Antibacterial Susceptibility of Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae and Escherichia coli
J. Bishara, G. Livne, S. Ashkenazi, I. Levy, S. Pitlik, O. Ofir, B. Lev and Z. Samra
Click on the icon on the upper right hand side for the article by Jihad Bishara, MD, Gilat Livne, MD, Shai Ashkenazi, MD, Itzhak Levy, MD, Silvio Pitlik, MD, Orit Ofir, MSc, Bruria Lev, MSc and Zmira Samra, PhD.
IMAJ 2005: 7: May: 298-301
Abstract
Background: The prevalence of extended-spectrum β-lactamase-producing organisms and their antimicrobial resistance patterns may vary between geographic areas.
Objectives: To evaluate the prevalence and susceptibility of ESBL[1]-producing organisms among Klebsiella pneumoniae and Escherichia coli isolated from adult and pediatric patients in two Israeli hospitals.
Methods: ESBL production was tested according to recommendations of the Clinical and Laboratory Standards Institute, using ceftazidime (30 μg) and a combination of ceftazidime/clavulanate (30/10 μg) disks with a ≥5 mm difference indicating positivity. Antibiotic susceptibilities were determined by the disk diffusion method according to CLSI[2] standards. Minimum inhibitory concentrations were determined by the E-test.
Results: The prevalence of ESBL-producing organisms was significantly higher among K. pneumoniae than E. coli isolates – 32% (241/765) vs. 10% (57/547) respectively (P < 0.001), and more frequently isolated from adults than children (odds ratio 2.27 for K. pneumoniae and 12.94 for E. coli). Resistance rates for amoxicillin/clavulanate, piperacillin-tazobactam, amikacin, and ciprofloxacin among the ESBL-producing K. pneumoniae and E. coli isolates were 95%, 82%, 49% and 77% for K. pneumoniae, and 77%, 35%, 25% and 100% for E. coli. Two (0.8%) ESBL-producing and 4 (0.7%) ESBL-negative K. pneumoniae isolates showed intermediate susceptibility (MIC[3] 6 μg/ml) to meropenem. All isolates were sensitive to ertapenem and colistin.
Conclusion: ESBL production among K. pneumoniae and E. coli is more prevalent in the adult population than the pediatric population and is associated with multidrug resistance.
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