{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,26]],"date-time":"2026-07-26T04:14:02Z","timestamp":1785039242417,"version":"3.55.0"},"reference-count":45,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T00:00:00Z","timestamp":1768348800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010883","name":"Traditional Chinese Medicine Bureau of Guangdong Province","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100010883","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"\n Background<\/jats:title>\n \n Corynebacterium parakroppenstedtii<\/jats:italic>\n , and\n C<\/jats:italic>\n .\n pseudokroppenstedtii<\/jats:italic>\n are emerging as significant pathogens in mastitis. Despite its clinical significance, data on its epidemiological, microbiological, and clinical features remain limited.\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n We conducted a comprehensive study on mastitis cases associated with\n Corynebacterium kroppenstedtii<\/jats:italic>\n complex (CKC) in Guangdong, China (September 2021\u2013September 2023). A total of 101 bacterial isolates were collected and initially identified as CKC using MALDI-TOF MS. Species-level confirmation was achieved through partial sequencing of the 16S rRNA,\n ropB<\/jats:italic>\n , and\n fusA<\/jats:italic>\n genes. Unclassified isolates were further characterized by whole genome sequencing (WGS). Clinical information was collected, and antimicrobial susceptibility testing was performed.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Among the 101cases,\n C<\/jats:italic>\n .\n parakroppenstedtii<\/jats:italic>\n accounted for 86% of infections, while\n C<\/jats:italic>\n .\n pseudokroppenstedtii<\/jats:italic>\n for 12%, and a potential novel species for the remaining 2%. Notably, no\n C<\/jats:italic>\n .\n kroppenstedtii<\/jats:italic>\n infections were detected. Granulomatous lobular mastitis (GLM) was the predominant presentation, occurring in 72% of all cases. Comparative analysis revealed that\n C<\/jats:italic>\n .\n pseudokroppenstedtii<\/jats:italic>\n infections were associated with higher rates of pus formation and recurrence, whereas\n C<\/jats:italic>\n .\n parakroppenstedtii<\/jats:italic>\n infections were more prevalent among parous women. Moreover,\n C<\/jats:italic>\n .\n pseudokroppenstedtii<\/jats:italic>\n exhibited higher resistance rates to ceftriaxone (32.15% vs. 20.00%) and ciprofloxacin (75.00% vs. 19.09%) compared with\n C<\/jats:italic>\n .\n parakroppenstedtii<\/jats:italic>\n .\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n \n These findings challenge the prevailing understanding that\n C<\/jats:italic>\n .\n kroppenstedtii<\/jats:italic>\n is the main pathogen in mastitis and underscore the need for species-level identification to guide diagnosis and optimize antibiotic therapy for CKC-related mastitis. These insights are vital for improving clinical management and informing treatment strategies.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fcimb.2025.1723551","type":"journal-article","created":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T06:39:55Z","timestamp":1768372795000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Emerging mastitis-associated Corynebacterium parakroppenstedtii and Corynebacterium pseudokroppenstedtii: clinical, microbiological, and epidemiological features from a two-year study in Guangdong, China"],"prefix":"10.3389","volume":"15","author":[{"given":"Minling","family":"Zheng","sequence":"first","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiongdan","family":"Mai","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasha","family":"Luo","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaowei","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Panyu Hospital of Chinese Medicine","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weiming","family":"Lai","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junfei","family":"Guo","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanting","family":"Qin","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]},{"name":"Guangzhou Medical University","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lingling","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhiyu","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]},{"name":"Guangzhou Medical University","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongyu","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenyu","family":"Deng","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pinghua","family":"Qu","sequence":"additional","affiliation":[{"name":"School of Medicine, Foshan University","place":["Foshan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mingyong","family":"Luo","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Guangdong Women and Children Hospital","place":["Guangzhou, China"]},{"name":"Department of Clinical Laboratory, Women and Children\u2019s Hospital, Southern University of Science and Technology","place":["Guangzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,1,14]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1358","DOI":"10.1111\/tbj.13822","article-title":"Idiopathic granulomatous mastitis: Management and predictors of recurrence in 474 patients","volume":"26","author":"Azizi","year":"2020","journal-title":"Breast J."},{"key":"B2","doi-asserted-by":"publisher","first-page":"3152","DOI":"10.1128\/JCM.00796-12","article-title":"The genus corynebacterium and other medically relevant coryneform-like bacteria","volume":"50","author":"Bernard","year":"2012","journal-title":"J. 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