Phylogenomics of Enterococcus faecalis from wild birds: new insights into host‐associated differences in core and accessory genomes of the species

Wild birds have been suggested to be reservoirs of antimicrobial resistant and/or pathogenic Enterococcus faecalis (Efs) strains, but the scarcity of studies and available sequences limit our understanding of the population structure of the species in these hosts. Here, we analysed the clonal and plasmid diversity of 97 Efs isolates from wild migratory birds. We found a high diversity, with most sequence types (STs) being firstly described here, while others were found in other hosts including some predominant in poultry. We found that pheromone‐responsive plasmids predominate in wild bird Efs while 35% of the isolates entirely lack plasmids. Then, to better understand the ecology of the sp…

Complete Genome Sequence of Acidaminococcus intestini RYC-MR95, a Gram-Negative Bacterium from the Phylum Firmicutes

ABSTRACT Acidaminococcus intestini belongs to the family Acidaminococcaceae , order Selenomonadales , class Negativicutes , phylum Firmicutes . Negativicutes show the double-membrane system of Gram-negative bacteria, although their chromosomal backbone is closely related to that of Gram-positive bacteria of the phylum Firmicutes . The complete genome of a clinical A. intestini strain is here presented.

Simulating the impact of non-pharmaceutical interventions limiting transmission in COVID-19 epidemics using a membrane computing model

Epidemics caused by microbial organisms are part of the natural phenomena of increasing biological complexity. The heterogeneity and constant variability of hosts, in terms of age, immunological status, family structure, lifestyle, work activities, social and leisure habits, daily division of time and other demographic characteristics make it extremely difficult to predict the evolution of epidemics. Such prediction is, however, critical for implementing intervention measures in due time and with appropriate intensity. General conclusions should be precluded, given that local parameters dominate the flow of local epidemics. Membrane computing models allows us to reproduce the objects (virus…

Mutational Events in Cefotaximase Extended-Spectrum β-Lactamases of the CTX-M-1 Cluster Involved in Ceftazidime Resistance

ABSTRACT CTX-M β-lactamases, which show a high cefotaxime hydrolytic activity, constitute the most prevalent extended-spectrum β-lactamase (ESBL) type found among clinical isolates. The recent explosive diversification of CTX-M enzymes seems to have taken place due to the appearance of more efficient enzymes which are capable of hydrolyzing both cefotaxime and ceftazidime, especially among the CTX-M-1 cluster. A combined strategy of in vitro stepwise evolution experiments using bla CTX-M-1 , bla CTX-M-3 , and bla CTX-M-10 genes and site-directed mutagenesis has been used to evaluate the role of ceftazidime and other β-lactam antibiotics in triggering the diversity found among enzymes belong…

Simulating multilevel dynamics of antimicrobial resistance in a membrane computing model

Membrane computing is a bio-inspired computing paradigm whose devices are the so-called membrane systems or P systems. The P system designed in this work reproduces complex biological landscapes in the computer world. It uses nested “membrane-surrounded entities” able to divide, propagate, and die; to be transferred into other membranes; to exchange informative material according to flexible rules; and to mutate and be selected by external agents. This allows the exploration of hierarchical interactive dynamics resulting from the probabilistic interaction of genes (phenotypes), clones, species, hosts, environments, and antibiotic challenges. Our model facilitates analysis of several aspects…

La historia natural de las epidemias

Intelligibility in microbial complex systems: Wittgenstein and the score of life

Knowledge in microbiology is reaching an extreme level of diversification and complexity, which paradoxically results in a strong reduction in the intelligibility of microbial life. In our days, the “score of life” metaphor is more accurate to express the complexity of living systems than the classic “book of life.” Music and life can be represented at lower hierarchical levels by music scores and genomic sequences, and such representations have a generational influence in the reproduction of music and life. If music can be considered as a representation of life, such representation remains as unthinkable as life itself. The analysis of scores and genomic sequences might provide mechanistic…

Epidemias ayer y hoy. Presentación del dossier

Un ecosistema malalt: la lluita contra la resistència a antibiòtics des d’una perspectiva global

La produccio antropogenica d'antibiotics ha provocat una malaltia dels ecosistemes microbians de dimensio planetaria, la repercussio mes immediata de la qual per a l'home es la intractabilitat de les infeccions. La comprensio del fenomen i les possibilitats d'intervencio requereixen nous metodes conceptuals, analitics i tecnologics.

A membrane computing simulator of trans-hierarchical antibiotic resistance evolution dynamics in nested ecological compartments (ARES)

In this article, we introduce ARES (Antibiotic Resistance Evolution Simulator) a software device that simulates P-system model scenarios with five types of nested computing membranes oriented to emulate a hierarchy of eco-biological compartments, i.e. a) peripheral ecosystem; b) local environment; c) reservoir of supplies; d) animal host; and e) host's associated bacterial organisms (microbiome). Computational objects emulating molecular entities such as plasmids, antibiotic resistance genes, antimicrobials, and/or other substances can be introduced into this framework and may interact and evolve together with the membranes, according to a set of pre-established rules and specifications. AR…

"No creo que la fármaco-resistencia provoque un apocalipsis inminente por la propagación sin control de enfermedades infecciosas": Bruce lewis entrevistado por Andrés Moya y Fernando Baquero

Simulating the Influence of Conjugative Plasmids Kinetic Values on the Multilevel Dynamics of Antimicrobial Resistance in a Membrane Computing Model

AbstractPlasmids harboring antibiotic resistance genes differ in their kinetic values as plasmid conjugation rate, segregation rate by incompatibility with related plasmids, rate of stochastic loss during replication, cost reducing the host-cell fitness, and frequency of compensatory mutations to reduce plasmid cost, depending on the cell mutation frequency. How variation in these values influence the success of a plasmid and their resistance genes in complex ecosystems, as the microbiota? Genes are located in plasmids, plasmids in cells, cells in populations. These populations are embedded in ensembles of species in different human hosts, are able to exchange between them bacterial ensembl…