{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T04:20:22Z","timestamp":1787804422283,"version":"build-2784847793"},"reference-count":38,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:00:00Z","timestamp":1787616000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["32170199"],"award-info":[{"award-number":["32170199"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["32470193"],"award-info":[{"award-number":["32470193"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["32170199"],"award-info":[{"award-number":["32170199"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"award":["32470193"],"award-info":[{"award-number":["32470193"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004945","name":"Nankai University","doi-asserted-by":"publisher","award":["63241535"],"award-info":[{"award-number":["63241535"]}],"id":[{"id":"10.13039\/501100004945","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004945","name":"Nankai University","doi-asserted-by":"publisher","award":["63241534"],"award-info":[{"award-number":["63241534"]}],"id":[{"id":"10.13039\/501100004945","id-type":"DOI","asserted-by":"publisher"}]},{"award":["63241535"],"award-info":[{"award-number":["63241535"]}],"id":[{"id":"https:\/\/ror.org\/01y1kjr75","id-type":"ROR","asserted-by":"publisher"}]},{"award":["63241534"],"award-info":[{"award-number":["63241534"]}],"id":[{"id":"https:\/\/ror.org\/01y1kjr75","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100010041","name":"Tianjin Municipal Science and Technology Commission","doi-asserted-by":"publisher","award":["22JCYBJC00560"],"award-info":[{"award-number":["22JCYBJC00560"]}],"id":[{"id":"10.13039\/501100010041","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100010041","name":"Tianjin Municipal Science and Technology Commission","doi-asserted-by":"publisher","award":["22JCYBJC00790"],"award-info":[{"award-number":["22JCYBJC00790"]}],"id":[{"id":"10.13039\/501100010041","id-type":"DOI","asserted-by":"publisher"}]},{"award":["22JCYBJC00560"],"award-info":[{"award-number":["22JCYBJC00560"]}],"id":[{"id":"https:\/\/ror.org\/03wb1xh22","id-type":"ROR","asserted-by":"publisher"}]},{"award":["22JCYBJC00790"],"award-info":[{"award-number":["22JCYBJC00790"]}],"id":[{"id":"https:\/\/ror.org\/03wb1xh22","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Ehrlichia chaffeensis is an obligate intracellular bacterium that proliferates within monocytes or macrophages and causes human monocytic ehrlichiosis (HME), an emerging life-threatening zoonosis. Doxycycline is the choice of treatment for HME, yet it has prominent side effects. Host cells lack the lysine biosynthetic pathway; thus, the enzymes in this pathway are essential for bacterial growth and recognized as potential targets for the development of novel antibiotics. Here, we demonstrated that inhibitors targeting DapE, which is a key enzyme in the lysine biosynthetic pathway, especially disulfiram, effectively inhibit E. chaffeensis infection and intracellular growth. Through complementation experiments and peptide nucleic acid-mediated dapE knockdown, we showed that DapE in E. chaffeensis is functional and essential for bacterial intracellular growth. Using purified recombinant protein, we found that DapE induces IL-8 expression in host cells. Finally, we identified that NtrX, the response regulator of the two-component system NtrY\/NtrX, regulates dapE expression using an electrophoretic mobility shift assay and a reporter assay. Our findings deepen the understanding of E. chaffeensis pathogenesis as well as illustrate that DapE in E. chaffeensis is a potential therapeutic target for the development of novel HME treatments.<\/jats:p>","DOI":"10.3390\/microorganisms14091889","type":"journal-article","created":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T15:01:07Z","timestamp":1787670067000},"page":"1889","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Ehrlichia chaffeensis DapE Is Essential for Intracellular Growth and Represents a Promising Therapeutic Target"],"prefix":"10.3390","volume":"14","author":[{"given":"Mengyao","family":"Wang","sequence":"first","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuhong","family":"Zhou","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mengxiao","family":"Li","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shanhua","family":"Qin","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ziyue","family":"Qi","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Meifang","family":"Li","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-1075-9277","authenticated-orcid":false,"given":"Nan","family":"Yang","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Zhou","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5681-0764","authenticated-orcid":false,"given":"Xiaoya","family":"Wei","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yujie","family":"Zhang","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhonghui","family":"Yang","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhihui","family":"Cheng","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China"},{"name":"Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2741","DOI":"10.1128\/jcm.29.12.2741-2745.1991","article-title":"Isolation and characterization of an Ehrlichia sp. from a patient diagnosed with human ehrlichiosis","volume":"29","author":"Dawson","year":"1991","journal-title":"J. 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