Entre la idealización y el pragmatismo: planes para la reconstrucción de la ciudad de San Juan, Argentina (1944/1948)

La ciudad de San Juan, Argentina, se ubica en una zona de alto riesgo sísmico y registró en 1944 el terremoto más significativo en su historia, pues su ocurrencia provocó una fractura a todo nivel: urbano, arquitectónico, económico, social. Para la reconstrucción se propusieron entre 1944 y 1948 siete Planes cuya revisión tiene como objetivo demostrar el proceso de transición entre la idealización teórica y el necesario pragmatismo de la realidad, a través del recorrido de las sucesivas propuestas. Este rasgo particular distingue a San Juan del resto de las ciudades argentinas y latinoamericanas en general. Si bien estos Planes no se concretaron espacialmente en su totalidad, dejaron ciertas huellas retomadas en la reconstrucción de la ciudad a través de una adecuación de ésas teorías con una reafirmación de los patrones de asentamiento avalados históricamente como forma de apropiación del espacio y de la identidad urbana.ENG: San Juan city in Argentina is located in arid and high seismic risk zone. The earthquake of 1944 is the most significant natural event in the history of the city. It caused a fracture in all levels: urban, architectural, economic, social. For the reconstruction between 1944 and 1948, seven "Official Plans" were proposed and the review of them shows a process of transition between theoretical ideas and the necessary pragmatism of reality, through the course of successive proposals. This feature distinguishes San Juan from other Argentine and Latin American cities. Though the Plans did not materialize in space, they left some traces that were recaptured in the reconstruction of the city with an adaptation of these theories and the reaffirmation of the historic settlement patterns as a form of appropriation of space and urban identity.Peer Reviewe

Impact of safety-related dose reductions or discontinuations on sustained virologic response in HCV-infected patients: Results from the GUARD-C Cohort

BACKGROUND: Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice. METHODS: A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0-9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively. RESULTS: SVR24 rates were 46.1% (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1, 2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced 651 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with 651 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not 655. CONCLUSIONS: In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with peginterferon alfa-2a/ribavirin

Entre la idealización y el pragmatismo: planes para la reconstrucción de la ciudad de San Juan, Argentina (1944/1948)

ENG: San Juan city in Argentina is located in arid and high seismic risk zone. The earthquake of 1944 is the most significant natural event in the history of the city. It caused a fracture in all levels: urban, architectural, economic, social. For the reconstruction between 1944 and 1948, seven Official Plans were proposed and the review of them shows a process of transition between theoretical ideas and the necessary pragmatism of reality, through the course of successive proposals. This feature distinguishes San Juan from other Argentine and Latin American cities. Though the Plans did not materialize in space, they left some traces that were recaptured in the reconstruction of the city with an adaptation of these theories and the reaffirmation of the historic settlement patterns as a form of appropriation of space and urban identity

Entre la idealización y el pragmatismo: planes para la reconstrucción de la ciudad de San Juan, Argentina (1944/1948)

La ciudad de San Juan, Argentina, se ubica en una zona de alto riesgo sísmico y registró en 1944 el terremoto más significativo en su historia, pues su ocurrencia provocó una fractura a todo nivel: urbano, arquitectónico, económico, social. Para la reconstrucción se propusieron entre 1944 y 1948 siete Planes cuya revisión tiene como objetivo demostrar el proceso de transición entre la idealización teórica y el necesario pragmatismo de la realidad, a través del recorrido de las sucesivas propuestas. Este rasgo particular distingue a San Juan del resto de las ciudades argentinas y latinoamericanas en general. Si bien estos Planes no se concretaron espacialmente en su totalidad, dejaron ciertas huellas retomadas en la reconstrucción de la ciudad a través de una adecuación de ésas teorías con una reafirmación de los patrones de asentamiento avalados históricamente como forma de apropiación del espacio y de la identidad urbana.ENG: San Juan city in Argentina is located in arid and high seismic risk zone. The earthquake of 1944 is the most significant natural event in the history of the city. It caused a fracture in all levels: urban, architectural, economic, social. For the reconstruction between 1944 and 1948, seven "Official Plans" were proposed and the review of them shows a process of transition between theoretical ideas and the necessary pragmatism of reality, through the course of successive proposals. This feature distinguishes San Juan from other Argentine and Latin American cities. Though the Plans did not materialize in space, they left some traces that were recaptured in the reconstruction of the city with an adaptation of these theories and the reaffirmation of the historic settlement patterns as a form of appropriation of space and urban identity.Peer Reviewe

Isolation, Characterization, and Antibacterial Activity of Hard-to-Culture Actinobacteria from Cave Moonmilk Deposits

Cave moonmilk deposits host an abundant and diverse actinobacterial population that has a great potential for producing novel natural bioactive compounds. In our previous attempt to isolate culturable moonmilk-dwelling Actinobacteria, only Streptomyces species were recovered, whereas a metagenetic study of the same deposits revealed a complex actinobacterial community including 46 actinobacterial genera in addition to streptomycetes. In this work, we applied the rehydration-centrifugation method to lessen the occurrence of filamentous species and tested a series of strategies to achieve the isolation of hard-to-culture and rare Actinobacteria from the moonmilk deposits of the cave “Grotte des Collemboles”. From the “tips and tricks” that were tested, separate autoclaving of the components of the International Streptomyces Project (ISP) medium number 5 (ISP5) medium, prolonged incubation time, and dilution of the moonmilk suspension were found to most effectively improve colony forming units. Taxonomic analyses of the 40 isolates revealed new representatives of the Agromyces, Amycolatopsis, Kocuria, Micrococcus, Micromonospora, Nocardia, and Rhodococcus species, as well as additional new streptomycetes. The applied methodologies allowed the isolation of strains associated with both the least and most abundant moonmilk-dwelling actinobacterial operational taxonomic units. Finally, bioactivity screenings revealed that some isolates displayed high antibacterial activities, and genome mining uncovered a strong potential for the production of natural compounds

Una ciudad oasis de zona sísmica

Peer Reviewe

Complete Genome Sequence of Streptomyces lunaelactis MM109T, Isolated from Cave Moonmilk Deposits

peer reviewe

Assessment of the Potential Role of Streptomyces in Cave Moonmilk Formation

Moonmilk is a karstic speleothem mainly composed of fine calcium carbonate crystals (CaCO3) with different textures ranging from pasty to hard, in which the contribution of biotic rock-building processes is presumed to involve indigenous microorganisms. The real microbial input in the genesis of moonmilk is difficult to assess leading to controversial hypotheses explaining the origins and the mechanisms (biotic vs. abiotic) involved. In this work, we undertook a comprehensive approach in order to assess the potential role of filamentous bacteria, particularly a collection of moonmilk-originating Streptomyces, in the genesis of this speleothem. Scanning electron microscopy (SEM) confirmed that indigenous filamentous bacteria could indeed participate in moonmilk development by serving as nucleation sites for CaCO3 deposition. The metabolic activities involved in CaCO3 transformation were furthermore assessed in vitro among the collection of moonmilk Streptomyces, which revealed that peptides/amino acids ammonification, and to a lesser extend ureolysis, could be privileged metabolic pathways participating in carbonate precipitation by increasing the pH of the bacterial environment. Additionally, in silico search for the genes involved in biomineralization processes including ureolysis, dissimilatory nitrate reduction to ammonia, active calcium ion transport, and reversible hydration of CO2 allowed to identify genetic predispositions for carbonate precipitation in Streptomyces. Finally, their biomineralization abilities were confirmed by environmental SEM, which allowed to visualize the formation of abundant mineral deposits under laboratory conditions. Overall, our study provides novel evidences that filamentous Actinobacteria could be key protagonists in the genesis of moonmilk through a wide spectrum of biomineralization processes

A Phenotypic and Genotypic Analysis of the Antimicrobial Potential of Cultivable Streptomyces Isolated from Cave Moonmilk Deposits

Moonmilk speleothems of limestone caves host a rich microbiome, among which Actinobacteria represent one of the most abundant phyla. Ancient medical texts reported that moonmilk had therapeutical properties, thereby suggesting that its filamentous endemic actinobacterial population might be a source of natural products useful in human treatment. In this work, a screening approach was undertaken in order to isolate cultivable Actinobacteria from moonmilk of the Grotte des Collemboles in Belgium, to evaluate their taxonomic profile, and to assess their potential in biosynthesis of antimicrobials. Phylogenetic analysis revealed that all 78 isolates were exclusively affiliated to the genus Streptomyces and clustered into 31 distinct phylotypes displaying various pigmentation patterns and morphological features. Phylotype representatives were tested for antibacterial and antifungal activities and their genomes were mined for secondary metabolite biosynthetic genes coding for non-ribosomal peptide synthetases (NRPS), and polyketide synthases (PKS). The moonmilk Streptomyces collection was found to display strong inhibitory activities against a wide range of reference organisms, as 94%, 71%, and 94% of the isolates inhibited or impaired the growth of Gram-positive, Gram-negative bacteria, and fungi, respectively. Interestingly, 90% of the cave strains induced strong growth suppression against the multi-drug resistant Rasamsonia argillacea, a causative agent of invasive mycosis in cystic fibrosis and chronic granulomatous diseases. No correlation was observed between the global antimicrobial activity of an individual strain and the number of NRPS and PKS genes predicted in its genome, suggesting that approaches for awakening cryptic metabolites biosynthesis should be applied to isolates with no antimicrobial phenotype. Overall, our work supports the common belief that moonmilk might effectively treat various infectious diseases thanks to the presence of a highly diverse population of prolific antimicrobial producing Streptomyces, and thus may indeed constitute a promising reservoir of potentially novel active natural compounds

Streptomyces from Moonmilk, an Untapped Source of New Bioactive Compounds

Moonmilk speleothems of limestone caves host a rich microbiome, among which Actinobacteria represent one of the most abundant phyla. Ancient medical texts reported that moonmilk had therapeutical properties, thereby suggesting that its filamentous endemic actinobacterial population might be a source of natural products useful in human treatment. In this work, a screening approach was undertaken in order to isolate cultivable Actinobacteria from moonmilk of the Grotte des Collemboles in Belgium, to evaluate their taxonomic profile, and to assess their potential in biosynthesis of antimicrobials. Phylogenetic analysis revealed that all 78 isolates were exclusively affiliated to the genus Streptomyces and clustered into 31 distinct phylotypes displaying various pigmentation patterns and morphological features. Phylotype representatives were tested for antibacterial and antifungal activities and their genomes were mined for secondary metabolite biosynthetic genes coding for non-ribosomal peptide synthetases (NRPSs), and polyketide synthases (PKS). The moonmilk Streptomyces collection was found to display strong inhibitory activities against a wide range of reference organisms, as 94, 71, and 94% of the isolates inhibited or impaired the growth of Gram-positive, Gram-negative bacteria, and fungi, respectively. Interestingly, 90% of the cave strains induced strong growth suppression against the multi-drug resistant Rasamsonia argillacea, a causative agent of invasive mycosis in cystic fibrosis and chronic granulomatous diseases. We are currently identifying molecules responsible for the observed antimicrobial activities which, next to few known bioactive compounds, also reveals many active compounds with molecular masses that do not correspond to known antibiotic deposited in web biomolecules databases such as KNapSAcK, Pubchem, Chemspider. The challenge is to increase the production yields of these unknown compounds, and purify them to further characterize their structure by NMR. Overall, our work supports the common belief that moonmilk might effectively treat various infectious diseases thanks to the presence of a highly diverse population of prolific antimicrobial producing Streptomyces, and thus may indeed constitute a promising reservoir of potentially novel active natural compounds.Carractérisation du métabolisme secondaire des Streptomyces d'origine karstiqu