Implementation of Chromatic Super CAZ/AVI ® medium for active surveillance of ceftazidime-avibactam resistance: preventing the loop from becoming a spiral

AbstractAcquired 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-producingKlebsiella 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-resistantPseudomonas aeruginosa (n = 41; 28.1%) and carbapenem-resistantA. 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-producingK. 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 andP. aeruginosa, r...
Source: European Journal of Clinical Microbiology and Infectious Diseases - Category: Microbiology Source Type: research