Objective To isolate and identificate Streptomyce strain from cow dung and observe its antimicrobial activity. Methods Strains were isolated from cow dung by dilution coating method.Strong antibacterial strains were screened out by agar block method with fixed Staphylococcus aureus and Escherichia coli as indicative bacteria.The strains were identified based on physiological and biochemical characteristics as well as 16S rDNA gene sequence analysis.Active antibacterial fermentation broth substance was determined by disk diffusion method,and antibacterial active substance of strains fermentation broth was extracted by water-saturated n-butanol.Antibacterial substance of strains was identified by Molish reaction,biuret test and ninhydrin reaction. Results Eight strains were isolated from cow dung and one strong antibacterial strain was screened out and named B5-2,identified as Streptomyces.The results showed that the strain had the highly antibacterial effect on Staphylococcus aureus,Escherichia coli,Citrobacter freundii,Enterobacter cloacae,Klebsiella pneumoniae,Enterobacter aerogenes.The strain antibacterial active substance of fermentation broth preliminary analysis showed that strong antibacterial active substance of B5-2 was the water-soluble substance.Antibacterial substance of B5-2 was preliminarily identified as glycoside and protein by Molish reaction,biuret test and ninhydrin reaction. Conclusion The strain isolated have a strong inhibition effect on clinical pathogenic bacteria in clinical practice.

Objective: To investigate the inhibitory effect of recombinant oncolytic adenovirusAd-Apoptin-hTERTp-E1A(ATV) on luciferase-labeled human lung cancer cells (A549-luc) and human lung cancerA549 cells, and to compare the differences in the inhibitory effect on two cell lines. Methods:ATV was used to infectA549-luc cells andA549 cells respectively. WST-1 and crystal violet staining were used to determine the difference in the inhibitory effect of ATV. Hoechst and Annexin V-FITC/PI staining were used to verify the inhibition mode ofATV. Results: WST-1 and crystal violet staining showed thatATV had significant inhibitory effect on bothA549-luc and A549 cells ( P <0.05). ATV showed significant inhibitory effect on both cells at 24, 48 and 72 h ( P <0.05 or P <0.01), and reached the peak at 72 h; ATV at concentrations of 1, 10 and 100 MOI all showed inhibitory effect on both cells, and reached the peak at 100 MOI. Hoechst staining showed that A549-luc cells and A549 cells infected with ATV showed typical nuclear fragmentation and marginal set. The results of Annexin V-FITC/PI Flow cytometry showed that ATV infection resulted in apoptosis of A549-luc and A549 cells, which was in a time-dependent manner and reached the peak at 72 h( P <0.05 or P <0.01). Conclusion: Insertion of luciferase didn’t significantly change the inhibitory effect and inhibitory mode ofATV onA549-luc cells.ATV exerted its in vitro inhibitory effect onA549-luc and A549 cells by inducing cell apoptosis.