AUTHOR=Cui Xiaoyan , Shan Bin , Zhang Xue , Qu Fen , Jia Wei , Huang Bin , Yu Hua , Tang Yi-Wei , Chen Liang , Du Hong 

TITLE=Reduced Ceftazidime-Avibactam Susceptibility in KPC-Producing Klebsiella pneumoniae From Patients Without Ceftazidime-Avibactam Use History – A Multicenter Study in China

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.01365

DOI=10.3389/fmicb.2020.01365

ISSN=1664-302X

ABSTRACT=<p><italic>KPC-producing Klebsiella pneumoniae</italic> (KPC-KP) is the most widely spread carbapenem-resistant <italic>Enterobacteriaceae</italic> (CRE) in China. Avibactam is a novel non-β-lactam β-lactamase inhibitor which is highly active against KPC. Recently, <italic>ceftazidime-avibactam</italic> (CAZ-AVI) was approved for clinical treatment in China. Here we conducted a retrospective study to examine the antimicrobial susceptibility of CAZ-AVI prior to its usage in China, and evaluated the potential to develop resistance in KPC-KP. CAZ-AVI MICs were tested in 347 KPC-KP isolates collected from patients with no prior treatment with this combination from six medical centers in China. Almost all isolates (<italic>n</italic> = 346; 99.7%) were CAZ-AVI-susceptible, with only 12 (3.5%) which showed reduced susceptibility (MIC ≥ 4/4 μg/ml) or resistance. The 12 isolates belong to ST11 and half of them carry virulence genes. In comparison to susceptible isolates, these isolates demonstrated higher <italic>bla</italic><sub><italic>KPC–2</italic></sub> copy numbers and expressions, and demonstrated higher frequency of developing CAZ-AVI resistance.</p>