{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T22:33:58Z","timestamp":1787610838356,"version":"build-2736575974"},"reference-count":19,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,5,27]],"date-time":"2025-05-27T00:00:00Z","timestamp":1748304000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"AbbVie"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Objective: To evaluate the antimicrobial susceptibility of Enterobacterales isolated from patients with intra-abdominal infections (IAI) in United States (US) medical centres. Methods: A total of 2036 isolates (1\/patient) were consecutively collected from patients with IAI in 63 US hospitals in 2019\u20132023 and susceptibility tested by broth microdilution. Carbapenem-resistant Enterobacterales (CRE) were screened for carbapenemases by whole genome sequencing. Results: The most common Enterobacterales species were E. coli (47.1%), K. pneumoniae (18.7%), and E. cloacae species complex (9.8%). The most active agents were aztreonam-avibactam (MIC50\/90, \u22640.03\/0.12 mg\/L), ceftazidime-avibactam (MIC50\/90, 0.12\/0.25 mg\/L), and meropenem-vaborbactam (MIC50\/90, 0.03\/0.06 mg\/L) with 99.9% susceptibility. A multidrug-resistant (MDR) phenotype (nonsusceptibility to \u22653 classes) was observed in 21.4% of Enterobacterales (n = 436). Piperacillin-tazobactam was active against 87.2% of Enterobacterales overall and 50.2% of MDR isolates, and meropenem was active against 99.2% of Enterobacterales and 96.1% of MDR isolates. Only 51.6% of Enterobacterales were susceptible to ampicillin-sulbactam. An acquired broad-spectrum \u03b2-lactamase gene was identified in 207 (10.2%) isolates and included extended-spectrum \u03b2-lactamases (ESBL; n = 182), transferable AmpC (n = 24) and carbapenemases (n = 9). Eight isolates produced two \u03b2-lactamase classes. Conclusions: Aztreonam-avibactam, ceftazidime-avibactam, and meropenem-vaborbactam exhibited almost complete activity (99.9% susceptibility) against Enterobacterales causing IAI in US hospitals. In contrast, piperacillin-tazobactam exhibited limited activity against these organisms, especially those with a MDR phenotype.<\/jats:p>","DOI":"10.3390\/antibiotics14060544","type":"journal-article","created":{"date-parts":[[2025,5,28]],"date-time":"2025-05-28T03:52:08Z","timestamp":1748404328000},"page":"544","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Activity of \u03b2-Lactamase Inhibitor Combinations Against Enterobacterales Isolated from Patients with Intra-Abdominal Infection from United States Medical Centres (2019\u20132023)"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7022-6644","authenticated-orcid":false,"given":"Helio S.","family":"Sader","sequence":"first","affiliation":[{"name":"JMI Laboratories, Element Iowa City, North Liberty, IA 52317, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John H.","family":"Kimbrough","sequence":"additional","affiliation":[{"name":"JMI Laboratories, Element Iowa City, North Liberty, IA 52317, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marisa L.","family":"Winkler","sequence":"additional","affiliation":[{"name":"JMI Laboratories, Element Iowa City, North Liberty, IA 52317, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rodrigo E.","family":"Mendes","sequence":"additional","affiliation":[{"name":"JMI Laboratories, Element Iowa City, North Liberty, IA 52317, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariana","family":"Castanheira","sequence":"additional","affiliation":[{"name":"JMI Laboratories, Element Iowa City, North Liberty, IA 52317, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"S81","DOI":"10.1093\/cid\/ciae346","article-title":"2024 Clinical Practice Guideline Update by the Infectious Diseases Society of America on Complicated Intra-abdominal Infections: Risk Assessment, Diagnostic Imaging, and Microbiological Evaluation in Adults, Children, and Pregnant People","volume":"79","author":"Bonomo","year":"2024","journal-title":"Clin. Infect. Dis."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1089\/sur.2024.137","article-title":"The Surgical Infection Society Guidelines on the Management of Intra-Abdominal Infection: 2024 Update","volume":"25","author":"Huston","year":"2024","journal-title":"Surg. Infect."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/j.cmi.2021.11.025","article-title":"European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidelines for the treatment of infections caused by multidrug-resistant Gram-negative bacilli (endorsed by European society of intensive care medicine)","volume":"28","author":"Paul","year":"2022","journal-title":"J. Clin. Microbiol. Infect."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Chong, Y.P., Bae, I.G., Lee, S.R., Chung, J.W., Jun, J.B., Choo, E.J., Moon, S.Y., Lee, M.S., Jeon, M.H., and Song, E.H. (2015). Clinical and economic consequences of failure of initial antibiotic therapy for patients with community-onset complicated intra-abdominal infections. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0119956"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Kong, W., Deng, T., Li, S., Shu, Y., and Wu, Y. (2023). Efficacy, safety, and tolerability of antimicrobial agents for complicated intra-abdominal infection: A systematic review and network meta-analysis. BMC Infect. Dis., 23.","DOI":"10.1186\/s12879-023-08209-9"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.jcrc.2018.12.001","article-title":"Risk factors for mortality and cost implications of complicated intra-abdominal infections in critically ill patients","volume":"50","author":"Carelli","year":"2019","journal-title":"J. Crit. Care"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Tamma, P.D., Heil, E.L., Justo, J.A., Mathers, A.J., Satlin, M.J., and Bonomo, R.A. (2024). Infectious Diseases Society of America 2024 Guidance on the Treatment of Antimicrobial-Resistant Gram-Negative Infections. Clin. Infect. Dis., ciae403.","DOI":"10.1093\/cid\/ciae403"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"ofaf005","DOI":"10.1093\/ofid\/ofaf005","article-title":"Frequency, Antimicrobial Susceptibility, and Molecular Characterization of Carbapenem-Resistant Enterobacterales Stratified by United States Census Divisions: Results From the INFORM Program (2018\u20132022)","volume":"12","author":"Sader","year":"2025","journal-title":"Open Forum Infect. Dis."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1016\/S1473-3099(24)00499-7","article-title":"Aztreonam-avibactam versus meropenem for the treatment of serious infections caused by Gram-negative bacteria (REVISIT): A descriptive, multinational, open-label, phase 3, randomised trial","volume":"25","author":"Carmeli","year":"2025","journal-title":"Lancet Infect. Dis."},{"key":"ref_10","unstructured":"(2025). Performance Standards for Antimicrobial Susceptability Testing; 35 the Informational Supplement (Standard No. CLSI M100Ed35)."},{"key":"ref_11","unstructured":"EUCAST (2025). Breakpoint Tables for Interpretation of MICs and Zone Diameters Version 15.0, European Committee on Antimicro-Bial Susceptibility Testing."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1089\/sur.2016.036","article-title":"Ceftazidime-Avibactam Activity against Aerobic Gram Negative Organisms Isolated from Intra-Abdominal Infections in United States Hospitals, 2012\u20132014","volume":"17","author":"Sader","year":"2016","journal-title":"Surg. Infect."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e0025622","DOI":"10.1128\/aac.00256-22","article-title":"New Perspectives on Antimicrobial Agents: Imipenem-Relebactam","volume":"66","author":"Lodise","year":"2022","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"dlab092","DOI":"10.1093\/jacamr\/dlab092","article-title":"Extended-spectrum \u03b2-lactamases: An update on their characteristics, epidemiology and detection","volume":"3","author":"Castanheira","year":"2021","journal-title":"JAC Antimicrob. Resist."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"ofad038","DOI":"10.1093\/ofid\/ofad038","article-title":"Trends of beta-lactamase occurrence among Escherichia coli and Klebsiella pneumoniae in United States hospitals during a 5-year period and activity of antimicrobial agents against isolates stratified by beta-lactamase type","volume":"10","author":"Castanheira","year":"2023","journal-title":"Open Forum Infect. Dis."},{"key":"ref_16","unstructured":"(2024). Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically (Standard No. CLSI M07Ed12)."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"455","DOI":"10.1089\/cmb.2012.0021","article-title":"SPAdes: A new genome assembly algorithm and its applications to single-cell sequencing","volume":"19","author":"Bankevich","year":"2012","journal-title":"J. Comput. Biol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"S69","DOI":"10.1093\/ofid\/ofz004","article-title":"Application of next-generation sequencing for characterization of surveillance and clinical trial isolates: Analysis of the distribution of beta-lactamase resistance genes and lineage background in the United States","volume":"6","author":"Mendes","year":"2019","journal-title":"Open Forum Infect. Dis."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2833","DOI":"10.1093\/jac\/dkab279","article-title":"Investigation of mechanisms responsible for decreased susceptibility of aztreonam\/avibactam activity in clinical isolates of Enterobacterales collected in Europe, Asia and Latin America in 2019","volume":"76","author":"Mendes","year":"2021","journal-title":"J. Antimicrob. Chemother."}],"container-title":["Antibiotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6382\/14\/6\/544\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:41:01Z","timestamp":1760031661000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6382\/14\/6\/544"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,5,27]]},"references-count":19,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["antibiotics14060544"],"URL":"https:\/\/doi.org\/10.3390\/antibiotics14060544","relation":{},"ISSN":["2079-6382"],"issn-type":[{"value":"2079-6382","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,5,27]]}}}