A potential bacterial biocontrol agent,strain S2V2 against pathogenic marine <Emphasis Type="Italic">Vibrio</Emphasis> in aquaculture

We isolated a marine bacterium strain S2V2 which inhibited the growth of pathogenic marine Vibrio spp. The aims of this research were to identify a new antibiotic-producing marine bacterium strain S2V2, and evaluate its spectrum activity and pathogenic property. Analysis of 16S rDNA sequence placed strain S2V2 in the genus Pseudoalteromonas, but the sequence similarity was low (95.46%) implying the strain might be a new species in this genus. Strain S2V2 inhibited the growth of 67.9% of 28 Vibrio strains tested. This strain inhibited V. alginolyticus, V. anguillarum, V. fluvialis, V. harveyi, V. metschnikovii, V. splendidus, V. ordalii, V. parahaemolyticus, and V. vulnificus, but inactive against V. campbellii, Aeromonas hydrophyla and Staphylococcus aureus. Strain S2V2 produced extracellular non proteinaceous antibacterial substances. The highest antibacterial activity was found when strain S2V2 was cultured for 96 h in ZoBell broth medium. An artificial infection to post larvae of Lithopenaeus vanname indicated that strain S2V2 was a non pathogenic bacterium. Non pathogenic property and specific antibacterial activity against a broad range of fish pathogenic marine Vibrio of strain S2V2 suggest that this strain is a prospective source of unique antibiotic and a potential biocontrol agent in marine aquaculture.     

Identification of multi-SH3 domain-containing protein interactome in pancreatic cancer: a yeast two-hybrid approach

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease that shows minimal response to chemotherapy. Genetic changes involved in the progression of PDAC concern genes that encode proteins related to signal transduction networks. This fact reveals the importance in identifying the role and the relations between multiple signaling cascades in PDAC. One of the major factors that modulate signaling events is multidomain scaffold proteins that function by binding several proteins simultaneously, inducing their proximity and influencing the outcome of signaling. A particular group among them, containing multiple Src homology 3 (SH3) domains that can bind proteins containing proline-rich motifs, was associated to different aspects of cancer cell homeostasis. In this work, using a microarray-based analysis, we have shown that 13 multiple SH3 domain containing scaffold proteins are expressed in PDAC cells. Using a yeast two-hybrid approach, we have identified proteins that interact with these adaptor proteins. Among them we have found several molecules that modulate cell proliferation and survival (CIZ1, BIRC6, RBBP6), signaling (LTBP4, Notch2, TOM1L1, STK24) and membrane dynamics (PLSCR1, DDEF2, VCP). Our results indicate that interactions mediated by multi-SH3 domain-containing proteins could lead to the formation of dynamic protein complexes that function in pancreatic cancer cell signaling. The identification of such protein complexes is of paramount importance in deciphering pancreatic cancer biology and designing novel therapeutic approaches.