Genomic and biological characterization of vB_PvuS_Pm34, a novel lytic bacteriophage that infects Proteus vulgaris.

Proteus phage vB_PvuS_Pm34 (Pm34) isolated from the sewage, is a novel virus specific to Proteus vulgaris. Pm34 belonged to the family Siphovirodae with an icosahedron capsid head and a non-contractile tail. Its genome was 39,558 bp in length with a G + C content of 41.4%. Similarity analysis showed that Pm34 shared low identities of 27.6%-38.4% with any other Proteus phages, but had the 96% high identity with Proteus mirabilis AOUC-001. In the genome of Pm34, 70 open reading frames was deduced and 32 had putative functions including integrase and host lysis proteins. No tRNAs, antibiotic resistance and virulence genes were detected. Pm 34 presented a broad pH (4-8) and good temperature tolerance (<40 °C). This is the first report of the bacteriophage specific to P. vulgaris, which can enrich the knowledge of bacteriophages of Prouteus bacteria and provide the possibility for the alternative treatment of P. vulgaris infection.

[Effect of Aloe emodin on invasion and metastasis of high metastatic breast cancer MDA-MB-231 cells].

OBJECTIVE: To investigate the effect of Aloe emodin (AE) on the invasive and metastatic abilities of human high metastatic breast cancer MDA-MB-231 cells. METHODS: MTT assay was used to evaluate the viability of MDA-MB-231 cells after treated with AE for 6 h and 24 h. The adhesive potential of MDA-MB-231 cells to FN and LN was tested by cell-matrix adhesion assay. The effect of AE on invasion of MDA-MB-231 cells was measured by Transwell chamber assay. Scratch wound healing assay was applied to determine the effect on migration of MDA-MB-231 cells. The effect of AE on MDA-MB-231 lung metastasis was determined on an experimental metastatic model. RESULTS: 80 micromol/L AE significantly inhibited the invasion, adhesion to FN, LN of MDA-MB-231 cells in vitro, the inhibitory rates were (52.98 +/- 5.46)%, (34.99 +/- 2.63)%, (28.73 +/- 7.00)%, respectively. After 24 h treatment, AE significantly inhibited the migration of MDA-MB-231 cells. The number and volume of lung metastatic nodules formed by MDA-MB-231 cells after 80 micromol/L AE 24 h treatment were decreased compared with control group. CONCLUSION: AE can suppress the metastasis of MDA-MB-231 cells. Their mechanisms may be related to the inhibition of the capabilities of invasion and migration of MDA-MB-231 cells.