Substantial reduction in child stunting is differentially associated to geographical and socioeconomic disparities in Misiones Province, Argentina.

OBJECTIVE: To estimate trends in the prevalence of child stunting in the population of children under 5 years of age covered by public health programmes, between 2009 and 2014 in Misiones, Argentina. METHODS: Using Bayesian model-based geostatistics, we evaluated 724 872 anthropometric measurements corresponding to 110 633 children. In order to identify disparities at local scale, we evaluated the hypotheses of a differential reduction of stunting according to the geographical location (at two-level spatial resolution) and to the socioeconomic level in a rural or urban environment. RESULTS: The prevalence of stunting had fallen significantly in the province overall. Sex and age defined gender disparities at individual level, and there were regional disparities with higher prevalence values in the north and northeast regions. In these areas, stunting decreased to a greater degree during the studied period, although the spatial pattern remained smoother. Stunting increased in peripheral urban and dispersed rural areas that are socioeconomically vulnerable. CONCLUSIONS: The spatial multi-level geostatistical estimates of child undernutrition provide a precision public health tool to target public policies to those populations with the greatest need, in order to reduce health disparities.

OBJECTIF: Estimer les tendances dans la prévalence du retard de croissance dans la population des enfants de moins de 5 ans couverts par les programmes de santé publique, entre 2009 et 2014 à Misiones, en Argentine. MÉTHODES: En utilisant la géostatistique basée sur un modèle bayésien, nous avons évalué 724.872 mesures anthropométriques correspondant à 110.633 enfants. Afin d'identifier les disparités à l'échelle locale, nous avons évalué les hypothèses d'une réduction différentielle du retard de croissance en fonction de la situation géographique (à une résolution spatiale à deux niveaux) et du niveau socioéconomique en milieu rural ou urbain. RÉSULTATS: La prévalence du retard de croissance avait considérablement diminué dans l'ensemble de la province. Le sexe et l'âge définissaient des disparités entre les sexes au niveau individuel, et il y avait des disparités régionales avec des valeurs de prévalence plus élevées dans les régions du nord et du nord-est. Dans ces régions, le retard de croissance a diminué plus fortement au cours de la période étudiée, bien que le modèle spatial soit resté plus lisse. Le retard de croissance a augmenté dans les zones urbaines périphériques et les zones rurales dispersées qui sont socioéconomiquement vulnérables. CONCLUSIONS: Les estimations géostatistiques spatiales à plusieurs niveaux de la sous-nutrition infantile fournissent un outil de santé publique de précision pour cibler les politiques publiques sur les populations qui en ont le plus besoin, afin de réduire les disparités en matière de santé.

Impact of Universal Health Coverage on Child Growth and Nutrition in Argentina.

OBJECTIVES: To estimate trends of undernutrition (stunting and underweight) among children younger than 5 years covered by the universal health coverage programs Plan Nacer and Programa Sumar. METHODS: From 2005 to 2013, Plan Nacer and Programa Sumar collected high-quality information on birth and visit dates, age (in days), gender, weight (in kg), and height (in cm) for 1.4 million children in 6386 health centers (13 million records) with broad coverage of vulnerable populations in Argentina. RESULTS: The prevalence of stunting and underweight decreased 45.0% (from 20.6% to 11.3%) and 38.0% (from 4.0% to 2.5%), respectively, with differences between rural versus urban areas, gender, regions, age, and seasons. CONCLUSIONS: Undernutrition prevalence substantially decreased in 2 programs in Argentina as a result of universal health coverage.

Immunogenicity of hypothetical highly conserved proteins as novel antigens in Anaplasma marginale.

Anaplasma marginale is a tick-transmitted Gram-negative intraerythrocytic bacterium and the etiological agent of bovine Anaplasmosis. Even though considerable research efforts have been undertaken, Anaplasmosis vaccine development remains a challenging field. Outer-membrane-specific antigens responsible for the ability of more complex immunogens could have a significant role in the protective response. Thus, the identification of outer-membrane antigens represents a major goal in the development of bacterial vaccines. Considering that 40 % of the annotated proteins in A. marginale remain as hypothetical, we selected three candidate antigens, AM1108, AM127, and AM216 based on experimental evidence, in silico structure prediction of ß-barrel outer membrane, and orthology clustering. Sequence alignment and analysis demonstrated a high degree of conservation for the three proteins between the isolates from Argentina compared to the American strains. We confirmed the transcription of the three genes in the intraerythrocytic stage. AM1108 and AM216 recombinant proteins elicited specific T-cell response proliferation and a significant rise in TNF-α and IFN-γ transcript levels, respectively. Only AM1108 was able to be recognized by specific antibodies from infected bovines. This study allowed the identification of new candidate components of the outer-membrane fraction of A. marginale. Further studies will be required to analyze their potential as effective antigens for being included in rational vaccine strategies.

Natural selection for operons depends on genome size.

In prokaryotes, genome size is associated with metabolic versatility, regulatory complexity, effective population size, and horizontal transfer rates. We therefore analyzed the covariation of genome size and operon conservation to assess the evolutionary models of operon formation and maintenance. In agreement with previous results, intraoperonic pairs of essential and of highly expressed genes are more conserved. Interestingly, intraoperonic pairs of genes are also more conserved when they encode proteins at similar cell concentrations, suggesting a role of cotranscription in diminishing the cost of waste and shortfall in gene expression. Larger genomes have fewer and smaller operons that are also less conserved. Importantly, lower conservation in larger genomes was observed for all classes of operons in terms of gene expression, essentiality, and balanced protein concentration. We reached very similar conclusions in independent analyses of three major bacterial clades (α- and ß-Proteobacteria and Firmicutes). Operon conservation is inversely correlated to the abundance of transcription factors in the genome when controlled for genome size. This suggests a negative association between the complexity of genetic networks and operon conservation. These results show that genome size and/or its proxies are key determinants of the intensity of natural selection for operon organization. Our data fit better the evolutionary models based on the advantage of coregulation than those based on genetic linkage or stochastic gene expression. We suggest that larger genomes with highly complex genetic networks and many transcription factors endure weaker selection for operons than smaller genomes with fewer alternative tools for genetic regulation.

The twin-arginine translocation pathway in α-proteobacteria is functionally preserved irrespective of genomic and regulatory divergence.

The twin-arginine translocation (Tat) pathway exports fully folded proteins out of the cytoplasm of Gram-negative and Gram-positive bacteria. Although much progress has been made in unraveling the molecular mechanism and biochemical characterization of the Tat system, little is known concerning its functionality and biological role to confer adaptive skills, symbiosis or pathogenesis in the α-proteobacteria class. A comparative genomic analysis in the α-proteobacteria class confirmed the presence of tatA, tatB, and tatC genes in almost all genomes, but significant variations in gene synteny and rearrangements were found in the order Rickettsiales with respect to the typically described operon organization. Transcription of tat genes was confirmed for Anaplasma marginale str. St. Maries and Brucella abortus 2308, two α-proteobacteria with full and partial intracellular lifestyles, respectively. The tat genes of A. marginale are scattered throughout the genome, in contrast to the more generalized operon organization. Particularly, tatA showed an approximately 20-fold increase in mRNA levels relative to tatB and tatC. We showed Tat functionality in B. abortus 2308 for the first time, and confirmed conservation of functionality in A. marginale. We present the first experimental description of the Tat system in the Anaplasmataceae and Brucellaceae families. In particular, in A. marginale Tat functionality is conserved despite operon splitting as a consequence of genome rearrangements. Further studies will be required to understand how the proper stoichiometry of the Tat protein complex and its biological role are achieved. In addition, the predicted substrates might be the evidence of role of the Tat translocation system in the transition process from a free-living to a parasitic lifestyle in these α-proteobacteria.