{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T21:59:20Z","timestamp":1773352760739,"version":"3.50.1"},"reference-count":27,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T00:00:00Z","timestamp":1760054400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002855","name":"Ministry of Science and Technology of the People's Republic of China","doi-asserted-by":"publisher","award":["2022YFC2304000"],"award-info":[{"award-number":["2022YFC2304000"]}],"id":[{"id":"10.13039\/501100002855","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>This study aimed to isolate and identify <jats:italic>Chlamydia psittaci<\/jats:italic> (<jats:italic>C. psittaci<\/jats:italic>) and <jats:italic>Enterococcus faecalis<\/jats:italic> (<jats:italic>E. faecalis<\/jats:italic>) from a patient suspected of community-acquired pneumonia.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>The samples from the patient (lung lavage and throat swab) and his son (throat swab) were tested to determine antibodies against COVID-19 and <jats:italic>C. psittaci<\/jats:italic>-specific IgG. Afterward, 40 female mice were inoculated intranasally with coinfection of <jats:italic>C. psittaci<\/jats:italic> and <jats:italic>E. faecalis<\/jats:italic> and primary infection of <jats:italic>C. psittaci<\/jats:italic> followed by <jats:italic>E. faecalis<\/jats:italic>. Meanwhile, eight mice with <jats:italic>C. psittaci<\/jats:italic> and <jats:italic>E. faecalis<\/jats:italic> infection alone served as the control group. Clinical signs, lung lesions, and pathogen loads were monitored.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Positive <jats:italic>C. psittaci<\/jats:italic> genomics were detected in both the patient\u2019s lung lavage and his son\u2019s swabs, while <jats:italic>C. psittaci<\/jats:italic> and <jats:italic>E. faecalis<\/jats:italic> were isolated and identified from the patient\u2019s lung lavage samples. Moreover, positive <jats:italic>C. psittaci<\/jats:italic>-specific IgG and negative COVID-19 antibodies were determined. The patient recovered after 10-day doxycycline treatment. Mice showed weight loss, breathing difficulties, and diffuse alveolar damage after inoculation with <jats:italic>C. psittaci<\/jats:italic> followed by <jats:italic>E. faecalis<\/jats:italic>.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Our experiment demonstrated that coinfection, particularly sequential infection with <jats:italic>C. psittaci<\/jats:italic> followed by <jats:italic>E. faecalis<\/jats:italic>, can duplicate severe respiratory distress and typical pathological lesions.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fcimb.2025.1662902","type":"journal-article","created":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T05:27:59Z","timestamp":1760074079000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Coinfection of Chlamydia psittaci and Enterococcus faecalis exacerbated respiratory distress in patients: from isolation to mouse model"],"prefix":"10.3389","volume":"15","author":[{"given":"Xuedi","family":"Zhang","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yihui","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuhan","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuehui","family":"Cui","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Huimin","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zongyang","family":"Huang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lin","family":"Luo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Linlin","family":"Tang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jianlin","family":"Chen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cheng","family":"He","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,10,10]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"305","DOI":"10.1016\/j.jinf.2016.07.012","article-title":"Enterococcus faecalis urinary-tract infections: Do they have a zoonotic origin","volume":"73","author":"Abat","year":"2016","journal-title":"J. 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