Abstract:

Objective To investigate the infection status of Campylobacter jejuni isolated from diarrhea syndrome and pathogenic monitoring study in Shanghai from 2012 to 2013. To study the immune regulation of human beta-defensin （hBD） in gastrointestinal infection caused by Campylobacter jejuni. Methods Campylobacter jejuni were isolated from diarrhea syndrome and pathogenic monitoring study in Shanghai from 2012 to 2013. Minimal inhibitory concentrations（MIC） to 7 antibiotics [gentamycin（GEN）,tetracycline（TET）,azithromycin（AZI）,erythromycin（ERY）,clindamycin（CLI）,ciprofloxacin（CIP） and nalidixic acid（NAL）] were determined by agar dilution method. Sodium dodecyl sulfate-pulsed-field gel electrophoresis （SDS-PFGE） was carried out for analyzing molecular epidemic trend. Human intestinal epithelial cell line Caco-2 was infected with Campylobacter jejuni. The transcription levels of hBD-1,hBD-2,hBD-3,TLR2 and TLR4 genes were determined by fluorescence quantitation polymerase chain reaction （PCR）,and the expressions of hBD-1,hBD-2,hBD-3,TLR2 and TLR4 were determined by western blotting. Results The isolation rate of Campylobacter jejuni isolated from diarrhea syndrome and pathogenic monitoring study in Shanghai from 2012 to 2013 was 1.6%. The drug resistance rates to TET and NAL were high （95.7% and 97.8%）. There were 9 PFGE patterns. After Campylobacter jejuni infected human intestinal epithelial cell line Caco-2,the transcription levels of hBD-1,hBD-2 and hBD-3 genes reached the highest at 6 h,and the expressions of hBD-1,hBD-2 and hBD-3 reached the highest at 24 h. The transcription level of TLR2 at 24 h was higher than those at 0,6 and 10 h. However,the transcription level of TLR4 reached the highest at 6 h. The expressions of TLR2 and TLR4 were the same as their transcription levels. Conclusions hBD plays a role in defense of Campylobacter jejuni infection.

Key words: Human beta-defensin, Campylobacter jejuni, Immune defense