Phylogenomic study of tick-borne bacteria in Nepal

A recent study at KRIBS has identified different genotypes of tick-borne bacteria among febrile patients.

Result summary (Unpublished paper, under preparation)

Phylogenetic analysis of the partial genome of Orientia tsutsugamushi 47kDa gene (GenBank accession: OL770337-OL770352) showed a close genetic relation with Karp-UK strain (among the 87.5% of the patients), as well with CRF93-Thailand strain (6.25% of the patients), and Karp-Thailand strain (6.25% of the patients). Similarly, phylogenetic analysis of Orientia tsutsugamushi 56kDa gene (GenBank accession: OL770323-OL770336) showed close relation with Gilliam-Bangladesh strain (among the 35.7% of the patients), Karp-Bangladesh strain (28.6% of the patients), Gilliam-UK strain (14.3% of the patients), Shimokoshi-Taiwan strain (14.3% of the patients), and with Vietnam strain (7.14% of the patients). We also show that the patient-derived groEL gene of Anaplasma (GenBank accession: OL770355 -OL770356) was closely related to the D-GB-gro-8-South Korea strain (5.5% of typhus suspected patients), and the rpoB gene of Leptospira (GenBank accession: OL770353-OL770354) was closely related to Linhai 56609-China strain (5.5% of typhus suspected patients).

This study shows that the Karp, Gilliam, and Shimokoshi strains of Orientia tsutsugamushi are circulating in southwest Nepal. Additionally, this study identifies the co-presence of Anaplasma, and Leptospira in the febrile symptomatic patient. Further genotype and serotype screening study for these bacteria among febrile patients is a current need so as to identify the tick-borne bacterial diversity and its associated disease burden among the Nepalese population.


GenBank sequence link

Orientia tsutsugamushi 47kDa gene (GenBank accession of 16 sequences: OL770337-OL770352) 


Orientia tsutsugamushi 56kDa gene (GenBank accession of 14 sequences: OL770323-OL770336)


Anaplasma, (GenBank accession of 2 sequences: OL770355 -OL770356)


Leptospira, (GenBank accession of 2 sequences: OL770353-OL770354)