Genetic and Antigenic Characterization of Campylobacter Major Membrane Protein

NON-TECHNICAL SUMMARY: Campylobacter jejuni is the leading bacterial cause of human enterocolitis in the United States and presents a major threat to public health. Although this foodborne pathogen has received extensive studies, limited information is known about the genetic characteristics of the major outer membrane protein (MOMP), which is an abundant surface protein essential for the survival of C. jejuni under different environments. Recently, we have characterized the genetic element encoding MOMP from a limited number of C. jejuni strains, and our preliminary studies revealed genetic variation of MOMP among different strains and the possibility of using MOMP sequences for differentiating Campylobacter strains. Based on these findings, we propose to i) examine the genetic repertoire of the MOMP gene in primary Campylobacter isolates and ii) determine the correlation between MOMP sequence polymorphism and the macrorestriction profiles of chromosomal DNA of various Campylobacter strains. The rationale underlying the proposed studies is that, once we have finished the work, we will have a better understanding of whether MOMP sequence polymorphisms reflects the phylogenetic relationship of C. jejuni strains. Consequently, new diagnostic/typing tools for C. jejuni will be developed for rapid identification of this important foodborne pathogen. The developed tools will be useful to trace the sources of infections or outbreaks of foodbone illnesses.
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APPROACH: The genes encoding MOMP will be amplified from various Campylobacter strains. The PCR products will be directly sequenced. The macrorestriction profiles of chromosomal DNA of each strain will be determined using pulsed field gel electrophoresis. The MOMP sequence data and the PFGE patterns will be compared using BioNumerics to determine the correlation between these two types of data.