| Campylobacter jejuni(C.jejuni) is a Gram negative microaerophilic bacterium with a curved, helical-shaped, non-spore forming. C.jejuni is an important foodborne disease pathogen which can contaminate food and water. The detectable rate of C.jejuni in developing countries elevates significantly in summer and autumn. C.jejuni is the leading cause of bacterial food-borne diarrhoeal disease throughout the world. Infection with C.jejuni usually results in gastroenteritis, which is self-limited and characterized by abdominal pain, diarrhea and fever. Campylobacter enteritis affects people of all ages. Besides, infection of C.jejuni can also cause other complications like bacteremia, reactive arthritis and meningitis. Guillain-Barr e syndrome (GBS) is the most serious complication after an antecedent infection of C.jejuni. Although the incidence of GBS caused by C.jejuni infection is only0.1%-0.3%, the specific type of C.jejuni infection can result in an significantly increased risk risk of GBS. The infection rate of C.jejuni is85.0%in GBS patients with preceding diarrhea symptom. In China, most GBS cases are related to antecedent C.jejuni infection. Ho TW reported that76%AMAN and42%AIDP patients had serological evidence of recent C.jejuni infection in nortern China. In addition to sporadic GBS cases, C.jejuni infection can also lead to GBS outbreak. In2007and2011, there were2GBS outbreak occurred in Ji Lin, China and the boundary area of the US and Mexico. C.jejuni can cause serious public health problem which bring heavy disease burden to both country and family. Although specific strain type and genemic feature analysis have important value in the diagnosis of GBS caused by C.jejuni infection, GBS oftern appeared after10-14days of infection when the isolation and culture for pathogen become very different. So specific antibody detection is one of the most useful methods for the diagnosis. The main aim of this research is to analyze the genetic diversity of the GBS associated C. jejuni strains and the pathogenesis of the LPSs from C. jejuni.There are many reports about the genetic diversity studies of C.jejuni, but the data from Chinese strains is limited. More and more C.jejuni strains’completed genomes have been sequenced, which makes it possible for us to design high-throughout microarray to carry out comparative analysis of large number of strains at genomic level. According to the results of our previous genomic comparative study, we designed a Combimatrix tiling CustomArrayTM90K chip.1673ORFs of ICDCCJ07001,90ORFs of2plasmids associated with antibiotic resistance and pathogenicity,1783ORFs specific to5strins compared to ICDCCJ07001,16and7gene clusters related to LOS and capusuler(CAP) biosynthesis respectively were represented in the microarray. The present of the ORFs in different strains and the hierarchical clustering analysis were involved in this research for27C.jejuni strains from different sources. The results revealed that the main hypervariable regions located in genes clusters related to LOS and CAP biosynthesis, flagellum modification, Campylobacter Mu-like phage(CMLP) as well as DNA restriction and modification. Nonoe host attribution feature was obtained by hierarchical clustering analysis of ORF distribution among strains from different sources at genomic level. But the composition of LOS biosynthesis genes of GBS-related strains shared common character based on the component analysis.Molecular mimicry accounts for the pathogensis of GBS caused by C.jejuni infection. The gangliosides-like structure of LPS expressed by C.jejuni was considered as the pathogenic factor. The antibody induced by C.jejuni has cross-reactivity with ganglioside on the nerve cell and make lesion of nervous tissue. Well charactered China GBS-related C.jejuni strains and their purified LPS were involved in this research to immunize New Zealand Rabbits. Immunogenicity and antigenicity were analyzed by the detection of specific antibody. The types, titer and kinetic feature of antibody were investigated in this study which will provide a basis for the study of pathogenesis and the development of diagnostic methods and reagents. The results revealed that antibody induced by specific LPS had cross-reactivity with specific ganglioside. The titer of antibody elevated until reached its peak at111days after the1st immunization and then declined. Meanwhile, the antibodies examination results for the GBS patients and control people revealed that the antibodies tests against specific LPS is more reliable for the diagnosis of C. jejuni associated GBS compared to the antibodies tests against the whole cell lysis. |
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