{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T06:17:30Z","timestamp":1774937850402,"version":"3.50.1"},"reference-count":53,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,2,5]],"date-time":"2021-02-05T00:00:00Z","timestamp":1612483200000},"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. Microbiol."],"abstract":"<jats:p>We examined the prevalence and transmission of the <jats:italic>fosA3<\/jats:italic> gene among <jats:italic>Citrobacter freundii<\/jats:italic> isolates from flowers and the retail environments. We identified 11 fosfomycin-resistant <jats:italic>C. freundii<\/jats:italic> strains (&amp;gt;256 \u03bcg\/mL) from 270 samples that included petals (<jats:italic>n<\/jats:italic> = 7), leaves (<jats:italic>n<\/jats:italic> = 2), dust (<jats:italic>n<\/jats:italic> = 1) and water (<jats:italic>n<\/jats:italic> = 1). These 11 isolates were multidrug-resistant and most were simultaneously resistant to fosfomycin, cefotaxime, ciprofloxacin and amikacin. Consistently, all 11 isolates also possessed <jats:italic>bla<\/jats:italic><jats:sub><jats:italic>CTX\u2013M\u2013<\/jats:italic><\/jats:sub><jats:sub>14<\/jats:sub>, <jats:italic>bla<\/jats:italic><jats:sub><jats:italic>CMY\u2013<\/jats:italic><\/jats:sub><jats:sub>65<\/jats:sub><jats:sub>\/<\/jats:sub><jats:sub>122<\/jats:sub>, <jats:italic>aac(6\u2019)-Ib-cr<\/jats:italic>, <jats:italic>qnrS1<\/jats:italic>, <jats:italic>qnrB13\/6\/38<\/jats:italic> and <jats:italic>rmtB<\/jats:italic>. These <jats:italic>fosA3<\/jats:italic>-positive isolates were assigned to two distinct PFGE patterns and one (<jats:italic>n<\/jats:italic> = 9) predominated indicating clonal expansion of <jats:italic>fosA3<\/jats:italic>-positive isolates across flower markets and shops. Correspondingly, <jats:italic>fosA3<\/jats:italic> was co-transferred with <jats:italic>bla<\/jats:italic><jats:sub><jats:italic>CTX\u2013M\u2013<\/jats:italic><\/jats:sub><jats:sub>14<\/jats:sub><jats:italic>via<\/jats:italic> two plasmid types by conjugation possessing sizes of 110 kb (<jats:italic>n<\/jats:italic> = 9) and 260 kb (<jats:italic>n<\/jats:italic> = 2). Two representatives were fully sequenced and p12-1 and pS39-1 possessed one and two unclassified replicons, respectively. These plasmids shared a distinctive and conserved backbone in common with <jats:italic>fosA3<\/jats:italic>-carrying <jats:italic>C. freundii<\/jats:italic> and other <jats:italic>Enterobacteriaceae<\/jats:italic> from human and food animals. However, the <jats:italic>fosA3<\/jats:italic>-<jats:italic>bla<\/jats:italic><jats:sub><jats:italic>CTX\u2013M\u2013<\/jats:italic><\/jats:sub><jats:sub>14<\/jats:sub>-containing multidrug resistance regions on these untypable plasmids were highly heterogeneous. To the best of our knowledge, this is the first report of <jats:italic>fosA3<\/jats:italic> and <jats:italic>bla<\/jats:italic><jats:sub><jats:italic>CTX\u2013M\u2013<\/jats:italic><\/jats:sub><jats:sub>14<\/jats:sub> that were present in bacterial contaminants from flower shops and markets. These findings underscore a public health threat posed by untypable and transferable p12-1-like and pS39-1-like plasmids bearing <jats:italic>fosA3<\/jats:italic>-<jats:italic>bla<\/jats:italic><jats:sub><jats:italic>CTX\u2013M\u2013<\/jats:italic><\/jats:sub><jats:sub>14<\/jats:sub> that could circulate among <jats:italic>Enterobacteriaceae<\/jats:italic> species and in particular <jats:italic>C. freundi<\/jats:italic> in environmental isolates.<\/jats:p>","DOI":"10.3389\/fmicb.2021.586504","type":"journal-article","created":{"date-parts":[[2021,2,8]],"date-time":"2021-02-08T04:41:11Z","timestamp":1612759271000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":10,"title":["Emergence of fosA3 and blaCTX\u2013M\u201314 in Multidrug-Resistant Citrobacter freundii Isolates From Flowers and the Retail Environment in China"],"prefix":"10.3389","volume":"12","author":[{"given":"Ke","family":"Cheng","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liang-Xing","family":"Fang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qian-Wen","family":"Ge","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dong","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bing","family":"He","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jia-Qi","family":"Lu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zi-Xing","family":"Zhong","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xi-Ran","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yang","family":"Yu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xin-Lei","family":"Lian","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiao-Ping","family":"Liao","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jian","family":"Sun","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ya-Hong","family":"Liu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2021,2,5]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2164-12-402","article-title":"BLAST ring image generator (BRIG): simple prokaryote genome comparisons.","volume":"12","author":"Alikhan","year":"2011","journal-title":"BMC Genomics"},{"key":"B2","doi-asserted-by":"publisher","first-page":"455","DOI":"10.1089\/cmb.2012.0021","article-title":"SPAdes: a new genome assembly algorithm and its applications to single-cell sequencing.","volume":"19","author":"Bankevich","year":"2012","journal-title":"J. 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