":"An evaluation on the efficacy of agar plate culture for detection of Strongyloides stercoralis.","volume":"2","author":"Kia","year":"2007"},{"key":"b23","series-title":"Korean J Parasitol","first-page":"261","article-title":"A case of fatal strongyloidiasis in a patient with chronic lymphocytic leukemia and molecular characterization of the isolate","volume":"46","author":"Kia","year":"2008"},{"key":"b24","series-title":"J Guilan Univ Med Sci","first-page":"57","article-title":"Comparative efficacy of nutrient agar plate culture and formalin ether concentration methods in the laboratory diagnosis of human trichostrongyliasis","volume":"25","author":"Najmi","year":"2016"},{"key":"b25","series-title":"J Helminthol","first-page":"351","article-title":"The occurrence of severe infections with Rhabditis axei in AIDS patients in Iran","volume":"81","author":"Meamar","year":"2007"},{"key":"b26","series-title":"Mol Biol Evol","first-page":"1870","article-title":"MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets","volume":"33","author":"Kumar","year":"2016"},{"key":"b27","series-title":"Mol Ecol","first-page":"839","article-title":"Molecular barcodes for soil nematode identification","volume":"11","author":"Floyd","year":"2002"},{"key":"b28","series-title":"Int J Parasitol","first-page":"1507","article-title":"Molecular phylogenetic analysis of the genus Strongyloides and related nematodes","volume":"32","author":"Dorris","year":"2002"},{"key":"b29","series-title":"PLoS Negl Trop Dis","first-page":"e0007396","article-title":"Characterization of a non-sexual population of Strongyloides stercoralis with hybrid 18S rDNA haplotypes in Guangxi, Southern China","volume":"13","author":"Zhou","year":"2019"},{"key":"b30","series-title":"Acta Trop","first-page":"43","article-title":"Genetic diversity of Strongyloides stercoralis in humans from north Argentina revealed by analysis of the mitochondrial gene cox1","volume":"183","author":"Repetto","year":"2018"},{"key":"b31","series-title":"Iran J Parasitol","first-page":"465","article-title":"Genetic diversity of Strongyloides stercoralis with attention to clinical features in patients from three endemic provinces in the north and south of Iran","volume":"19","author":"Semnan","year":"2024"},{"key":"b32","series-title":"Parasit Vectors","first-page":"496","article-title":"From the feces to the genome: A guideline for the isolation and preservation of Strongyloides stercoralis in the field for genetic and genomic analysis of individual worms","volume":"12","author":"Zhou","year":"2019"},{"key":"b33","series-title":"BMC Infect Dis","first-page":"776","article-title":"Molecular characterization of human isolates of Strongyloides stercoralis and Rhabditis spp. based on mitochondrial cytochrome c oxidase subunit 1 (cox1)","volume":"19","author":"Fadaei Tehrani","year":"2019"},{"key":"b34","series-title":"J Helminthol","first-page":"e88","article-title":"Comparison of different PCR amplification targets for molecular diagnosis of Strongyloides stercoralis.","volume":"97","author":"Marquet","year":"2023"},{"key":"b1","series-title":"Trans R Soc Trop Med Hyg","first-page":"967","article-title":"Strongyloidiasis\u2013The most neglected of the neglected tropical diseases?","volume":"103","author":"Olsen","year":"2009"},{"key":"b2","series-title":"PLoS Negl Trop Dis","first-page":"e2288","article-title":"Strongyloides stercoralis: Global distribution and risk factors","volume":"7","author":"Sch\u00e4r","year":"2013"},{"key":"b3","series-title":"PLoS Negl Trop Dis","first-page":"e0008505","article-title":"The global progress of soil-transmitted helminthiases control in 2020 and World Health Organization targets for 2030","volume":"14","author":"Montresor","year":"2020"},{"key":"b4","series-title":"Parasitol Res","first-page":"891","article-title":"The roundworm Strongyloides stercoralis in children, dogs, and soil inside and outside a segregated settlement in Eastern Slovakia: Frequent but hardly detectable parasite","volume":"116","author":"\u0160trkolcov\u00e1","year":"2017"},{"key":"b5","series-title":"Oxford Med Case Rep","first-page":"83","article-title":"Pulmonary strongyloidiasis following renal transplantation without travel to an endemic area","volume":"2014","author":"Agarwala","year":"2014"},{"key":"b6","series-title":"Am J Case Rep","first-page":"339","article-title":"Strongyloides stercoralis infection among human immunodeficiency virus (HIV)-infected patients in the United States of America: A case report and review of literature","volume":"18","author":"Vazquez Gillamet","year":"2017"},{"key":"b7","series-title":"Parasitol Today","first-page":"335","article-title":"Strongyloides fuelleborni kellyi: Infection and disease in humans","volume":"8","author":"Ashford","year":"1992"},{"key":"b8","series-title":"Trans R Soc Trop Med Hyg","first-page":"454","article-title":"Strongyloidiasis: A neglected tropical disease","volume":"108","author":"Grove","year":"2014"},{"key":"b9","series-title":"Curr Opin Infect Dis","first-page":"458","article-title":"Screening, prevention, and treatment for hyperinfection syndrome and disseminated infections caused by Strongyloides stercoralis","volume":"25","author":"Mejia","year":"2012"},{"key":"b10","series-title":"Parasitol Int","first-page":"102155","article-title":"Molecular diagnosis of Strongyloides infections","volume":"79","author":"Sato","year":"2020"},{"key":"b11","series-title":"Am J Trop Med Hyg","first-page":"1285","article-title":"Comparison of nested polymerase chain reaction and real-time polymerase chain reaction with parasitological methods for detection of Strongyloides stercoralis in human fecal samples","volume":"93","author":"Sharifdini","year":"2015"},{"key":"b12","series-title":"PLoS Negl Trop Dis","first-page":"e0005752","article-title":"Different but overlapping populations of Strongyloides stercoralis in dogs and humans\u2014Dogs as a possible source for zoonotic strongyloidiasis","volume":"11","author":"Jaleta","year":"2017"},{"key":"b13","series-title":"Iran J Public Health","first-page":"16","article-title":"A DNA-based identification of Strongyloides stercoralis isolates from Iran","volume":"36","author":"Nilforoushan","year":"2007"},{"key":"b14","series-title":"Int J Parasitol","first-page":"527","article-title":"Molecular prospecting for cryptic species of nematodes: Mitochondrial DNA versus internal transcribed spacer","volume":"32","author":"Blouin","year":"2002"},{"key":"b15","series-title":"Parasitol Int","first-page":"407","article-title":"Molecular identification of the causative agent of human strongyloidiasis acquired in Tanzania: Dispersal and diversity of Strongyloides spp. and their hosts","volume":"59","author":"Hasegawa","year":"2010"},{"key":"b16","series-title":"Parasitol Res","first-page":"869","article-title":"Hyper-variable regions in 18S rDNA of Strongyloides spp. as markers for species-specific diagnosis","volume":"104","author":"Hasegawa","year":"2009"},{"key":"b17","series-title":"Sci Rep","first-page":"4844","article-title":"A possible origin population of pathogenic intestinal nematodes, Strongyloides stercoralis, unveiled by molecular phylogeny","volume":"7","author":"Nagayasu","year":"2017"},{"key":"b18","series-title":"Iran J Parasitol","first-page":"155","article-title":"An analysis of clinical characteristics of Strongyloides stercoralis in 70 indigenous patients in Iran","volume":"9","author":"Sharifdini","year":"2014"},{"key":"b19","series-title":"Ann Parasitol","first-page":"333\u2013339","article-title":"Critical diagnosis of complicated strongyloidiasis with nested PCR and high resolution melting analysis (HRM)","volume":"65","author":"Fakhrieh-Kashan","year":"2019"},{"key":"b20","series-title":"Parasitol Res","first-page":"663","article-title":"Strongyloides stercoralis hyperinfection syndrome in HIV+\/AIDS patients in Iran","volume":"101","author":"Meamar","year":"2007"},{"key":"b21","series-title":"Parasit Vectors","first-page":"21","article-title":"Strongyloides stercoralis genotyping in a human population in southwestern Iran","volume":"17","author":"Beiromvand","year":"2024"},{"key":"b22","series-title":"Iran J Parasitol","first-page":"29","article-title":"An evaluation on the efficacy of agar plate culture for detection of Strongyloides stercoralis.","volume":"2","author":"Kia","year":"2007"},{"key":"b23","series-title":"Korean J Parasitol","first-page":"261","article-title":"A case of fatal strongyloidiasis in a patient with chronic lymphocytic leukemia and molecular characterization of the isolate","volume":"46","author":"Kia","year":"2008"},{"key":"b24","series-title":"J Guilan Univ Med Sci","first-page":"57","article-title":"Comparative efficacy of nutrient agar plate culture and formalin ether concentration methods in the laboratory diagnosis of human trichostrongyliasis","volume":"25","author":"Najmi","year":"2016"},{"key":"b25","series-title":"J Helminthol","first-page":"351","article-title":"The occurrence of severe infections with Rhabditis axei in AIDS patients in Iran","volume":"81","author":"Meamar","year":"2007"},{"key":"b26","series-title":"Mol Biol Evol","first-page":"1870","article-title":"MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets","volume":"33","author":"Kumar","year":"2016"},{"key":"b27","series-title":"Mol Ecol","first-page":"839","article-title":"Molecular barcodes for soil nematode identification","volume":"11","author":"Floyd","year":"2002"},{"key":"b28","series-title":"Int J Parasitol","first-page":"1507","article-title":"Molecular phylogenetic analysis of the genus Strongyloides and related nematodes","volume":"32","author":"Dorris","year":"2002"},{"key":"b29","series-title":"PLoS Negl Trop Dis","first-page":"e0007396","article-title":"Characterization of a non-sexual population of Strongyloides stercoralis with hybrid 18S rDNA haplotypes in Guangxi, Southern China","volume":"13","author":"Zhou","year":"2019"},{"key":"b30","series-title":"Acta Trop","first-page":"43","article-title":"Genetic diversity of Strongyloides stercoralis in humans from north Argentina revealed by analysis of the mitochondrial gene cox1","volume":"183","author":"Repetto","year":"2018"},{"key":"b31","series-title":"Iran J Parasitol","first-page":"465","article-title":"Genetic diversity of Strongyloides stercoralis with attention to clinical features in patients from three endemic provinces in the north and south of Iran","volume":"19","author":"Semnan","year":"2024"},{"key":"b32","series-title":"Parasit Vectors","first-page":"496","article-title":"From the feces to the genome: A guideline for the isolation and preservation of Strongyloides stercoralis in the field for genetic and genomic analysis of individual worms","volume":"12","author":"Zhou","year":"2019"},{"key":"b33","series-title":"BMC Infect Dis","first-page":"776","article-title":"Molecular characterization of human isolates of Strongyloides stercoralis and Rhabditis spp. based on mitochondrial cytochrome c oxidase subunit 1 (cox1)","volume":"19","author":"Fadaei Tehrani","year":"2019"},{"key":"b34","series-title":"J Helminthol","first-page":"e88","article-title":"Comparison of different PCR amplification targets for molecular diagnosis of Strongyloides stercoralis.","volume":"97","author":"Marquet","year":"2023"}],"container-title":["The American Journal of Tropical Medicine and 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