Microarray-based method for screening of immunogenic proteins from bacteria

Four proteins that have previously been described as immunogenic have successfully been assessed immunogenic abilities with our method. One protein with no known immunogenic behaviour before suggested potential immunogenicity.We incorporated a fusion tag prior to our genes of interest and attached the expressed fusion proteins covalently on microarrays. This enhances the specific binding of the proteins compared to nitrocellulose. Thus, it helps to reduce the number of false positives significantly. It enables us to screen for immunogenic proteins in a shorter time, with more samples and statistical reliability. We validated our method by employing several known genes from Campylobacter jejuni NCTC 11168.The method presented offers a new approach for screening of bacterial expression libraries to illuminate novel proteins with immunogenic features. It could provide a powerful and attractive alternative to existing methods and help to detect and identify vaccine candidates, biomarkers and potential virulence-associated factors with immunogenic behaviour furthering the knowledge of virulence and pathogenicity of studied bacteria.Campylobacter jejuni is one of the principal causing agents of bacterial gastroenteritis in industrialized countries [1]. From January to mid September 2011 52.940 Campylobacter infections have occurred in Germany alone [2]. Although infections predominantly result in mild self-limiting gastroenteritis, in some cases severe post-infection ramifications have been reported with the Guillain-Barré syndrome the major contributor [3]. The main route of infection and transmission is believed to be the incorrect handling and incomplete cooking of poultry. In fact, studies mention 62% of poultry carcasses to be contaminated with Campylobacter after slaughter [4].On account of its widespread occurrence and clinical relevance testing for contamination of meat or the presence of Campylobacter infections in patients is necessary. Although several genomic