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The Scientific World Journal
Volume 2015, Article ID 572128, 13 pages
Research Article

Ultrastructural Changes in Clinical and Microbiota Isolates of Klebsiella pneumoniae Carriers of Genes blaSHV, blaTEM, blaCTX-M, or blaKPC When Subject to β-Lactam Antibiotics

1Setor de Microscopia Eletrônica, Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco (UFPE), Avenida Professor Moraes Rego, s/n, Cidade Universitária, 50670-901 Recife, PE, Brazil
2Departamento de Parasitologia, Centro de Pesquisas Aggeu Magalhães (CPqAM)-Fiocruz, Avenida Professor Moraes Rego, s/n, Caixa Postal 7472, Cidade Universitária, 50670-420 Recife, PE, Brazil
3Departamento de Medicina Tropical, Universidade Federal de Pernambuco (UFPE), Avenida Professor Moraes Rego, s/n, Cidade Universitária, 50670-901 Recife, PE, Brazil
4Departamento de Enfermagem, Faculdade de Ciências Humanas de Olinda (FACHO), Rod PE-015, Jatobá, 53060-775 Olinda, PE, Brazil
5Instituto de Ciências Biológicas, Universidade de Pernambuco (UPE), Rua Arnobio Marques 310, Santo Amaro, 50100-130 Recife, PE, Brazil

Received 5 June 2015; Revised 3 August 2015; Accepted 30 August 2015

Academic Editor: Paolo Ruggerone

Copyright © 2015 Dyana Leal Veras et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The aim of this study was to characterize the ultrastructural effects caused by β-lactam antibiotics in Klebsiella pneumoniae isolates. Three K. pneumoniae clinical isolates were selected for the study with resistance profiles for third-generation cephalosporins, aztreonam, and/or imipenem and with different resistance genes for extended-spectrum β-lactamases (ESBL) or Klebsiella pneumoniae carbapenemase (KPC). Two K. pneumoniae isolates obtained from the microbiota, which were both resistant to amoxicillin and ampicillin, were also analyzed. In accordance with the susceptibility profile, the clinical isolates were subjected to subminimum inhibitory concentrations (sub-MICs) of cefotaxime, ceftazidime, aztreonam, and imipenem and the isolates from the microbiota to ampicillin and amoxicillin, for analysis by means of scanning and transmission electron microscopy. The K. pneumoniae isolates showed different morphological and ultrastructural changes after subjection to β-lactams tested at different concentrations, such as cell filamentation, loss of cytoplasmic material, and deformation of dividing septa. Our results demonstrate that K. pneumoniae isolates harboring different genes that encode for β-lactamases show cell alterations when subjected to different β-lactam antibiotics, thus suggesting that they possess residual activity in vitro, despite the phenotypic resistance presented in the isolates analyzed.