ORIGINAL PAPER High resolution melting technique for molecular epidemiological studies of cystic echinococcosis: differentiating G1, G3, and G6 genotypes of Echinococcus granulosus sensu lato Sima Rostami & Saeed Talebi & Zahra Babaei & Mitra Sharbatkhori & Naser Ziaali & Habib Rostami & Majid Fasihi Harandi Received: 22 April 2013 / Accepted: 25 June 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract Reliable and rapid genotyping of large number of Echinococcus granulosus sensu lato isolates is crucial for un- derstanding the epidemiology and transmission of cystic echi- nococcosis. We have developed a method for distinguishing and discriminating common genotypes of E. granulosus s.l. (G1, G3, and G6) in Iran. This method is based on polymerase chain reaction coupled with high resolution melting curve (HRM), ramping from 70 to 86 °C with fluorescence data acquisition set at 0.1 °C increments and continuous fluores- cence monitoring. Consistency of this technique was assessed by inter- and intra-assays. Assessment of intra- and inter-assay variability showed low and acceptable coefficient of variations ranging from 0.09 to 0.17 %. Two hundred and eighty E. granulosus s.l. isolates from sheep, cattle, and camel were used to evaluate the applicability and accuracy of the method. The isolates were categorized as G1 (93, 94, and 25 %), G3 (7, 4, and 4 %), and G6 (0, 2, and 71 %) for sheep, cattle, and camel, respectively. HRM results were completely compatible with those obtained from sequencing and rostellar hook measure- ment. This method proved to be a valuable screening tool for large-scale molecular epidemiological studies. Introduction Cystic echinococcosis (CE) is one of the most important parasitic zoonoses in the world caused by larval stages of Echinococcus granulosus s.l., a tapeworm that lives in the small intestine of dogs and other carnivores as definitive host and a wide range of domestic herbivores, e.g., sheep, cattle, buffalo, goat, camel, horse, pig, as well as wild ungulates as intermediate hosts. Human can be infected as an accidental host via ingestion of contaminated vegetables and water and direct contact with dogs. Metacestodes usually infect the liver and lungs of the intermediate host and cause hydatid cysts in those organs (Thompson and McManus 2002). CE imposes great monetary and non-monetary burden on the society in areas where the disease is endemic (Budke et al. 2006; Harandi et al. 2012; Murray et al. 2012). There are wide molecular genetic, biological, and morpho- logical variations within E. granulosus sensu lato. This leads to the erection of several new species and genotypes, desig- nated as G1 to G10 (Nakao et al. 2010). Knowledge about E. granulosus species and genotypes has important implications for the epidemiology, control, and prevention of the disease as well as future vaccine and drug designs (Thompson 2008; Maillard et al. 2007). Iran is an endemic area for E. granulosus S. Rostami : Z. Babaei : N. Ziaali Research Center of Tropical and Infectious Diseases, Kerman University of Medical Sciences, Kerman, Iran S. Rostami : Z. Babaei : N. Ziaali Department of Medical Parasitology, School of Medicine, Kerman University of Medical Sciences, Kerman 76169-14111, Iran S. Talebi Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran M. Sharbatkhori Infectious Diseases Research Center, Department of Medical Parasitology and Mycology, Golestan University of Medical Sciences, Gorgan, Iran H. Rostami Shariati Hospital, Karaj, Alborz, Iran M. F. Harandi (*) Research Center for Hydatid Disease in Iran, Kerman University of Medical Sciences, Kerman 76169-14111, Iran e-mail: fasihi@kmu.ac.ir Parasitol Res DOI 10.1007/s00436-013-3523-z