{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T11:30:58Z","timestamp":1781523058982,"version":"3.54.1"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2024,4,19]],"date-time":"2024-04-19T00:00:00Z","timestamp":1713484800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec><jats:title>Objective<\/jats:title><jats:p>To outline the epidemiology of puerperal mastitis caused by methicillin-resistant <jats:italic>Staphylococcus aureus<\/jats:italic> (MRSA) and evaluate the effect of an infection control bundle on its incidence.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>A surge in MRSA puerperal mastitis was noted in a community hospital in September 2009. MRSA samples from mastitis cases and the environment underwent typing using multilocus sequence typing (MLST), staphylococcal cassette chromosome <jats:italic>mec<\/jats:italic> (SCC<jats:italic>mec<\/jats:italic>), gene encoding surface protein A (<jats:italic>spa<\/jats:italic>), accessory gene regulator (<jats:italic>agr<\/jats:italic>), and pulsed-field gel electrophoresis (PFGE). The phenotypic characteristics, including superantigen toxin profiles, gene encoding Panton-Valentine leucocidin (<jats:italic>pvl<\/jats:italic>), and minimal inhibitory concentration (MIC) against vancomycin, were ascertained. Subsequently, an infection control bundle emphasizing contact precautions was introduced, and mastitis incidence rates pre- and post-intervention were compared.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The majority of cases occurred within 6\u2009weeks post-delivery in first-time mothers. Of the 42 <jats:italic>S. aureus<\/jats:italic> isolates (27 from mastitis and 15 from colonized staff and environmental sources), 25 (92.6%) clinical and 3 (20%) colonized MRSA were identified as ST59-SCC<jats:italic>mec<\/jats:italic>V<jats:sub>T<\/jats:sub>-<jats:italic>spa<\/jats:italic> t437-<jats:italic>agr<\/jats:italic> group I with a vancomycin MIC of 1\u2009mg\/L, <jats:italic>pvl<\/jats:italic>-positive, and predominantly with a consistent toxin profile (<jats:italic>seb<\/jats:italic>-s<jats:italic>elk<\/jats:italic>-<jats:italic>selr<\/jats:italic>). PFGE revealed 13 patterns; pulsotype B exhibited clonal relatedness between two clinical and three colonized MRSA samples. Post-intervention, the incidence of both mastitis and MRSA mastitis notably decreased from 13.01 to 1.78 and from 3.70 to 0.99 episodes per 100 deliveries, respectively.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Distinct community-associated MRSA (CA-MRSA) clones were detected among puerperal mastitis patients and colonized staff. The outbreak was effectively controlled following the implementation of a targeted infection control bundle.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fmed.2024.1378207","type":"journal-article","created":{"date-parts":[[2024,4,19]],"date-time":"2024-04-19T04:28:13Z","timestamp":1713500893000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":5,"title":["Puerperal mastitis caused by limited community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clones"],"prefix":"10.3389","volume":"11","author":[{"given":"Yu-Cheng","family":"Lin","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu-Lin","family":"Lee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi-Hsin","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shih-Ming","family":"Tsao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei-Yao","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2024,4,19]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"298","DOI":"10.3201\/eid1302.060989","article-title":"Postpartum mastitis and community-acquired methicillin-resistant Staphylococcus aureus","volume":"13","author":"Reddy","year":"2007","journal-title":"Emerg Infect Dis"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"51","DOI":"10.1097\/01.JAA.0000795040.66115.51","article-title":"Breast mastitis or abscess","volume":"34","author":"Bates","year":"2021","journal-title":"JAAPA"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"287","DOI":"10.1016\/j.emc.2019.01.014","article-title":"Postdelivery emergencies","volume":"37","author":"Wheaton","year":"2019","journal-title":"Emerg Med Clin North Am"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"83","DOI":"10.1007\/s00430-017-0532-z","article-title":"The microbiology and treatment of human mastitis","volume":"207","author":"Angelopoulou","year":"2018","journal-title":"Med Microbiol Immunol"},{"key":"ref5","first-page":"727","article-title":"Management of mastitis in breastfeeding women","volume":"78","author":"Spencer","year":"2008","journal-title":"Am Fam Physician"},{"key":"ref6","year":"2000"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"533","DOI":"10.1097\/AOG.0b013e31818187b0","article-title":"Community-acquired Staphylococcus aureus among patients with puerperal mastitis requiring hospitalization","volume":"112","author":"Stafford","year":"2008","journal-title":"Obstet Gynecol"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"373","DOI":"10.1007\/s10911-011-9237-x","article-title":"Methicillin resistant S. aureus in human and bovine mastitis","volume":"16","author":"Holmes","year":"2011","journal-title":"J Mammary Gland Biol Neoplasia"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"360","DOI":"10.1089\/bfm.2022.29207.kbm","article-title":"Academy of breastfeeding medicine clinical protocol #36: the mastitis Spectrum, revised 2022","volume":"17","author":"Mitchell","year":"2022","journal-title":"Breastfeed Med"},{"key":"ref10","volume-title":"Performance standards for antimicrobial disk susceptibility tests. 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