Molecular Characterization of the NAD1 Gene Region in Human, Sheep, and Cattle Cystic Echinococcosis Isolates

The study aims to molecularly characterize the mitochondrial NAD1 gene region in cyst samples from humans, sheep, and cattle with cystic echinococcosis. It used 75 human cyst materials and 25 each from sheep and cattle. All 125 samples underwent processes for molecular characterization of Echinococcus granulosus 's NAD1 mitochondrial gene region. The distribution of hydatid cyst samples from humans showed similar lung localization in both genders, but a higher liver localization in males. In cattle, liver localization was primary, while in sheep, lung localization was more common. All samples produced a band of 864 bp in size upon amplification. Sequence comparison of the isolates with Genbank entries confirmed all our samples as E. granulosus sensu stricto. Among these, nine were identified as G3 strain and 51 as G1 strain. Host-wise, 24 of 30 human samples were G1, 6 were G3; in sheep, 13 were G1, 2 were G3; in cattle, 14 were G1 and one was G3. Comparison of the 51 G1 strain samples with Genbank's reference G1 strains showed that 42 matched 100%, while 9 had mutations in different regions, a new finding. The study concluded that the G1 strain is dominant in all three hosts and identified various mutations. These findings contribute to the molecular epidemiological data of cystic echinococcosis.