Factores predictivos de desarrollo y evolución de infección activa por citomegalovirus en el transplante alogénico de precursores hematopoyéticos

Citomegalovirus (CMV) es una causa elevada de morbimortalidad en el receptor de trasplante alogénico de precursores hematopoyéticos (alo-TPH). Con la introducción de fármacos específicos frente al virus el riesgo de sufrir enfermedad orgánica por CMV de estos pacientes se ha reducido notablemente; siendo el tratamiento anticipado la estrategia terapéutica más extendida en el manejo de la infección por CMV en el alo-TPH. Sin embargo, esta estrategia es mejorable. En este sentido, nos propusimos analizar una serie de factores que influyen en la monitorización virológica, la cual es inherente a la estrategia de tratamiento anticipado. Dada la elevada variación inter-ensayo e intercentro de las distintas técnicas QRT-PCR disponibles en el mercado, no es posible la comparación de experiencias entre hospitales. Por ello propusimos que el análisis de la cinética de la ADNemia de CMV en sangre (tiempo de duplicación, Td) permitiría esta comparación, habida cuenta de la exquisita linealidad que tienen los ensayos QRT-PCR en su rango de cuantificación. Se diseñó un panel de muestras de plasma que recreaba 3 situaciones clínicas diferentes y se remitió a 9 laboratorios. Todos ellos categorización correctamente la tercera situación y hubo gran concordancia en las otras dos. Además, esta monitorización se puede hacer en plasma (PL) o sangre completa (SC). Analizamos 245 pares de PL y SC procedentes de 43 episodios de ADNemia de CMV. En general, la carga viral de CMV fue mayor en PL que en SC. También fue así en pares de muestras tras el inicio del tratamiento antiviral, pero no en las pre-tratamiento. Además, el recuento total de leucocitos también afectó significativamente a la cuantificación de la carga de ADN de CMV en ambas matrices. En línea con todo lo anterior, analizamos las interacciones sinérgicas entre CMV y bacterias en el post-trasplante inmediato ya que podrían ser un factor de riesgo para el desarrollo de infección activa por CMV. La incidencia acumulada de ADNemia de CMV no fue significativamente diferente estuviera precedida o no de una infección bacteriana (p =0,189). Además, el debut de la infección bacteriana durante el episodio de infección activa por CMV no tuvo impacto en la cinética de la ADNemia de CMV. Por otro lado, un factor que se ha asociado con mayores cargas de CMV y un retraso en el aclaramiento del virus en el trasplante de órgano sólido ha sido la complejidad genética de CMV. En esta tesis nos propusimos analizar si también ocurría en el alo-TPH. El genotipado de CMV se realizó por secuenciación masiva de los genes que codifican para gN y gO. Los episodios producidos por poblaciones mixtas de CMV tuvieron mayores picos de carga de ADN de CMV, episodios más largos de ADNemia y tasas de aclaramiento más lentas que aquellos episodios producidos por una sola variante de CMV. Sin embargo, la duración del tratamiento antiviral hasta alcanzar el aclarado de la ADNemia de CMV fue significativamente mayor en las infecciones mixtas

Inhibition of LpxC Increases the Activity of Iron Chelators and Gallium Nitrate in Multidrug-Resistant Acinetobacter baumannii

Infections caused by multidrug-resistant Acinetobacter baumannii would benefit from the development of novel treatment approaches. Compounds that interfere with bacterial iron metabolism, such as iron chelators and gallium nitrate, have previously been shown to have antimicrobial activity against A. baumannii. In this study, we characterize the effect of LpxC inhibitors on the antimicrobial activity of previously characterized iron chelators, 2,2'-bipyridyl (BIP) and deferiprone (DFP), and gallium nitrate (Ga(NO3)3) against A. baumannii reference strains and multidrug-resistant clinical isolates. The LpxC inhibitor LpxC-2 was synergistic with BIP for 30% of strains tested (FICI values: 0.38-1.02), whereas inhibition with LpxC-4 was synergistic with BIP for 60% of strains tested (FICI values: 0.09-0.75). In time-kill assays, combinations of BIP with both LpxC inhibitors demonstrated synergistic activity, with a more than 3 log10 reduction in bacterial counts compared to BIP alone. LpxC-2 was synergistic with Ga(NO3)3 for 50% of strains tested (FICI values: 0.27-1.0), whereas LpxC-4 was synergistic with Ga(NO3)3 for all strains tested (FICI values: 0.08-≤0.50). In time-kill assays, combinations of Ga(NO3)3 with LpxC-2 and LpxC-4 decreased the growth of both strains compared to each compound separately; however, only the combination with LpxC-4 met the defined criteria for synergy. These results identify a novel synergy between two antimicrobial classes against A. baumannii strains.This research was supported by grants MPY 380/18 from the Instituto de Salud Carlos III (ISCIII) awarded to M.J.M. V.V. is supported by the Río Hortega Program from the Instituto de Salud Carlos III. The APC was funded by MPY 380/18 from the Instituto de Salud Carlos III (ISCIII) awarded to M.J.M.S

Genomic lineages of Rhizobium etli revealed by the extent of nucleotide polymorphisms and low recombination

<p>Abstract</p> <p>Background</p> <p>Most of the DNA variations found in bacterial species are in the form of single nucleotide polymorphisms (SNPs), but there is some debate regarding how much of this variation comes from mutation versus recombination. The nitrogen-fixing symbiotic bacteria <it>Rhizobium etli </it>is highly variable in both genomic structure and gene content. However, no previous report has provided a detailed genomic analysis of this variation at nucleotide level or the role of recombination in generating diversity in this bacterium. Here, we compared draft genomic sequences versus complete genomic sequences to obtain reliable measures of genetic diversity and then estimated the role of recombination in the generation of genomic diversity among <it>Rhizobium etli</it>.</p> <p>Results</p> <p>We identified high levels of DNA polymorphism in <it>R. etli</it>, and found that there was an average divergence of 4% to 6% among the tested strain pairs. DNA recombination events were estimated to affect 3% to 10% of the genomic sample analyzed. In most instances, the nucleotide diversity (π) was greater in DNA segments with recombinant events than in non-recombinant segments. However, this degree of recombination was not sufficiently large to disrupt the congruence of the phylogenetic trees, and further evaluation of recombination in strains quartets indicated that the recombination levels in this species are proportionally low.</p> <p>Conclusion</p> <p>Our data suggest that <it>R. etli </it>is a species composed of separated lineages with low homologous recombination among the strains. Horizontal gene transfer, particularly via the symbiotic plasmid characteristic of this species, seems to play an important role in diversity but the lineages maintain their evolutionary cohesiveness.</p

Phylogenomic Rhizobium Species Are Structured by a Continuum of Diversity and Genomic Clusters

The bacterial genus Rhizobium comprises diverse symbiotic nitrogen-fixing species associated with the roots of plants in the Leguminosae family. Multiple genomic clusters defined by whole genome comparisons occur within Rhizobium, but their equivalence to species is controversial. In this study we investigated such genomic clusters to ascertain their significance in a species phylogeny context. Phylogenomic inferences based on complete sets of ribosomal proteins and stringent core genome markers revealed the main lineages of Rhizobium. The clades corresponding to R. etli and R. leguminosarum species show several genomic clusters with average genomic nucleotide identities (ANI &gt; 95%), and a continuum of divergent strains, respectively. They were found to be inversely correlated with the genetic distance estimated from concatenated ribosomal proteins. We uncovered evidence of a Rhizobium pangenome that was greatly expanded, both in its chromosomes and plasmids. Despite the variability of extra-chromosomal elements, our genomic comparisons revealed only a few chromid and plasmid families. The presence/absence profile of genes in the complete Rhizobium genomes agreed with the phylogenomic pattern of species divergence. Symbiotic genes were distributed according to the principal phylogenomic Rhizobium clades but did not resolve genome clusters within the clades. We distinguished some types of symbiotic plasmids within Rhizobium that displayed different rates of synonymous nucleotide substitutions in comparison to chromosomal genes. Symbiotic plasmids may have been repeatedly transferred horizontally between strains and species, in the process displacing and substituting pre-existing symbiotic plasmids. In summary, the results indicate that Rhizobium genomic clusters, as defined by whole genomic identities, might be part of a continuous process of evolutionary divergence that includes the core and the extrachromosomal elements leading to species formation

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Bone-cracking hyenas (Carnivora, Hyaenidae) from the European Neogene and Quaternary: taxonomy, paleobiology and evolution

La familia Hyaenidae (Mammalia, Carnivora) incluye actualmente cuatro especies, que están restringidas a África y Asia: las hienas rompedoras de huesos (Crocuta crocuta, Hyaena hyaena, Parahyaena brunnea) y el mirmecófago lobo de tierra (Proteles cristata). Durante el Neógeno y el Cuaternario, las hienas tenían mayor diversidad y se distribuían ampliamente por todo el Viejo Mundo y parte de Norteamérica, aunque su diversidad y disparidad ecomorfológica fueron disminuyendo progresivamente desde finales del Mioceno. El origen y diversificación de los hiénidos sigue siendo objeto de controversias. Esta tesis tiene como objetivo abordar algunas de estas problemáticas mediante el estudio ​de nuevos restos y el uso de técnicas innovadoras. Esta tesis está formada por un compendio de artículos, organizados en dos bloques: el primero consta de cinco publicaciones sobre hiénidos extintos (Hyaenictis, Pliocrocuta y Pachycrocuta), principalmente dedicadas a la descripción y comparación morfométrica de fósiles inéditos y sus problemas taxonómicos, con énfasis en las adaptaciones dentales a la durofagia; el segundo bloque se centra en el estudio la anatomía craneal interna de los hiénidos extintos (Pliocrocuta, Crocuta), obtenida mediante écnicas de visualización aplicadas a escáneres de tomografía computarizada (CT), con especial énfasis en la morfología cerebral y sus proporciones, en base a las cuales se pueden realizar inferencias paleobiológicas sobre el comportamiento social de cada especie. Las conclusiones principales de la tesis se pueden agrupar de la siguiente manera: 1. Taxonomía: el material inédito de Ronda Oest de Sabadell (Mioceno superior), La Puebla de Valverde y Villarroya (Plioceno Superior-Pleistoceno Inferior) y Cueva Victoria (Pleistoceno Inferior tardío) se atribuye, respectivamente, a Hyaenictis aff. almerai, Pliocrocuta perrieri y Pachycrocuta brevirostris. La autoría de este último se corrige de "Aymard, 1846" a "Gervais, 1850". Diferencias en la morfología cerebral, tanto en Crocuta spelaea como en Crocuta ultima, con respecto a Crocuta crocuta apoyan su distinción con rango de especie. 2. Paleobiología: El estudio tafonómico de los grandes restos de herbívoros de la Sección de Vallparadís (Pleistoceno Inferior tardío) indica que Pachycrocuta brevirostris fue el principal agente modificador de huesos en el yacimiento. A su vez, los senos frontales desarrollados de Pliocrocuta perrieri, relacionados con la resistencia mejorada del cráneo durante las tensiones en la mordida, respaldan una dieta durófaga para esta especie. Esto se aplica también al patrón microestructural en zig-zag del esmalte de Pliocrocuta perrieri y Hyaenictis aff. almerai, que permite reasignar esta última al ecomorfotipo 5 (hienas rompedoras de huesos transicionales). La morfología cerebral de Pliocrocuta perrieri, Crocuta spelaea y Crocuta ultima se parece a la de las hienas actuales, aunque su lóbulo frontal está menos desarrollado que en Crocuta crocuta, lo que sugiere una menor complejidad del comportamiento social que la presente en esta última (comparable a las de Hyaena y Parahyaena). Los datos paleoneurológicos disponibles indican que el cerebro de los hiénidos evolucionó hacia una mayor complejidad y tamaño a lo largo del Mioceno y que Proteles presenta, probablemente, el cerebro más plesiomórfico entre hiénidos actuales. 3. Historia evolutiva: En base los nuevos datos morfofuncionales y paleoneurológicos presentados, se proponen nuevas hipótesis para la evolución de las hienas rompedoras de huesos, como el origen de los hyaeninos actuales a partir de Hyaenictis. Algunas de estas hipótesis difieren de los análisis cladísticos basados en morfología, pero están en mayor concordancia con los datos moleculares. Los resultados destacan el potencial del estudio de la morfología interna del craneo como posible fuente de datos filogenéticamente informativos que, en el futuro, podrían permitir un análisis filogenético más completos y más bien resueltos que podría zanjar algunos de los debates actuales sobre la historia evolutiva de los hiénidos.The family Hyaenidae (Mammalia, Carnivora) include four extant species restricted to Africa and Asia: the bone-cracking hyenas (Crocuta crocuta, Hyaena hyaena, Parahyaena brunnea) and the myrmecophagous aardwolf (Proteles cristata). During the Neogene and Quaternary, hyaenids were more diverse and widely distributed throughout the Old World and even North America, although their diversity and ecomorphological disparity progressively declined since the late Miocene onwards. Many controversies remain about the origin and diversification of hyaenids. This dissertation aims to address some of these topics based on new remains and innovative techniques. It includes a compendium of published articles, organized in two blocks: the first consists of five papers about extinct hyaenids (Hyaenictis, Pliocrocuta and Pachycrocuta), mostly devoted to the morphological description and morphometric comparison of previously unpublished fossils and related taxonomic issues, with emphasis on dental adaptations to durophagy; the second block relies on 3D imaging techniques applied to computed tomography (CT) scans to study the internal cranial anatomy of extinct hyaenids (Pliocrocuta, Crocuta), with emphasis on brain morphology and proportions to derive paleoneurological inferences on social behavior. The main conclusions of the dissertation may be grouped as follows: 1. Taxonomy: The unpublished material from Ronda Oest de Sabadell (late Miocene), La Puebla de Valverde and Villarroya (Late Pliocene-Early Pleistocene), and Cueva Victoria (Late Early Pleistocene) is attributed, respectively, to Hyaenictis aff. almerai, Pliocrocuta perrieri, and Pachycrocuta brevirostris. The authorship of the latter is corrected from “Aymard, 1846” to “Gervais, 1850”. Differences in brain morphology support the distinction of both Crocuta spelaea and Crocuta ultima from Crocuta crocuta at the species rank. 2. Paleobiology: The taphonomic study of the large herbivore remains from the Vallparadís Section (Late Early Pleistocene) indicates that Pachycrocuta brevirostris was the main bone modificator agent in the site. In turn, the developed frontal sinuses of Pliocrocuta perrieri, related to improved skull resistance against bite stresses, support a durophagous diet for this species, and the same holds for the zig-zag enamel microstructural pattern of both Pliocrocuta perrieri and Hyaenictis aff. almerai, which enable to reassign the latter to the transitional bone-cracking ecomorphotype 5. With regard to brain morphology, Pliocrocuta perrieri, Crocuta spelaea and Crocuta ultima resemble extant hyaenines, although their frontal lobe is less developed than in Crocuta crocuta, suggesting a less complex social behavior than in the latter species (comparable to that of Hyaena and Parahyaena). Currently available paleoneurological evidence indicates that the hyaenid brain evolved towards greater relative size and complexity throughout the Miocene and that Proteles probably displays the most plesiomorphic brain among extant hyaenids. 3. Evolutionary history: Based on the new morphofunctional and paleoneurological evidence presented, new hypotheses for the evolution of bone-cracking hyaenids are proposed, such as the origin of hyaenines from Hyaenictis. Some of these hypotheses differ from those supported by morphology-based cladistic analyses but are in greater agreement with molecular evidence. The results highlight the potential of cranial internal morphology as a source of phylogenetically informative data that, in the future, might hopefully enable more comprehensive and better resolved phylogenetic analyses that could settle some of the current debates about the evolutionary history of hyaenids

Bone-cracking hyenas (Carnivora, Hyaenidae) from the European Neogene and Quaternary: taxonomy, paleobiology and evolution

La familia Hyaenidae (Mammalia, Carnivora) incluye actualmente cuatro especies, que están restringidas a África y Asia: las hienas rompedoras de huesos (Crocuta crocuta, Hyaena hyaena, Parahyaena brunnea) y el mirmecófago lobo de tierra (Proteles cristata). Durante el Neógeno y el Cuaternario, las hienas tenían mayor diversidad y se distribuían ampliamente por todo el Viejo Mundo y parte de Norteamérica, aunque su diversidad y disparidad ecomorfológica fueron disminuyendo progresivamente desde finales del Mioceno. El origen y diversificación de los hiénidos sigue siendo objeto de controversias. Esta tesis tiene como objetivo abordar algunas de estas problemáticas mediante el estudio ​de nuevos restos y el uso de técnicas innovadoras. Esta tesis está formada por un compendio de artículos, organizados en dos bloques: el primero consta de cinco publicaciones sobre hiénidos extintos (Hyaenictis, Pliocrocuta y Pachycrocuta), principalmente dedicadas a la descripción y comparación morfométrica de fósiles inéditos y sus problemas taxonómicos, con énfasis en las adaptaciones dentales a la durofagia; el segundo bloque se centra en el estudio la anatomía craneal interna de los hiénidos extintos (Pliocrocuta, Crocuta), obtenida mediante écnicas de visualización aplicadas a escáneres de tomografía computarizada (CT), con especial énfasis en la morfología cerebral y sus proporciones, en base a las cuales se pueden realizar inferencias paleobiológicas sobre el comportamiento social de cada especie. Las conclusiones principales de la tesis se pueden agrupar de la siguiente manera: 1. Taxonomía: el material inédito de Ronda Oest de Sabadell (Mioceno superior), La Puebla de Valverde y Villarroya (Plioceno Superior-Pleistoceno Inferior) y Cueva Victoria (Pleistoceno Inferior tardío) se atribuye, respectivamente, a Hyaenictis aff. almerai, Pliocrocuta perrieri y Pachycrocuta brevirostris. La autoría de este último se corrige de "Aymard, 1846" a "Gervais, 1850". Diferencias en la morfología cerebral, tanto en Crocuta spelaea como en Crocuta ultima, con respecto a Crocuta crocuta apoyan su distinción con rango de especie. 2. Paleobiología: El estudio tafonómico de los grandes restos de herbívoros de la Sección de Vallparadís (Pleistoceno Inferior tardío) indica que Pachycrocuta brevirostris fue el principal agente modificador de huesos en el yacimiento. A su vez, los senos frontales desarrollados de Pliocrocuta perrieri, relacionados con la resistencia mejorada del cráneo durante las tensiones en la mordida, respaldan una dieta durófaga para esta especie. Esto se aplica también al patrón microestructural en zig-zag del esmalte de Pliocrocuta perrieri y Hyaenictis aff. almerai, que permite reasignar esta última al ecomorfotipo 5 (hienas rompedoras de huesos transicionales). La morfología cerebral de Pliocrocuta perrieri, Crocuta spelaea y Crocuta ultima se parece a la de las hienas actuales, aunque su lóbulo frontal está menos desarrollado que en Crocuta crocuta, lo que sugiere una menor complejidad del comportamiento social que la presente en esta última (comparable a las de Hyaena y Parahyaena). Los datos paleoneurológicos disponibles indican que el cerebro de los hiénidos evolucionó hacia una mayor complejidad y tamaño a lo largo del Mioceno y que Proteles presenta, probablemente, el cerebro más plesiomórfico entre hiénidos actuales. 3. Historia evolutiva: En base los nuevos datos morfofuncionales y paleoneurológicos presentados, se proponen nuevas hipótesis para la evolución de las hienas rompedoras de huesos, como el origen de los hyaeninos actuales a partir de Hyaenictis. Algunas de estas hipótesis difieren de los análisis cladísticos basados en morfología, pero están en mayor concordancia con los datos moleculares. Los resultados destacan el potencial del estudio de la morfología interna del craneo como posible fuente de datos filogenéticamente informativos que, en el futuro, podrían permitir un análisis filogenético más completos y más bien resueltos que podría zanjar algunos de los debates actuales sobre la historia evolutiva de los hiénidos.The family Hyaenidae (Mammalia, Carnivora) include four extant species restricted to Africa and Asia: the bone-cracking hyenas (Crocuta crocuta, Hyaena hyaena, Parahyaena brunnea) and the myrmecophagous aardwolf (Proteles cristata). During the Neogene and Quaternary, hyaenids were more diverse and widely distributed throughout the Old World and even North America, although their diversity and ecomorphological disparity progressively declined since the late Miocene onwards. Many controversies remain about the origin and diversification of hyaenids. This dissertation aims to address some of these topics based on new remains and innovative techniques. It includes a compendium of published articles, organized in two blocks: the first consists of five papers about extinct hyaenids (Hyaenictis, Pliocrocuta and Pachycrocuta), mostly devoted to the morphological description and morphometric comparison of previously unpublished fossils and related taxonomic issues, with emphasis on dental adaptations to durophagy; the second block relies on 3D imaging techniques applied to computed tomography (CT) scans to study the internal cranial anatomy of extinct hyaenids (Pliocrocuta, Crocuta), with emphasis on brain morphology and proportions to derive paleoneurological inferences on social behavior. The main conclusions of the dissertation may be grouped as follows: 1. Taxonomy: The unpublished material from Ronda Oest de Sabadell (late Miocene), La Puebla de Valverde and Villarroya (Late Pliocene-Early Pleistocene), and Cueva Victoria (Late Early Pleistocene) is attributed, respectively, to Hyaenictis aff. almerai, Pliocrocuta perrieri, and Pachycrocuta brevirostris. The authorship of the latter is corrected from “Aymard, 1846” to “Gervais, 1850”. Differences in brain morphology support the distinction of both Crocuta spelaea and Crocuta ultima from Crocuta crocuta at the species rank. 2. Paleobiology: The taphonomic study of the large herbivore remains from the Vallparadís Section (Late Early Pleistocene) indicates that Pachycrocuta brevirostris was the main bone modificator agent in the site. In turn, the developed frontal sinuses of Pliocrocuta perrieri, related to improved skull resistance against bite stresses, support a durophagous diet for this species, and the same holds for the zig-zag enamel microstructural pattern of both Pliocrocuta perrieri and Hyaenictis aff. almerai, which enable to reassign the latter to the transitional bone-cracking ecomorphotype 5. With regard to brain morphology, Pliocrocuta perrieri, Crocuta spelaea and Crocuta ultima resemble extant hyaenines, although their frontal lobe is less developed than in Crocuta crocuta, suggesting a less complex social behavior than in the latter species (comparable to that of Hyaena and Parahyaena). Currently available paleoneurological evidence indicates that the hyaenid brain evolved towards greater relative size and complexity throughout the Miocene and that Proteles probably displays the most plesiomorphic brain among extant hyaenids. 3. Evolutionary history: Based on the new morphofunctional and paleoneurological evidence presented, new hypotheses for the evolution of bone-cracking hyaenids are proposed, such as the origin of hyaenines from Hyaenictis. Some of these hypotheses differ from those supported by morphology-based cladistic analyses but are in greater agreement with molecular evidence. The results highlight the potential of cranial internal morphology as a source of phylogenetically informative data that, in the future, might hopefully enable more comprehensive and better resolved phylogenetic analyses that could settle some of the current debates about the evolutionary history of hyaenids

Recent Advances in Iron Chelation and Gallium-Based Therapies for Antibiotic Resistant Bacterial Infections.

Iron is essential for multiple bacterial processes and is thus required for host colonization and infection. The antimicrobial activity of multiple iron chelators and gallium-based therapies against different bacterial species has been characterized in preclinical studies. In this review, we provide a synthesis of studies characterizing the antimicrobial activity of the major classes of iron chelators (hydroxamates, aminocarboxylates and hydroxypyridinones) and gallium compounds. Special emphasis is placed on recent in-vitro and in-vivo studies with the novel iron chelator DIBI. Limitations associated with iron chelation and gallium-based therapies are presented, with emphasis on limitations of preclinical models, lack of understanding regarding mechanisms of action, and potential host toxicity. Collectively, these studies demonstrate potential for iron chelators and gallium to be used as antimicrobial agents, particularly in combination with existing antibiotics. Additional studies are needed in order to characterize the activity of these compounds under physiologic conditions and address potential limitations associated with their clinical use as antimicrobial agents.This research was supported by grants MPY 380/18 from the Instituto de Salud Carlos III (ISCIII) awarded to M.J.M. V.V. is supported by the Río Hortega Program from the Instituto de Salud Carlos III.S