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Shiga toxin-producing Escherichia coli (STEC) are zoonotic food pathogens associated with foodborne diarrheal illness, hemorrhagic colitis, and complications such as hemolytic uremic syndrome (HUS). The ability to adhere to epithelial cells is an important virulence trait, and pathogenicity islands (PAIs) play an important role on it. Some STEC carrying a PAI named locus of enterocyte effacement (LEE-positive) have been frequently associated to HUS; however, STEC that do not carry LEE (LEE-negative) have also been associated with this outcome. The burden of disease caused by LEE-negative STEC has increased recently in several countries like Argentina, Chile, and Paraguay. A new PAI –the Locus of Adhesion and Autoagregation (LAA)—has been associated to severe disease in humans. In this study, we aimed to analyze the distribution of LAA and its possible predictor, the gene hes, in LEE-negative STEC strains isolated from Chile and Paraguay from different sources. The presence of the different LAA modules and hes were detected by PCR. LAA was found in 41.6% and 41.0% of strains isolated from Chile and Paraguay, respectively. Strains were isolated from diverse origins and belonged to several serogroups including O91, O103, and O113. The hes gene was detected in 50% of the isolates from Paraguay and Chile. Therefore, the detection of LAA and hes in STEC could complement current genetic evaluation schemes, allowing to classify LEE negative STEC strains as LAA-positive or LAA-negative STEC strains. [ABSTRACT FROM AUTHOR]

Since 2015, Araucaria araucana, an ecologically and economically important conifer native to Argentina and Chile, has suffered an unusual partial death of the crown throughout almost all of the distribution range in Argentina. No primary pathogen or pest was evident, associated with the phenomenon. Isolates of Mortierella, a poorly studied fungal genus in Patagonia, were obtained from the margins of necrotic phloem tissue of symptomatic trees. Five species of Mortierella were isolated from affected tissues. In inoculation tests, Mortierella alpina and M. aff. basiparvispora were pathogenic to A. araucana. These species caused necrosis of phloem, leading to chlorosis, foliar desiccation and eventually death, demonstrating that Mortierellales may play a role in the decline of the tree. [ABSTRACT FROM AUTHOR]

Antiphospholipid antibodies (aPL) are a heterogeneous family of antibodies associated with thrombotic events and other complications. The objective of this study was to investigate the prevalence of aPL in a group of Chilean patients with thrombosis. Two hundred and twenty-six patients with venous and arterial thrombosis and 95 healthy controls were studied. Anticardiolipin (aCL), anti-β2 glycoprotein I (anti-β2GPI), and antiprothrombin (aPT) antibodies were determined. Eighty-eight out of 226 (38.9%) patients with thrombosis had some type of aPL. Fifty-seven patients (25.2%) were positive for aCL, 31 (13.7%) for aPT, and 14 (6.2%) for anti-β2GPI antibodies. Twelve patients (5.3%) were positive for more than one aPL. IgG, IgM and IgA isotypes were observed in aCL, anti-β2GPI, and aPT antibodies. Twenty-six out of 92 (28.3%) patients with venous thrombosis and 31/134 (23.1%) patients with arterial thrombosis were positive for aCL antibodies. With regard to the control group (4/95=4.2%), the odd ratios (OR) were 5.2 (1.3–19.8; p0.01) and 5.7 (1.6–22.3; p0.01), respectively. Additionally, we observed statistically significant OR with aPT and anti-β2GPI antibodies; in the first, with venous and arterial thrombosis, and in the second, only with arterial thrombosis. Our results show a significant prevalence of aPL, predominantly aCL and aPT antibodies, in patients with thrombosis. Additionally, aCL and aPT antibodies appear to be a risk factor for venous and arterial thrombosis, and anti-β2GPI antibodies appear to be a risk factor for arterial thrombosis. [ABSTRACT FROM AUTHOR]

The Planchón – Peteroa Volcanic Complex exhibits two active degassing areas: Peteroa crater, PC, and peripheral hydrothermal areas, analyzed in three sampling sites, namely Valle Baños del Azufre, VBA, Valle del Peñón, VP and Valle Valenzuela, VZ. This prospective study was designed to investigate the soil diffuse emissions of CO 2 at this volcanic complex. The survey consisted of 560 measurements of CO 2 soil diffuse flux and temperature carried out at PC, VBA, VP. The results of this work show that diffuse CO 2 is emitted at PC through two well-defined diffuse degassing structures and flux distribution that can be modeled by combining two log-normal populations. Here, the main source of soil CO 2 is a shallow aquifer recharged by steam condensation and meteoric fluids that interact with rising magmatic gases. The carbon isotopic signature reveals that CO 2 diffuse degassing is affected by secondary soil processes during its ascent. The total diffuse CO 2 output at the surveyed area of PC, which covers ̴77,000 m2 around the crater fumarolic field, is 6.49 ± 0.32 t d−1. Soil diffuse emissions at the hydrothermal peripheral sites, VBA and VP, were studied covering a total area of ̴590,000 m2. These emissions are characterized by poorly defined diffuse degassing structures and flux distributions that can be modeled by combining three log-normal populations, which suggest that multiple sources feed CO 2 diffuse emissions. In concordance, the isotopic analysis also suggests a mixed source of CO 2 and degassing affected by secondary processes that modify the original isotope composition. CO 2 soil degassing at VZ shows a clear relation with the vegetated areas of the soil. The minimum endogenous CO 2 output estimation here proposed for the Planchón – Peteroa Volcanic Complex is that of PC, ̴6.5 t d−1. The thermal energy release was computed for PC, and the estimation is 2.57 ± 0.53 MW. • Planchón – Peteroa Volcanic Complex emits over 6 tons per day of volcanic- hydrothermal diffuse carbon dioxide. • Deep CO 2 is emitted through the active crater of Peteroa volcano. The peripheral hydrothermal sites emit mainly biogenic CO 2. • The carbon isotopic composition suggests that secondary processes deeply modify the original isotope composition. • The thermal energy release was estimated by assessing the flux of steam. The heat flux at Peteroa crater is 2.5 MW. [ABSTRACT FROM AUTHOR]

Introduction. Antiphospholipid Antibodies (aPL) has been associated with thrombotic events. The objective of this study was to investigate the prevalence of aPL in a group of Chilean patients with venous and arterial thrombosis. Patients and Methods. Two hundred twenty six patients with venous and arterial thrombosis and 95 healthy controls were included in this study. Anticardiolipin (aCL), Anti-β2Glycoprotein I (anti-β2GPI) and Antiprothrombin (aPT) antibodies, were determined by ELISA using "in-house" assays. Results. Eighty eight out of 226 (38.9%) patients with thrombosis had some type of aPL. The prevalence of aCL, anti-β2GPI and aPT in patients with TV y TA, and in control group, shows in the following table: Twelve patients (5.3%) were positive for mixture of aPL. IgG, IgM and IgA isotypes were observed in aCL, Anti-β2GPI and aPT antibodies. Twenty four out of 78 (30.8%) patients with deep venous thrombosis, 2/14 (14.3%) with retinal venous thrombosis 17/68 (25.0%) with ischemic stroke and 14/66 (21.2%) with acute myocardial infarction, were positive for aCL antibodies. Anti-β2GPI and aPT antibodies were also present in these groups although in minor proportion. Conclusion. Our results show an important prevalence of aPL in patients with thrombosis, and aCL and aPT seem to be a risk factor of venous and arterial thrombosis. [ABSTRACT FROM AUTHOR]

Background: Factor V Leiden and G20210A mutation of prothrombin gene are two important genetic polymorphisms associated with an increased risk for thrombosis., Aim: To establish the prevalence of factor V Leiden and prothrombin G20210A mutation in the Chilean population and their association to venous and arterial thromboembolism., Material and Methods: A case-control study was conducted where 149 patients with thrombosis (87 with arterial and 62 with venous thrombosis) confirmed by CAT-scan, electrocardiogram and cardiac enzymes or Doppler depending on the case, and 160 healthy blood donors were genetically analyzed for the presence of both polymorphisms., Results: Factor V Leiden mutation was found in 5.4% of patients and in 1.3% of healthy controls (p=0.04). Heterozygosity for G20210A prothrombin mutation was found in 5.4% of patients and in 2.5% of the control group (p=NS). When arterial and venous thrombosis were considered as separate entities, 4.6% of patients with arterial thrombosis and 6.5% with venous thrombosis presented factor V Leiden (p=NS). Likewise, 8.1% of patients with venous thrombosis and 3.5% of patients with arterial thrombosis had G20210A prothrombin mutation (p=NS)., Conclusions: In non selected consecutive Chilean patients with arterial and venous thrombosis the frequency of factor V Leiden and prothrombin G20210A is less than we could expect from their prevalence in the general population.