{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T08:59:23Z","timestamp":1790067563807,"version":"4.0.1"},"reference-count":14,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"6","license":[{"start":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:00:00Z","timestamp":1787616000000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2026,11]]},"abstract":"Abstract<\/jats:title>\n \n Introduction:<\/jats:title>\n \n Emergence of carbapenem-resistant Gram-negative pathogens poses a significant challenge due to limited treatment options and higher mortality rates associated with infections caused by these pathogens. A combination of aztreonam (AT) and ceftazidime\/avibactam (CZA-AVI) is an effective combination with synergistic activity against metallo-beta-lactamase (MBL) producing carbapenem resistant\n Enterobacterales<\/jats:italic>\n (CRE). This study aimed to compare the disc elution and disc-E strip method for assessing the synergistic effect of aztreonam and ceftazidime\/avibactam against MBL-producing CRE, with the potential to inform effective treatment strategies.\n <\/jats:p>\n <\/jats:sec>\n \n Methodology:<\/jats:title>\n \n A total of 55 samples were isolated from clinical samples, in which 65.45%\n Klebsiella pneumoniae<\/jats:italic>\n and 27.27%\n Escherichia coli<\/jats:italic>\n were resistant to the tested carbapenem (meropenem) by the Vitek-2 compact system. Molecular detection of the New Delhi MBL, Verona integron-encoded MBL, or imipenemase gene was performed by conventional multiplex polymerase chain reaction. The synergy between aztreonam (30 \u00b5g) and ceftazidime\u2013avibactam (30\/20 \u00b5g) against MBL-producing CRE was assessed using both the disc elution and the disc-E strip synergy method.\n <\/jats:p>\n <\/jats:sec>\n \n Results:<\/jats:title>\n \n Out of the 55 carbapenem-resistant isolates,\n K. pneumoniae<\/jats:italic>\n (65.4%) being the most common isolate, and urinary tract and bloodstream infections were the primary sources. Neutropenia was a significant risk factor, and high antibiotic resistance was observed, where 63.4% isolates were extensively drug-resistant, whereas 21% were pan-drug resistant, and 15.4% multidrug-resistant. With increasing awareness among clinicians, CZA-AVI + AT is being used. Comparison between disc elution and disc E-test showed 96.4% concordance.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion:<\/jats:title>\n \n This study highlights the need to evaluate ATM and CAZ\/AVI as potential therapeutic alternative for the treatment of infections caused by MBL-producing\n Enterobacterales<\/jats:italic>\n . Hence, synergy testing should be incorporated into routine laboratory practises to save time and give appropriate targeted therapy.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.4103\/aam.aam_495_26","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T13:11:05Z","timestamp":1787577065000},"page":"1478-1483","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":0,"title":["Assessing the Synergistic Potential of Ceftazidime\u2013avibactam and Aztreonam against Metallo-beta-lactamase Producing Enterobacterales by Disc Elution and Disc E Strip \u2013 Synergy Method"],"prefix":"10.4103","volume":"25","author":[{"given":"K. M. Aysha","family":"Linsy","sequence":"first","affiliation":[{"name":"Department of Microbiology, Kasturba Medical College Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna Rajan","family":"Thomas","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Kasturba Medical College Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nivedha","family":"Srinivasan","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Kasturba Medical College Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sevitha","family":"Bhat","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Kasturba Medical College Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Archana","family":"Bhat","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Kasturba Medical College Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2026,8,25]]},"reference":[{"key":"R1-20260922","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1007\/s10096-014-2249-x","article-title":"Molecular characterization of carbapenem-resistant Enterobacteriaceae at a tertiary care laboratory in Mumbai","volume":"34","author":"Kazi","year":"2015","journal-title":"Eur J Clin Microbiol Infect Dis"},{"key":"R2-20260922","doi-asserted-by":"crossref","first-page":"S521","DOI":"10.1093\/cid\/ciz824","article-title":"Epidemiology and diagnostics of carbapenem resistance in gram-negative bacteria","volume":"69","author":"Nordmann","year":"2019","journal-title":"Clin 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hospital","volume":"11","author":"Jayakaran","year":"2019","journal-title":"J Lab Physicians"},{"key":"R12-20260922","doi-asserted-by":"crossref","first-page":"415","DOI":"10.3390\/tropicalmed7120415","article-title":"Treatments and predictors of mortality for carbapenem-resistant gram-negative bacilli infections in Malaysia: A retrospective cohort study","volume":"7","author":"Abubakar","year":"2022","journal-title":"Trop Med Infect Dis"},{"key":"R13-20260922","doi-asserted-by":"crossref","first-page":"4717","DOI":"10.2147\/IDR.S485915","article-title":"Risk factors analysis and prediction model establishment for carbapenem-resistant Enterobacteriaceae colonization: A retrospective cohort study","volume":"17","author":"Guo","year":"2024","journal-title":"Infect Drug Resist"},{"key":"R14-20260922","doi-asserted-by":"crossref","first-page":"e0429923","DOI":"10.1128\/spectrum.04299-23","article-title":"Risk factors and molecular epidemiology of intestinal colonization by carbapenem-resistant gram-negative bacteria in patients with hematological diseases: A multicenter case-control study","volume":"12","author":"Hu","year":"2024","journal-title":"Microbiol Spectr"},{"key":"R15-20260922","doi-asserted-by":"crossref","first-page":"5887","DOI":"10.2147\/IDR.S378579","article-title":"Analysis of in vitro activity of cefiderocol against carbapenem-resistant gram-negative bacilli by broth microdilution and disk diffusion method: A single-center study in Odisha, India","volume":"15","author":"Nayak","year":"2022","journal-title":"Infect Drug Resist"},{"key":"R16-20260922","doi-asserted-by":"crossref","first-page":"1871","DOI":"10.1093\/cid\/ciaa586","article-title":"Efficacy of Ceftazidime-avibactam plus aztreonam in patients with bloodstream infections caused by metallo-\u03b2-lactamase-producing Enterobacterales","volume":"72","author":"Falcone","year":"2021","journal-title":"Clin Infect Dis"},{"key":"R17-20260922","doi-asserted-by":"crossref","first-page":"542","DOI":"10.1093\/jac\/dkx393","article-title":"Ceftazidime\/avibactam alone or in combination with aztreonam against colistin-resistant and carbapenemase-producing Klebsiella pneumoniae","volume":"73","author":"Jayol","year":"2018","journal-title":"J Antimicrob Chemother"}],"container-title":["Annals of African 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