PZ-601 antibacterial activity against well-characterised and fresh Enterobacteriaceae isolates

Abstract number: 1733_1168

Mezzatesta M., Trovato M., Gona F., Santagati M., Campanile F., Stefani S.

Objectives: The in vitro activity of PZ-601, formerly SMP-601, an investigational broad-spectrum carbapenem antibiotic, with potent activity against multi-drug resistant Gram-positive and Gram-negative bacteria, was tested in comparison with other drugs against a group of well-characterised and fresh Enterobacteriaceae isolates.

Methods: The strains included in the study –Escherichia coli, Klebsiella spp. and Enterobacter spp. – were the first 70 Enterobacteriaceae consecutive non-repetitive strains collected from urine and respiratory tract specimens of inpatients and outpatients, isolated from the Policlinico of Catania (I) in a 4-month period, and 23 strains of Enterobacteriaceae previously molecularly characterised for their ESBL production (Luzzaro et al. JCM 2006; 44: 1659). All bacterial isolates were identified at the species level using standard procedures. Antibiotic susceptibility was determined by the standard broth microdilution method (MICs) following CLSI guidelines. The antibiotics used were: PZ-601, imipenem (IMI), ceftriaxone (CRO), cefepime (CPE), piperacillin/tazobactam (PIP/TAZ), levofloxacin (LEVO) and tobramycin (TOBRA). PZ-601 was freshly prepared and maintained in ice.

Results: PZ-601 was highly active against Enterobacteriaceae and ESBL-producing strains with MIC90 of 2 mg/L, comparable with that of imipenem, and superior to that of the other drugs tested. Among ESBL isolates, PZ-601 showed a variable activity against the strains possessing different enzymes, with a MIC90 value of 0.5 mg/L in SHV-containing strains, while it showed MIC90 values of 2 in strains containing CTX-M-type enzyme.

Table 1. MIC90 (mg/L) of PZ-601 and comparators against Enterobacteriaceae

StrainsMIC90 (mg/L)
Enterobacteriaceae (n = 70)212845124322
  ESBLs producers (n = 23)2>128128>51216642
  SHV strains (n = 7)0.564425616641
  CTX-M (n = 16)2>128128>51216641

Conclusion: In this small sample, PZ-601 was highly active against Enterobacteriaceae and ESBL-producing isolates, demonstrating that this carbapenem is a potentially outstanding alternative drug in the empiric treatment of infections caused by these multiresistant microrganisms resistant to cephalosporins, protected penicillins, quinolones, and aminoglycosides.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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