Complex evolutionary history of the Aeromonas veronii group revealed by host interaction and DNA sequence data
Basic science / phylogenetics published in PLoS One (2011)
Abstract
Aeromonas veronii biovar sobria, Aeromonas veronii biovar veronii, and Aeromonas allosaccharophila are a closely related group of organisms, the Aeromonas veronii Group, that inhabit a wide range of host animals as a symbiont or pathogen. In this study, the ability of various strains to colonize the medicinal leech as a model for beneficial symbiosis and to kill wax worm larvae as a model for virulence was determined. Isolates cultured from the leech out-competed other strains in the leech model, while most strains were virulent in the wax worms. Three housekeeping genes, recA, dnaJ and gyrB, the gene encoding chitinase, chiA, and four loci associated with the type three secretion system, ascV, ascFG, aexT, and aexU were sequenced. The phylogenetic reconstruction failed to produce one consensus tree that was compatible with most of the individual genes. The Approximately Unbiased test and the Genetic Algorithm for Recombination Detection both provided further support for differing evolutionary histories among this group of genes. Two contrasting tests detected recombination within aexU, ascFG, ascV, dnaJ, and gyrB but not in aexT or chiA. Quartet decomposition analysis indicated a complex recent evolutionary history for these strains with a high frequency of horizontal gene transfer between several but not among all strains. In this study we demonstrate that at least for some strains, horizontal gene transfer occurs at a sufficient frequency to blur the signal from vertically inherited genes, despite strains being adapted to distinct niches. Simply increasing the number of genes included in the analysis is unlikely to overcome this challenge in organisms that occupy multiple niches and can exchange DNA between strains specialized to different niches. Instead, the detection of genes critical in the adaptation to specific niches may help to reveal the physiological specialization of these strains.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Multilocus phylogenetic analysis and host-interaction studies (leech colonization, wax worm virulence) of the Aeromonas veronii group, revealing horizontal gene transfer that obscures vertical inheritance signals among niche-adapted strains.
Por qué esto importa para la hirudoterapia
Este estudio investigó las relaciones evolutivas dentro del grupo Aeromonas veronii (A. veronii biovariedad sobria, biovariedad veronii y A. allosaccharophila) mediante la secuenciación de múltiples genes de mantenimiento y genes asociados a virulencia, y evaluando la capacidad de diversas cepas de colonizar la sanguijuela medicinal como modelo de simbiosis beneficiosa y de matar larvas de gusano de la cera como modelo de virulencia. Los aislamientos cultivados a partir de la sanguijuela superaron a otras cepas en el modelo de colonización de la sanguijuela, y los análisis filogenéticos revelaron complejas historias evolutivas con una importante transferencia horizontal de genes entre las cepas, lo que dificulta la resolución a nivel de especie. Para el dominio de ASH, esto es relevante para comprender la especificidad y la adaptación de los simbiontes de Aeromonas en el intestino de la sanguijuela medicinal, con posibles implicaciones para las consideraciones a nivel de cepa en la cría de sanguijuelas y la microbiología asociada a la hirudoterapia. La advertencia es que se trata de un estudio de evolución molecular y genómica comparativa; no aporta datos clínicos, ni resultados de terapia con sanguijuelas, ni orientación directa para la práctica de la hirudoterapia.
Citación
Complex evolutionary history of the Aeromonas veronii group revealed by host interaction and DNA sequence data.
Silver AC et al. · PLoS One, 2011
Contexto clínico relacionado
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026