caa a22 4500 606156348 CHVBK 20210128100608.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s10096-015-2498-3 doi (NATIONALLICENCE)springer-10.1007/s10096-015-2498-3 Activity of temocillin, mecillinam, ceftazidime, and ceftazidime/avibactam against carbapenem-non-susceptible Enterobacteriaceae without carbapenemase production [Elektronische Daten] [N. Mutters, S. Zimmermann, M. Kaase, A. Mischnik] Treatment options for multidrug-resistant Gram-negative infections are scarce and therefore alternatives with a narrow spectrum or new agents are sought. Antimicrobial susceptibility to temocillin, mecillinam, ceftazidime, and ceftazidime/avibactam was determined using Etest and disk diffusion according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodology. A total of 77 carbapenem-nonsusceptible Enterobacteriaceae were studied, including Klebsiella pneumoniae (26%), Escherichia coli (26%), Enterobacter cloacae (26%), and Enterobacter aerogenes (22%). Several phenotypic tests, PCRs followed by sequencing and a microbiological bioassay excluded carbapenemase production in all isolates. Antimicrobial susceptibility rates were low for temocillin (15.6%, minimum inhibitory concentration [MIC] range 2 to >1,024μg/ml), moderate for mecillinam (59.7%, MIC range 0.25 to >256μg/ml), and excellent for ceftazidime/avibactam (100%, zone diameter range 19 to 32mm, median 25mm). 5.2% of the isolates were susceptible to ceftazidime alone (zone diameter range 6 to 32mm). In this study, mecillinam exhibited moderate and ceftazidime/avibactam excellent in vitro antimicrobial activity against carbapenem-nonsusceptible Enterobacteriaceae without carbapenemase production. Ceftazidime/avibactam was able to restore previously reduced susceptibility to ceftazidime in all isolates, thus potentiating its activity. Temocillin only exhibited low in vitro antimicrobial activity against the isolates. Further evaluation of mecillinam and ceftazidime/avibactam with regard to the potential clinical utility against infections caused by these pathogens has to be performed. Springer-Verlag Berlin Heidelberg, 2015 Mutters N. Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120, Heidelberg, Germany aut Zimmermann S. Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120, Heidelberg, Germany aut Kaase M. National Reference Laboratory for Multidrug-Resistant Gram-Negative Bacteria, Department of Medical Microbiology, Ruhr University Bochum, 44801, Bochum, Germany aut Mischnik A. Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120, Heidelberg, Germany aut European Journal of Clinical Microbiology & Infectious Diseases Springer Berlin Heidelberg 34/12(2015-12-01), 2429-2437 0934-9723 34:12<2429 2015 34 10096 https://doi.org/10.1007/s10096-015-2498-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10096-015-2498-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mutters N. Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120, Heidelberg, Germany aut NATIONALLICENCE 700 1- Zimmermann S. Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120, Heidelberg, Germany aut NATIONALLICENCE 700 1- Kaase M. National Reference Laboratory for Multidrug-Resistant Gram-Negative Bacteria, Department of Medical Microbiology, Ruhr University Bochum, 44801, Bochum, Germany aut NATIONALLICENCE 700 1- Mischnik A. Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, 69120, Heidelberg, Germany aut NATIONALLICENCE 773 0- European Journal of Clinical Microbiology & Infectious Diseases Springer Berlin Heidelberg 34/12(2015-12-01), 2429-2437 0934-9723 34:12<2429 2015 34 10096