Research Article Open Access

Strains of Klebsiella Pneumoniae from Intensive Care Unit Producing CTX-M-15 Extended Spectrum Beta Lactamases

I.R. Iroha1, A.E. Oji1, A.E. Nwakaeze2, T.E. Ayogu3, F.N. Afiukwa1, P.C. Ejikeugwu2 and C.O. Esimone2
  • 1 Ebonyi State University, Nigeria
  • 2 Nnamdi Azikiwe University, Nigeria
  • 3 Institute of Management and Technology, Nigeria


Problem statement: Resistance to third generation cephalosporins due to acquisition and expression of Extended Spectrum β-Lactamase (ESBL) among Gram-negative bacteria is on the increase. Infections involving extended spectrum beta lactamase bacteria are associated with significant morbidity and mortality. Therefore, infections due to ESBL isolates continue to pose a serious challenge to infection management worldwide. Since screening for ESBL is not a common practice in hospitals in Enugu state, this study was undertaken to characterize ESBL genes in K. pneumoniae strains from intensive care unit of the University of Nigeria Teaching Hospital (UNTH) Enugu. Approach: Over a period of 29 months, 57 patients out of 140 receiving treatment in the intensive care unit of the University of Nigeria Teaching Hospitals Enugu were found to be infected with extended-spectrum β-lactamase-producing strains of K. pneumoniae. Species identification of K. pneumoniae strains was performed by Standard Microbiology methods and re-confirmed by MALDI-TOF technology. Phenotypic characterization of Extended Spectrum Beta Lactamase (ESBL) was determined by double disc synergy test and presence of ESBL genes was determined by specific PCR. Results: All ESBL producers were positive in a PCR for blaCTX-M-1 cluster and on sequencing, blaCTXM-15 were found to be present. Genotypic characterization of extended spectrum beta-lactamase producing K. pneumoniae showed that all isolates carried CTX-M-15and SHV genes, 41(71.9%) carried aac (6’)-Ib-cr and blaOXA-1, 19(33%) carried blaTEM. ISEcp1 was found upstream and ORF 477 downstream of blaCTX-M. in all strains. Random amplified polymorphic DNA analysis grouped the strains into two clonal groups- A and B and majority of the strains belong to clonal group A (n = 42). Conclusion: This study shows for the first time the presence of ESBL genes in K. pneumoniae from the ICU of UNTH Enugu and therefore strongly butresses the need for regular screening for ESBL-producing bacteria in clinical specimen in ICU and other wards in Nigerian hospitals.

Current Research in Microbiology
Volume 2 No. 2, 2011, 35-39


Submitted On: 3 February 2012 Published On: 6 March 2012

How to Cite: Iroha, I., Oji, A., Nwakaeze, A., Ayogu, T., Afiukwa, F., Ejikeugwu, P. & Esimone, C. (2011). Strains of Klebsiella Pneumoniae from Intensive Care Unit Producing CTX-M-15 Extended Spectrum Beta Lactamases. Current Research in Microbiology, 2(2), 35-39.

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  • Extended Spectrum β-Lactamase (ESBL)
  • University of Nigeria Teaching Hospital (UNTH)
  • Klebsiella pneumoniae
  • CTX-M-15
  • Intensive care unit