ABSTRACT
To detect Salmonella more efficiently and isolate strains more easily, a novel and simple detection method that uses an enrichment assay and two chromogenic reactions on a chromatography membrane was developed. Grade 3 chromatography paper is used as functionalized solid phase support (SPS), which contains specially optimized medium. One reaction for screening is based on the sulfate-reducing capacity of Salmonella. Hydrogen sulfide (H2S) generated by Salmonella reacts with ammonium ferric citrate to produce black colored ferrous sulfide. Another reaction is based on Salmonella C8 esterase that is unique for Enterobacteriaceae except Serratia and interacts with 4-methylumbelliferyl caprylate (MUCAP) to produce fluorescent umbelliferone, which is visible under ultraviolet light. A very low detection limit (10(1) CFU ml(-1)) for Salmonella was achieved on the background of 10(5) CFU ml(-1) Escherichia coli. More importantly, testing with more than 1,000 anal samples indicated that our method has a high positive detection rate and is relatively low cost, compared with the traditional culture-based method. It took only 1 day for the preliminary screening and 2 days to efficiently isolate the Salmonella cells, indicating that the new assay is specific, rapid, and simple for Salmonella detection. In contrast to the traditional culture-based method, this method can be easily used to screen and isolate targeted strains with the naked eye. The results of quantitative and comparative experiments showed that the visual detection technique is an efficient alternative method for the screening of Salmonella spp. in many applications of large-sized samples related to public health surveillance.
Subject(s)
Bacteriological Techniques , Chromatography, Paper/methods , Salmonella/isolation & purification , Humans , Hydrogen Sulfide/metabolism , Hymecromone/analogs & derivatives , Hymecromone/chemistry , Salmonella/classification , Salmonella/metabolism , Salmonella Infections/diagnosis , Salmonella Infections/microbiology , Sensitivity and SpecificityABSTRACT
Objective:To assess the efficiency and safety of balloon dilation tracheoplasty technique in the management of acquired subglottic stenosis in children. Method:Twenty-three cases were diagnosed as acquired subglottic stenosis by chest CT scan and bronchoscpyï¼and received the treatment of the balloon dilatation tracheoplasty.The data about the efficiencyï¼complication and prognosis of the treatment were collected. Result:In the 23 casesï¼6 of All 11 patients with tracheotomy were decannulated,11 patients were successfully managed without tracheotomyï¼1 patients received laryngotracheal reconstruction(LTR) surgery, 5 cases were still under observation. The overall response rate was 73.91%.All cases were divided into three stages according to Cotton stage system:1 cases were stage â stenosisï¼6 cases were stage â ¡ and 16 cases were stage â ¢. The response rate was 100.00%ï¼83.33%ï¼and 68.75% respectively. The most common complication in the balloon dilatation tracheoplasty was restenosis. Restenosis occurs in 12ï¼52.17%ï¼ cases who received more than 1 dilation procedures in this study. Over all average dilation times is 1.87. Eight cases(88.9%) of 9 in fresh leision group were recoverd, the average dilation time is 1.22; 8 cases (57.14%) of 14 in old leision group were recoverd, the average dilation time is 2.23. The average dilation time between two group is significant(P<0.05). Conclusion:Subglottic stenosis in pediatric patients can be successfully managed with balloon dilation tracheoplasty. In patients without prior tracheotomy, tracheotomy can often be safely avoided with appropriate postoperative management.
