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The Scientific World Journal
Volume 2014, Article ID 593546, 14 pages
http://dx.doi.org/10.1155/2014/593546
Research Article

Characterization of the algC Gene Expression Pattern in the Multidrug Resistant Acinetobacter baumannii AIIMS 7 and Correlation with Biofilm Development on Abiotic Surface

1Institute of Bioinformatics and Biotechnology, University of Pune, Pune 411 007, India
2Ispat General Hospital, SAIL, Rourkela 769 005, India
3Department of Biotechnology, Shivaji University, Kolhapur 416 004, India
4Structural Bioinformatics Unit, Department of Biochemistry, Shivaji University, Kolhapur 416 004, India
5Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431 001, India

Received 30 July 2014; Revised 10 November 2014; Accepted 10 November 2014; Published 3 December 2014

Academic Editor: Jose Correa Basurto

Copyright © 2014 Praveen K. Sahu 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.

Abstract

Relative quantification of algC gene expression was evaluated in the multidrug resistant strain Acinetobacter baumannii AIIMS 7 biofilm (3 to 96 h, on polystyrene surface) compared to the planktonic counterparts. Comparison revealed differential algC expression pattern with maximum 81.59-fold increase in biofilm cells versus 3.24-fold in planktonic cells (). Expression levels strongly correlated with specific biofilm stages (scale of 3 to 96 h), coinciding maximum at initial surface attachment stage (9 h) and biofilm maturation stage (48 h). Cloning, heterologous expression, and bioinformatics analyses indicated algC gene product as the bifunctional enzyme phosphomannomutase/phosphoglucomutase (PMM/PGM) of ∼53 kDa size, which augmented biofilms significantly in algC clones compared to controls (lacking algC gene), further localized by scanning electron microscopy. Moreover, molecular dynamics analysis on the three-dimensional structure of PMM/PGM (simulated up to 10 ns) revealed enzyme structure as stable and similar to that in P. aeruginosa (synthesis of alginate and lipopolysaccharide core) and involved in constitution of biofilm EPS (extracellular polymeric substances). Our observation on differential expression pattern of algC having strong correlation with important biofilm stages, scanning electron-microscopic evidence of biofilm augmentation taken together with predictive enzyme functions via molecular dynamic (MD) simulation, proposes a new basis of A. baumannii AIIMS 7 biofilm development on inanimate surfaces.