Shuba Varshini Alampalli, Akshay C Uttarkar, Suchithra Ventakesh, Sivarajan T Chettinar, Rishi Kumar Nageshan, Vidya Niranjan and Utpal S Tatu
Giardia lamblia (syn. Giardia duodenalis and Giardia intestinalis) is a major human infecting intestinal parasite. It is a frequent cause of endemic and epidemic diarrhea. G. lamblia is divided into eight genotypes (A-H) which infect a wide range of mammals and humans, but human infections are caused by Genotypes A and B only. Giardia lamblia strains are speculated to undergo zoonotic transmission and also considerable genetic variation has been identified. To unambiguously determine the genotype of the Indian isolate, we sequenced the genome to high depth coverage and compared the assemblies with the nearly completed WB and DH genome and draft genome of Genotypes E (P15; pig isolate) and B (GS and GS-B; human isolate).
Our results identified the Indian isolate to be very closely related to isolate WB and ~97.71% of the sequencing reads aligned to the isolate WBC6 genome. This gave a list of SNPs, InDels and repeat motifs specific to the Indian isolate with the majority of the genome being conserved.
This work will layout a framework for the future studies. This study provides an opportunity to develop targeted and genome-wide genetic marker for better understanding of genotypes of Giardia lamblia prevalent in the developing world.