Progress in the functional analysis of rickettsial genes through directed mutagenesis of Rickettsia prowazekii phospholipase D

Evaluation of: Driskell LO, Yu X-J, Zhang L et al.: Directed mutagenesis of the Rickettsia prowazekii pld gene encoding phospholipase D. Infect. Immun. 77(8), 3244–3248 (2009). Rickettsioses have afflicted humans worldwide throughout the course of history. Rickettsia prowazekii is the etiological agent of epidemic typhus, a disease transmitted by body lice and capable of massive outbreaks under conditions of compromised hygiene, such as famine, mass migration and war. Fastidious growth requirements and an obligately intracellular lifestyle, preferably within the cytoplasm of the host cell, pose a number of challenges in genetic manipulation of rickettsiae. Driskell et al. describe the successful application of a combination of molecular approaches to generate, isolate and characterize a R. prowazekii mutant lacking a 93-bp sequence of the pld gene responsible for phospholipase D activity. In initial studies, this Δpld mutant of R. prowazekii is shown to be capable of infecting macrophage-like RAW 264.7 ce...