OBJECTIVETo study the distributional feature and clinical characteristics of infectious diarrhea caused by enterohemorrhagic Escherichia coli O157:H7, and to understand its pollution to the environment and the carrier status among livestock and poultry.

METHODSTo describing the incidence of diarrhea, to isolate and culture the pathogenic bacteria from samples of the patients with diarrhea and livestock or poultry with methods of microbiology, molecular biology and cytology, and then to determine the toxic factors.

RESULTSIn the first epidemic area in Suixian county, Henan province, 35 cases had been found during 17 March and 6 July with 91% of them above age of 60. Of them, 32 were complicated with acute renal failure, including 28 death (death rate: 87.50%). One hundred and seven strains of O157:H7 were isolated from the samples of livestock or poultry and 48 strains were isolated from patients. It was found that 67 strains having toxic gene through microbiological, molecular biological and cytological technologies. Five types of toxic factors were found.

CONCLUSIONThe main factor causing death was the complicated acute renal failure from diarrhea infected by E. coli O157:H7. The pathogen from livestock or poultry with high carrying rate might infect people through polluted water, food flies and close contacts. The outbreak of acute hemolytic uremic syndrome in Suixian county was caused by Enterohemorrhagic Escherichia coli O157:H7 infection.

Acute Kidney Injury ; etiology ; Adult ; Aged ; Aged, 80 and over ; China ; epidemiology ; Diarrhea ; epidemiology ; Disease Outbreaks ; Escherichia coli Infections ; complications ; epidemiology ; Escherichia coli O157 ; isolation & purification ; Female ; Humans ; Male ; Middle Aged

Objective:To investigate the effects of emodin on lipopolysaccharide(LPS)induced pyroptosis of human dental pulp fibro-blasts(HDPFs)by regulating the high mobility group protein B1(HMGB1)/Toll-like receptor 4(TLR4)signaling pathway.Methods:HDPFs were in vitro cultured and grouped into control(normal culture),LPS with low,medium and high dose emodin groups,pcDNA(transfected with pcDNA3.1)and pcDNA-HMGB1 groups(transfected with pcDNA3.1 HMMGB1).qRT-PCR was applied to detect the expression level of HMGB1 mRNA in cells,MTT assay,plate cloning assay and flow cytometry were applied to detect cell prolifera-tion and pyrotosis,respectively.ELISA was applied to detect levels of IL-18,IL-1β and TNF-α in cell supernatant.Western blot was applied to detect the expression of pyroptosis protein Nod-like receptor protein 3(NLRP3),cleaved caspase-1,GSDMD,HMGB1 and TLR4 proteins in the cells.Results:Compared with the control group,the HMGB1 mRNA level,pyrotosis rate,IL-18,IL-1β,TNF-α levels,NLRP3,cleaved Caspase-1,GSDMD,HMGB1,TLR4 protein levels in the LPS group obviously increased,the A490 value and colony formation obviously decreased(P＜0.05).Compared with the LPS group,the above indicators in the low,medium,and high dose emodin groups decreased,the A490 value and colony formation increased,the high-dose emodin group showed more obvious changes(P＜0.05);overexpression of HMGB1 attenuated the inhibitory effects of emodin on LPS-induced pyroptosis and inflammation of HDPFs,and promoted cell proliferation(P＜0.05).Conclusion:Emodin inhibit the activation of NLRP3 inflammasome by inhibiting the HMGB1/TLR4 pathway,thereby reduces LPS induced pyroptosis of HDPFs.