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Ítem Acceso Abierto A coiled coil switch mediates cold sensing by the thermosensory protein DesK(Wiley, 2015-10-08) Saita, Emilio Adolfo; Abriata, Luciano Andrés; Tsai, Yi-Ting; Trajtenberg, Felipe; Lemmin, Thomas; Buschiazzo, Alejandro; Dal Peraro, Matteo; De Mendoza, Diego; Albanesi, DanielaThe thermosensor histidine kinase DesK from Bacillus subtilis senses changes in membrane fluidity initiating an adaptive response. Structural changes in DesK have been implicated in transmembrane signaling, but direct evidence is still lacking. On the basis of structure-guided mutagenesis, we now propose a mechanism of DesK-mediated signal sensing and transduction. The data indicate that stabilization/destabilization of a 2-helix coiled coil, which connects the transmembrane sensory domain of DesK to its cytosolic catalytic region, is crucial to control its signaling state. Computational modeling and simulations reveal couplings between protein, water and membrane mechanics. We propose that membrane thickening is the main driving force for signal sensing and that it acts by inducing helix stretching and rotation prompting an asymmetric kinase-competent state. Overall, the known structural changes of the sensor kinase, as well as further dynamic rearrangements that we now predict, consistently link structure determinants to activity modulation.Ítem Acceso Abierto A duo of Potassium-responsive Histidine Kinases govern the multicellular destiny of Bacillus subtilis(American Society for Microbiology, 2015-07-07) Grau, Roberto Ricardo; De Oña, Paula; Kunert, Maritta; Leñini, Cecilia; Gallegos Monterrosa, Ramses; Mhatre, Eisha; Vileta, Darío; Donato, Verónica; Hölscher, Theresa; Boland, Sebastian; Kuipers, Oscar P.; Kovács, Ákos T.; http://orcid.org/0000-0001-6430-7122; http://orcid.org/0000-0001-6784-2534Multicellular biofilm formation and surface motility are bacterial behaviors considered mutually exclusive. However, the basic decision to move over or stay attached to a surface is poorly understood. Here, we discover that in Bacillus subtilis, the key root biofilm-controlling transcription factor Spo0A~Pi (phosphorylated Spo0A) governs the flagellum-independent mechanism of social sliding motility. A Spo0A-deficient strain was totally unable to slide and colonize plant roots, evidencing the important role that sliding might play in natural settings. Microarray experiments plus subsequent genetic characterization showed that the machineries of sliding and biofilm formation share the same main components (i.e., surfactin, the hydrophobin BslA, exopolysaccharide, and de novo-formed fatty acids). Sliding proficiency was transduced by the Spo0A-phosphorelay histidine kinases KinB and KinC. We discovered that potassium, a previously known inhibitor of KinC-dependent biofilm formation, is the specific sliding-activating signal through a thus-far-unnoticed cytosolic domain of KinB, which resembles the selectivity filter sequence of potassium channels. The differential expression of the Spo0A~Pireporter abrB gene and the different levels of the constitutively active form of Spo0A, Sad67, in spo0A cells grown in optimized media that simultaneously stimulate motile and sessile behaviors uncover the spatiotemporal response of KinB and KinC to potassium and the gradual increase in Spo0A~Pi that orchestrates the sequential activation of sliding, followed by sessile biofilm formation and finally sporulation in the same population. Overall, these results provide insights into how multicellular behaviors formerly believed to be antagonistic are coordinately activated in benefit of the bacterium and its interaction with the host. IMPORTANCE Alternation between motile and sessile behaviors is central to bacterial adaptation, survival, and colonization. However, how is the collective decision to move over or stay attached to a surface controlled? Here, we use the model plantbeneficial bacterium Bacillus subtilis to answer this question. Remarkably, we discover that sessile biofilm formation and social sliding motility share the same structural components and the Spo0A regulatory network via sensor kinases, KinB and KinC. Potassium, an inhibitor of KinC-dependent biofilm formation, triggers sliding via a potassium-perceiving cytosolic domain of KinB that resembles the selectivity filter of potassium channels. The spatiotemporal response of these kinases to variable potassium levels and the gradual increase in Spo0A~Pi levels that orchestrates the activation of sliding before biofilm formation shed light on how multicellular behaviors formerly believed to be antagonistic work together to benefit the population fitness.Ítem Acceso Abierto A novel Tetrahymena thermophila sterol C-22 desaturase belongs to the fatty acid hydroxylase/desaturase superfamily(Elsevier, 2022-10) Sanchez Granel, María L.; Siburu, Nicolás G.; Fricska, Annamária; Maldonado, Lucas L.; Gargiulo, Laura B.; Nudel, Clara B.; Uttaro, Antonio Domingo; Nusblat, Alejandro D.Ítem Acceso Abierto A preliminary study of the virome of the South American Free-Tailed Bats (Tadarida brasiliensis) and identification of two novel mammalian viruses(MDPI, 2020-04-09) Bolatti, Elisa María; Zorec, Tomaž M.; Montani, María E.; Hošnjak, Lea; Chouhy, Diego; Viarengo, Gastón; Casal, Pablo E.; Barquez, Rubén M.; Poljak, Mario; Giri, Adriana Angélica; Irene Villa, German Saigo, Mauricio Taborda, and Violeta Di Domenica, for collecting bat samplesÍtem Acceso Abierto A serralysin-like protein of Candidatus Liberibacter asiaticus modulates components of the bacterial extracellular matrix(2022-10) García, Lucila; Molina, María Celeste; Padgett Pagliai, Kaylie Allyson; Torres, Pablo S.; Bruna, Roberto Emanuel; García Véscovi, Eleonora; González, Claudio F.; Gadea, José; Marano, María RosaÍtem Acceso Abierto Acinetobacter baumannii NCIMB8209: a rare environmental strain displaying extensive insertion sequence-mediated genome remodeling resulting in the loss of exposed cell structures and defensive mechanisms(American Society for Microbiology, 2020-07-29) Repizo, Guillermo Daniel; Espariz, Martín; Seravalle, Joana L.; Díaz Miloslavich, Juan Ignacio; Steimbrüch, Bruno A.; Shuman, Howard A.; Viale, Alejandro M.Ítem Acceso Abierto Acquisition of plasmids conferring carbapenem and aminoglycoside resistance and loss of surface-exposed macromolecule structures as strategies for the adaptation of Acinetobacter baumannii CC104O/CC15P strains to the clinical setting(Microbiology Society, 2020-03-26) Cameranesi, María Marcela; Paganini, Julián; Limansky, Adriana S.; Moran-Barrio, Jorgelina; Salcedo, Suzana P.; Viale, Alejandro M.; Repizo, Guillermo DanielÍtem Acceso Abierto Action of Colloidal Bismuth Hydroxide Gel and its Commercial Cream on Enteropathogens and Colonizers of the Gastrointestinal Tract(Wolters Kluwer, 2018-10) Subils, Tomás; Casabonne, Cecilia; González, Agustina; Aquili, Virginia; Balagué, Claudia ElizabethBackground: Acute diarrheal diseases constitute a world public health problem because they are the second cause of death in children under 5 years of age. Colloidal bismuth hydroxide gel (CBHG) is an active ingredient in low-cost, antidiarrhetic drugs for oral use; it does not inhibit intestinal motility, and it features very low intestinal absorption of <1%. Materials and Methods: We analyzed the sensitivity by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC); the effect on bacterial growth by studying the specific growth velocity and the generation time in growth curves; and bacterial attachment by counting viable plaques, of enteropathogenic Escherichia coli, shigatoxigenic E. coli O157:H7, Klebsiella pneumoniae, Salmonella spp., and Shigella flexneri in the commercial cream (Chobet® bismuth cream with pectin [CBCHP]), its active ingredient (CBHG), and its excipients (E) separately. Results: CBCHP: MIC 6–10 mg/ml and MBC 7.5–15 mg/ml of bismuth; CBHG: MIC 6–10 mg/ml of bismuth. E: No inhibition was observed at the concentration studied in this study. At very low subinhibitory concentrations of CBCHP and CBHG, there was already evidence of a significant decrease in growth, which could not be recorded for E. CBCHP and CBHG presented an elevated capacity for bacterial displacement, significantly greater than E. Conclusions: We believed that the results obtained in this study are very promising from the treatment standpoint, as a possible treatment for cases of diagnosis or suspicion of bacterial gastroenteritis. The antimicrobial and attachment effects of CBCHP are exclusively due to its active ingredient CBHG; these effects are promoted in the presence of E.Ítem Acceso Abierto Alpha-tubulin acetylation in Trypanosoma cruzi: a dynamic instabilityof microtubules is required for replication and cell cycle progression(Frontiers Media, 2021-03-11) Alonso, Victoria Lucía; Carloni, Mara Emilia; Silva Gonçalves, Camila; Martínez Peralta, Gonzálo; Chesta, Maria Eugenia; Pezza, Alejandro; Tavernelli, Luis Emilio; Motta, María Cristina M.; Serra, Esteban CarlosTrypanosomatids have a cytoskeleton arrangement that is simpler than what is found in most eukaryotic cells. However, it is precisely organized and constituted by stable microtubules. Such microtubules compose the mitotic spindle during mitosis, the basal body, the flagellar axoneme and the subpellicular microtubules, which are connected to each other and also to the plasma membrane forming a helical arrangement along the central axis of the parasite cell body. Subpellicular, mitotic and axonemal microtubules are extensively acetylated in Trypanosoma cruzi. Acetylation on lysine (K) 40 of a-tubulin is conserved from lower eukaryotes to mammals and is associated with microtubule stability. It is also known that K40 acetylation occurs significantly on flagella, centrioles, cilia, basal body and the mitotic spindle in eukaryotes. Several tubulin posttranslational modifications, including acetylation of K40, have been cataloged in trypanosomatids, but the functional importance of these modifications for microtubule dynamics and parasite biology remains largely undefined. The primary tubulin acetyltransferase was recently identified in several eukaryotes as Mec-17/ATAT, a Gcn5-related N-acetyltransferase. Here, we report that T. cruzi ATAT acetylates a-tubulin in vivo and is capable of autoacetylation. TcATAT is located in the cytoskeleton and flagella of epimastigotes and colocalizes with acetylated a-tubulin in these structures. We have expressed TcATAT with an HA tag using the inducible vector pTcINDEX-GW in T. cruzi. Over-expression of TcATAT causes increased levels of the alpha tubulin acetylated species, induces morphological and ultrastructural defects, especially in the mitochondrion, and causes a halt in the cell cycle progression of epimastigotes, which is related to an impairment of the kinetoplast division. Finally, as a result of TcATAT over-expression we observed thatÍtem Acceso Abierto Analysis of the genetic diversity and phylogenetic relationships of putative human papillomavirus types(2013-11) Chouhy, Diego; Bolatti, Elisa María; Perez, Germán Roberto; Giri, Adriana AngélicaÍtem Acceso Abierto Assessing Gammapapillomavirus infections of mucosal epithelia with two broad-spectrum PCR protocols(BMC, 2020-04-07) Bolatti, Elisa María; Hošnjak, Lea; Chouhy, Diego; Casal, Pablo E.; Re Louhau, María F.; Bottai, Hebe; Komloš , Kristina Fujs; Poljak, Mario; Giri, Adriana Angélica; https://orcid.org/0000-0003-4925-9075Background: Human papillomaviruses (HPVs) have been divided into mucosal and cutaneous types according to their primary epithelial tissue tropism. However, recent studies showed the presence of several cutaneous types in mucosal lesions and healthy mucosa from different anatomical sites. Methods: Here, the HPV prevalence and type-specific distribution were assessed in a variety of mucosal samples from 435 individuals using a combination of two established broad-spectrum primer systems: Gamma-PV PCR and CUT PCR. Results: Overall HPV prevalence in anal canal swabs, cervical cancer biopsies, genital warts and oral swabs was 85, 47, 62 and 4%, respectively. In anal canal swabs, Alpha-PVs were most frequently found (59%), followed by Gamma-(37%) and Beta-PVs (4%). The prevalence and persistence of HPV infection in the anal canal of 226 individuals were further explored. Overall HPV, Gamma-PVs and multiple HPV infections were significantly higher in men vs. women (p = 0.034, p = 0.027 and p = 0.003, respectively); multiple HPV infections were more common in individuals ≤40 years (p = 0.05), and significantly higher prevalence of Gamma-PVs and multiple HPV infections was observed in HIV-1-positive vs. HIV-1-negative individuals (p = 0.003 and p = 0.04, respectively). Out of 21 patients with follow-up anal swabs, only one persistent infection with the same type (HPV58) was detected. Conclusions: Our findings suggest that Gamma-PVs (except species Gamma-6) are ubiquitous viruses with dual muco-cutaneous tissue tropism. Anal canal Gamma-PV infections may be associated with sexual behavior and the host immune status. This study expands the knowledge on Gamma-PVs’ tissue tropism, providing valuable data on the characteristics of HPV infection in the anal canal.Ítem Acceso Abierto Assessment of Chemosensory Response to Volatile Compounds in Healthy, Aged, and Neurodegenerative Caenorhabditis elegans Models(Bio-protocol L.L.C., 2023-05-05) Grau, Roberto Ricardo; Crespo, CiraA basic function of the nervous system is to confer the ability to detect external stimuli and generate appropriate behavioral and physiological responses. These can be modulated when parallel streams of information are provided to the nervous system and neural activity is appropriately altered. The nematode Caenorhabditis elegans utilizes a simple and well characterized neural circuit to mediate avoidance or attraction responses to stimuli, such as the volatile odorant octanol or diacetyl (DA), respectively. Aging and neurodegeneration constitute two important factors altering the ability to detect external signals and, therefore, changing behavior. Here, we present a modified protocol to assess avoidance or attraction responses to diverse stimuli in healthy individuals and Caenorhabditis elegans models associated with neurodegenerative diseases.Ítem Acceso Abierto Bacillus subtilis biofilm extends Caenorhabditis elegans longevity through downregulation of the insulin-like signalling pathway(Nature, 2017-01-30) Donato, Verónica; Rodríguez Ayala, Facundo; Cogliati, Sebastián; Bauman, Carlos; Costa, Juan Gabriel; Leñini, Cecilia; Grau, Roberto RicardoÍtem Acceso Abierto Bioinformatic analysis of the Type VI Secretion System and its potential toxins in the Acinetobacter genus(Frontiers Media, 2019-11-01) Repizo, Guillermo Daniel; Espariz, Martín; Seravalle, Joana L.; Salcedo, Suzana P.Ítem Acceso Abierto Catalases of the polyextremophylic andean isolate Acinetobacter sp. Ver 3 confer adaptive response to H2O2 and UV radiation(Wiley, 2020-02-09) Sartorio, Mariana Gabriela; Repizo, Guillermo Daniel; Cortez, Néstor; https://orcid.org/0000-0003-1318-8738; Perdomo, Virginia: assistance with qRT-PCR measurements; Dr. Carrillo, Néstor: review of the manuscriptThe polyextremophilic strain Acinetobacter sp. Ver3 isolated from high-altitude Andean lakes exhibits elevated tolerance to UV-B radiation and to pro-oxidants, a feature that has been correlated to its unusually high catalase activity. The Ver3 genome sequence analysis revealed the presence of two genes coding for monofunctional catalases: AV3KatE1 and AV3KatE2, the latter harboring an N-terminal signal peptide. We show herein that AV3KatE1 displays one of the highest catalytic activities reported so far and is constitutively expressed at relatively high amounts in the cytosol, acting as the main protecting catalase against H2O2 and UV-B radiation. The second catalase, AV3KatE2, is a periplasmic enzyme strongly induced by both peroxide and UV, conferring supplementary protection against pro-oxidants. The N-terminal signal present in AV3KatE2 was required not only for transport to the periplasm via the twin-arginine translocation pathway, but also for proper folding and subsequent catalytic activity. The analysis of catalase distribution among 114 Acinetobacter complete genomes revealed a great variability in the catalase classes, with A. baumannii clinical isolates exhibiting higher numbers of isoenzymes and the most variable profiles.Ítem Acceso Abierto Cerulenin inhibits unsaturated fatty acids synthesis in Bacillus subtilis by modifying the input signal of DesK thermosensor(Wiley, 2014-04-09) Porrini, Lucía; Cybulski, Larisa Estefanía; Altabe, Silvia Graciela; Mansilla, María Cecilia; De Mendoza, DiegoBacillus subtilis responds to a sudden decrease in temperature by transiently inducing the expression of the des gene encoding for a lipid desaturase, Δ5-Des, which introduces a double bond into the acyl chain of preexisting membrane phospholipids. This Δ5-Des-mediated membrane remodeling is controlled by the cold-sensor DesK. After cooling, DesK activates the response regulator DesR, which induces transcription of des. We show that inhibition of fatty acid synthesis by the addition of cerulenin, a potent and specific inhibitor of the type II fatty acid synthase, results in increased levels of short-chain fatty acids (FA) in membrane phospholipids that lead to inhibition of the transmembrane-input thermal control of DesK. Furthermore, reduction of phospholipid synthesis by conditional inactivation of the PlsC acyltransferase causes significantly elevated incorporation of long-chain FA and constitutive upregulation of the des gene. Thus, we provide in vivo evidence that the thickness of the hydrophobic core of the lipid bilayer serves as one of the stimulus sensed by the membrane spanning region of DesK.Ítem Acceso Abierto Characterization of the diverse plasmid pool harbored by the blaNDM-1-containing Acinetobacter bereziniae HPC229 clinical strain(Public Library of Science (PLOS), 2019-11-19) Brovedan, Marco Alcides; Repizo, Guillermo Daniel; Marchiaro, Patricia M.; Viale, Alejandro M.; Limansky, Adriana S.Ítem Acceso Abierto Comparative genomic and phylogenetic analyses of gammaproteobacterial glg genes traced the origin of the Escherichia coli glycogen glgBXCAP pperon to the last common ancestor of the sister orders enterobacteriales and pasteurellales(Public Library of Science, 2015-01-21) Almagro, Goizeder; Viale, Alejandro M.; Montero, Manuel; Rahimpour, Mehdi; Muñoz, Francisco José; Baroja Fernández, Edurne; Bahaji, Abdellatif; Zúñiga, Manuel; González Candelas, Fernando; Pozueta Romero, JavierProduction of branched α-glucan, glycogen-like polymers is widely spread in the Bacteria domain. The glycogen pathway of synthesis and degradation has been fairly well characterized in the model enterobacterial species Escherichia coli (order Enterobacteriales, class Gammaproteobacteria), in which the cognate genes (branching enzyme glgB, debranching enzyme glgX, ADP-glucose pyrophosphorylase glgC, glycogen synthase glgA, and glycogen phosphorylase glgP) are clustered in a glgBXCAP operon arrangement. However, the evolutionary origin of this particular arrangement and of its constituent genes is unknown. Here, by using 265 complete gammaproteobacterial genomes we have carried out a comparative analysis of the presence, copy number and arrangement of glg genes in all lineages of the Gammaproteobacteria. These analyses revealed large variations in glg gene presence, copy number and arrangements among different gammaproteobacterial lineages. However, the glgBXCAP arrangement was remarkably conserved in all glg-possessing species of the orders Enterobacteriales and Pasteurellales (the E/P group). Subsequent phylogenetic analyses of glg genes present in the Gammaproteobacteria and in other main bacterial groups indicated that glg genes have undergone a complex evolutionary history in which horizontal gene transfer may have played an important role. These analyses also revealed that the E/P glgBXCAP genes (a) share a common evolutionary origin, (b) were vertically transmitted within the E/P group, and (c) are closely related to glg genes of some phylogenetically distant betaproteobacterial species. The overall data allowed tracing the origin of the E. coli glgBXCAP operon to the last common ancestor of the E/P group, and also to uncover a likely glgBXCAP transfer event from the E/P group to particular lineages of the Betaproteobacteria.Ítem Acceso Abierto Complete genome sequence of the Microbacterium foliorum bacteriophage Garey24(American Society for Microbiology, 2024-02-05) Migueletti, Matías R.; García Rey, Julieta; Micheloni, Josefina; Lomanto , Camila; Martelli, Elisa; Sánchez, Gastón; Colombo, Julián M.; Vallecillo, Luciano M.; Lamagni, Francisco; Giusti, Tomás; Acosta, Fabrina; Villagrán, Franco; Gvozdenovich, Martín; Pricco Frakich, Abril; Pianesi, Tulio; Tulin, Gonzalo; Mascali, Florencia Carla; Petitti, Tomás D.; Torres Manno, Mariano A.; Fusari, Corina M.; Buttigliero, Laura; Giordana, María Florencia; Gramajo, Hugo Cesar; Diacovich, Lautaro; Espariz, Martín; Mussi, María Alejandra; http://orcid.org/0000-0002-3339-0100; http://orcid.org/0000-0002-4090-515X; http://orcid.org/0000-0002-4168-3624In this work, we report the discovery and characterization of Garey24, a bacteriophage that forms medium-size plaques with halo rings isolated from a soil sample in Funes, Argentina. Its 41,522 bp circularly permuted genome contains 63 putative protein-coding genes. Based on gene content similarity, Garey24 was assigned to subcluster EA1.Ítem Acceso Abierto Complete sequence of a blaNDM-1-harboring plasmid in an Acinetobacter bereziniae clinical strain isolated in Argentina(American Society for Microbiology, 2015-10) Brovedan, Marco Alcides; Marchiaro, Patricia M.; Morán-Barrio, Jorgelina; Cameranesi, Marcela; Cera, Gabriela; Rinaudo, Mariangel; Viale, Alejandro M.; Limansky, Adriana S.