Open AccessIn Vitro Susceptibility of Multidrug-Resistant Pseudomonas aeruginosa following Treatment-Emergent Resistance to Ceftolozane-Tazobactam
Author(s) -
Abigail M Rubio,
Ellen G Kline,
Chelsea E Jones,
Liang Chen,
Barry N. Kreiswirth,
M. Hong Nguyen,
Cornelius J. Clancy,
Vaughn S. Cooper,
Ghady Haidar,
Daria Van Tyne,
Ryan K. Shields
Publication year - 2021
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.00084-21
Subject(s) - pseudomonas aeruginosa , tazobactam , microbiology and biotechnology , multiple drug resistance , in vitro , antibiotics , medicine , biology , bacteria , piperacillin , genetics
We compared the in vitro susceptibility of multidrug-resistant Pseudomonas aeruginosa isolates collected before and after treatment-emergent resistance to ceftolozane-tazobactam. Median baseline and postexposure ceftolozane-tazobactam MICs were 2 and 64 μg/ml, respectively. Whole-genome sequencing identified treatment-emergent mutations in ampC among 79% (11/14) of paired isolates. AmpC mutations were associated with cross-resistance to ceftazidime-avibactam but increased susceptibility to piperacillin-tazobactam and imipenem. A total of 81% (12/16) of ceftolozane-tazobactam-resistant isolates with ampC mutations were susceptible to imipenem-relebactam.