Mon, Jul 6, 2026
1- Department of Parasitology and Mycology, Faculty of Medicine, Zabol University of Medical Sciences, Sistan-Baluchistan Province, Zabol, Iran , mdabirzadeh20002000@gmail.com
2- Department of Parasitology, Medical School, Zabol University of Medical Sciences, Sistan-Baluchistan Province, Zabol, Iran
3- Zabol Medical Plants Research Center, Zabol University of Medical Sciences, Zabol, Iran
2- Department of Parasitology, Medical School, Zabol University of Medical Sciences, Sistan-Baluchistan Province, Zabol, Iran
3- Zabol Medical Plants Research Center, Zabol University of Medical Sciences, Zabol, Iran
Abstract: (3735 Views)
Background: Cryptosporidium is one of the most important protozoan parasites causing waterborne diseases worldwide. The parasite’s oocysts are resistant to conventional water treatment, making molecular detection crucial for identifying contamination sources.
Methods: A total of water samples were collected from different sites in Zabol and Zahedan, southeastern Iran. Microscopic screening was performed after concentration and staining with modified Ziehl-Neelsen and Trichrome methods under 1000× oil-immersion magnification. DNA was extracted from positive samples, and the SSU rRNA gene (~800-900 bp) was amplified by PCR. The resulting products were subjected to enzymatic digestion using AluI and RsaI restriction enzymes, and representative amplicons were sequenced.
Results: Microscopic examination confirmed the presence of Cryptosporidium oocysts in several water samples. PCR amplification successfully produced fragments of the expected size without nonspecific bands. AluI digestion revealed distinct fragment patterns consistent with Cryptosporidium spp., while RsaI showed no cutting sites. Sequence analysis through BLAST showed high identity (≥99%) with C. parvum isolates. The phylogenetic tree constructed using the BLAST distance-tree method grouped the sequence closely with C. parvum, confirming its identity.
Conclusion: Molecular characterization of Cryptosporidium from water samples in southeastern Iran indicated contamination primarily with C. parvum. These findings emphasize the necessity of continuous molecular surveillance to ensure the safety of drinking and recreational waters in the region.
Methods: A total of water samples were collected from different sites in Zabol and Zahedan, southeastern Iran. Microscopic screening was performed after concentration and staining with modified Ziehl-Neelsen and Trichrome methods under 1000× oil-immersion magnification. DNA was extracted from positive samples, and the SSU rRNA gene (~800-900 bp) was amplified by PCR. The resulting products were subjected to enzymatic digestion using AluI and RsaI restriction enzymes, and representative amplicons were sequenced.
Results: Microscopic examination confirmed the presence of Cryptosporidium oocysts in several water samples. PCR amplification successfully produced fragments of the expected size without nonspecific bands. AluI digestion revealed distinct fragment patterns consistent with Cryptosporidium spp., while RsaI showed no cutting sites. Sequence analysis through BLAST showed high identity (≥99%) with C. parvum isolates. The phylogenetic tree constructed using the BLAST distance-tree method grouped the sequence closely with C. parvum, confirming its identity.
Conclusion: Molecular characterization of Cryptosporidium from water samples in southeastern Iran indicated contamination primarily with C. parvum. These findings emphasize the necessity of continuous molecular surveillance to ensure the safety of drinking and recreational waters in the region.
Keywords: Cryptosporidium, DNA Sequencing, Polymerase Chain Reaction, Water Pollution, Zabol, Zahedan
References
1. Enaigbe AA, Imade OS. Validation of the shelf life of NAFDAC‐certified sachet‐packed drinking water brands ended in Nigeria. Lett Appl Microbiol. 2021;73(5):634-45. [View at Publisher] [DOI] [PMID] [Google Scholar]
2. Karimi P, Shafaghi-Sisi S, Meamar AR, Razmjou E. Molecular identification of Cryptosporidium, Giardia, and Blastocystis from stray and household cats and cat owners in Tehran, Iran. Sci Rep. 2023;13(1):1554. [View at Publisher] [DOI] [PMID] [Google Scholar]
3. King BJ, Monis PT. Critical processes affecting Cryptosporidium oocyst survival in the environment. Parasitology. 2007;134(3):309-23. [View at Publisher] [DOI] [PMID] [Google Scholar]
4. Dabirzadeh M, Mohammadian H, Azizi H, Khoshsima Shahreki M. Genotype and subtype analyses of Cryptosporidium isolate from humans by gp60 PCR-RLFP in Zabol, Southeast of Iran. Mod Med Lab J. 2021;4(1):5-10. [View at Publisher] [DOI] [Google Scholar]
5. Bilal H, Li X, Iqbal MS, Mu Y, Tulcan RXS, Ghufran MA. Surface water quality, public health, and ecological risks in Bangladesh-a systematic review and meta-analysis over the last two decades. Environ Sci Pollut Res Int. 2023;30(40):91710-28. [View at Publisher] [DOI] [PMID] [Google Scholar]
6. Mohammadian H, Azizi H, Dabirzadeh M. Genetic study of Cryptosporidium with SSU-rRNA in children younger than ten referring to hospitals of Zabol, Southeast of Iran. Shiraz E Med J. 2019;20(4). [View at Publisher] [DOI] [Google Scholar]
7. Keomoungkhoun B, Arjentinia IPGY, Sangmaneedet S, Taweenan W. Molecular prevalence and associated risk factors of Cryptosporidium spp infection in dairy cattle in Khon Kaen, Thailand. Vet World. 2024;17(2):371-8. [View at Publisher] [DOI] [PMID] [Google Scholar]
8. Matas-Méndez P, Ávalos G, Caballero-Gómez J, Dashti A, Castro-Scholten S, Jiménez-Martín D, et al. Detection and molecular diversity of Cryptosporidium spp and Giardia duodenalis in the endangered Iberian lynx (Lynx pardinus), Spain. Animals (Basel). 2024;14(2):340. [View at Publisher] [DOI] [PMID] [Google Scholar]
9. Zhao W, Ren G, Jiang W, Wang L, Wang J, Yuan Z, et al. Genetic characterizations of Cryptosporidium spp from children with or without diarrhea in Wenzhou, China: high probability of zoonotic transmission. BMC Microbiol. 2024;24(1):113. [View at Publisher] [DOI] [PMID] [Google Scholar]
10. Nasser AM. Removal of Cryptosporidium by wastewater treatment processes: a review. J Water Health. 2016;14(1):1-13. [View at Publisher] [DOI] [PMID] [Google Scholar]
11. Koloren Z, Sotiriadou I, Karanis P. Investigations and comparative detection of Cryptosporidium species by microscopy, nested PCR and LAMP in water supplies of Ordu, Middle Black Sea, Turkey. Ann Trop Med Parasitol. 2011;105(8):607-15. [View at Publisher] [DOI] [PMID] [Google Scholar]
12. Xiao L, Morgan UM, Limor J, Escalante A, Arrowood M, Shulaw W, et al Genetic diversity within Cryptosporidium parvum and related Cryptosporidium species. Appl Environ Microbiol. 1999;65(8):3386-91. [DOI] [PMID] [Google Scholar]
13. Zhang Z, 2, Hu S, Zhao W, Guo Y, Li N, Zheng Z, et al. Population structure and geographical segregation of Cryptosporidium parvum IId subtypes in cattle in China. Parasites Vectors. 2020;13(1):425. [View at Publisher] [DOI] [PMID] [Google Scholar]
14. Daraei H, Conti GO, Sahlabadi F, Thai VN, Gholipour S, Turki H, et al. Prevalence of Cryptosporidium spp in water: a global systematic review and meta-analysis. Environ Sci Pollut Res Int. 2021;28(8):9498-507. [View at Publisher] [DOI] [PMID] [Google Scholar]
15. Pinto P, Ribeiro CA, Hoque S, Hammouma O, Leruste H, Détriché S, et al. Cross-border investigations on the prevalence and transmission dynamics of Cryptosporidium species in dairy cattle farms in western mainland Europe. Microorganisms. 2021;9(11):2394. [View at Publisher] [DOI] [PMID] [Google Scholar]
16. Poor BM, Rashedi J, Asgharzadeh M, Fallah E, Hatam-Nahavandi K, Dalimi A, et al. Molecular characterization of Cryptosporidium species in children with diarrhea in the northwest of Iran. Int J Mol Cell Med. 2015;4(4):235-9. [View at Publisher] [PMID] [Google Scholar]
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