Anti-Salmonella Polyclonal antibody

It is difficult to detect a small amount of pathogens present in ready-to-eat foods without enriching it. Although enrichment is needed to increase the bacterial population, the time required for this impedes the rapid detection of pathogens. This study was designed to detect Escherichia coli O157:H7 and Salmonella Typhimurium more quickly and sensitively by concentrating bacteria and DNA. Short-term enrichment was used to increase bacterial number and to recovery injured bacteria. Filtration was used to concentrate pathogens and to lower the detection limit. DNA concentration was performed to improve sensitivity by reducing elution volume. Samples were analyzed using real-time PCR. The results showed filtration after enrichment for 2 h allowed the effective detection of E. coli O157:H7 and S. Typhimurium. S. Typhimurium was detected following enrichment for 1 h when DNA concentration was performed. After validation, enrichment for 3 h was shown to be required for detecting E. coli O157:H7 and S. Typhimurium. With DNA concentration, enrichment for 3 h was necessary for the complete detection of E. coli O157:H7, but that for 2 h was needed for S. Typhimurium. The results of this study indicate that this combined method is a rapid and efficient way of detecting pathogens.

In the present study four bacterial strains Escherichia Coli, Salmonella typhi, Shiegella and Pseudomonas aeruginosa were used to evaluate their dye decolorization/degradation ability. Out of these bacterial strains Pseudomonas aeruginosa exhibited high potential for selected dye decolorization and hence it was used in subsequent experiments. The effect of dye concentration, pH, temperature, time, glucose and sodium chloride concentrations on decolorization were also studied to determine the optimal conditions required for maximum decolorization/degradation of selected dye by Pseudomonas aeruginosa. Maximum decolorization was observed at: 0.01 mg/L dye concentration, pH 10, temperature 45 degrees C, 0.1 mg/L glucose concentration, 0.1 mg/L sodium chloride concentration and 3 days incubation period at 37 degrees C. The metabolites formed after degradation by selected bacteria at optimum conditions were isolated and characterized by FTIR and mass spectrometry. In the mass spectra molecular ion peak was not observed and it was difficult to draw a conclusion from it. However, FTIR spectra provided some valuable information. The peaks at 1301.8 cm(-1) for C-N and 1231.5 cm(-1) for O-H stretch observed for original dye were completely absent in the decolorized products. The disappearance of C-N (part of the porphyrin ring system) peak in FTIR spectra shows that the porphyrin ring has been destroyed by bacteria. The extensive fragmentations in the mass spectra also confirm the degradation of the dye parental structure.