{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T15:10:14Z","timestamp":1790694614673,"version":"4.1.0"},"reference-count":20,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,12,19]],"date-time":"2022-12-19T00:00:00Z","timestamp":1671408000000},"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":"\n Introduction<\/jats:title>\n Infections caused by multidrug-resistant microorganisms have become increasingly common in hospital environments around the world. Gram-negative bacilli stands out among multidrug-resistant bacteria mostly due to the production of carbapenemase enzymes which lead to resistance to most \u03b2-lactam antibiotics including the carbapenems. As a consequence, polymyxins have been reintroduced in the clinic as a last resort to treat infections caused by Gram-negative bacilli resistant to carbapenems. However, the only reliable method to evaluate the susceptibility to polymyxins is the broth microdilution, a laborious and time-consuming technique. Among infections caused by multidrug-resistant bacteria, bloodstream infections are the most worrisome as they can lead to sepsis and septic shock with high mortality rates.<\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n \n Considering the severity of sepsis and the need for a treatment guided for the susceptibility test\n in vitro<\/jats:italic>\n , this work aimed to evaluate a rapid method of polymyxins susceptibility either from colonies grown on agar or directly from positive blood culture bottles using the technology of MALDI-TOF.\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n The method was based on the \u201cdirect on target microdroplets growth assay\u201d (DOT-MGA) originally developed by Idelevich and collaborators with some modifications (Adapted DOT-MGA). Isolates of\n Enterobacterales<\/jats:italic>\n and non-fermenting Gram-negative bacilli resistant to carbapenems were obtained from patients attending a tertiary care hospital in southern Brazil and tested as follows: 122 isolates from colonies grown on agar plates and 117 isolates directly from spiked positive blood cultures.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n The adapted DOT-MGA presented 95 and 100% of categorical agreement considering the colonies grown on agar plates and directly from positive blood cultures, respectively.<\/jats:p>\n <\/jats:sec>\n \n Discussion<\/jats:title>\n The adapted DOT-MGA test proved to be a reliable technique to evaluate the susceptibility to polymyxins to be used in microbiology laboratories with the MALDI-TOF equipment.<\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fmicb.2022.1075650","type":"journal-article","created":{"date-parts":[[2022,12,18]],"date-time":"2022-12-18T23:33:01Z","timestamp":1671406381000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":8,"title":["Evaluation of a rapid susceptibility test of polymyxin B by MALDI-TOF"],"prefix":"10.3389","volume":"13","author":[{"given":"Patricia Orlandi","family":"Barth","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabiana Caroline Zempulski","family":"Volpato","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nat\u00e1lia Kehl","family":"Moreira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Priscila Lamb","family":"Wink","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c2ndrea Celestino","family":"de Souza","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Afonso Lu\u00eds","family":"Barth","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2022,12,19]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"124","DOI":"10.1016\/j.jgar.2017.09.011","article-title":"Polymyxin susceptibility testing, interpretative breakpoints and resistance mechanisms: an update","volume":"12","author":"Bakthavatchalam","year":"2018","journal-title":"J. Glob. Antimicrob. Resist."},{"key":"ref2","first-page":"102721","volume-title":"Braz J Infect Dis.","author":"Barth","year":"2021"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"74","DOI":"10.3389\/fmed.2019.00074","article-title":"Treatment of infections due to MDR gram-negative bacteria","volume":"6","author":"Bassetti","year":"2019","journal-title":"Front. Med."},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1744","DOI":"10.3389\/fmicb.2018.01744","article-title":"Susceptibility testing of bacteria using Maldi-Tof mass spectrometry","volume":"9","author":"Burckhard","year":"2018","journal-title":"Front. Microbiol."},{"key":"ref5","doi-asserted-by":"publisher","first-page":"5071","DOI":"10.1038\/s41598-017-05167-6","article-title":"An allelic variant of the PmrB sensor kinase responsible for colistin resistance in an Escherichia coli strain of clinical origin","volume":"7","author":"Cannatelli","year":"2017","journal-title":"Sci. Rep."},{"key":"ref6","year":"2022"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"e0181419","DOI":"10.1128\/JCM.01814-19","article-title":"Matrix-assisted laser desorption ionization\u2013time of flight mass spectrometry for antimicrobial susceptibility testing","volume":"59","author":"Idelevich","year":"2021","journal-title":"J. Clin. Microbiol."},{"key":"ref8","doi-asserted-by":"publisher","first-page":"1803","DOI":"10.3390\/diagnostics11101803","article-title":"Rapid simultaneous testing of multiple antibiotics by the MALDI-TOF MS direct-on-target microdroplet growth assay","volume":"11","author":"Idelevich","year":"2021","journal-title":"Diagnostics"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"738","DOI":"10.1016\/j.cmi.2017.10.016","article-title":"Rapid detection of antibiotic resistance by MALDI-TOF mass spectrometry using a novel direct-on-target microdroplet growth assay","volume":"24","author":"Idelevich","year":"2018","journal-title":"Clin. Microbiol. Infect."},{"key":"ref10","year":"2006"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"2273","DOI":"10.1128\/JCM.00918-16","article-title":"Rapid detection of Polymyxin-resistant Enterobacteriaceae from blood cultures","volume":"54","author":"Jayol","year":"2016","journal-title":"J. Clin. Microbiol."},{"key":"ref12","doi-asserted-by":"publisher","first-page":"823684","DOI":"10.3389\/fcimb.2022.823684","article-title":"Global threat of Carbapenem-resistant gram-negative bacteria","volume":"12","author":"Jean","year":"2022","journal-title":"Front. Cell. Infect. Microbiol."},{"key":"ref13","doi-asserted-by":"publisher","first-page":"1237","DOI":"10.1378\/chest.09-0087","article-title":"Initiation of inappropriate antimicrobial therapy results in a fivefold reduction of survival in human septic shock","volume":"136","author":"Kumar","year":"2009","journal-title":"Chest"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"1589","DOI":"10.1097\/01.CCM.0000217961.75225.E9","article-title":"Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in human septic shock","volume":"34","author":"Kumar","year":"2006","journal-title":"Crit. Care Med."},{"key":"ref15","doi-asserted-by":"publisher","first-page":"112","DOI":"10.1111\/j.1469-0691.2009.03116.x","article-title":"Acquired carbapenemases in gram-negative bacterial pathogens: detection and surveillance issues","volume":"16","author":"Miriagou","year":"2010","journal-title":"Clin. Microbiol. Infect."},{"key":"ref16","doi-asserted-by":"publisher","first-page":"561","DOI":"10.1016\/S1473-3099(19)30210-5","article-title":"Carbapenem-resistant Enterobacteriaceae: global action required","volume":"19","author":"Perez","year":"2019","journal-title":"Lancet Infect. Dis."},{"key":"ref17","doi-asserted-by":"publisher","first-page":"e00052","DOI":"10.1128\/mSphere.00052-19","article-title":"A cohort study of the impact of Carbapenem-resistant Enterobacteriaceae infections on mortality of patients presenting with sepsis","volume":"10","author":"Sabino","year":"2019","journal-title":"mSphere."},{"key":"ref18","doi-asserted-by":"publisher","first-page":"318","DOI":"10.1016\/S1473-3099(17)30753-3","article-title":"Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis","volume":"18","author":"Tacconelli","year":"2018","journal-title":"Lancet Infect. 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Rev."},{"key":"ref20","year":"2017"}],"container-title":["Frontiers in Microbiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmicb.2022.1075650\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,18]],"date-time":"2022-12-18T23:33:04Z","timestamp":1671406384000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmicb.2022.1075650\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,19]]},"references-count":20,"alternative-id":["10.3389\/fmicb.2022.1075650"],"URL":"https:\/\/doi.org\/10.3389\/fmicb.2022.1075650","relation":{},"ISSN":["1664-302X"],"issn-type":[{"value":"1664-302X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,19]]},"article-number":"1075650"}}