Journal Article

Echinococcus granulosus (sensu stricto) (G1, G3) and E. ortleppi (G5) in Pakistan: phylogeny, genetic diversity and population structural analysis based on mitochondrial DNA

Li, Li, Alvi, Anum Aizaz, Ohiolei, John Asekhaen, Alvi, Mughees Aizaz, Yan, Hong-Bin, Saqib, Muhammad, Tayyab, Muhammad Haleem, Fu, Bao-Quan, Jia, Wan-Zhong, Wu, Yan-Tao

2020

Overview

Background Cystic echinococcosis (CE) is a serious tapeworm infection caused by Echinococcus granulosus ( sensu lato ) which infects a wide range of animals and humans worldwide. Despite the millions of livestock heads reared in Pakistan, only a few reports on CE prevalence and even fewer on the genetic diversity are available for the country. Meanwhile, the available reports on the genetic diversity are predominantly based on short sequences of the cox 1 gene. Methods To close this knowledge gap, this study was designed to investigate the genetic diversity and population structure of Echinococcus spp. in Pakistan using the complete mitochondrial cytochrome c oxidase subunit 1 ( cox 1) and NADH dehydrogenase subunit 1 ( nad 1) genes. Results Based on BLAST searches of the generated cox 1 and nad 1 gene sequences from a total of 60 hydatid cysts collected from cattle ( n  = 40) and buffalo ( n  = 20), 52 isolates were identified as E . granulosus ( s.s. ) (G1, G3) and 8 as E . ortleppi (G5). The detection of the G5 genotype represents the first in Pakistan. The phylogeny inferred by the Bayesian method using nucleotide sequences of cox 1 -nad 1 further confirmed their identity. The diversity indices indicated a high haplotype diversity and a low nucleotide diversity. The negative values of Tajima’s D and Fu’s Fs test demonstrated deviation from neutrality suggesting a recent population expansion. Conclusions To the best of our knowledge, this report described the genetic variation of E. granulosus population for the first time in Pakistan using the complete cox 1 and nad 1 mitochondrial genes and confirms E. ortleppi as one of the causative agents of CE among livestock in Pakistan. While this report will contribute to baseline information for CE control, more studies considering species diversity and distribution in different hosts across unstudied regions of Pakistan are highly needed.

• Publisher: BioMed Central,Springer Nature B.V,BMC
• Subject: Animals / Bayesian analysis / Bayesian theory / Biomedical and Life Sciences / Biomedicine / buffaloes / Cattle / Cattle Diseases - epidemiology / Cattle Diseases - parasitology / Cysts / Cytochrome / Cytochrome-c oxidase / Cytochromes / Deoxyribonucleic acid / Diversity indices / DNA / DNA, Helminth - genetics / DNA, Mitochondrial - genetics / Echinococcosis / Echinococcosis - epidemiology / Echinococcosis - parasitology / Echinococcosis - veterinary / Echinococcus - genetics / Echinococcus - isolation & purification / Echinococcus granulosus / Echinococcus granulosus - genetics / Echinococcus granulosus - isolation & purification / Echinococcus ortleppi / Electron Transport Complex I - genetics / Electron Transport Complex IV - genetics / Endoparasites / Entomology / Gene sequencing / Genes / Genetic analysis / Genetic diversity / Genetic Variation / Genetics, Population / Genotype / Genotypes / Geographical distribution / Haplotype diversity / Haplotypes / Humans / Infectious Diseases / Livestock / Livestock - parasitology / mitochondria / Mitochondrial DNA / Mutation / NADH / NADH dehydrogenase / Nicotinamide adenine dinucleotide / Nucleotides / Pakistan / Pakistan - epidemiology / Parasitic diseases / Parasitology / Phylogenetics / Phylogeny / Polymorphism / Population / Population genetics / Population growth / Population structure / Probability theory / Species diversity / Structural analysis / tapeworms / Tropical Medicine / Veterinary Medicine/Veterinary Science / Virology