Antimicrobial susceptibility of Gram-negative bacteria from intensive care unit and non-intensive care unit patients from United States hospitals (2018-2020).

We evaluated the antimicrobial susceptibility of Gram-negative bacteria recovered from ICU patients in US hospitals and compared them to those from non-ICU patients from the same hospitals during the same period. Overall, 4,680 isolates from ICU patients and 16,263 isolates from non-ICU patients were collected from 70 US medical centers in 2018-2020 and susceptibility tested by the broth microdilution method. Ceftazidime-avibactam and ceftolozane-tazobactam were the most active agents against P. aeruginosa and retained activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) isolates. Minocycline and trimethoprim-sulfamethoxazole were very active against S. maltophilia, whereas most antimicrobial agents exhibited low susceptibility to A. baumannii. Ceftazidime-avibactam and meropenem-vaborbactam were the most active agents against Enterobacterales, and retained potent activity against ESBL producers, carbapenem-resistant Enterobacterales (CRE), MDR, and XDR isolates. In summary, antimicrobial susceptibility was generally lower and the occurrence of ESBL, CRE, MDR, and XDR phenotypes were clearly higher among ICU compared to non-ICU isolates.