Rickettsial infections have played a significant role in the history of Western civilization through epidemic Typhus and Rickettsia used arthropod vector for the spread of Typhus fever. R. typhi (Rickettsia typhi) is a smaller in size than normal bacteria and obligately intracellular pathogen. However, they are true bacteria, small coccobacilli that are normally stained with Giemsa and poorly by the Gram stain. Its cell wall morphology is that of a Gram-negative bacillus. Phylogenetically a member of the Alpha-subgroup of Proteobacteria, R. typhi along with R. prowazekii (Rickettsia prowazekii) is considered to be Typhus group Rickettsia (Ref.1). R. typhi evolved in close association with its arthropod vectors, various species of fleas. In its best known zoonotic cycle, R. typhi is acquired [...]