Small molecule inhibitors of type III secretion in Yersinia block the Chlamydia pneumoniae infection cycle

Intracellular parasitism by Chlainydiales is a complex process involving transmission of metabolically inactive particles that differentiate, replicate, and re-differentiate within the host cell. A type three secretion system (T3SS) has been implicated. p in this process. We have here identified small molecules of a chemical class of acylated hydrazones of salicylaidehydes that specifically blocks the T3S of Chlamydia. These compounds also affect the developmental cycle showing that the T3SS has a pivotal role in the pathogenesis of Chlaniydia. Our results suggest a previously unexplored avenue for development of novel anti-chlamydial drugs. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.