Given that persistent chlamydial infections may lead to chronic conditions there is a need find more to develop novel anti-microbials to eradicate chlamydial infections. All chlamydiae

spp. exhibit a developmental cycle that begins when an infectious elementary body attaches to and invades a eukaryotic host cell. During invasion the EB becomes enveloped by the host cell plasma membrane, ultimately creating an intracellular vacuole known as an inclusion, within which the bacterium undergoes replication. The EB next transforms into a reticulate body, a developmental process that is characterized by reduction of EB outer membrane proteins [31–33] and DNA decondensation. RB are non-infectious, 2-5 times larger than EB and metabolically active. Division of RB occurs once every 2-3 hours for C. trachomatis and 6-7 hours for C. pneumoniae [34–36]. A

hallmark of chlamydial replication is the expansion Evofosfamide cost of the host cell-derived inclusion membrane to accommodate increasing numbers of bacteria. In response to an as yet unidentified signal, RB begin to asynchronously differentiate into infectious EB by transformation through the IB stage that contains partially condensed chromosomal DNA. The end of the developmental cycle occurs when EB are released from the host Fenbendazole cell following inclusion lysis, or extrusion of the inclusion into neighbouring cells [37]. In addition to the three developmental forms seen during the chlamydial developmental cycle, Chlamydia may be induced to form persistent bodies,

a morphological state not part of check details normal growth and development. The PB is an abnormally large form of chlamydia that occurs in response to interferon-γ [27], antibiotics [26], or iron limitation [38], and is characterized by an inability to segregate into daughter cells after genomic DNA replication. The arrest of the developmental cycle at the PB stage can be reversed when the inducer stimulus in the case of iron deprivation is removed [38]. In addition to interferon-γ, and conventional antibiotics such as β-lactams and macrolides, other compounds exhibit bacteriostatic activity against Chlamydia in cell culture. These include selective cycloxygenase inhibitors, rottlerin and inhibitors of type III secretion [34, 38–42]. Rottlerin is a pan-specific inhibitor of eukaryotic protein kinases and was recently shown to inhibit the growth of C. pneumoniae in HeLa cells [40]. Rottlerin may interfere with activation of the host MEK/ERK pathway which has been shown to be necessary for chlamydial cell invasion [43] and therefore indirectly cause inhibition of chlamydial growth.