Expression ofampC,oprD, andmexA, outer membrane protein analysis and carbapenemases in multidrug resistant clinical isolates ofPseudomonas aeruginosafrom Egypt

2014 ◽  
Vol 26 (6) ◽  
pp. 379-381 ◽  
Author(s):  
Taghrid S. El-Mahdy
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Protein Analysis ◽  
Multidrug Resistant ◽  
Clinical Isolates

scholarly journals Channel Formation by CarO, the Carbapenem Resistance-Associated Outer Membrane Protein of Acinetobacter baumannii

2005 ◽  
Vol 49 (12) ◽  
pp. 4876-4883 ◽  
Author(s):  
Axel Siroy ◽  
Virginie Molle ◽  
Christelle Lemaître-Guillier ◽  
David Vallenet ◽  
Martine Pestel-Caron ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Acinetobacter Baumannii ◽  
Outer Membrane ◽  
Lipid Bilayers ◽  
Outer Membrane Protein ◽  
Carbapenem Resistance ◽  
Protein Band ◽  
Multidrug Resistant ◽  
Channel Formation ◽  
Artificial Lipid Bilayers

ABSTRACT It has been recently shown that resistance to both imipenem and meropenem in multidrug-resistant clinical strains of Acinetobacter baumannii is associated with the loss of a heat-modifiable 25/29-kDa outer membrane protein, called CarO. This study aimed to investigate the channel-forming properties of CarO. Mass spectrometry analyses of this protein band detected another 25-kDa protein (called Omp25), together with CarO. Both proteins presented similar physicochemical parameters (M w and pI). We overproduced and purified the two polypeptides as His-tagged recombinant proteins. Circular dichroism analyses demonstrated that the secondary structure of these proteins was mainly a β-strand conformation with spectra typical of porins. We studied the channel-forming properties of proteins by reconstitution into artificial lipid bilayers. In these conditions, CarO induced ion channels with a conductance value of 110 pS in 1 M KCl, whereas the Omp25 protein did not form any channels, despite its suggested porin function. The pores formed by CarO showed a slight cationic selectivity and no voltage closure. No specific imipenem binding site was found in CarO, and this protein would rather form unspecific monomeric channels.

scholarly journals Comparative Outer Membrane Protein Analysis of High and Low-Invasive Strains of Cronobacter malonaticus

2017 ◽  
Vol 8 ◽  
Author(s):  
Maha A. Aldubyan ◽  
Ibtesam S. Almami ◽  
Fatiha M. Benslimane ◽  
Abdlrhman M. Alsonosi ◽  
Stephen J. Forsythe
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Protein Analysis

scholarly journals β-lactam resistance associated with β-lactamase production and porin alteration in clinical isolates of E. coli and K. pneumoniae

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251594
Author(s):  
Sara M. Khalifa ◽  
Abeer M. Abd El-Aziz ◽  
Ramadan Hassan ◽  
Eman S. Abdelmegeed
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Antimicrobial Treatment ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
University Hospitals ◽  
E Coli ◽  
Serum Killing ◽  
Resistant Strains

β-lactam resistance represents a worldwide problem and a serious challenge for antimicrobial treatment. Hence this research was conducted to recognize several mechanisms mediating β-lactam resistance in E. coli and K. pneumoniae clinical isolates collected from Mansoura University hospitals, Egypt. A total of 80 isolates, 45 E. coli and 35 K. pneumoniae isolates, were collected and their antibiotic susceptibility was determined by the Disc diffusion method followed by phenotypic and genotypic detection of extended-spectrum β-lactamases (ESBLs), AmpC β-lactamase, carbapenemase enzymes. The outer membrane protein porins of all isolates were analyzed and their genes were examined using gene amplification and sequencing. Also, the resistance to complement-mediated serum killing was estimated. A significant percentage of isolates (93.8%) were multidrug resistance and showed an elevated resistance to β-lactam antibiotics. The presence of either ESBL or AmpC enzymes was high among isolates (83.75%). Also, 60% of the isolated strains were carbapenemase producers. The most frequently detected gene of ESBL among all tested isolates was blaCTX-M-15 (86.3%) followed by blaTEM-1 (81.3%) and blaSHV-1 (35%) while the Amp-C gene was present in 83.75%. For carbapenemase-producing isolates, blaNDM1 was the most common (60%) followed by blaVIM-1 (35%) and blaOXA-48 (13.8%). Besides, 73.3% and 40% of E. coli and K. pneumoniae isolates respectively were serum resistant. Outer membrane protein analysis showed that 93.3% of E. coli and 95.7% of K. pneumoniae isolates lost their porins or showed modified porins. Furthermore, sequence analysis of tested porin genes in some isolates revealed the presence of frameshift mutations that produced truncated proteins of smaller size. β-lactam resistance in K. pneumoniae and E. coli isolates in our hospitals is due to a combination of β-lactamase activity and porin loss/alteration. Hence more restrictions should be applied on β-lactams usage to decrease the emergence of resistant strains.

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