Circulation and etiological characterization of Salmonella enterica serotype in human in Guangdong province, 2007-2016 / 中华流行病学杂志

Objective: To understand the circulation, drug resistance and molecular characteristics of Salmonella1, 4, [5], 12: i:- in human in Guangdong province. Methods:Salmonella1, 4, [5], 12: i:- isolated from diarrhea patients in Guangdong during 2007-2016 were detected for drug resistance, genes and PFGE characteristics. Results: A total of 2 960 strains Salmonella1, 4, [5], 12: i: - were isolated from human diarrhea cases during this period. The positive rates of the isolation increased year by year. The male to female ratio of the infection cases was 1.58∶1, and the infection mainly occurred in infants and young children. Except imipenem, Salmonella1, 4, [5], 12: i: - was resistant to other 17 antibiotics to some extent. The drug resistant rates to ceftazidime, cefotaxime and ciprofloxacin increased from 2011 to 2016. Multi-drug resistance was serious, for example, the multi-drug resistant strains with ASSuT accounted for 70.62% (435/616) and the multi-drug resistant strains with ACSuGSTTm accounted for 27.11% (167/616). The lack of fljA, fljB and hin genes, as well as the retaining of iroB, STM2740, STM2757 genes, resulted in the unable expression of FljBenx gene with 8 different defection profiles. There were 934 different PFGE patterns observed in 2 347 strains, which displayed a relatively large fingerprint polymorphism. The major PFGE pattern was JPXX01. GD0226, which was found in 97 strains, accounting for 4.13% (97/2 347). The PFGE patterns in 168 Salmonella1, 4, [5], 12: i: - strains were consistent with that of Salmonella typhimurium. Conclusions:Salmonella1,4,[5], 12: i: - strains has become the major serotype of Salmonella that cause diarrhea in human in Guangdong. The multi-drug resistance of Salmonella1,4, [5], 12: i: - was serious, and since the defection of fljA, fljB and hin genes, the expression of FljBenx protein failed. The PFGE results were diverse, which displayed polymorphism in inheritance.

Gaseous phase benzene decomposition by non-thermal plasma coupled with nano titania catalyst

Synergistic effect of atmospheric non-thermal plasma generated by dielectric barrier discharge and nano titania photocatalyst for benzene decomposition was tested. The paper indicated the effect of photocatalyst on removal efficiency of benzene, the compare of photocatalyst characteristic in different high temperatures by heat treatment, analysis of by-products. The results showed that the effect of degradation was visible by added photocatalyst in the plasma reactor. When concentration of benzene was 600 mg/m[3] and electric field strength was 10 kV/cm, the removal efficiency of benzene was increased up to 81% without photocatalyst. At the same condition, the removal efficiency was increased to 15% higher with photocatalyst. Nano titania crystal was anatase crystal in 450 °C heat treatment which is best for benzene removal. The plasma reactor packed with photocatalyst shows a better selectivity of carbon dioxide than that without photocatalyst. By-products are mostly carbon dioxide, water and a small quantity of carbon monoxide