Most type VI secretion systems (T6SSs) described to date are protein delivery apparatuses that mediate bactericidal activities. Several T6SSs were also reported to mediate virulence activities, although only few anti‐eukaryotic effectors have been described. Here, we identify three T6SSs in the marine bacterium Vibrio proteolyticus and show that T6SS1 mediates bactericidal activities under warm marine‐like conditions. Using comparative proteomics, we find nine potential T6SS1 effectors, five of which belong to the polymorphic MIX‐effector class. Remarkably, in addition to six predicted bactericidal effectors, the T6SS1 secretome includes three putative anti‐eukaryotic effectors. One of these is a MIX‐effector containing a cytotoxic necrotizing factor 1 domain. We demonstrate that T6SS1 can use this MIX‐effector to target phagocytic cells, resulting in morphological changes and actin cytoskeleton rearrangements. In conclusion, the V. proteolyticus T6SS1, a system homologous to one found in pathogenic vibrios, uses a suite of polymorphic effectors that target both bacteria and eukaryotic neighbors.

In pediatric patients submitted to living related liver transplantation, hepatic venous reconstruction is critical because of the diameter of the hepatic veins and the potential risk of twisting of the graft over the line of the anastomosis. The aim of the present study is to present our experience in hepatic venous reconstruction performed in pediatric living related donor liver transplantation. Fifty-four consecutive transplants were performed and two methods were utilized for the reconstruction of the hepatic vein: direct anastomosis of the orifice of the donor left or left and middle hepatic veins and the common orifice of the recipient left and middle hepatic veins (group 1-26 cases), and wide triangular anastomosis after creating a wide triangular orifice in the recipient inferior vena cava at the confluence of all the hepatic veins with an additional longitudinal incision in the inferior angle of the orifice (group 2-28 cases). In group 1, eight patients were excluded because of graft problems in the early postoperative period and five among the remaining 18 patients (27.7%) presented stricture at the site of the hepatic vein anastomosis. All these patients had to be submitted to two or three sessions of balloon dilatations of the anastomoses and in four of them a metal stent had to be placed. The liver histopathological changes were completely reversed by the placement of the stent. Among the 28 patients of the group 2, none of them presented hepatic vein stenosis (p = 0.01). The results of the present series lead to the conclusion that hepatic venous reconstruction in pediatric living donor liver transplantation must be preferentially performed by using a wide triangulation on the recipient inferior vena cava, including the orifices of the three hepatic veins. In cases of stenosis, the endovascular dilatation is the treatment of choice followed by stent placement in cases of recurrence.

No abstract

No abstract

Vibrio parahaemolyticus is a globally disseminated Gram-negative marine bacterium and the leading cause of seafood-borne acute gastroenteritis. Pathogenic bacterial isolates encode two type III secretion systems (T3SS), with the second system (T3SS2) considered the main virulence factor in mammalian hosts. For many decades, V. parahaemolyticus has been studied as an exclusively extracellular bacterium. However, the recent characterization of the T3SS2 effector protein VopC has suggested that this pathogen has the ability to invade, survive, and replicate within epithelial cells. Herein, we characterize this intracellular lifestyle in detail. We show that following internalization, V. parahaemolyticus is contained in vacuoles that develop into early endosomes, which subsequently mature into late endosomes. V. parahaemolyticus then escapes into the cytoplasm prior to vacuolar fusion with lysosomes. Vacuolar acidification is an important trigger for this escape. The cytoplasm serves as the pathogen’s primary intracellular replicative niche; cytosolic replication is rapid and robust, with cells often containing over 150 bacteria by the time of cell lysis. These results show how V. parahaemolyticus successfully establishes an intracellular lifestyle that could contribute to its survival and dissemination during infection.