{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T16:47:46Z","timestamp":1790095666243,"version":"4.0.1"},"reference-count":54,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,1,15]],"date-time":"2021-01-15T00:00:00Z","timestamp":1610668800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000265","name":"Medical Research Council","doi-asserted-by":"publisher","award":["MR L008696\/1"],"award-info":[{"award-number":["MR L008696\/1"]}],"id":[{"id":"10.13039\/501100000265","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Prokaryotic communities coordinate quorum behaviour in response to external stimuli to control fundamental processes including inter-bacterial communication. The obligate intracellular bacterial pathogen Chlamydia adopts two developmental forms, invasive elementary bodies (EBs) and replicative reticulate bodies (RBs), which reside within a specialised membrane-bound compartment within the host cell termed an inclusion. The mechanisms by which this bacterial community orchestrates different stages of development from within the inclusion in coordination with the host remain elusive. Both prokaryotic and eukaryotic kingdoms exploit ion-based electrical signalling for fast intercellular communication. Here we demonstrate that RBs specifically accumulate potassium (K+) ions, generating a gradient. Disruption of this gradient using ionophores or an ion-channel inhibitor stalls the Chlamydia lifecycle, inducing persistence. Using photobleaching approaches, we establish that the RB is the master regulator of this [K+] differential and observe a fast K+ exchange between RBs revealing a role for this ion in inter-bacterial communication. Finally, we demonstrate spatio-temporal regulation of bacterial membrane potential during RB to EB differentiation within the inclusion. Together, our data reveal that Chlamydia harnesses K+ to orchestrate host sensing, inter-bacteria communication and pathogen differentiation.<\/jats:p>","DOI":"10.3390\/microorganisms9010173","type":"journal-article","created":{"date-parts":[[2021,1,15]],"date-time":"2021-01-15T12:44:05Z","timestamp":1610714645000},"page":"173","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Chlamydia Uses K+ Electrical Signalling to Orchestrate Host Sensing, Inter-Bacterial Communication and Differentiation"],"prefix":"10.3390","volume":"9","author":[{"given":"Susan C.","family":"Andrew","sequence":"first","affiliation":[{"name":"Institute of Structural and Molecular Biology, University College London &amp; Birkbeck, Malet Street, London WC1E 7HX, UK"},{"name":"Mint Diagnostics, Unit 1093b Kent Science Park, Sittingbourne ME9 8GA, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1732-1041","authenticated-orcid":false,"given":"Maud","family":"Dumoux","sequence":"additional","affiliation":[{"name":"Institute of Structural and Molecular Biology, University College London &amp; Birkbeck, Malet Street, London WC1E 7HX, UK"},{"name":"Rosalind Franklin Institute, Harwell Campus, Didcot OX11 0DE, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1710-2172","authenticated-orcid":false,"given":"Richard D.","family":"Hayward","sequence":"additional","affiliation":[{"name":"Institute of Structural and Molecular Biology, University College London &amp; Birkbeck, Malet Street, London WC1E 7HX, UK"},{"name":"Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,15]]},"reference":[{"key":"ref_1","first-page":"61","article-title":"Chlamydia trachomatis is bad for your sperm!","volume":"30","author":"Eley","year":"2003","journal-title":"Microbiol. Today"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1843","DOI":"10.1128\/IAI.72.4.1843-1855.2004","article-title":"Chlamydial Persistence: Beyond the Biphasic Paradigm","volume":"72","author":"Hogan","year":"2004","journal-title":"Infect. Immun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.micres.2005.04.004","article-title":"Chlamydia trachomatis persistence: An update","volume":"161","author":"Mpiga","year":"2006","journal-title":"Microbiol. Res."},{"key":"ref_4","first-page":"68","article-title":"Persistence of Chlamydia pneumoniae in degenerative aortic valve stenosis indicated by heat shock protein 60 homologues","volume":"12","author":"Skowasch","year":"2003","journal-title":"J. Heart Valve Dis."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1016\/j.atherosclerosis.2007.09.026","article-title":"Evidence for persistent Chlamydia pneumoniae infection of human coronary","volume":"199","author":"Borel","year":"2008","journal-title":"Atherosclerosis"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"686","DOI":"10.1128\/mr.58.4.686-699.1994","article-title":"Persistence in Chlamydiae: From cell culture to a paradigm for chlamydial pathogenesis","volume":"58","author":"Beatty","year":"1994","journal-title":"Microbiol. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2001","DOI":"10.1099\/00221287-129-7-2001","article-title":"Amino Acid Requirements of Strains of Chlamydia trachomatis and C. psittaci growing in McCoy Cells: Relationship with Clinical Syndrome and Host Origin","volume":"129","author":"Allan","year":"1983","journal-title":"Microbiology"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2503","DOI":"10.1128\/iai.56.9.2503-2506.1988","article-title":"Inhibition of Chlamydia trachomatis growth by recombinant tumor necrosis factor","volume":"56","author":"Wallach","year":"1988","journal-title":"Infect. Immun."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1128\/iai.63.1.199-205.1995","article-title":"Reactivation of persistent Chlamydia trachomatis infection in cell culture","volume":"63","author":"Beatty","year":"1995","journal-title":"Infect. Immun."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Pettengill, M.A., Lam, V.W., and Ojcius, D.J. (2009). The Danger Signal Adenosine Induces Persistence of Chlamydial Infection through Stimulation of A2b Receptors. PLoS ONE, 4.","DOI":"10.1371\/journal.pone.0008299"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4539","DOI":"10.1128\/iai.65.11.4539-4547.1997","article-title":"Response of Chlamydia trachomatis serovar E to iron restriction in vitro and evidence for iron-regulated chlamydial proteins","volume":"65","author":"Raulston","year":"1997","journal-title":"Infect. Immun."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1038\/nrmicro.2016.30","article-title":"Chlamydia cell biology and pathogenesis","volume":"14","author":"Elwell","year":"2016","journal-title":"Nat. Rev. Genet."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1038\/s41467-017-02432-0","article-title":"Replication-dependent size reduction precedes differentiation in Chlamydia trachomatis","volume":"9","author":"Lee","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_14","first-page":"59","article-title":"Ion channels enable electrical communication in bacterial communities","volume":"527","author":"Prindle","year":"2015","journal-title":"Nat. Cell Biol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"e12319","DOI":"10.1111\/micc.12319","article-title":"Boosting the signal: Endothelial inward rectifier K+ channels","volume":"24","author":"Jackson","year":"2017","journal-title":"Microcirculation"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"47","DOI":"10.3389\/fnmol.2016.00047","article-title":"Energy and Potassium Ion Homeostasis during Gamma Oscillations","volume":"9","author":"Kann","year":"2016","journal-title":"Front. Mol. Neurosci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1128\/IAI.01027-08","article-title":"The Potassium Transporter Trk and External Potassium Modulate Salmonella enterica Protein Secretion and Virulence","volume":"77","author":"Su","year":"2008","journal-title":"Infect. Immun."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/j.molbiopara.2007.07.004","article-title":"Exposure of Plasmodium sporozites to the intracellular concentration of potassium enhances infectivity and reduces cell passage activity","volume":"156","author":"Kumar","year":"2007","journal-title":"Mol. Biochem. Parasitol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"41492","DOI":"10.1074\/jbc.M106154200","article-title":"The Loss of Cytoplasmic Potassium upon Host Cell Breakdown Triggers Egress of Toxoplasma gondii","volume":"276","author":"Moudy","year":"2001","journal-title":"J. Biol. Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1016\/j.micinf.2010.04.008","article-title":"Chlamydial infection of monocytes stimulates IL-1b secretion through activation of the NLRP3 inflammasome","volume":"12","author":"Padilla","year":"2010","journal-title":"Microbes Infect."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"827","DOI":"10.1128\/iai.19.3.827-832.1978","article-title":"Loss of inorganic ions from host cells infected with Chlamydia psittaci","volume":"19","author":"Chang","year":"1978","journal-title":"Infect. Immun."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1612","DOI":"10.1111\/tra.12002","article-title":"ChlamydiaeAssemble a Pathogen Synapse to Hijack the Host Endoplasmic Reticulum","volume":"13","author":"Dumoux","year":"2012","journal-title":"Traffic"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Wickstrum, J., Sammons, L.R., Restivo, K.N., and Hefty, P.S. (2013). Conditional Gene Expression in Chlamydia trachomatis using the Tet System. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0076743"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Dumoux, M., Le Gall, S.M., Habbeddine, M., Delarbre, C., Hayward, R.D., Kanellopoulos-Langevin, C., and Verbeke, P. (2013). Penicillin Kills Chlamydia following the Fusion of Bacteria with Lysosomes and Prevents Genital Inflammatory Lesions in C. muridarum-Infected Mice. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0083511"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"907","DOI":"10.1002\/jps.2600600621","article-title":"Atomic Absorption Analysis of Sodium, Potassium, and Calcium in Ringer\u2019s Solution","volume":"60","author":"Smith","year":"1971","journal-title":"J. Pharm. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"697","DOI":"10.1038\/nmeth.2084","article-title":"Biological imaging software tools","volume":"9","author":"Eliceiri","year":"2012","journal-title":"Nat. Methods"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1038\/nmeth.2089","article-title":"NIH Image to ImageJ: 25 years of image analysis","volume":"9","author":"Schneider","year":"2012","journal-title":"Nat. Methods"},{"key":"ref_28","first-page":"1","article-title":"Fluorescence recovery after photobleaching with the Leica TCS SP2","volume":"18","author":"Kappel","year":"2004","journal-title":"Confocal Appl. Lett."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2828","DOI":"10.1128\/AAC.02211-12","article-title":"Activities of First-Choice Antimicrobials against Gamma Interferon-Treated Chlamydia trachomatis Differ in Hypoxia","volume":"57","author":"Shima","year":"2013","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1242\/jeb.128.1.349","article-title":"Intracellular free potassium, sodium and chloride measured with ion-selective microelectrodes from salivary gland cells of snail Planorbis Corneus","volume":"128","author":"Barber","year":"1987","journal-title":"J. Exp. Biol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"14864","DOI":"10.1074\/jbc.M510916200","article-title":"Simultaneous Monitoring of Ionophore- and Inhibitor-mediated Plasma and Mitochondrial Membrane Potential Changes in Cultured Neurons","volume":"281","author":"Nicholls","year":"2006","journal-title":"J. Biol. Chem."},{"key":"ref_32","first-page":"101","article-title":"Molecular Biology of Adenosine Triphosphate-Sensitive Potassium Channels","volume":"20","author":"Bryan","year":"1999","journal-title":"Endocr. Rev."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1085\/jgp.200709936","article-title":"How Highly Charged Anionic Lipids Bind and Regulate Ion Channels","volume":"131","author":"Tucker","year":"2008","journal-title":"J. Gen. Physiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/0014-4800(65)90021-3","article-title":"Electron microscopic studies on the mode of reproduction of trachoma virus and psittacosis virus in cell cultures","volume":"4","author":"Higashi","year":"1965","journal-title":"Exp. Mol. Pathol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"5734","DOI":"10.1128\/JB.00293-09","article-title":"Kinematics of intracellular Chlamydiae provide evidence for contact-dependent development","volume":"191","author":"Wilson","year":"2009","journal-title":"J. Bacteriol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/0304-4157(90)90008-Z","article-title":"Alteration of intracellular traffic by monensin; mechanism, specificity and relationship to toxicity","volume":"1031","author":"Mollenhauer","year":"1990","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1402","DOI":"10.1128\/AAC.48.4.1402-1405.2004","article-title":"First-Choice Antibiotics at Subinhibitory Concentrations Induce Persistence of Chlamydia pneumoniae","volume":"48","author":"Gieffers","year":"2004","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"5358","DOI":"10.1128\/jb.177.18.5358-5363.1995","article-title":"Cytochemical localization of glycogen in Chlamydia trachomatis inclusions","volume":"177","author":"Chiappino","year":"1995","journal-title":"J. Bacteriol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1111\/j.1432-1033.1974.tb03540.x","article-title":"Interaction between membrane functions and protein synthesis in reticulocytes","volume":"45","author":"Herzberg","year":"1974","journal-title":"Eur. J. Biochem."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1007\/s004380050538","article-title":"Genes required for assembly and function of the protein syn-thetic system in Chlamydia trachomatis are expressed early in elementary to reticulate body transformation","volume":"255","author":"Hudson","year":"1997","journal-title":"Mol. Gen. Genet."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1396","DOI":"10.1053\/gast.2001.24045","article-title":"Inhibition of Na+, K+-ATPase by interferon gamma down-regulates in-testinal epithelial transport and barrier function","volume":"120","author":"Sugi","year":"2001","journal-title":"Gastroenterology"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2434","DOI":"10.1161\/CIRCULATIONAHA.106.633735","article-title":"Activation of inward rectifier potassium channels accelerates atrial fibrillation in humans: Evidence for a re-entrant mechanism","volume":"114","author":"Atienza","year":"2006","journal-title":"Circulation"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"610","DOI":"10.1007\/BF00170160","article-title":"Acetylcholine and adenosine activate the G protein-gated muscarinic K+ channel in ferret ventricular myocytes","volume":"351","author":"Ito","year":"1995","journal-title":"Naunyn Schmiedeberg\u2019s Arch. Pharmacol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"330","DOI":"10.1038\/nrmicro2549","article-title":"Molecular aspects of bacterial pH sensing and homeostasis","volume":"9","author":"Krulwich","year":"2011","journal-title":"Nat. Rev. Genet."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1046\/j.1462-5822.2002.00191.x","article-title":"Determination of the physical environment within the Chlamydia trachomatis inclusion using ion-selective ratiometric probes","volume":"4","author":"Grieshaber","year":"2002","journal-title":"Cell. Microbiol."},{"key":"ref_46","unstructured":"Kem, D.C., and Trachewsky, D. (1983). Potassium metabolism. Potassium: Its Biologic Significances, CRC Press."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"2521","DOI":"10.1099\/00221287-136-12-2521","article-title":"Determination of turgor pressure in Bacillus subtilis: A possible role for K+ in turgor reg-ulation","volume":"136","author":"Whatmore","year":"1990","journal-title":"J. Gen. Microbiol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1016\/S0079-6603(03)75008-9","article-title":"The Roles and Regulation of Potassium in Bacteria","volume":"75","author":"Epstein","year":"2003","journal-title":"Prog. Nucleic Acid Res. Mol. Biol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2477","DOI":"10.1016\/j.bbamem.2014.12.008","article-title":"Involvement of potassium channels in the progression of cancer to a more malignant phenotype","volume":"1848","author":"Comes","year":"2015","journal-title":"Biochim. Biophys. Acta Biomembr."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1111\/j.1469-185X.1966.tb01501.x","article-title":"Chemiosmotic coupling in oxidative and photosynthetic phosphorylation","volume":"64","author":"Mitchell","year":"1966","journal-title":"Biol. Rev. Camb. Philos. Soc."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/B978-0-12-152506-4.50010-8","article-title":"Membranes and Energy Transduction in Bacteria","volume":"6","author":"Harold","year":"1977","journal-title":"Curr. Top. Bioenerg."},{"key":"ref_52","unstructured":"Dean, D., Myers, G.S., and Read, T.D. (2006). Lessons and challenges arising from the \u2018first wave\u2019 of Chlamydia genome sequencing. Chlamydia: Genomics and Pathogenesis, Horizon Scientific Press."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"741","DOI":"10.1016\/j.str.2016.03.017","article-title":"The potassium binding protein KBP is a cytoplasmic potassium sensor","volume":"24","author":"Ashraf","year":"2016","journal-title":"Structure"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"12281","DOI":"10.1073\/pnas.1005485107","article-title":"Membrane potential is important for bacterial cell division","volume":"107","author":"Strahl","year":"2010","journal-title":"Proc. Natl. Acad. Sci. USA"}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/9\/1\/173\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:11:26Z","timestamp":1760159486000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/9\/1\/173"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,15]]},"references-count":54,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2021,1]]}},"alternative-id":["microorganisms9010173"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms9010173","relation":{},"ISSN":["2076-2607"],"issn-type":[{"value":"2076-2607","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,15]]}}}