{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T18:12:59Z","timestamp":1784657579585,"version":"3.55.0"},"reference-count":19,"publisher":"SAGE Publications","issue":"4","license":[{"start":{"date-parts":[[2020,4,1]],"date-time":"2020-04-01T00:00:00Z","timestamp":1585699200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Microbial Drug Resistance"],"published-print":{"date-parts":[[2020,4]]},"abstract":"\n Polymyxins (colistin and polymyxin B) have recently regained significant importance as last-line drugs to treat infectious diseases due to multidrug-resistant gram-negative bacteria. However, resistance to polymyxins has increased, and the recognition of plasmid-mediated resistance (by the\n mcr<\/jats:italic>\n gene) has led to an epidemiological concern. We aimed to evaluate the reduction of the polymyxin B minimum inhibitory concentration (MIC) in the presence of EDTA or dipicolinic acid (DPA) by using the broth microdilution (BMD) method for phenotypic screening of acquired polymyxin resistance mediated by the\n mcr<\/jats:italic>\n -1 gene. Overall, 94\n Enterobacterales<\/jats:italic>\n (48 polymyxin-resistant and 46 polymyxin-susceptible) were evaluated: 47\n mcr<\/jats:italic>\n -1 positive (36\n Escherichia coli<\/jats:italic>\n , 2\n Klebsiella pneumoniae<\/jats:italic>\n , and 9\n Salmonella<\/jats:italic>\n spp.) and 47\n mcr<\/jats:italic>\n -1 negative (3\n E. coli<\/jats:italic>\n and 44\n K. pneumoniae\u2014<\/jats:italic>\n 27 isolates with MIC from \u22640.125 to 8\u2009\u03bcg\/mL and 20 isolates with MIC from 16 to 64\u2009\u03bcg\/mL). Results were categorized as positive when the chelator decreased the original BMD MIC by \u22652 logs. The majority (95.7%) of\n mcr<\/jats:italic>\n -1 positive isolates displayed at least a 3 log dilution decrease in the MIC of polymyxin B with EDTA or DPA. The EDTA-based BMD assay detected 45\n mcr<\/jats:italic>\n -1-positive isolates, with only one false-positive among the\n mcr<\/jats:italic>\n -1-negative isolates (sensitivity [SN], 95.7%; specificity [SP], 97.9%), whereas the DPA-based BMD assay detected 44\n mcr<\/jats:italic>\n -1-positive isolates (SN, 93.6%; SP, 95.7%), with two false-positive results. The accuracy of EDTA- and DPA-based BMD assays were 97% and 95%, respectively. The EDTA- and DPA-based assays were demonstrated to be reliable methods to detect\n mcr<\/jats:italic>\n -1 positive isolates with excellent accuracy.\n <\/jats:p>","DOI":"10.1089\/mdr.2019.0172","type":"journal-article","created":{"date-parts":[[2019,10,8]],"date-time":"2019-10-08T10:43:46Z","timestamp":1570531426000},"page":"329-333","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":5,"title":["Evaluation of EDTA and Dipicolinic Acid in Broth Microdilution with Polymyxin B as a Phenotypic Test to Detect the\n mcr<\/i>\n -1 Gene"],"prefix":"10.1177","volume":"26","author":[{"given":"Priscila Lamb","family":"Wink","sequence":"first","affiliation":[{"name":"LABRESIS\u2014Laborat\u00f3rio de Pesquisa em Resist\u00eancia Bacteriana, Hospital de Cl\u00ednicas de Porto Alegre, Porto Alegre, Brazil."},{"name":"Programa de P\u00f3s-Gradua\u00e7\u00e3o em Ci\u00eancias Farmac\u00eauticas, Faculdade de Farm\u00e1cia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juliana","family":"Caier\u00e3o","sequence":"additional","affiliation":[{"name":"Faculdade de Farm\u00e1cia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aline Gabrielle Alves","family":"Nunes","sequence":"additional","affiliation":[{"name":"Faculdade de Farm\u00e1cia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriela da Silva","family":"Collar","sequence":"additional","affiliation":[{"name":"Faculdade de Farm\u00e1cia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jessica Berghahn","family":"Martins","sequence":"additional","affiliation":[{"name":"Curso de Especializa\u00e7\u00e3o em Microbiologia Cl\u00ednica, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tanise Vendruscolo","family":"Dalmolin","sequence":"additional","affiliation":[{"name":"LABRESIS\u2014Laborat\u00f3rio de Pesquisa em Resist\u00eancia Bacteriana, Hospital de Cl\u00ednicas de Porto Alegre, Porto Alegre, Brazil."},{"name":"Programa de P\u00f3s-Gradua\u00e7\u00e3o em Ci\u00eancias Farmac\u00eauticas, Faculdade de Farm\u00e1cia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcelo","family":"Pilonetto","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Central de Sa\u00fade P\u00fablica do Paran\u00e1, S\u00e3o Jos\u00e9 dos Pinhais, Brazil."},{"name":"Medicina, Escola de Medicina, Pontif\u00edcia Universidade Cat\u00f3lica do Paran\u00e1, Curitiba, Curitiba, Brazil."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Afonso Lu\u00eds","family":"Barth","sequence":"additional","affiliation":[{"name":"LABRESIS\u2014Laborat\u00f3rio de Pesquisa em Resist\u00eancia Bacteriana, Hospital de Cl\u00ednicas de Porto Alegre, Porto Alegre, Brazil."},{"name":"Programa de P\u00f3s-Gradua\u00e7\u00e3o em Ci\u00eancias Farmac\u00eauticas, Faculdade de Farm\u00e1cia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil."},{"name":"Faculdade de Farm\u00e1cia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2020,4,10]]},"reference":[{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1086\/429323"},{"key":"e_1_3_4_3_2","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1016\/j.idc.2016.02.005","article-title":"Agents of last resort: polymyxin resistance","volume":"30","author":"Kaye K.S.","year":"2016","unstructured":"Kaye K.S., , Pogue J.M, , Tran T.B, , Nation R.L, , and Li J.. 2016. Agents of last resort: polymyxin resistance. Infect. Dis. Clin. North Am. 30:391\u2013414.","journal-title":"Infect. Dis. Clin. North Am"},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.00064-16"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2014.00643"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(15)00424-7"},{"key":"e_1_3_4_7_2","first-page":"22","volume":"35","author":"Humphries, R.M","year":"2015","unstructured":"Humphries, R.M. 2015. Susceptibility testing of the polymyxins: where are we now? Pharmacotherapy, 35:22\u201327.","journal-title":"Susceptibility testing of the polymyxins: where are we now? 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Rapid detection of polymyxin resistance in Enterobacteriaceae. Emerg. Infect. Dis. 22:1038\u20131043.","journal-title":"Emerg. Infect. Dis"},{"key":"e_1_3_4_10_2","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.cmi.2017.06.002","article-title":"Comparison of methods for detection of plasmid-mediated and chromosomally encoded colistin resistance in Enterobacteriaceae","volume":"24","author":"Jayol A.","year":"2018","unstructured":"Jayol A., , Nordmann P., , Lehours P., , Poirel L., , and Dubois V.. 2018. Comparison of methods for detection of plasmid-mediated and chromosomally encoded colistin resistance in Enterobacteriaceae. Clin. Microbiol. Infect. 24:175\u2013179.","journal-title":"Clin. Microbiol. 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