Genotyping and Phylogenetic Analysis of Cystic Echinococcosis Isolated from Camels and Humans in Egypt

Abstract

The objectives of the present study were to investigate strain identification of Echinococcus granulosus infecting camel and human in Qalyubia, Egypt. Therefore partial sequences were generated after gel purification of nested PCR amplified products of mitochondrial NADH 1gene of Echinococcus granulosus complex. Sequences were further examined by sequence analysis and subsequent phylogeny to compare these sequences to those from known strains of E.granulosus circulating globally and retrieved from GenBank. All isolates are homologous to the camel strain, E. canadensis (G6) genotype. Nucleotide mutations generate polymorphism at position of 275 nucleotide, where a thymine replaced a cytosine and at the levels of 385 and 386 nucleotides, where two cytosine substituted a guanine and a thymine respectively. KF815488 Egypt showed typical identity (99.5%) with JN637176 Sudan, HM853659 Iran, AF386533 France and AJ237637 Poland with 0.5% diversion.. Phylogenetic analysis showed a robust tree clustering all isolates with sequences belonging to the camel genotype (G6) variant with strong bootstrap values at relevant nodes and the evolutionary distance between groups is very short. There are two mutations in the sequences of amino acids at the position of 92, where an Alanine is changed to a Valine and at the position of 129, where a Valine is transformed to a Proline. Our record of a single genotype determined a strain which could be incriminated for camel and human infectivity and responsible for its persistence in the endemic areas. Such epidemiological data could guide the application of efficient control strategies of hydatidosis in Egypt.

Taxonomy and molecular epidemiology of Echinococcus granulosus sensu lato

“…E. granulosus s.s. is the most frequent agent of human cystic echinococcosis worldwide: 88% of 1661 genotyped human isolates belonged to this species (Alvarez Rojas et al, 2014). Exceptions are only countries where E. granulosus s.s. is absent or rare in animals in favour of other Echinococcus spp., as is the case in Sudan and Egypt (Khalifa et al, 2014;Omer et al, 2011). Cysts are often fertile in humans, and numerous observations indicate that the high number of cases may be due to increased infectivity (or pathogenicity) of E. granulosus s.s. compared to other Echinococcus species.…”

Epidemiology and Genetic Variants within Echinococcus granulosus Identified based on ITS-1 Ribosomal DNA in North-West Egypt

“…Take into consideration that a few studies used nPCR-ITS1 of rDNA on contrary to NAD1, COX1-mDNA, consequently, a decrease in the number of the reference E. granulosus strains deposited in GenBank (Amer et al, 2015, Khalifa et al, 2014. In the current study, the ITS sequences obtained from human and animals isolates were between 96.9-98.3% homologous to sequences of E. granulosus strains previously detected in Iran, India and Australia.…”

“…In Egypt, except for a few molecular studies have recorded only the presence of the camel strain (G6), equine strain (G4) and buffalo strain (G5) in definite regions and advised to use gene sequencing of ITS1-PCR (Craig et al, 2005). Many studies have shown clearly that we face a predominant sheep strain (G1) with a high percentage (Abd El Baki et al, 2009;Aboelhadid et al, 2013;Khalifa et al, 2014;Taha, 2012). The current study supported the prevalent and dominance of G1 and G6 E. granulosus in most parts of Egypt, especially in rural areas where slaughter is practiced on farms.…”

Molecular and epidemiological updates on cystic echinococcosis infecting water buffaloes from Egypt

“…Studies illustrated the wide domination of the G6 (camel strain), which favors the role the camel-dog cycle in the transmission of echinococcosis [11,13,30,31]. Here, we have notice that all the collected samples in these studies were originated from the same area (Cairo and Qalubiya provinces), which considered the main localities in Egypt for importing camels and consuming their meats.…”