In vitro activity of temocillin against prevalent extended-spectrum beta-lactamases producing Enterobacteriaceae from Belgian intensive care units
Temocillin is a narrow spectrum penicillin with high stability to most β-lactamases including AmpC types and extended-spectrum types (ESBLs). We have analysed its in vitro activity against 652 clinical isolates of Enterobacteriaceae prospectively collected from patients hospitalised in intensive care units at seven different university hospitals in Belgium in 2005. Strains were screened for ESBL production using cefotaxime and ceftazidime screen agar plates and by double ESBL E-tests. The MIC of temocillin and of five comparators was determined using the E-test method. ESBLs were characterized at one central laboratory by isoelectric focusing, PCR for bla genes of the SHV, TEM, and CTX-M families, and by DNA sequencing. The prevalence of ESBL-producing Enterobacteriaceae averaged 11.8% and ranged between 3.0 and 29% in the different hospitals. Meropenem exhibited the highest in vitro activity overall (mode MIC 0.064 μg; MIC90; 0.19 μg/ml), whereas ceftazidime (MIC90 > 256 μg/ml) and ciprofloxacin (MIC90 > 32 μg/ml) scored the worst. Temocillin was active against more than 90% of the isolates including most AmpC- and ESBL-producing isolates. These data indicate the well preserved activity of temocillin over the years against Enterobacteriaceae and show the wide variation in prevalence of ESBL-producing Enterobacteriaceae isolates in Belgian intensive care units. Prospective clinical studies are, however, needed to validate the usefulness of temocillin in the treatment of microbiologically documented infections caused by ESBL- and/or AmpC- overproducing nosocomial Enterobacteriaceae pathogens.
KeywordsCeftazidime Meropenem AmpC Enterobacter Cloaca Temocillin
This study was supported in part by a grant of Eumedica S.A., Brussels, Belgium. We are indebted to S. Carryn for logistic support in the set up of the studies and for providing the required study material.
- 7.Rodriguez-Villalobos H, Malaviolle V, Frankard J, de Mendonça R, Nonhoff C, Struelens MJ (2006) In vitro activity of temocillin against extended spectrum β-lactamase-producing Escherichia coli. J Antimicrob Chemother 57:771–774Google Scholar
- 9.Clinical and Laboratory Standards Institute (2006) Performance standards for antimicrobial susceptibility testing. Approved standard MS100-S16. CLSI, Wayne, PA, USAGoogle Scholar
- 13.De Gheldre Y, Glupczynski Y, Berhin C et al (2004) Epidemiology of Enterobacter aerogenes in Belgium: results of a multicentre survey. In: Abstracts of the 14th European Congress of Clinical Microbiology and Infectious Diseases. Abstract no. P-1122. Clin Microbiol Infect 10(Suppl 3):305 (abstract)Google Scholar
- 16.Ieven M, Delmee M, De Mol P et al (2006) Eight years of Belgian MYSTIC surveillance: 1998–2005. In: Abstracts of the 16th European Congress of Clinical Microbiology and Infectious Diseases, Nice, France, April 2006, Abstract no. P-1387Google Scholar
- 17.Rodriguez-Villalobos H, Malaviolle V, Frankard J et al (2005) Emergence of CTX-M extended-spectrum β-lactamase-producing Escherichia coli in Belgium. Euro-surveillance Weekly 10:63. Available online: (http://www.eurosurveillance.org/ew/2005/050224.asp#3)