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Salmonella pullorum phage Pu29 was comprehensively analyzed for its biological and genomic characteristics. A magnetic separation and enrichment technique for Salmonella was established using the phage Pu29 as a recognition element. The phage belonged to the genus Roufvirus and had an icosahedron head and an irreducible long tail. Pu29 had a wide host spectrum with an adsorption rate of 88.67% on host cells in 15 min, a latent period of 30 min, a rise period of 180 min, and a burst size of 115.74 PFU/cell. Meanwhile, Pu29 had good heat resistance (30–60 ℃) and pH tolerance (pH 4–11). Its genome was composed of 45 715 bp (GC content 46.08%) and 81 open reading frames (ORFs), including 18 ORFs with known functions that did not carry genes encoding toxicity or resistance factors. PhagePu29-MBs were prepared as a probe by coupling the phage with carboxylated nano-magnetic beads (MBs) through amide reaction. When 25 μg of the probe was incubated with Salmonella at 37 ℃ for 20 min, the highest capture rate of Salmonella of 83.93% and the lowest captured bacterial concentration of 45 CFU/mL were obtained. Transmission electron microscopy (TEM) was used to observe that PhagePu29-MBs could specifically capture Salmonella. In spiked samples, the highest capture rate of Salmonella separated and enriched by the probe reached 92.92%. The separation and enrichment process took approximately 30 min. Therefore, this study established a fast and highly specific magnetic separation method for Salmonella based on phage Pu29, which may lay the foundation for the development of a phage-based method for the rapid separation and enrichment of foodborne pathogens in food samples.

Objective: To clarify the incidence and survival of colorectal carcinoma (CRC) patients among permanent residents in Yangpu district of Shanghai, from 2002 to 2012., Methods: Data of CRC patients in permanent residents of Yangpu district were collected from the database of the registration and management system in Shanghai city. Temporal trend in the incidence of CRC was analyzed by using Annual Percent Change (APC) model. Kaplan-Meier analysis with Log-rank testing was employed to estimate the survival. Incidence and mortality rates were standardized on age composition of standard population from 2000 nationwide census., Results: A total of 5 881 CRC cases were diagnosed from 2002 to 2012 with crude incidence as 50.60/10(5) and standardized one as 31.21/10(5). The crude incidence rates of colon cancer and rectal cancer were 31.09/10(5) and 18.27/10(5), respectively and the standardized rates were 14.49/10(5) and 8.83/10(5), respectively. The incidence rates of colon cancer were not significantly different between different gender. However, the incidence of rectal cancer in males was significantly higher than in females (P < 0.001). The incidence rates of CRC significantly increased in the age group older than 50 years. However, the standardized incidence rate did not change significantly(APC = 0.39). A total of 3 735 cases died of CRC in this period. The annual crude mortality of CRC was 31.35/10(5) with the standardized rate as 13.72/10(5). The mortality kept increasing significantly in the population older than 60 years. Mortality of rectal cancer was significantly higher in males than in females (P < 0.001). The 5-year survival rates in both colon cancer and rectal cancer patients were 48.88% and 54.16%, respectively. Survivals were significantly higher in those who had received surgical treatments than in those without surgical treatments (colon cancer: 58.10% vs. 37.22%, P < 0.001; rectal cancer:66.18% vs. 39.37%, P < 0.001)., Conclusion: Age seemed to have contributed to an increased morbidity and mortality of CRC in Yangpu district of Shanghai. The mortality of CRC appeared higher than the incidence. Surgical treatment could significantly prolong the survival of CRC patients.