Genetic characterization of Echinococcus granulosus in camels, cattle and sheep from the south-east of Iran indicates the presence of the G3 genotype E. Hajialilo 1 , M.F. Harandi 1 *, M. Sharbatkhori 2 , H. Mirhendi 3 and S. Rostami 1 1 Department of Parasitology, School of Medicine, Kerman University of Medical Sciences, Kerman 76169-14111, Iran: 2 Department of Medical Parasitology and Mycology, Faculty of Medicine, Infectious Diseases Research Center, Golestan University of Medical Sciences, Gorgan 49155, Iran: 3 Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran 14155-6446, Iran (Accepted 7 June 2011) Abstract Echinococcus granulosus, the aetiologic agent of cystic echinococcosis (CE), is one of the most important zoonotic helminthes worldwide. Isolates of the parasite show considerable genetic variation in different intermediate hosts. Several genotypes and species are described in different eco-epidemiological settings. This study investigated E. granulosus genotypes existing in livestock and humans from the province of Kerman, located in south-eastern Iran, using sequencing data of cox1 and nad1 mitochondrial genes. Fifty-eight E. granulosus isolates, including 35 from sheep, 11 from cattle, 9 from camels and 3 from goats, were collected from slaughterhouses throughout Kerman. One human isolate was obtained from a surgical case of CE. Mitochondrial cox1 and nad1 regions were amplified using polymerase chain reaction (PCR) and 38 isolates were sequenced. Genotypes G1 (73.7%), G3 (13.2%) and G6 (13.1%) were identified from the isolates. G1 was the most common genotype from sheep (86.7%), cattle (80%), camels (44.4%) and goats (100%). Sheep, cattle and camels were also found to be infected with the G3 genotype (buffalo strain). The human isolate was identified as the G6 genotype. Results showed that the G3 genotype occurred in different animal hosts in addition to G1 and G6 genotypes. Introduction Cystic echinococcosis (CE), caused by the cestode Echinococcus granulosus, is a globally distributed zoonotic disease. In endemic regions, the condition causes human and animal health-related losses as well as economic losses (Moro & Schantz, 2009). Intermediate hosts, which acquire parasitic cysts in the liver, lungs and other organs, include a variety of herbivorous mammals as well as humans. CE is a major public health concern in Iran, and is endemic in many areas of the country. The overall prevalence of CE in livestock (sheep, cattle, camels and goats) in Iran was reported to be 6.7%. Serological studies on humans indicated seroprevalence from 1.2 to 21.4% in different regions of the country (Rokni, 2009). Echinococcus granulosus presents a high level of intraspecific variation and several host-adapted geno- types have been described in different geographical areas (Thompson, 2008). A revision in the classification of the genus Echinococcus has been proposed based on nuclear *Fax: þ 98-341-3221676 E-mail: fasihi@kmu.ac.ir Journal of Helminthology , page 1 of 8 doi:10.1017/S0022149X11000320 q Cambridge University Press 2011