{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T04:10:30Z","timestamp":1790741430018,"version":"4.1.0"},"reference-count":32,"publisher":"Scientific Scholar","issue":"4","content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2018,4]]},"abstract":"<jats:sec>\n            <jats:title>Background &amp; objectives:<\/jats:title>\n            <jats:p>Overexpression of efflux pumps is a cause of acquired resistance to fluoroquinolones in <jats:italic toggle=\"yes\">Acinetobacter baumannii<\/jats:italic>. The present study was done to investigate the presence and overexpression of AdeABC efflux system and to analyze the sequences of AdeR-AdeS regulatory system in ciprofloxacin-resistant <jats:italic toggle=\"yes\">A. baumannii<\/jats:italic> isolates.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods:<\/jats:title>\n            <jats:p>Susceptibility of 50 clinical <jats:italic toggle=\"yes\">A. baumannii<\/jats:italic> isolates to ciprofloxacin, imipenem, ceftazidime, cefepime and gentamicin antimicrobials was evaluated by agar dilution method. Isolates were screened for the evidence of active efflux pump. Isolates were also examined for <jats:italic toggle=\"yes\">adeR-adeS<\/jats:italic> and <jats:italic toggle=\"yes\">adeB<\/jats:italic> efflux genes by polymerase chain reaction (PCR). The <jats:italic toggle=\"yes\">adeR<\/jats:italic> and <jats:italic toggle=\"yes\">adeS<\/jats:italic> regulatory genes were sequenced to detect amino acid substitutions. Expression of <jats:italic toggle=\"yes\">adeB<\/jats:italic> was evaluated by quantitative reverse-transcriptase PCR.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results:<\/jats:title>\n            <jats:p>There were high rates of resistance to ciprofloxacin (88%), ceftazidime (88%), cefepime (74%) and imipenem (72%) and less resistance rate to gentamicin (64%). Phenotypic assay showed involvement of active efflux in decreased susceptibility to ciprofloxacin among 16 isolates. The 12.27-fold increase and 4.25-fold increase were found in <jats:italic toggle=\"yes\">adeB<\/jats:italic> expression in ciprofloxacin-full-resistant and ciprofloxacin-intermediate-resistant isolates, respectively. Several effective mutations, including A91V, A136V, L192R, A94V, G103D and G186V, were detected in some domains of AdeR-AdeS regulators in the overexpressed ciprofloxacin-resistant isolates.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Interpretation &amp; conclusions:<\/jats:title>\n            <jats:p>The results of this study indicated that overexpression of the AdeABC efflux pump was important to reduce susceptibility to ciprofloxacin and cefepime in <jats:italic toggle=\"yes\">A. baumannii<\/jats:italic> that, in turn, could be triggered by alterations in the AdeR-AdeS two-component system. However, gene expression alone does not seem adequate to explain multidrug resistance phenomenon. These results could help plan improved active efflux pump inhibitors.<\/jats:p>\n          <\/jats:sec>","DOI":"10.4103\/ijmr.ijmr_644_16","type":"journal-article","created":{"date-parts":[[2018,7,10]],"date-time":"2018-07-10T09:41:06Z","timestamp":1531215666000},"page":"413-421","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":63,"title":["AdeR-AdeS mutations &amp; overexpression of the AdeABC efflux system in ciprofloxacin-resistant Acinetobacter baumannii clinical isolates"],"prefix":"10.25259","volume":"147","author":[{"given":"Abdolaziz Rastegar","family":"Lari","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abdollah","family":"Ardebili","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ali","family":"Hashemi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"10894","reference":[{"key":"R1-14-20241212","doi-asserted-by":"crossref","first-page":"407","DOI":"10.2217\/fmb.11.23","article-title":"Global spread of drug-resistant Acinetobacter baumannii: Molecular epidemiology and management of antimicrobial resistance","volume":"6","author":"Durante-Mangoni","year":"2011","journal-title":"Future Microbiol"},{"key":"R2-14-20241212","doi-asserted-by":"crossref","first-page":"243","DOI":"10.4161\/viru.19700","article-title":"Acinetobacter baumannii: An emerging opportunistic 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