Genetic characterization of ESBL producing strains of Klebsiella pneumoniae from Tehran hospitals

  • Mohammad Mehdi Feizabadi Tehran University of Medical sciences
  • Samira Mahamadi-Yeganeh Tehran University of Medical Sciences
  • Akbar Mirsalehian Tehran University of Medical Sciences
  • Seyed-Mohammad Mirafshar Tehran University of Medical Sciences
  • Mohaddeseh Mahboobi Barij Pharmaceutical Industry
  • Firoozeh Nili Tehran University of Medical Sciences
  • Davood Yadegarinia Shahid Beheshti University of Medical Sciences
Keywords: Klebsiella pneumoniae, ESBL, PCR, PFGE, FIGE, Iran

Abstract

Introduction: This study was conducted to determine the genetic characterization of extended-spectrum beta-lactamase (ESBL) producing strains of Klebsiella  pneumoniae isolated from Iranian patients in hospitals in Tehran.

Methodology: Antibiotic susceptibility of 104 isolates was determined using the disk diffusion test. The Minimum Inhibitory Concentrations (MICs) of imipenem and meropenem were determined for isolates showing reduced susceptibility to carbapenems. The phenotypic confirmatory test (PCT) was used to screen the isolates for ESBL production. PCR was used to detect blaSHV, blaTEM and blaCTX-M and the amplicons from selected clones were sequenced. Isolates producing ESBLs were analyzed by pulsed-field gel electrophoresis (PFGE).

Results:  One isolate showed resistance to imipenem (MIC = 16 µg/ml). Resistance to amikacin and ciprofloxacin was 44.2% and 25.0%, respectively. ESBL production was detected in 72.1% (n = 75) of isolates. The prevalence of blaSHV, blaTEM and blaCTX-M genes among the isolates was 55.7% (n = 58), 30.7% (n = 32) and 45.2% (n = 47), respectively. The sequencing revealed the amplicons corresponding to bla (TEM-1, TEM-79, SHV-1, SHV-12, SHV-31, CTX-M-15) genes. While the blaCTX-M-15 is the dominant gene among the Iranian isolates, we detected the blaSHV-31 and blaTEM-79 genes for the first time in the country.  PFGE differentiated the 71 ESBL-producing isolates into 62 different genotypes. Clonal dissemination of ESBLs was found in the neonatal intensive care unit and intensive care unit of one hospital.

Conclusion: The findings are evidence of the spread of multi-resistant clones of ESBL producers in Tehran hospitals.

Author Biographies

Mohammad Mehdi Feizabadi, Tehran University of Medical sciences

Department of Microbiology

School of Medicine

Tehran University of Medical Sciences

Samira Mahamadi-Yeganeh, Tehran University of Medical Sciences
Department of Microbiology, School of Medicine
Akbar Mirsalehian, Tehran University of Medical Sciences
Department of Microbiology, School of Medicine
Seyed-Mohammad Mirafshar, Tehran University of Medical Sciences
Department of Microbiology, School of Medicine
Mohaddeseh Mahboobi, Barij Pharmaceutical Industry
Research Laboratory of Microbiology, Barij Pharmaceutical Industry
Firoozeh Nili, Tehran University of Medical Sciences
Department of Pediatrics Disease, School of Medicine, Medical Science, University of Tehran. Tehran, Iran
Davood Yadegarinia, Shahid Beheshti University of Medical Sciences
Infectious Diseases and tropical Medicine Research Center
Published
2010-10-11
How to Cite
1.
Feizabadi MM, Mahamadi-Yeganeh S, Mirsalehian A, Mirafshar S-M, Mahboobi M, Nili F, Yadegarinia D (2010) Genetic characterization of ESBL producing strains of Klebsiella pneumoniae from Tehran hospitals. J Infect Dev Ctries 4:609-615. doi: 10.3855/jidc.1059
Section
Original Articles