Research Article Outer Membrane Proteome Analysis of Indian Strain of Pasteurella multocida Serotype B:2 by MALDI-TOF/MS Analysis A. Prasannavadhana, 1 Santosh Kumar, 1 Prasad Thomas, 1,2 Laxmi Narayan Sarangi, 1,3 Santosh Kumar Gupta, 1 Adyasha Priyadarshini, 1 Viswas Konasagara Nagaleekar, 1 and Vijendra Pal Singh 1 1 Division of Veterinary Bacteriology and Mycology, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122, India 2 Institute of Bacterial Infections and Zoonoses, Friedrich Loeler Institut, Namburger Straße 96 a, 07743 Jena, Germany 3 Regional Medical Research Centre, Bhubaneswar, Odisha 751023, India Correspondence should be addressed to Santosh Kumar Gupta; vetsantosh@gmail.com Received 31 July 2014; Accepted 21 November 2014; Published 22 December 2014 Academic Editor: Kunio Ohmiya Copyright © 2014 A. Prasannavadhana et al. his 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. Identiication of outer membrane proteins (OMPs) is important to understand the bacteria structure and function, host-pathogen interaction, development of novel vaccine candidates, and diagnostic antigens. But till now the key antigens of P. multocida B:2 isolate causing haemorrhagic septicaemia (HS) in animals are not clearly deined. In this study, P52 strain of P. multocida serotype B:2 was grown in vitro under iron-rich and iron-limited condition. he OMPs were extracted by sarkosyl method followed by SDS- PAGE and the proteins were identiied by MALDI-TOF/MS analysis. In total, 22 proteins were identiied, of which 7 were observed exclusively under iron-limited condition. Most of the high molecular weight proteins (TbpA, HgbA, HgbB, HasR, IroA, and HemR) identiied in this study were involved in iron acquisition. Some hypothetical proteins (HP-KCU-10206, HP and AAUPMB 08244, HP AAUPMB 21592, HP AAUPMB 19766, AAUPMB 11295) were observed for the irst time in this study which could be unique to serotype B:2. Further functional in vivo study of the proteins identiied are required to explore the utility of these proteins in developing diagnostics and vaccine against HS. 1. Introduction Haemorrhagic septicaemia (HS) is an important bacterial disease causing high mortality in cattle and bufaloes. he outbreak of the disease is seen frequently all over India and is responsible for approximately 50–60% of mortality in bovines and other species of animals causing huge economic losses [1]. he causative organism Pasteurella multocida belonging to family Pasteurellaceae is grouped into ive serogroups A, B, D, E, and F, based on their capsular typing and 16 serotypes based on somatic typing [2, 3]. In India, HS is mostly caused by serotype B:2. Outer membrane proteins (OMPs) are important viru- lence factors involved in colonization, invasion, and patho- genesis and many of them have been found to provide pro- tective immunity against P. multocida infection [4–6]. hus, identiication of OMPs is critical to understand the bacterial structure and function, host-pathogen interactions, to iden- tify the protective antigens and to develop novel diagnostics [7]. It is important to have thorough knowledge of the outer membrane proteome of P. multocida which will help in identiication of potential virulence factors, diagnostic antigens, drug targets, and vaccine candidates. Although various workers have used diferent methods to study the OMPs, proteomic studies by using mass spectrometers (LC MS/MS, MALDI-TOF-MS) combined with bioinformatic tools (protein prediction algorithms/sotware) have been found promising. he key antigens of P. multocida B:2 that evoke protective immunity against HS in cattle have still not been well deined, but its OMPs have been found as protective antigens [6, 8, 9]. Boyce et al. [5] have studied the OMPs of P. multocida Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 617034, 10 pages http://dx.doi.org/10.1155/2014/617034