Ayesha Khan, Carmila Manuel, Richard Maynard, Romney M Humphries
{"title":"两种梯度扩散试验测定氨曲南和头孢他啶-阿维巴坦联合用药敏感性的评价。","authors":"Ayesha Khan, Carmila Manuel, Richard Maynard, Romney M Humphries","doi":"10.1128/aac.01736-24","DOIUrl":null,"url":null,"abstract":"<p><p>The combination of aztreonam and ceftazidime-avibactam (ATM-CZA) is a last resort regimen against recalcitrant infections caused by metallo-β-lactamase (MBL)-producing organisms. Susceptibility testing is warranted due to emerging resistance to the combination, but there are no widely implemented methods for use in clinical laboratories. Here, we used a cohort of 100 Enterobacterales<i>, Pseudomonas aeruginosa</i>, and <i>Stenotrophomonas maltophilia</i> strains, including 68 MBL producers, to evaluate the performance of two ETEST strip-based synergy testing methods: the side-by-side (SS) method with an ATM ETEST placed next to a CZA ETEST (10 mm apart) and the strip cross (SX) method with a CZA ETEST placed perpendicularly on top of the ATM ETEST (at the 8 µg/mL mark). By reference broth microdilution (BMD), 89.1% (41/46) of the Enterobacterales, 15% (3/20) of the <i>P. aeruginosa</i>, and 97.1% (33/34) of the <i>S. maltophilia</i> isolates tested susceptible to the ATM-CZA combination. The SS method yielded 72% categorical agreement with BMD and 28 major errors (ME, 36.4%). Initial testing with the SX method yielded three ME , of which one was resolved upon repeat testing, yielding a final categorical agreement of 98% with BMD with two ME (2.6%). The SX method also yielded 100% reproducibility across three brands of Mueller Hinton agar (BD, Hardy, Remel). Our study demonstrates that the SX method is accurate, precise, and feasible for clinical laboratories to perform ATM-CZA susceptibility testing to guide use of the combination for treatment of multidrug-resistant gram-negative pathogens.</p>","PeriodicalId":8152,"journal":{"name":"Antimicrobial Agents and Chemotherapy","volume":" ","pages":"e0173624"},"PeriodicalIF":4.1000,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11881574/pdf/","citationCount":"0","resultStr":"{\"title\":\"Evaluation of two gradient diffusion tests to determine susceptibility to aztreonam and ceftazidime-avibactam in combination.\",\"authors\":\"Ayesha Khan, Carmila Manuel, Richard Maynard, Romney M Humphries\",\"doi\":\"10.1128/aac.01736-24\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The combination of aztreonam and ceftazidime-avibactam (ATM-CZA) is a last resort regimen against recalcitrant infections caused by metallo-β-lactamase (MBL)-producing organisms. Susceptibility testing is warranted due to emerging resistance to the combination, but there are no widely implemented methods for use in clinical laboratories. Here, we used a cohort of 100 Enterobacterales<i>, Pseudomonas aeruginosa</i>, and <i>Stenotrophomonas maltophilia</i> strains, including 68 MBL producers, to evaluate the performance of two ETEST strip-based synergy testing methods: the side-by-side (SS) method with an ATM ETEST placed next to a CZA ETEST (10 mm apart) and the strip cross (SX) method with a CZA ETEST placed perpendicularly on top of the ATM ETEST (at the 8 µg/mL mark). By reference broth microdilution (BMD), 89.1% (41/46) of the Enterobacterales, 15% (3/20) of the <i>P. aeruginosa</i>, and 97.1% (33/34) of the <i>S. maltophilia</i> isolates tested susceptible to the ATM-CZA combination. The SS method yielded 72% categorical agreement with BMD and 28 major errors (ME, 36.4%). Initial testing with the SX method yielded three ME , of which one was resolved upon repeat testing, yielding a final categorical agreement of 98% with BMD with two ME (2.6%). The SX method also yielded 100% reproducibility across three brands of Mueller Hinton agar (BD, Hardy, Remel). Our study demonstrates that the SX method is accurate, precise, and feasible for clinical laboratories to perform ATM-CZA susceptibility testing to guide use of the combination for treatment of multidrug-resistant gram-negative pathogens.</p>\",\"PeriodicalId\":8152,\"journal\":{\"name\":\"Antimicrobial Agents and Chemotherapy\",\"volume\":\" \",\"pages\":\"e0173624\"},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2025-03-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11881574/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Antimicrobial Agents and Chemotherapy\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1128/aac.01736-24\",\"RegionNum\":2,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2025/2/7 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q2\",\"JCRName\":\"MICROBIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Antimicrobial Agents and Chemotherapy","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1128/aac.01736-24","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/2/7 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
Evaluation of two gradient diffusion tests to determine susceptibility to aztreonam and ceftazidime-avibactam in combination.
The combination of aztreonam and ceftazidime-avibactam (ATM-CZA) is a last resort regimen against recalcitrant infections caused by metallo-β-lactamase (MBL)-producing organisms. Susceptibility testing is warranted due to emerging resistance to the combination, but there are no widely implemented methods for use in clinical laboratories. Here, we used a cohort of 100 Enterobacterales, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia strains, including 68 MBL producers, to evaluate the performance of two ETEST strip-based synergy testing methods: the side-by-side (SS) method with an ATM ETEST placed next to a CZA ETEST (10 mm apart) and the strip cross (SX) method with a CZA ETEST placed perpendicularly on top of the ATM ETEST (at the 8 µg/mL mark). By reference broth microdilution (BMD), 89.1% (41/46) of the Enterobacterales, 15% (3/20) of the P. aeruginosa, and 97.1% (33/34) of the S. maltophilia isolates tested susceptible to the ATM-CZA combination. The SS method yielded 72% categorical agreement with BMD and 28 major errors (ME, 36.4%). Initial testing with the SX method yielded three ME , of which one was resolved upon repeat testing, yielding a final categorical agreement of 98% with BMD with two ME (2.6%). The SX method also yielded 100% reproducibility across three brands of Mueller Hinton agar (BD, Hardy, Remel). Our study demonstrates that the SX method is accurate, precise, and feasible for clinical laboratories to perform ATM-CZA susceptibility testing to guide use of the combination for treatment of multidrug-resistant gram-negative pathogens.
期刊介绍:
Antimicrobial Agents and Chemotherapy (AAC) features interdisciplinary studies that build our understanding of the underlying mechanisms and therapeutic applications of antimicrobial and antiparasitic agents and chemotherapy.