How are gene sequences analyses modifying bacterial taxonomy? The case of Klebsiella

Bacterial names are continually being changed in order to more adequately describe natural groups (the units of microbial diversity) and their relationships. The problems in Klebsiella taxonomy are illustrative and common to other bacterial genera. Like other bacteria, Klebsiella spp. were isolated long ago, when methods to identify and classify bacteria were limited. However, recently developed molecular approaches have led to taxonomical revisions in several cases or to sound proposals of novel species. [Int Microbiol 2004; 7(4):261-268

Genome Sequence of a Novel Archaeal Rudivirus Recovered from a Mexican Hot Spring

We report the consensus genome sequence of a novel GC-rich rudivirus, designated SMR1 (Sulfolobales Mexican rudivirus 1), assembled from a high-throughput sequenced environmental sample from a hot spring in Los Azufres National Park in western Mexico

Genome Sequence of the Acidophilic Bacterium <em>Acidocella</em> sp. Strain MX-AZ02

Here, we report the draft genome sequence of Acidocella sp. strain MX-AZ02, an acidophilic and heterotrophic alphaproteobacterium isolated from a geothermal lake in western Mexico

Alcohol use and family‑related factors among Spanish university students: the unHicos project

Background: During adolescence and youth there are relevant changes in the consolidation, gain or loss of consumption habits and lifestyles and the family factors has a fundamental role to development these habits. The study of the consumption of toxins, such as alcohol intake, is crucial at this stage due to the repercussions that said consumption presents in adulthood. Therefore, the objective of our study was to evaluate the associations between alcohol consumption patterns and related family factors (family functioning, family history of alcohol consumption) in Spanish university students. Methods: Observational, descriptive, cross-sectional, multicenter study, carried out in first-year university students from 11 Spanish universities. Through an online questionnaire, alcohol consumption (risky consumption and intensive consumption or binge drinking), family functioning and history of alcohol in the family were evaluated. Risky alcohol consumption and binge drinking were assessed using the AUDIT test, and family functioning was assessed using the family APGAR questionnaire. A descriptive analysis of the data was performed, as well as the Chi- Square test and Student’s T-Test, and non-conditional logistic regression models were carried out to examine this association. Results: The prevalence of risky alcohol consumption identified in the 10,167 respondents was 16.9% (95% CI = 16.2–17.6), and that of BD was 48.8% (95% CI = 47.9–48.8). There is a significant association between risky alcohol consumption and family functioning in students of both sexes, with greater consumption in the face of severe dysfunctional support (men OR = 1.72; p < 0.001 and women OR = 1.74; p < 0.001) and family history of consumption (p = 0.005). Regarding the binge drinking pattern, no statistically significant differences were observed. Conclusions: Risky alcohol consumption in university students is associated with dysfunctional family support, unlike the binge drinking pattern, where there is no such association. The findings of this study show the importance of creating prevention programs focused on the family approach in university students, which include alcohol screening in the population with a family history of this substance, and greater social support from health services.National Drug Plan, Ministry of Health, Social Services and Equality of Spain 2010|145 2013|034 PI16/0194

Population genetics and diversity structure of an invasive earthworm in tropical and temperate pastures from Veracruz, Mexico

Pontoscolex corethrurus (Müller, 1857) is an invasive tropical earthworm, globally distributed. It reproduces through parthenogenesis, which theoretically results in low genetic diversity. The analysis of the population structure of P. corethrurus using molecular markers may significantly contribute to understanding the ecology and reproductive system of this earthworm species. This work assessed the genetic diversity and population structure of P. corethrurus with 34 polymorphic inter simple sequence repeat markers, covering four populations in tropical and temperate pastures from Veracruz State. Nuclear markers distinguished two genetic clusters, probably corresponding to two distinct genetic lineages. The number of clones detected in the AC population was lower than expected for a parthenogenetic species. Also, the apparent lack of differences in population structures related to the geographic region among the populations studied may indicate that human-mediated transference is prevalent in these areas. Still, most individuals apparently belong to lineage A, and only a few individuals seem to belong to the lineage B. Thus, the admixture signatures found among the four populations of P. corethrurus may have facilitated a successful invasion by directly increasing fitness. In summary, addressing the genetic variation of P. corethrurus with ISSR markers was a suitable approach, as it evidenced the genetic diversity and relationships in the populations evaluated

Analysis of the bacterial diversity associated with the roots of maize ( Zea mays L.) through culture-dependent and culture-independent methods

The present study investigated bacterial diversity associated with the roots of maize through the use of culture-dependent and culture-independent methods. Bacterial 16S–23S rDNA internal transcribed spacer sequences (ITS) primers were used to amplify sequences obtained directly from the root matrix by Percoll gradient separation. This assay showed that ã-Proteobacteria within Enterobacter, Erwinia, Klebsiella, Pseudomonas, and Stenotrophomonas genera were predominant groups. The culturable component of the bacterial community was also assessed, revealing that the predominant group was Firmicutes, mainly of Bacillus genus, while Achromobacter, Lysinibacillus, and Paenibacillus genera were rarely found in association with the roots. Only two genera within ã-Proteobacteria, Enterobacter and Pseudomonas, were found in the culture collection. Differences in richness and diversity between the rhizospheric and endophytic bacterial communities were also evidenced. The spectrum of bacteria naturally associated with maize roots is wide and the magnitude of such diversity will depend on the methods chosen for analysis. The knowledge of this spectrum will facilitate the search of microorganisms capable of exerting antagonism to diverse pathogens or detecting plant growth enhancersFil: Pereira, Paola Patricia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; ArgentinaFil: Ibañez, Fernando Julio. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Rosenblueth Laguette, Mónica Teresa. Universidad Nacional Autónoma de México; MéxicoFil: Etcheverry, Miriam Graciela. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Martínez Romero, Esperanza. Universidad Nacional Autónoma de México; Méxic

The Symbiome of Llaveia Cochineals (Hemiptera: Coccoidea: Monophlebidae) Includes a Gammaproteobacterial Cosymbiont Sodalis TME1 and the Known Candidatus Walczuchella monophlebidarum

The genome and transcriptome of the endosymbiotic flavobacterium Candidatus Walczuchella monophlebidarum revealed its role in the synthesis of essential amino acids for its host, the wax cochineal Llaveia axin axin. There were, however, missing genes in the endosymbiont for some biosynthetic pathways. Here, we characterized TME1, another cochineal symbiont that may metabolically complement Walczuchella. TME1 was ascribed to the gammaproteobacterial genus Sodalis on a phylogenomic basis using gene sequences from 143 proteins core genome sequences and the core average nucleotide identity (ANI) confirmed its position. Additionally, we describe Sodalis as a coherent genus. TME1 genome is around 3.4 Mb and has complete gene sequences for the biosynthesis of 10 essential amino acids, for polyamines, flagella, nitrate respiration, and detoxification among many others. Transcripts from ovaries and bacteriomes allowed the identification of differentially transcribed genes from the endosymbionts and host. Highly transcribed genes were identified in TME1 and transcripts involved in amino acid biosynthesis were found. We review here that cosymbionts that derived from different bacterial classes and genera seem to be advantageous for insects that have Flavobacteria as the primary endosymbionts

Internal attribution of outcome moderates the cortisol response to a cooperative task in women

Las observaciones etológicas actuales indican que las conductas cooperativas desempeñan un papel adaptativo. En humanos, las situaciones competitivas han sido mayoritariamente investigadas en varones, aunque en escasas ocasiones se ha estudiado la cooperación. Se pretende analizar la respuesta psicológica y del cortisol a una situación cooperativa, en comparación con una competitiva en el laboratorio en mujeres. Se establecieron cuatro grupos en función de la tarea y su resultado: cooperación positiva, cooperación negativa, competición con victoria y competición con derrota. La cooperación produce efectos diferentes en cortisol que la competición, pero no en las variables psicológicas, aunque estos efectos únicamente se producen cuando se considera el resultado y su atribución. Solo las participantes que cooperaron y fueron evaluadas positivamente y las que compitieron y perdieron mostraron descensos signifi cativos de cortisol. La atribución interna se asocia a niveles de cortisol más estables, sugiriendo un efecto modulador de la controlabilidad en la vivencia de la situación. Estos resultados podrían hacerse extensibles a situaciones en las que la negociación, la mediación y las estrategias cooperativas son relevantes para la toma de decisiones y/o resolución de conflictos

Apertura del Gobierno de los Estados Unidos Mexicanos a la Inversión Minera de Canadá; consecuencias políticas y medioambientales. período 2012-2019

La presente investigación analiza la apertura del gobierno de México, respecto a las inversiones mineras canadienses y su impacto negativo en el área política y medio ambiental. A partir de 1993, en México, se crea el escenario de inversión extranjera perfecto, para que las transnacionales decidan instalarse en el territorio, cumpliendo con factores determinantes para la IED como: apertura comercial, costes laborales, bajos riesgos (políticos, jurídicos, medioambientales entre otros) políticas comerciales y otros aspectos importantes; lo anterior, se logra con la firma del TLCAN, el acuerdo más importante firmado en la historia, entre ambos Estados; sin embargo, México no fue el principal beneficiado, debido a problemas de corrupción internas y al impacto ambiental por parte de las compañías mineras. Por otra parte, las leyes internas de México fueron reformadas por los gobiernos neoliberales que administraron el país, para que hubiese una coherencia entre la ley y el TLC. El constante otorgamiento de concesiones por parte de México a compañías mineras aumentó con el TLCAN, cumpliendo con uno de los principales objetivos de este tratado; éstas fueron motivaciones para que las mineras estuvieran interesadas en la inversión en el país. A través de los medios de negociación Canadá obtiene presencia económica, específicamente en el sector minero, convirtiéndose en el socio comercial número uno en el área. Es importante mencionar que el impacto político y medioambiental ha sido negativo, porque se hace notar la fragilidad de las instituciones estatales y leyes; finalmente el sexenio de Enrique Peña Nieto se caracteriza por la incompetencia de no hacer cumplir las leyes y/o reglamentos que protegen los recursos naturales y de perpetuar el sistema neoliberal en el territorio; caso contrario, el presidente actual, López Obrador, este último ha creado esfuerzos que pretenden mitigar los daños

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