Insecticidal features displayed by the beneficial rhizobacterium Pseudomonas chlororaphis PCL1606 / Características insecticidas mostradas por la rhizobacterium beneficiosa Pseudomonas chlororaphis PCL1606

The biocontrol rhizobacterium Pseudomonas chlororaphis is one of the bacterial species of the P. fluorescens group where insecticide fit genes have been found. Fit toxin, supported with other antimicrobial compounds, gives the bacterial the ability to repel and to fight against eukaryotic organisms, such as nematodes and insect larvae, thus protecting the plant host and itself. Pseudomonas chlororaphis PCL1606 is an antagonistic rhizobacterium isolated from avocado roots and show efficient biocontrol against fungal soil-borne disease. The main antimicrobial compound produced by P. chlororaphis PCL606 is 2-hexyl-5-propyl resorcinol (HPR), which plays a crucial role in effective biocontrol against fungal pathogens. Further analysis of the P. chlororaphis PCL1606 genome showed the presence of hydrogen cyanide (HCN), pyrrolnitrin (PRN), and homologous fit genes. To test the insecticidal activity and to determine the bases for such activity, single and double mutants on the biosynthetic genes of these four compounds were tested in a Galleria mellonella larval model using inoculation by injection. The results revealed that Fit toxin and HPR in combination are involved in the insecticide phenotype of P. chlororaphis PCL1606, and additional compounds such as HCN and PRN could be considered supporting compounds.(AU)

Insecticidal features displayed by the beneficial rhizobacterium Pseudomonas chlororaphis PCL1606.

The biocontrol rhizobacterium Pseudomonas chlororaphis is one of the bacterial species of the P. fluorescens group where insecticide fit genes have been found. Fit toxin, supported with other antimicrobial compounds, gives the bacterial the ability to repel and to fight against eukaryotic organisms, such as nematodes and insect larvae, thus protecting the plant host and itself. Pseudomonas chlororaphis PCL1606 is an antagonistic rhizobacterium isolated from avocado roots and show efficient biocontrol against fungal soil-borne disease. The main antimicrobial compound produced by P. chlororaphis PCL606 is 2-hexyl-5-propyl resorcinol (HPR), which plays a crucial role in effective biocontrol against fungal pathogens. Further analysis of the P. chlororaphis PCL1606 genome showed the presence of hydrogen cyanide (HCN), pyrrolnitrin (PRN), and homologous fit genes. To test the insecticidal activity and to determine the bases for such activity, single and double mutants on the biosynthetic genes of these four compounds were tested in a Galleria mellonella larval model using inoculation by injection. The results revealed that Fit toxin and HPR in combination are involved in the insecticide phenotype of P. chlororaphis PCL1606, and additional compounds such as HCN and PRN could be considered supporting compounds.

Microbiota Alterations in Precancerous Colon Lesions: A Systematic Review.

Gut microbiota plays an important role in human health. It may promote carcinogenesis and is related to several diseases of the gastrointestinal tract. This study of microbial dysbiosis in the etiology of colorectal adenoma aimed to investigate the possible causative role of microbiota in the adenoma-carcinoma sequence and its possible preventive role. A systematic, PRISMA-guided review was performed. The PubMed database was searched using "adenoma microbiota" and selecting original articles between January 2010 and May 2020 independently screened. A higher prevalence of Proteobacteria, Fusobacteria, and Bacteroidetes phyla was observed in the fecal luminal and mucosa-associated microbiota of patients with adenoma. However, other studies provided evidence of depletion of Clostridium, Faecalibacterium, Bacteroides and Romboutsia. Results on the relationship between adenoma endoscopic resection and microbiota were inconsistent. In conclusion, none of the analyzed studies developed a predictive model that could differentiate adenoma from non-adenoma patients, and therefore, to prevent cancer progression. The impact of adenoma's endoscopic resection on microbiota was investigated, but the results were inconclusive. Further research in the field is required.

Relevance of Spontaneous Portosystemic Shunts Detected with CT in Patients with Cirrhosis.

Background Cirrhosis leads to portal hypertension and to the consequent formation of spontaneous portosystemic shunts (SPSSs), leading to complications related to the diversion of portal blood into the systemic circulation, which is called portosystemic shunt syndrome. Purpose To investigate the characteristics of patients with cirrhosis and an SPSS and secondarily to assess the prognostic impact of SPSSs on portal hypertension-related complications and transplant-free survival. Materials and Methods A retrospective database review of patients with cirrhosis (observed from March 2015 to July 2019) was performed to identify patients with CT imaging and outcomes data. For each patient, clinical and biochemical data were collected, and the presence, types, and sizes of SPSSs were investigated with CT. Patients were followed for a mean of 27.5 months ± 22.8. Multivariable logistic analysis was used to identify the clinical characteristics associated with the presence of SPSSs (any size) and presence of SPSSs 1 cm or larger. Competitive risk analysis (Fine and Gray model) was used to identify the association between SPSSs and complications and mortality. Results Two hundred twenty-two patients with cirrhosis (157 male, 65 female; mean age, 62 years ± 12 [standard deviation]) were evaluated. An SPSS was found in 141 of 222 patients (63.5%), and 40 of 222 (18%) had a shunt diameter of at least 1 cm. At presentation, variables independently associated with the presence of SPSSs (any size) were portal vein thrombosis (odds ratio, 5.5; P = .008) and Child-Pugh class C (odds ratio, 3.0; P = .03). Previous hepatic encephalopathy (odds ratio, 4.4; P = .001) and portal vein thrombosis (odds ratio, 5.3; P = .001) were the only variables associated with SPSSs larger than 1 cm. Patients with SPSSs of any size had higher mortality (subdistribution hazard ratio, 1.9; P < .001) and higher frequency of hepatic encephalopathy (subdistribution hazard ratio, 2.3; P = .023), gastrointestinal bleeding (subdistribution hazard ratio, 2.9; P = .039), and portal vein thrombosis (subdistribution hazard ratio, 7.6; P = .005). Conclusion The presence of spontaneous portosystemic shunts on CT images in patients with cirrhosis was associated with higher mortality and complications, including portal vein thrombosis, hepatic encephalopathy, and gastrointestinal bleeding. © RSNA, 2021 See also the editorial by Reeder in this issue.

[The European Association for the Study of Liver (EASL) nutrition guidelines.] / Le linee guida sulla nutrizione della Società europea per lo studio delle malattie epatiche (EASL).

This review explores the latest guidelines on nutrition in patients with chronic liver diseases of the European Association for the Study of the Liver (EASL) and recent studies on physiopathology, clinical outcomes and possible treatments of malnutrition and sarcopenia in liver cirrhosis. Chronic liver diseases are frequently associated with malnutrition, changes in skeletal muscle and bone quality and quantity. About 20% of patients with compensated liver cirrhosis and 50% of those with decompensated cirrhosis are sarcopenic. Malnutrition and sarcopenia are associated with a higher complication rate (ascites, bacterial infections and hepatic encephalopathy) and are independent predictors of lower survival in cirrhotic patients. In recent years, concomitant with the decline of post-viral cirrhosis, patients affected by post-metabolic cirrhosis are increasing. These patients are more frequently overweight or obese, but sarcopenia may also coexist. Sarcopenic obesity has been shown to worsen the prognosis in patients with liver cirrhosis. There is a general consensus about the need of improving the nutritional status and implementing skeletal muscle mass in cirrhotic patients, but this is not always achievable. Osteoporosis is present in about 30% of cirrhotic patients, with a higher prevalence in patients with cholestasis. Treatment with phosphonates, calcium and vitamin D are recommended in association with a periodic follow-up.

A Large Tn7-like Transposon Confers Hyper-Resistance to Copper in Pseudomonas syringae pv. syringae.

Copper resistance mechanisms provide an important adaptive advantage to plant pathogenic bacteria under exposure to copper treatments. Copper resistance determinants have been described in Pseudomonas syringae pv. syringae (Pss) strains isolated from mango intimately associated with 62 kb plasmids belonging to the pPT23A family (PFP). It has been previously described that the indiscriminate use of copper-based compounds promotes the selection of copper resistant bacterial strains and constitutes a selective pressure in the evolution of copper resistance determinants. Hence, we have explored in this study the copper resistance evolution and the distribution of specific genetic determinants in two different Pss mango populations isolated from the same geographical regions, mainly from southern Spain with an average of 20 years of difference. The total content of plasmids, in particular the 62 kb plasmids, and the number of copper resistant Pss strains were maintained at similar levels over the time. Interestingly, the phylogenetic analysis indicated the presence of a phylogenetic subgroup (PSG) in the Pss mango phylotype, mostly composed of the recent Pss population analyzed in this study that was strongly associated with a hyper-resistant phenotype to copper. Genome sequencing of two selected Pss strains from this PSG revealed the presence of a large Tn7-like transposon of chromosomal location, which harbored putative copper and arsenic resistance genes (COARS Tn7-like). Transformation of the copper sensitive Pss UMAF0158 strain with some putative copper resistance genes and RT-qPCR experiments brought into light the role of COARS Tn7-like transposon in the hyper-resistant phenotype to copper in Pss.IMPORTANCECopper compounds have traditionally been used as standard bactericides in agriculture in the past few decades. However, the extensive use of copper has fostered the evolution of bacterial copper resistance mechanisms. Pseudomonas syringae is a plant pathogenic bacterium used worldwide as a model to study plant-pathogen interactions. The adaption of P. syringae to plant surface environment is the most important step prior to an infection. In this scenario, copper resistance mechanisms could play a key role in improving its epiphytic survival. In this work, a novel Tn7-like transposon of chromosomal location was detected in P. syringae pv. syringae strains isolated from mango. This transposon conferred the highest resistance to copper sulfate described to date for this bacterial phytopathogen. Understanding in depth the copper resistance mechanisms and their evolution are important steps to the agricultural industry to get a better improvement of disease management strategies.

Outcomes of long-term anticoagulant treatment for the secondary prophylaxis of splanchnic venous thrombosis.

BACKGROUND: Splanchnic vein thrombosis (SVT) is an uncommon but potentially life-threatening disease usually related to different underlying clinical conditions. The risk of SVT recurrences is high over time in patients with an underlying permanent prothrombotic condition. Vitamin K antagonists (VKA) represent the mainstay of treatment for SVT. Data about the efficacy and safety of direct oral anticoagulants (DOACs) are reported in the literature for the treatment of acute SVT, but less is known about their application for the secondary prophylaxis of venous thromboembolism (VTE). The aim of this study was to assess the efficacy and safety of long-term DOACs therapy in patients at high-risk of thrombosis, compared to VKA. METHODS: This is a retrospective single-centre study including 70 patients with SVT on long-term anticoagulant treatment with VKA followed-up at our Units between January 2017 and December 2019. All the patients were at high thrombotic risk defined as the presence of a permanent prothrombotic condition requiring long-term anticoagulation. During follow-up, 28 patients were shifted to DOACs and their clinical outcomes were compared to those of the patients who continued VKA therapy. All the arterial and venous thrombotic events of the splanchnic and extra-splanchnic districts as well as the haemorrhagic adverse events occurring during follow-up were recorded. RESULTS: Of the seventy patients enrolled in the study, 36 patients (51.4%) had a single-segment involvement thrombosis (28.5% of portal vein, 7.1% of superior mesenteric vein, 4.3% of splenic vein, 11.5% of hepatic veins) and 34 patients (48.6%) had multi-segment involvement at the time of diagnosis. 42 patients (60%) continued VKA therapy and 28 (40%) were switched to DOACs. Median follow-up was 6 years (range 2-8) during VKA and 1.9 years (range 1-5.2) during DOACs. The incidence of thrombotic events was similar between patients on VKA and those on DOACs. Patients on VKA developed deep vein thrombosis (DVT), and of the patients on DOACs 1 developed NSTEMI and 1 DVT. No major haemorrhagic events occurred. Minor bleedings occurred in 26% of patients on VKA and in none of the DOACs patients (P: 0.09). CONCLUSIONS: Our results highlight that DOACs could represent an effective and safe alternative to the VKA for secondary prophylaxis in SVT patients at high risk of thrombosis.

Sarcopenic obesity in fatty liver.

PURPOSE OF REVIEW: Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steato hepatitis have an increasing prevalence among liver diseases. Overweight and obesity are frequently associated conditions in patients with fatty liver. Skeletal muscle mass depletion may also coexist with chronic liver disease even in obese patients. This review will focus on the relationship between sarcopenic obesity and fatty liver. RECENT FINDINGS: Obesity and sarcopenia are frequently encountered in patients with NAFLD. Adipose tissue is able to release molecules (adipokines) that regulate lipid metabolism, interact with insulin sensitivity and may contribute to induce fibrogenesis in the liver. Skeletal muscle tissue is able to secrete myokines regulating muscle metabolism and insulin sensitivity. Myokines perturbation has been reported to influence adipose tissue mass and fat deposition in the liver. Sarcopenia has been reported as independent risk factor for the development of NAFLD, and for a more severe liver fibrosis in patients with NAFLD. SUMMARY: The interaction between skeletal muscle, adipose tissue and the liver may play a role in the development of NAFLD. Sarcopenia and sarcopenic obesity are risk factors for the development of fatty liver and associated with more severe liver fibrosis. Management is not standardized, but dietary counseling and physical training have been proposed as promising strategies. Bariatric surgery may be considered in patients with severe 'resistant' obesity.

Natural history of patients with non cirrhotic portal hypertension: Comparison with patients with compensated cirrhosis.

BACKGROUND: The knowledge of natural history of patients with portal hypertension (PH) not due to cirrhosis is less well known than that of cirrhotic patients. AIM: To describe the clinical presentation and the outcomes of 89 patients with non-cirrhotic PH (25 with non-cirrhotic portal hypertension, INCPH, and 64 with chronic portal vein thrombosis, PVT) in comparison with 77 patients with Child A cirrhosis. METHODS: The patients were submitted to a standardized clinical, laboratory, ultrasonographic and endoscopic follow-up. Variceal progression, incidence of variceal bleeding, portal vein thrombosis, ascites and survival were recorded. RESULTS: At presentation, the prevalence of varices, variceal bleeding and ascites was similar in the 3 groups. During follow-up, the rate of progression to varices at risk of bleeding (p < 0.0001) and the incidence of first variceal bleeding (p = 0.02) were significantly higher in non-cirrhotic then in cirrhotic patients. A PVT developed in 32% of INCPH patients and in 18% of cirrhotics (p = 0.02). CONCLUSIONS: In the patients with non-cirrhotic PH variceal progression is more rapid and bleeding more frequent than in cirrhotics. Patients with INCPH are particularly prompt to develop PVT. This observational study suggests that the management of patients with non-cirrhotic PH should take into consideration the natural history of portal hypertension in these patients and cannot be simply derived by the observation of cirrhotic patients.