Abstract
Four hyper-variable regions (HVR-I to -IV) found in 18S ribosomal DNA sequences were compared among 34 isolates of 15 species of the genus Strongyloides to evaluate their diagnostic value. HVR-I to -III were short, and plural species exhibit the same nucleotide arrangement. Meanwhile, HVR-IV had 23 to 39 nucleotides, showing species-specific arrangements, except Strongyloides ransomi and Strongyloides venezuelensis, which had the same nucleotide sequence in HVR-IV but were readily distinguished by the difference in HVR-I and -III. Isolates of Strongyloides stercoralis from humans of USA, Japan, and Philippines, chimpanzees, and dogs had an identical sequence in this region. Meanwhile, intraspecific polymorphism in HVR-IV nucleotide arrangement was observed among isolates of Strongyloides fuelleborni and Strongyloides callosciureus, presumably reflecting process of geographical dispersal and adaptation to the hosts.
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Acknowledgments
Sincere thanks are rendered to G. Ogura (University of Ryukyus), Y. Nawa, Y. Horii (Miyazaki University), F. Nakamura (Bokuto Hospital), M. Nishimura (Okinawa Prefecture Institute of Public Health), E. Kimura (Aichi Medical University), M. Asakawa (Rakuno Gauken University), K. Imai (Naruto Veterinary Clinic), H. Kino (Hamamatsu Medical University), T. Udono (Sanwa Kagaku Co. Ltd.), K. Miyagi, K. Nobusue (Nagasaki University), and S. Fujita (Yamaguchi University) for their kindness in supplying Strongyloides nematodes. Thanks are also expressed to M. Nakao (Asahikawa Medical University) and K. Ando (Mie University) for their kind technical information on DNA extraction and PCR. This study was financially supported by grants-in-aid from the Japan Society for Promotion of Sciences, nos. 19580355 and 20570090, and Morinaga Service Foundation, Tokyo, Japan (2008).
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Hasegawa, H., Hayashida, S., Ikeda, Y. et al. Hyper-variable regions in 18S rDNA of Strongyloides spp. as markers for species-specific diagnosis. Parasitol Res 104, 869–874 (2009). https://doi.org/10.1007/s00436-008-1269-9
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DOI: https://doi.org/10.1007/s00436-008-1269-9