coli isolates resulted from a combination of different features, including modification of PBP3 protein sequence through specific amino acid insertions and production of CMY-type enzymes, particularly, CMY-42. We showed here that elevated MICs of ATM-AVI among MBL-producing E. The nature of the PBP3 protein sequence and the occurrence of bla CMY genes for susceptibility to ATM-AVI were investigated. coli isolates of various geographical origins for susceptibility to ATM-AVI.
#Aztreonam pbp3 series#
Here, we analyzed a series of 118 clinical MBL-producing E. aeruginosa infections in individuals with cystic fibrosis. Formulations containing aztreonam have been used in the treatment of P. It increases survival in mice with systemic Gram-negative bacterial infections (ED 50s 0.1-24.7 mg/kg). 1, 2 These altered PBP3 proteins conferred reduced susceptibility to a broad range of -lactams, such as ceftazidime, cefepime and aztreonam, due to the decreased accessibility of the. Lactam (g/ml) PBP1a/1b PBP2a PBP2b/H PBP3 PBP4 PBP5 Monobactam Aztreonam 0.01 21 104 99 106 107 104 Penem Faropenem 0. penicillin-binding protein 3 (PBP3 IC 100 0.1 µg/ml for all). Metallo-β-lactamase (MBL)-producing Escherichia coli isolates resistant to the newly developed β-lactam/β-lactamase inhibitor drug combination aztreonam-avibactam (ATM-AVI) have been reported. Unusual PBP3 substitutions, consisting of a four amino acid insertion of YRIN or YRIK after position P333 or TIPY after position Y334, have been reported in Escherichia coli clinical isolates.