596. Temocillin Might Be a Treatment Option for Infections Due to Multidrug-resistant ESBL- and/or AmpC β-lactamase-producing Enterobacteriaceae
Session: Poster Abstract Session: Novel Antimicrobial Agents
Friday, October 21, 2011
Room: Poster Hall B1

The emergence of infections due to multidrug-resistant Gram-negative pathogens leads to therapeutic difficulties and makes re-examination of ‘forgotten’ compounds necessary. Temocillin has a remarkable β-lactamase stability and is resilient to all classical extended-spectrum TEM, SHV and CTX-M enzymes and to AmpC β-lactamases. Temocillin susceptibility of multidrug-resistant pathogens including ESBL- and/or AmpC and/or carbapenemase-producing Enterobacteriaceae was determined in the present study.


Multiresistance was defined as being susceptible to only one class of first-line antimicrobials (penicillins, cephalosporins, quinolones and carbapenems) and being intermediate or resistant to all classes of second-line antimicrobials (aminoglycosides, tetracycline, co-trimoxazole and tigecycline) or as being intermediate or resistant to first-line antimicrobials (susceptibility to second-line antimicrobials not relevant). 80 multidrug-resistant Gram-negative pathogens with ESBL- and/or AmpC β-lactamases and/or porin mutations were tested by temocillin Etest as described by the manufacturer till now. Evaluation of further isolates is still ongoing. 15 carbapenemase-producing Enterobacteriaceae including KPC, VIM, IMP, Oxa-48 and NDM-1 were included in the study. Further evaluation is also ongoing.


Till now only 19 (24%) of the tested ESBL- and/or AmpC β-lactamases were intermediate or resistant to temocillin. The majority (n=61; 76%) of the isolates were tested susceptible to the antimicrobial. Among the carbapenemase-producing isolates even 3 (20%) were tested susceptible.


The results of our study for in vitro susceptibility testing of temocillin against multidrug-resistant pathogens with ESBL- and/or AmpC β-lactamases and/or porin mutations deliver promising results for this underestimated and ‘forgotten’ compound. The role of temocillin in the treatment of infections due to carbapenemase-producing pathogens requires further investigation. Randomized clinical trials have to be done to compare temocillin activity with carbapenem treatment which is still considered to be the standard treatment for infections due to multidrug-resistant pathogens.

Subject Category: A. Antimicrobial agents and Resistance

Alexander Mischnik, MD, Sabrina Klein, MD and Stefan Zimmermann, MD, Infectious Diseases, University Hospital Heidelberg, Heidelberg, Germany


A. Mischnik, None

S. Klein, None

S. Zimmermann, None

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