title: Penicillin kills Chlamydia following the fusion of bacteria with lysosomes and prevents genital inflammatory lesions in C. muridarum-infected mice.
abstract: The obligate intracellular bacterium Chlamydia exists as two distinct forms. Elementary bodies (EBs) are infectious and extra-cellular, whereas reticulate bodies (RBs) replicate within a specialized intracellular compartment termed an 'inclusion'. Alternative persistent intra-cellular forms can be induced in culture by diverse stimuli such as IFNγ or adenosine/EHNA. They do not grow or divide but revive upon withdrawal of the stimulus and are implicated in several widespread human diseases through ill-defined in vivo mechanisms. β-Lactam antibiotics have also been claimed to induce persistence in vitro. The present report shows that upon penicillin G (pG) treatment, inclusions grow as fast as those in infected control cells. After removal of pG, Chlamydia do not revert to RBs. These effects are independent of host cell type, serovar, biovar and species of Chlamydia. Time-course experiments demonstrated that only RBs were susceptible to pG. pG-treated bacteria lost their control over host cell apoptotic pathways and no longer expressed pre-16S rRNA, in contrast to persistent bacteria induced with adenosine/EHNA. Confocal and live-video microscopy showed that bacteria within the inclusion fused with lysosomal compartments in pG-treated cells. That leads to recruitment of cathepsin D as early as 3 h post pG treatment, an event preceding bacterial death by several hours. These data demonstrate that pG treatment of cultured cells infected with Chlamydia results in the degradation of the bacteria. In addition we show that pG is significantly more efficient than doxycycline at preventing genital inflammatory lesions in C. muridarum-C57Bl/6 infected mice. These in vivo results support the physiological relevance of our findings and their potential therapeutic applications.
authors.affiliation: Laboratory of Inflammation, Gestation and Autoimmunity, Institut Jacques Monod-UMR 7592, CNRS and University Paris Diderot, Paris, France.
authors.forename: Maud
authors.initials: M
authors.lastname: Dumoux
authors.affiliation: Laboratory of Inflammation, Gestation and Autoimmunity, Institut Jacques Monod-UMR 7592, CNRS and University Paris Diderot, Paris, France.
authors.forename: Sylvain M
authors.initials: SM
authors.lastname: Le Gall
authors.affiliation: Laboratory of Inflammation, Gestation and Autoimmunity, Institut Jacques Monod-UMR 7592, CNRS and University Paris Diderot, Paris, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Habbeddine
authors.affiliation: Laboratory of Inflammation, Gestation and Autoimmunity, Institut Jacques Monod-UMR 7592, CNRS and University Paris Diderot, Paris, France.
authors.forename: Christiane
authors.initials: C
authors.lastname: Delarbre
authors.affiliation: Institute of Structural and Molecular Biology, University College London & Birkbeck, University of London, London, United Kingdom.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Hayward
authors.affiliation: Laboratory of Inflammation, Gestation and Autoimmunity, Institut Jacques Monod-UMR 7592, CNRS and University Paris Diderot, Paris, France.
authors.forename: Colette
authors.initials: C
authors.lastname: Kanellopoulos-Langevin
authors.affiliation: Laboratory of Inflammation, Gestation and Autoimmunity, Institut Jacques Monod-UMR 7592, CNRS and University Paris Diderot, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Verbeke
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D002689:Chlamydia / Q000187:drug effects* / Q000502:physiology*; D002690:Chlamydia Infections / Q000188:drug therapy*; D005260:Female; D007249:Inflammation / Q000517:prevention & control; D008247:Lysosomes / Q000187:drug effects / Q000382:microbiology*; D051379:Mice; D010400:Penicillin G / Q000494:pharmacology* / Q000627:therapeutic use; D014621:Vagina / Q000187:drug effects* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D010400:Penicillin G