Objective To analyze the distribution and pulsed-field gel electrophoresis (PFGE)of pathogenic bacteria causing infectious diarrhea in a district of Beijing from 2011 to 2013,and provide basis for tracing infection sources.Methods A total of 1 179 stool specimens of infectious diarrhea from patients in a diarrhea outpatient department from January 2011 to December 2013 were collected,all isolated pathogens were identified by serotyping and PFGE analysis.Results 330 enteric pathogens were isolated from 1 179 specimens,the top 4 bacteria were Shi-gella spp .(28.18%,n=93),Salmonella spp .(20.91 %,n=69),Vibrio parahaemolyticus (13.33%,n =44),and diarrheagenic Escherichia coli (3.33%,n = 11 ).18 Shigella sonnei isolates were identified as 8 PFGE patterns, clustering similarity was close to 88%;69 Salmonella spp .strains belonged to 18 serotypes and 41 PFGE patterns, Salmonella senftenberg and Salmonella enteritidis had dominant patterns;no dominant PFGE patterns were obviously identified among 23 strains ofVibrio parahaemolyticus .Conclusion The serotypes and PFGE patterns of pathogenic bacteria in infectious diarrhea in past three years showed a wide distribution characteristics,the dominant PFGE patterns of Salmonella spp .and Shigella spp .need to be paid more attention,and outbreak of infectious diarrhea caused by Salmonella spp .and Shigella spp .should be alerted.

Mimecan belongs to a family of leucine-rich proteoglycans that are secreted into the extracellular matrix. In order to investigate the function of mimecan, the coding region of mimecan was amplifed from a human pituitary cDNA by PCR and the recombinant prokaryotic expression vector pGEX-M was constructed. The vactor was transformed into E.coli BL21(DE3)and the GST-M fusion protein of 38 Kd was ecpressed in the bacteria under induction of IPTG. After purification, the fusion protein was infucted into New Zealand rabbits to prepare polyclonal antibody. The antibody was tested by Western blotting for their specificity and sensitivity. Using the antibody it was found the mimecan was expressed highly in certain types of human pituitary tumor tissues. These results make it possible for studying the biological function of mimecan.