{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T13:03:26Z","timestamp":1789563806914,"version":"build-2803163510"},"reference-count":29,"publisher":"Oxford University Press (OUP)","issue":"4","license":[{"start":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T00:00:00Z","timestamp":1772582400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"funder":[{"name":"Ankara Y\u0131ld\u0131r\u0131m Beyaz\u0131t University\u2019s Research Foundation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,3,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>To search for colistin heteroresistance (CHR) prevalence in Acinetobacter baumannii bloodstream isolates, and to investigate potential molecular contributors to CHR using WGS.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A total of 267 A. baumannii isolates were recovered from bloodstream infections between January 2014 and July 2018 at a tertiary care hospital in T\u00fcrkiye. Antimicrobial susceptibility to colistin was assessed using the broth microdilution method. CHR was evaluated by population analysis profiling (PAP). WGS was performed on a representative heteroresistant strain (A325) to investigate putative CHR-associated mechanisms.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Thirty-five isolates (13.9%) were classified as colistin-resistant. CHR was identified in 86 of 267 isolates (32.2%) using PAP. Comparative genomic analysis of the colistin-susceptible main population and the colistin-resistant subpopulation of isolate A325 revealed identical mutational profiles in known resistance-associated genes, with the exception of a partial deletion in the lpxD gene between codons 2 and 75, identified exclusively in the resistant subpopulation. Notably, tetracyclines, macrolides and aminoglycosides were fully inactive in the colistin-susceptible main population, whereas an inhibition zone around these antibiotic discs was observed with the colistin-resistant subpopulation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>This study demonstrates a high prevalence of both colistin resistance and CHR among A. baumannii bloodstream isolates. The identification of a partial lpxD deletion in the resistant subpopulation of the colistin-heteroresistant isolate suggests a potential contributory role of LPS-related alterations in CHR. Inverse antimicrobial activity profiles between populations highlight distinct resistance mechanisms potentially shaped by evolutionary trade-offs and collateral sensitivity.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/jac\/dkag076","type":"journal-article","created":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T12:28:38Z","timestamp":1771331318000},"source":"Crossref","is-referenced-by-count":5,"title":["Genomic characterization of colistin heteroresistance in\n                    <i>Acinetobacter baumannii<\/i>\n                    : Evidence for\n                    <i>lpxD<\/i>\n                    deletion and collateral sensitivity"],"prefix":"10.1093","volume":"81","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0098-4674","authenticated-orcid":false,"given":"Banu","family":"Sancak","sequence":"first","affiliation":[{"name":"Department of Medical Microbiology, Faculty of Medicine, Hacettepe University, Ankara ,","place":["Turkey"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6574-7995","authenticated-orcid":false,"given":"Ekin","family":"K\u0131rba\u015f","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Faculty of Medicine, Eskisehir Osmangazi University , Eskisehir ,","place":["Turkey"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4930-5035","authenticated-orcid":false,"given":"Oguz","family":"Ari","sequence":"additional","affiliation":[{"name":"Central Research and Application Center, Ankara Yildirim Beyazit University, Ankara ,","place":["Turkey"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6561-778X","authenticated-orcid":false,"given":"R\u0131za","family":"Durmaz","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Faculty of Medicine, Ankara Yildirim Beyazit University, 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