Session Type: 1-hour Mini Oral Flash
Session Title: 1-hour Mini Oral Flash
Authors(s): H.S. Sader, C.G. Carvalhaes, L.R. Duncan, S.J.R. Arends, R.E. Mendes, M. Castanheira
Authors Affiliations(s): JMI Laboratories, United States
Background:
Resistance rates in the ICU can be elevated due to antimicrobial selection pressure. Rapid introduction of appropriate antimicrobial therapy is crucial to reduce morbidity and mortality. We evaluated the antimicrobial susceptibility of Gram-negative bacteria (GNB) isolated from ICU patients.
Methods:Clinical isolates were consecutively collected from 73 United States (US) medical centers in 2017-2019 as part of the INFORM Surveillance Program and tested for susceptibility at a central laboratory by reference broth microdilution methods. β-lactamase encoding genes were evaluated for all Enterobacterales with an ESBL-phenotype by whole genome sequencing. Results for isolates causing pneumonia and ventilator-associated pneumonia (VAP) were evaluated.
Results:The most frequent GNB were Pseudomonas aeruginosa (PSA; 23.6% of GNB isolates), Klebsiella pneumoniae (KPN; 17.7%), Escherichia coli (15.5%), and Enterobacter cloacae species complex (ECL; 8.8%). Ceftazidime-avibactam (CAZ-AVI) and ceftolozane-tazobactam (C-T) were the most active agents tested against PSA and retained good activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) PSA (Table). Among PSA isolates nonsusceptible to meropenem, piperacillin-tazobactam, and ceftazidime (n=165), susceptibility to CAZ-AVI and C-T were 67.9% and 71.0%, respectively. PSA from patients with pneumonia and VAP exhibited susceptibility rates similar to the entire PSA collection. CAZ-AVI was very active against Enterobacterales (99.9% susceptible [S]), including ESBL-producing (100.0%S), CRE (95.2%S), MDR (98.7%S), and XDR (96.7%S) isolates. C-T, meropenem, and most comparators showed limited activity against these resistant subsets. Sixty-four of 83 CRE isolates (77.1%) produced a carbapenemase. KPC was the most common carbapenemase type (59/64; 92.2%). CAZ-AVI was active against 95.3% of carbapenemase-producer and 94.7% of non-carbapenemase-producer CREs. The most common ESBLs among non-CPE-producer Enterobacterales (n=381) were CTX-M-type (n=331; 86.9%), OXA-1/30 (n=164; 43.0%), and SHV-type (n=52; 13.6%). The highest CAZ-AVI MIC value among Haemophilus influenzae (n=215; 3.3% of GNB) was 0.25 mg/L. Against Acinetobacter baumannii (n=207), the most active agent was amikacin (81.6%S) and 58.0% of isolates were inhibited at ≤8 mg/L of CAZ-AVI.
Conclusions:CAZ-AVI demonstrated potent activity against a large collection of GNB isolates from ICU patients and retained activity against clinically relevant resistant subsets for which treatment options are limited, such as MDR PSA and CRE.
Keyword(s): Pseudomonas aeruginosa, ESBL, CRECOI Institutional Grants: Yes
COI Other: This study was performed by JMI Laboratories and supported by AbbVie (formerly Allergan), which included funding for services related to preparing this abstract.
Session Type: 1-hour Mini Oral Flash
Session Title: 1-hour Mini Oral Flash
Authors(s): H.S. Sader, C.G. Carvalhaes, L.R. Duncan, S.J.R. Arends, R.E. Mendes, M. Castanheira
Authors Affiliations(s): JMI Laboratories, United States
Background:
Resistance rates in the ICU can be elevated due to antimicrobial selection pressure. Rapid introduction of appropriate antimicrobial therapy is crucial to reduce morbidity and mortality. We evaluated the antimicrobial susceptibility of Gram-negative bacteria (GNB) isolated from ICU patients.
Methods:Clinical isolates were consecutively collected from 73 United States (US) medical centers in 2017-2019 as part of the INFORM Surveillance Program and tested for susceptibility at a central laboratory by reference broth microdilution methods. β-lactamase encoding genes were evaluated for all Enterobacterales with an ESBL-phenotype by whole genome sequencing. Results for isolates causing pneumonia and ventilator-associated pneumonia (VAP) were evaluated.
Results:The most frequent GNB were Pseudomonas aeruginosa (PSA; 23.6% of GNB isolates), Klebsiella pneumoniae (KPN; 17.7%), Escherichia coli (15.5%), and Enterobacter cloacae species complex (ECL; 8.8%). Ceftazidime-avibactam (CAZ-AVI) and ceftolozane-tazobactam (C-T) were the most active agents tested against PSA and retained good activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) PSA (Table). Among PSA isolates nonsusceptible to meropenem, piperacillin-tazobactam, and ceftazidime (n=165), susceptibility to CAZ-AVI and C-T were 67.9% and 71.0%, respectively. PSA from patients with pneumonia and VAP exhibited susceptibility rates similar to the entire PSA collection. CAZ-AVI was very active against Enterobacterales (99.9% susceptible [S]), including ESBL-producing (100.0%S), CRE (95.2%S), MDR (98.7%S), and XDR (96.7%S) isolates. C-T, meropenem, and most comparators showed limited activity against these resistant subsets. Sixty-four of 83 CRE isolates (77.1%) produced a carbapenemase. KPC was the most common carbapenemase type (59/64; 92.2%). CAZ-AVI was active against 95.3% of carbapenemase-producer and 94.7% of non-carbapenemase-producer CREs. The most common ESBLs among non-CPE-producer Enterobacterales (n=381) were CTX-M-type (n=331; 86.9%), OXA-1/30 (n=164; 43.0%), and SHV-type (n=52; 13.6%). The highest CAZ-AVI MIC value among Haemophilus influenzae (n=215; 3.3% of GNB) was 0.25 mg/L. Against Acinetobacter baumannii (n=207), the most active agent was amikacin (81.6%S) and 58.0% of isolates were inhibited at ≤8 mg/L of CAZ-AVI.
Conclusions:CAZ-AVI demonstrated potent activity against a large collection of GNB isolates from ICU patients and retained activity against clinically relevant resistant subsets for which treatment options are limited, such as MDR PSA and CRE.
Keyword(s): Pseudomonas aeruginosa, ESBL, CRECOI Institutional Grants: Yes
COI Other: This study was performed by JMI Laboratories and supported by AbbVie (formerly Allergan), which included funding for services related to preparing this abstract.