Abstract
Acquired resistance towards ceftazidime-avibactam (CAZ-AVI) is increasingly reported. Several mechanisms can be involved, but mutations in the Ω-loop region of β-lactamases are the most described. Herein, we assessed the implementation of Chromatic Super CAZ/AVI ® medium in rectal swab surveillance cultures in a geographic area with endemic distribution of KPC-producing Klebsiella pneumoniae. Routine rectal swabs collected from the intensive care unit (ICU) and non-ICU patients were screened for carbapenemase-producing Enterobacterales (CPE), carbapenem-resistant Gram-negative organisms (CR-GN) and CAZ-AVI-resistant organisms by Chromatic CRE and Super CAZ/AVI ® media. Among the 1839 patients screened, 146 (7.9%) were found to be colonized by one or more CPE and/or CR-GN isolates during hospitalization. Overall, among colonized patients the most common bacteria encountered were KPC-producing Enterobacterales (n = 60; 41.1%), carbapenem-resistant Pseudomonas aeruginosa (n = 41; 28.1%) and carbapenem-resistant A. baumannii (n = 34; 23.3%). Among patients colonized by KPC-producing Enterobacterales, thirty-five (58.3%) had CAZ-AVI-resistant strains. A 30.5% rate of faecal carriage of CAZ-AVI-resistant KPC-producing K. pneumoniae, substantially higher than that of susceptible isolates (2.8%), was observed in the COVID-19 ICU. Prevalence of faecal carriage of metallo-β-lactamase-producing organisms was low (0.5% and 0.2% for Enterobacterales and P. aeruginosa, respectively). Chromatic Super CAZ/AVI ® medium showed 100% sensitivity in detecting CPE or CR-GN isolates resistant to CAZ-AVI regardless of both MIC values and carbapenemase content. Specificity was 86.8%. The Chromatic Super CAZ/AVI ® medium might be implemented in rectal swab surveillance cultures for identification of patients carrying CAZ-AVI-resistant organisms to contain the spread of these difficult-to-treat pathogens.
Keywords: Carbapenemase; Carbapenemase detection; Ceftazidime-avibactam resistance; KPC; Outbreak; Surveillance culture.
【저자키워드】 outbreak, Carbapenemase, Carbapenemase detection, Ceftazidime-avibactam resistance, KPC, Surveillance culture., 【초록키워드】 COVID-19, Mutation, intensive care, Hospitalization, intensive care unit, media, ICU, Spread, sensitivity, Culture, Surveillance, implementation, Patient, Pathogens, Bacteria, distribution, Strains, mechanism, CPE, Endemic, Pseudomonas aeruginosa, Klebsiella pneumoniae, acquired resistance, Ceftazidime, Organisms, carbapenem, medium, non-ICU, treat, organism, non-ICU patients, routine, pneumoniae, P. aeruginosa, rectal swab, isolate, susceptible, avibactam, described, collected, involved, reported, screened, increasingly, Acquired, non-ICU patient, 【제목키워드】 Active surveillance, medium, spiral,