TITLE:
Detection and Characterization of β-Lactamase Encoding Genes in Carbapenem Non-Susceptible Gram-Negative Bacteria and Susceptibility of Isolates to Ceftazidime-Avibactam at a New York City Community Hospital
AUTHORS:
Carl Urban, Rita Colon-Urban, Vincent J. LaBombardi, Noriel Mariano, Nishant Prasad, Geeti Dhillon, Marina Guralnik, Sorana Segal-Maurer
KEYWORDS:
Carbapenem Non-Susceptible, Check-MDR CT103 XL Microarray, β-Lactamase Detection, Resistance Mechanisms, Ceftazidime-Avibactam
JOURNAL NAME:
Open Journal of Medical Microbiology,
Vol.6 No.4,
December
19,
2016
ABSTRACT: A surveillance study was undertaken to identify
prominent β-lactamase encoding genes
in 131 carbapenem
non-susceptible gram-negative clinical isolates at a New York City community hospital. KPC carbapenemases were
detected in 89% of Enterobacteriaceae as well as additional TEM, SHV, and CTX-M
class A enzymes. OXA-23 and OXA-24 were the prevalent class D carbapenemases
identified in Acinetobacter species.
One OXA-23 in M. morganii and one
OXA-48 in K. pneumoniae were also
identified. Among class C β-lactamases
CMY, ACT/MIR, DHA, and FOX were detected. The in vitro activity of ceftazidime-avibactam by E-test methodology
was tested with minimal inhibitory concentrations (MIC) of ≤3 μg/ml for 97.8%
of all Enterobacteriaceae, MIC50/90 of 16/>256 μg/ml for carbapenem
non-susceptible Acinetobacter, and
3/6 μg/ml for carbapenem non-susceptible Pseudomonas
aeruginosa. Periodic surveillance of isolates to characterize current and emerging β-lactamase genotypes present in local
isolates may help identify outbreak situations, provide assistance to infection
control and antibiotic stewardship programs, and potentially improve patient
outcomes.