Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 131
Filtrar
1.
ISME J ; 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33558688

RESUMO

Bacteriophages play significant roles in the composition, diversity, and evolution of bacterial communities. Despite their importance, it remains unclear how phage diversity and phage-host interactions are spatially structured. Local adaptation may play a key role. Nitrogen-fixing symbiotic bacteria, known as rhizobia, have been shown to locally adapt to domesticated common bean at its Mesoamerican and Andean sites of origin. This may affect phage-rhizobium interactions. However, knowledge about the diversity and coevolution of phages with their respective Rhizobium populations is lacking. Here, through the study of four phage-Rhizobium communities in Mexico and Argentina, we show that both phage and host diversity is spatially structured. Cross-infection experiments demonstrated that phage infection rates were higher overall in sympatric rhizobia than in allopatric rhizobia except for one Argentinean community, indicating phage local adaptation and host maladaptation. Phage-host interactions were shaped by the genetic identity and geographic origin of both the phage and the host. The phages ranged from specialists to generalists, revealing a nested network of interactions. Our results suggest a key role of local adaptation to resident host bacterial communities in shaping the phage genetic and phenotypic composition, following a similar spatial pattern of diversity and coevolution to that in the host.

2.
J Infect Dis ; 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33528501

RESUMO

BACKGROUND: Trypanosoma cruzi, the causative agent of Chagas disease, can be transmitted to the offspring of infected women, which constitutes an epidemiologically significant parasite transmission route in non-endemic areas. It is relevant to evaluate differentially expressed factors in T. cruzi-infected pregnant women as potential markers of Chagas congenital transmission. METHODS: Circulating levels of twelve cytokines and chemokines were measured by ELISA or cytometric bead array in T. cruzi-infected and uninfected pregnant women in their second trimester of pregnancy, and control groups of T. cruzi-infected and uninfected non-pregnant women. RESULTS: T. cruzi-infected women showed a pro-inflammatory Th1-biased profile, with increased levels of TNF-α, IL-12p70, IL-15 and MIG. Uninfected pregnant women presented a biased response towards Th2/Th17/Treg profiles, with increased plasma levels of IL-5, IL-6, IL-1ß, IL-17A and IL-10. Finally, we identified that high parasitemia together with low levels of TNF-α, IL-15, and IL-17, low TNF-α/IL-10 ratio, and high IL-12p70 levels are factors associated with an increased probability of Chagas congenital transmission. CONCLUSIONS: T. cruzi-infected pregnant women who did not transmit the infection to their babies exhibited a distinct pro-inflammatory cytokine profile that might serve as a potential predictive marker of congenital transmission.

3.
J Med Virol ; 93(4): 2439-2445, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33368332

RESUMO

Diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) cases is based on the count of real-time reverse transcription-plymerase chain reaction (RT-PCR) positive people. Viral load by real-time RT-PCR has been suggested as a biomarker of the SARS-CoV-2 infection. However, the association of viral load and severity of the disease is not yet resolved. Nasopharyngeal samples from 458 patients were tested by RT-PCR for SARS-CoV-2 diagnosis. Relative quantitation was made by the comparative threshold cycle (ΔΔCt ) formula between ORF1ab viral and RNase P housekeeping genes. Absolute viral load was calculate using a reference positive control. Most prevalent clinical signs were cough (75.8%), myalgia (66.7%), and fever (48.5%). Hypertension (18.2%), neurological diseases (15.1%), and asthma and hypothyroidism (12.1%) were most frequent comorbidities. Fever, either as an exclusive symptom or combined with others, was associated with high viral loads ( 2 - ∆ ∆ C t range, 35.65-155.16; 4.25-4.89 log10 RNA copies/test]). During the first week after onset of symptoms in mild patients up to 60 years-old was detected the peak of viral load. Children under 10 years old have a high viral load (313.84; 2.50) in the first 2 days postinfection with a sharp decline thereafter. Cases between 10 and 49 years old mostly showed low and moderate viral load during the first 2 days postinfection (range, 0.03 to 17.24; -1.50 to 1.24). Patients over 60 years old have high viral load up to the second week after the onset of symptoms (range, 25.32-155.42; 1.40-2.19), indicating the longer presence of the virus in them. These findings suggest the viral load in nasopharyngeal swabs would help to monitor the SARS-CoV-2 infection in mild coronavirus disease 2019 cases.

4.
Exp Parasitol ; 220: 108044, 2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33253715

RESUMO

Trypanosoma cruzi is the causative agent of Chagas disease, which is endemic in Latin America and around the world through mother to child transmission. The heart is the organ most frequently affected in the chronic stage of the human infection and depends on mitochondria for the required energy for its activity. Cyclophilins are involved in protein folding and the mitochondrial isoform, Cyclophilin D (CyPD), has a crucial role in the opening of the mitochondrial permeability transition pore. In the present study, we infected CyPD deficient mice, with ablation of the Ppif gene, with T. cruzi parasites and the course of the infection was analyzed. Parasite load, quantified by PCR, was significantly lower in skeletal and cardiac tissues of Ppif-/- mice compared to wild type mice. In vitro cultured cardiomyocytes and macrophages from mice lacking CyPD exhibited lower percentage of infected cells and number of intracellular parasites than those observed for wild type mice. Although histopathological analysis of heart and mRNA of heart cytokines showed differences between T. cruzi-infected mice compared to the uninfected animals, no significant differences were found mice due to the ablation of the Ppif gene. Our results suggest that cells deficient for mitochondrial CyPD, inhibited for the mitochondrial membrane potential collapse, reduces the severity of parasite aggression and spread of cellular infection.

5.
Front Public Health ; 8: 562615, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33072699

RESUMO

The pandemic caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a worldwide public health concern. First confined in China and then disseminated widely across Europe and America, SARS-CoV-2 has impacted and moved the scientific community around the world to working in a fast and coordinated way to collect all possible information about this virus and generate new strategies and protocols to try to stop the infection. During March 2020, more than 16,000 full viral genomes have been shared in public databases that allow the construction of genetic landscapes for tracking and monitoring the viral advances over time and study the genomic variations present in geographic regions. In this work, we present the occurrence of genetic variants and lineages of SARS-CoV-2 in Chile during March to April 2020. Complete genome analysis of 141 viral samples from different regions of Chile revealed a predominance of variant D614G like in Europe and the USA and the major presence of lineage B.1. These findings could help take control measures due to the similarity of the viral variants present in Chile, compared with other countries, and monitor the dynamic change of virus variants in the country.

6.
AMB Express ; 10(1): 163, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32894363

RESUMO

Bacillus velezensis 83 was isolated from mango tree phyllosphere of orchards located in El Rosario, Sinaloa, México. The assessment of this strain as BCA (biological control agent), as well as PGPB (plant growth-promoting bacteria), were demonstrated through in vivo and in vitro assays. In vivo assays showed that B. velezensis 83 was able to control anthracnose (Kent mangoes) as efficiently as chemical treatment with Captan 50 PH™ or Cupravit hidro™. The inoculation of B. velezensis 83 to the roots of maize seedlings yielded an increase of 12% in height and 45% of root biomass, as compared with uninoculated seedlings. In vitro co-culture assays showed that B. velezensis 83 promoted Arabidopsis thaliana growth (root and shoot biomass) while, under the same experimental conditions, B. velezensis FZB42 (reference strain) had a suppressive effect on plant growth. In order to characterize the isolated strain, the complete genome sequence of B. velezensis 83 is reported. Its circular genome consists of 3,997,902 bp coding to 3949 predicted genes. The assembly and annotation of this genome revealed gene clusters related with plant-bacteria interaction and sporulation, as well as ten secondary metabolites biosynthetic gene clusters implicated in the biological control of phytopathogens. Despite the high genomic identity (> 98%) between B. velezensis 83 and B. velezensis FZB42, they are phenotypically different. Indeed, in vitro production of compounds such as surfactin and bacillomycin D (biocontrol activity) and γ-PGA (biofilm component) is significantly different between both strains.

7.
Rev. Bras. Saúde Mater. Infant. (Online) ; 20(3): 819-827, July-Sept. 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, Sec. Est. Saúde SP | ID: biblio-1136455

RESUMO

Abstract Objectives: to identify trendand factors associated with adverse birth weight. Methods: cross-sectional design. The analysis uses the 2009-2015 Uruguay Perinatal Computer Systemdata on 303,625 newborns. Results: the prevalence of macrosomia (> 3,999g) has increased from 7.0% to 8.4%. The prevalence of low birth weight (LBW) (< 2,500g) decreased, standing at 6.6% in the last year. The factors that determines more possibilities of LBW were preeclampsia (OR = 4.80; CI95%= 4.57-5.05), inadequate controls (OR = 2.29; CI95%= 2.20-2.39), shorter duration of pregnancy (OR = 2.52; CI95%= 2.50-2.55), previous hypertension (OR = 2.11; CI95%= 1.96-2.27), hypertensive disease of pregnancy (OR = 1.82; CI95%= 1.74-1.90), low prematernal maternal weight (OR = 1.65; CI95%= 1.58-1.74). Macrosomia was associated with type 1 diabetes (OR = 2.21; CI95%= 1.86-2.61), Type 2 or Gestational (OR = 1.78; CI95%= 1.70-1.87), obesity maternal (OR = 2.33; CI95%= 2.24-2.43) and longer gestation duration (OR = 2.62; CI95%= 2.53-2.72). Conclusions: the LBW decreases while the macrosomia increases. The health and nutritional status of women at the beginning of pregnancy, pathologies of the last trimester, smoking, shorter duration of pregnancy and inadequate controls are associated with BPN. Overweight, obesity and metabolic diseases determine macrosomia.


Resumen Objetivos: identificar tendencia y factores asociados al peso al nacer adverso. Métodos: diseño transversal, se analizaron nacimientos entre 2009-2015. El análisis utilizó el Sistema Informático Perinatal de Uruguay, de 2009-2015, datos de 303.625 recién nacidos. Resultados: la prevalencia de macrosomía (>3.999g) aumentó de 7% a 8,4%. La prevalencia de bajo peso al nacer (BPN) (<2.500g) disminuyó situándose en 6,6% en el último año. Los factores que determinaron mayores posibilidades de BPN fueron preeclampsia (OR=4,80; IC95%= 4,57-5,05), inadecuados controles (OR = 2,29; IC95%= 2,20-2,39), menor duración de la gestación (OR = 2,52; IC95%= 2,50-2,55), hipertensión arterial previa (OR = 2,11; IC95%= 1,96-2,27), enfermedad hipertensiva del embarazo (OR = 1,82; IC95%= 1,74-1,90), bajo peso materno pregestacional (OR = 1,65; IC95%= 1,58-1,74). Macrosomía se asoció con diabetes tipo 1 (OR = 2,21; IC95%= 1,86-2,61), tipo 2 o Gestacional (OR = 1,78; IC95%= 1,70-1,87), obesidad materna (OR = 2,33; IC95%= 2,242,43) y duración de gestación (OR = 2,62; IC95%= 2,53-2,72). Conclusiones: existe una tendencia a disminución del BPNy aumento de la macrosomía. La salud y estado nutricional de la mujer al inicio de la gestación, patologías del último trimestre, tabaquismo, menor duración de la gestación e inadecuados controles se asocian a BPN. El sobrepeso, la obesidad y enfermedades metabólicas determinan macrosomía.

8.
J Med Virol ; 92(9): 1562-1566, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32222995

RESUMO

The current pandemic caused by the new coronavirus is a worldwide public health concern. To aboard this emergency, and like never before, scientific groups around the world have been working in a fast and coordinated way to get the maximum of information about this virus when it has been almost 3 months since the first cases were detected in Wuhan province in China. The complete genome sequences of around 450 isolates are available, and studies about similarities and differences among them and with the close related viruses that caused similar epidemics in this century. In this work, we studied the complete genome of the first four cases of the new coronavirus disease in Chile, from patients who traveled to Europe and Southeast Asia. Our findings reveal at least two different viral variants entries to Chilean territory, coming from Europe and Asia. We also sub-classified the isolates into variants according to punctual mutations in the genome. Our work contributes to global information about transmission dynamics and the importance to take control measures to stop the spread of the infection.

9.
Euro Surveill ; 24(45)2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31718744

RESUMO

We compared 2019 influenza seasonality and vaccine effectiveness (VE) in four southern hemisphere countries: Australia, Chile, New Zealand and South Africa. Influenza seasons differed in timing, duration, intensity and predominant circulating viruses. VE estimates were also heterogeneous, with all-ages point estimates ranging from 7-70% (I2: 33%) for A(H1N1)pdm09, 4-57% (I2: 49%) for A(H3N2) and 29-66% (I2: 0%) for B. Caution should be applied when attempting to use southern hemisphere data to predict the northern hemisphere influenza season.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza B/genética , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Avaliação de Resultados em Cuidados de Saúde , Vacinação/estatística & dados numéricos , Potência de Vacina , Adolescente , Adulto , Austrália/epidemiologia , Criança , Chile/epidemiologia , Feminino , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/imunologia , Vírus da Influenza B/isolamento & purificação , Vacinas contra Influenza/administração & dosagem , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Nova Zelândia/epidemiologia , Vigilância da População , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estações do Ano , Vigilância de Evento Sentinela , África do Sul/epidemiologia
10.
PeerJ ; 7: e8068, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31768302

RESUMO

Staphylococcus epidermidis is a human commensal and pathogen worldwide distributed. In this work, we surveyed for multi-resistant S. epidermidis strains in eight years at a children's health-care unit in México City. Multidrug-resistant S. epidermidis were present in all years of the study, including resistance to methicillin, beta-lactams, fluoroquinolones, and macrolides. To understand the genetic basis of antibiotic resistance and its association with virulence and gene exchange, we sequenced the genomes of 17 S. epidermidis isolates. Whole-genome nucleotide identities between all the pairs of S. epidermidis strains were about 97% to 99%. We inferred a clonal structure and eight Multilocus Sequence Types (MLSTs) in the S. epidermidis sequenced collection. The profile of virulence includes genes involved in biofilm formation and phenol-soluble modulins (PSMs). Half of the S. epidermidis analyzed lacked the ica operon for biofilm formation. Likely, they are commensal S. epidermidis strains but multi-antibiotic resistant. Uneven distribution of insertion sequences, phages, and CRISPR-Cas immunity phage systems suggest frequent horizontal gene transfer. Rates of recombination between S. epidermidis strains were more prevalent than the mutation rate and affected the whole genome. Therefore, the multidrug resistance, independently of the pathogenic traits, might explain the persistence of specific highly adapted S. epidermidis clonal lineages in nosocomial settings.

11.
J Emerg Med ; 57(6): 780-790, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31591077

RESUMO

BACKGROUND: Nontraumatic headache is a frequent complaint in the emergency department (ED). Cranial computed tomography (CT) is a widely available test for the diagnostic work-up, despite the risk of exposure to ionizing radiation. OBJECTIVES: We sought to develop and evaluate a cranial CT request computerized decision support system (CDSS) for adults with their first presentation of unusual severe nontraumatic headache in the ED. METHODS: Electronic database searches identified clinical decision and prediction rules and studies delineating risk factors in nontraumatic headache. A long list of risk factors extracted from these articles was reduced by a 30-member multidisciplinary expert panel (radiologists, emergency physicians, methodologists), using a 90% agreement threshold. This shortlist was used to develop the algorithm for the cranial CT request CDSS, which was implemented in March 2016. Impact evaluation compared CT scan frequency and diagnostic yield of pathologic findings before (March-August 2015) and after (March-August 2016) implementation. RESULTS: From the 10 selected studies, 10 risk factors were shortlisted to activate a request for cranial CT. Before implementation, 377 cranial CTs were ordered (15.3% of 2469 CT scans) compared with 244 after (9.5% of 2561 CT scans; pre-post difference 5.74%; 95% confidence interval [CI] 3.92-7.56%; p < 0.001), corresponding to a 37.6% relative reduction in the test ordering rate (95% CI 25.7-49.5%; p < 0.001). Despite the reduction in cranial CT scans, we did not observe an increase in pathological findings after introducing the decision support system (70 cases before [18.5%] vs. 35 cases after [14.3%]; pre-post difference -4.0% [95% CI -10.0 to 1.6%]; p = 0.170). CONCLUSION: In nontraumatic headache among adults seen in the ED, CDSS decreased the cranial CT request rate but the diagnostic yield did not improve.


Assuntos
Técnicas de Apoio para a Decisão , Cefaleia/diagnóstico por imagem , Tomografia Computadorizada por Raios X/classificação , Distribuição de Qui-Quadrado , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/normas , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Cefaleia/classificação , Cefaleia/etiologia , Humanos , Masculino , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/estatística & dados numéricos
12.
PLoS One ; 14(9): e0222381, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31513690

RESUMO

We describe the epidemiological characteristics, pattern of circulation, and geographical distribution of influenza B viruses and its lineages using data from the Global Influenza B Study. We included over 1.8 million influenza cases occurred in thirty-one countries during 2000-2018. We calculated the proportion of cases caused by influenza B and its lineages; determined the timing of influenza A and B epidemics; compared the age distribution of B/Victoria and B/Yamagata cases; and evaluated the frequency of lineage-level mismatch for the trivalent vaccine. The median proportion of influenza cases caused by influenza B virus was 23.4%, with a tendency (borderline statistical significance, p = 0.060) to be higher in tropical vs. temperate countries. Influenza B was the dominant virus type in about one every seven seasons. In temperate countries, influenza B epidemics occurred on average three weeks later than influenza A epidemics; no consistent pattern emerged in the tropics. The two B lineages caused a comparable proportion of influenza B cases globally, however the B/Yamagata was more frequent in temperate countries, and the B/Victoria in the tropics (p = 0.048). B/Yamagata patients were significantly older than B/Victoria patients in almost all countries. A lineage-level vaccine mismatch was observed in over 40% of seasons in temperate countries and in 30% of seasons in the tropics. The type B virus caused a substantial proportion of influenza infections globally in the 21st century, and its two virus lineages differed in terms of age and geographical distribution of patients. These findings will help inform health policy decisions aiming to reduce disease burden associated with seasonal influenza.


Assuntos
Vírus da Influenza B/patogenicidade , Influenza Humana/epidemiologia , Epidemias/história , Epidemias/estatística & dados numéricos , Monitoramento Epidemiológico , Feminino , História do Século XXI , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A/imunologia , Vírus da Influenza B/imunologia , Vírus da Influenza B/metabolismo , Vacinas contra Influenza/imunologia , Influenza Humana/história , Masculino , Vigilância da População/métodos , Estações do Ano
13.
Cad Saude Publica ; 35Suppl 3(Suppl 3): e00073918, 2019 Aug 19.
Artigo em Espanhol | MEDLINE | ID: mdl-31433032

RESUMO

The aim of this study was to conduct a review of the health and nutritional status of Chilean indigenous children, specifically Mapuche children, as published in the literature and specific population-based studies. The searches were conducted in PubMed and LILACS in the last 15 years. From 2006 to 2015, the poverty rate was higher in the indigenous population, with a decrease in the gap from 16% in 2006 to 7.7% in 2015 (p < 0.001). In the first decade of this century, infant mortality in indigenous children was 17.1/1,000 live births, while in non-indigenous children it was 8.8/1,000, and the gap was maintained in the five-year follow-up (p < 0.001). Newborns with birthweight < 2,500g in the year 2000 did not reach 6% (5.6% in non-indigenous and 5.2% in indigenous children). Low height at first school enrollment was 8.4% in indigenous schoolchildren and 3.1% in non-indigenous children, decreasing to 3.7% in indigenous children and 2.6% in non-indigenous children in 2004, while obesity increased more in indigenous children, reaching 24.2% in indigenous and 25.3% in non-indigenous children (p < 0.001). Menarche appeared four months later on average in indigenous girls (12.7 years), and body mass index, waist circumference, and fat mass were significantly greater in indigenous girls at the time of thelarche, as was the overweight rate (55%, vs. 42% in non-indigenous). Mapuche children show favorable health and nutritional status compared to indigenous children elsewhere in Latin America, but there is still an adverse gap compared to non-indigenous Chilean children. This inequality affecting indigenous Chilean children should be acknowledged and corrected.


Assuntos
Peso ao Nascer , Índios Sul-Americanos/estatística & dados numéricos , Estado Nutricional , Grupos Populacionais/estatística & dados numéricos , Estatura/etnologia , Peso Corporal/etnologia , Criança , Mortalidade da Criança/etnologia , Chile , Humanos , Estado Nutricional/etnologia , Fatores Socioeconômicos
14.
Microbiol Resour Announc ; 8(30)2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31346014

RESUMO

Stenotrophomonas maltophilia strain SVIA2 was isolated from crude oil-contaminated soil from Tabasco, Mexico, and displayed a good potential for the degradation of polycyclic aromatic hydrocarbons (PAHs), using naphthalene, anthracene, phenanthridine, or biphenyl as the unique source of carbon. The SVIA2 genome contains essential genes involved in the degradation of PAHs.

15.
Front Microbiol ; 10: 1250, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31231337

RESUMO

Trypanosoma cruzi is the protozoan unicellular parasite that causes Chagas disease. It can be transmitted from infected mothers to their babies via the connatal route, thus being able to perpetuate even in the absence of Triatomine insect vectors. Chagas disease was originally endemic in Central and South America, but migration of infected women of childbearing age has spread the T. cruzi congenital infection to non-endemic areas like North America, Europe, Japan, and Australia. Currently, 7 million people are affected by this infection worldwide. This review focuses on the relevance of the T. cruzi parasite levels in different aspects of the congenital T. cruzi infection such as the mother-to-child transmission rate, the maternal and fetal immune response, and its impact on the diagnosis of infected newborns. Improvements in detection of this parasite, with tools that can be easily adapted to be used in remote rural areas, will make the early diagnosis of infected children possible, allowing a prompt trypanocidal treatment and avoiding the current loss of opportunities for the diagnosis of 100% of T. cruzi congenitally infected infants.

16.
Front Microbiol ; 10: 910, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31114559

RESUMO

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 > 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.

17.
Front Microbiol ; 10: 132, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30787915

RESUMO

Acinetobacter baumannii is an opportunistic pathogen and is one of the primary etiological agents of healthcare-associated infections (HAIs). A. baumannii infections are difficult to treat due to the intrinsic and acquired antibiotic resistance of strains of this bacterium, which frequently limits therapeutic options. In this study, five A. baumannii strains (810CP, 433H, 434H, 483H, and A-2), all of which were isolated from a child with leukemia M2, were characterized through antibiotic susceptibility profiling, the detection of genes encoding carbapenem hydrolyzing oxacillinases, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), adherence and invasion assays toward the A549 cell line, and the whole-genome sequence (WGS). The five strains showed Multidrug resistant (MDR) profiles and amplification of the bla OXA-23 gene, belonging to ST758 and grouped into two PFGE clusters. WGS of 810CP revealed the presence of a circular chromosome and two small plasmids, pAba810CPa and pAba810CPb. Both plasmids carried genes encoding the Sp1TA system, although resistance genes were not identified. A gene-by-gene comparison analysis was performed among the A. baumannii strains isolated in this study and others A. baumannii ST758 strains (HIMFG and INCan), showing that 86% of genes were present in all analyzed strains. Interestingly, the 433H, 434H, and 483H strains varied by 8-10 single-nucleotide variants (SNVs), while the A2 and 810CP strains varied by 46 SNVs. Subsequently, an analysis using BacWGSTdb showed that all of our strains had the same resistance genes and were ST758. However, some variations were observed in relation to virulence genes, mainly in the 810CP strain. The genes involved in the synthesis of hepta-acylated lipooligosaccharides, the pgaABCD locus encoding poly-ß-1-6-N-acetylglucosamine, the ompA gene, Csu pili, bap, the two-component system bfms/bfmR, a member of the phospholipase D family, and two iron-uptake systems were identified in our A. baumannii strains genome. The five A. baumannii strains isolated from the child were genetically different and showed important characteristics that promote survival in a hospital environment. The elucidation of their genomic sequences provides important information for understanding their epidemiology, antibiotic resistance, and putative virulence factors.

18.
Cad. Saúde Pública (Online) ; 35(supl.3): e00073918, 2019. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1019647

RESUMO

El objetivo de este trabajo fue realizar una revisión de la situación de salud y nutrición del niño indígena chileno, específicamente del Mapuche, en lo publicado en las bases de datos de referencias bibliográficas y en investigaciones específicas que tienen base poblacional. Para este trabajo se buscó lo publicado en PubMed, LILACS, organismos nacionales e internacionales, durante los últimos 15 años. Desde el 2006 hasta el 2015 la proporción de pobres era mayor en los indígenas, con disminución de la brecha de 16% el 2006 a 7,7% el 2015 (p < 0,001). En la primera década de este siglo la mortalidad infantil en los niños indígenas tenía una tasa de 17,1/1.000 nacidos vivos, mientras en los no indígenas era de de 8,8/1.000 y, en el seguimiento de cinco años, la brecha se mantuvo (p < 0,001). Los recién nacidos con peso < 2,500g el año 2000 no superaban el 6% (5,6% en no indígenas y 5,2% en los indígenas). La talla baja al ingreso a la escuela era 8,4% en los escolares indígenas y 3,1% en los no indígenas, disminuyendo a 3,7 en los indígenas y 2,6% en los no indígenas el 2004, la obesidad en cambio aumentó más en los indígenas, llegando a 24,2 y 25,3% en los no indígenas (p < 0,001). La menarquia se presentó cuatro meses más tarde en las indígenas (12,7 años) y el índice de masa corporal, circunferencia de cintura y el porcentaje de grasa, fueron significativamente mayores en las indígenas en el momento de la telarquia, así como la frecuencia de exceso de peso (55% vs. 42% en las no indígenas). Los niños Mapuche presentan una condición de salud y nutrición favorable, comparada con los indígenas de otros países del continente, sin embargo, aun existe una brecha adversa -comparada con los no indígenas-, en que la desigualdad desfavorece al niño indígena y esta debe ser reconocida y corregida.


The aim of this study was to conduct a review of the health and nutritional status of Chilean indigenous children, specifically Mapuche children, as published in the literature and specific population-based studies. The searches were conducted in PubMed and LILACS in the last 15 years. From 2006 to 2015, the poverty rate was higher in the indigenous population, with a decrease in the gap from 16% in 2006 to 7.7% in 2015 (p < 0.001). In the first decade of this century, infant mortality in indigenous children was 17.1/1,000 live births, while in non-indigenous children it was 8.8/1,000, and the gap was maintained in the five-year follow-up (p < 0.001). Newborns with birthweight < 2,500g in the year 2000 did not reach 6% (5.6% in non-indigenous and 5.2% in indigenous children). Low height at first school enrollment was 8.4% in indigenous schoolchildren and 3.1% in non-indigenous children, decreasing to 3.7% in indigenous children and 2.6% in non-indigenous children in 2004, while obesity increased more in indigenous children, reaching 24.2% in indigenous and 25.3% in non-indigenous children (p < 0.001). Menarche appeared four months later on average in indigenous girls (12.7 years), and body mass index, waist circumference, and fat mass were significantly greater in indigenous girls at the time of thelarche, as was the overweight rate (55%, vs. 42% in non-indigenous). Mapuche children show favorable health and nutritional status compared to indigenous children elsewhere in Latin America, but there is still an adverse gap compared to non-indigenous Chilean children. This inequality affecting indigenous Chilean children should be acknowledged and corrected.


O objetivo deste trabalho foi realizar una revisão da situação da saúde e nutrição da criança indígena chilena, especificamente da Mapuche, nas publicações relacionadas em bases de dados de referências bibliográficas e em pesquisas específicas que têm base populacional. A pesquisa foi realizada em publicações relacionadas: PubMed, LILACS, organismos nacionais e internacionais, nos últimos 15 anos. Desde 2006 até 2015 a proporção de pobres era maior nos indígenas, com diminuição de uma diferença de 16% em 2006 a 7,7% em 2015 (p < 0.001). Na primeira década de este século a mortalidade infantil nas crianças indígenas teve una taxa de 17,1/1.000 nascidas vivas, enquanto nos não indígenas era de 8,8/1.000 e, em um acompanhamento de cinco anos, a diferença se manteve (p < 0,001). Os recém-nascidos com peso < 2.500g no ano de 2000 não superavam 6% (5,6% em não indígenas e 5,2% nos indígenas). A baixa estatura ao momento do ingresso na escola era 8,4% nos escolares indígenas e 3,1% nos não indígenas, diminuindo a 3,7 nos indígenas e 2,6% nos não indígenas em 2004, a obesidade pelo contrário teve um aumento maior nos indígenas, chegando a 24,2 e 25,3% nos não indígenas (p < 0,001). A menarca ocorreu quatro meses mais tarde nas indígenas (12,7 anos) e o índice de massa corporal, circunferência da cintura e a porcentagem da gordura, foram significativamente maiores nas indígenas no período da telarca, à semelhança da frequência do sobrepeso (55% vs. 42% nas não indígenas). As crianças Mapuche apresentam uma condição de saúde e nutrição favorável, comparada com os indígenas de outros países do continente, no entanto, ainda existe uma brecha adversa - comparada com os não indígenas - , onde a desigualdade desfavorece a criança indígena e por isso deve ser reconhecida e corrigida.

19.
Biomolecules ; 8(4)2018 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-30384485

RESUMO

Trypanosoma cruzi is the etiological agent of Chagas disease. It affects eight million people worldwide and can be spread by several routes, such as vectorborne transmission in endemic areas and congenitally, and is also important in non-endemic regions such as the United States and Europe due to migration from Latin America. Cyclophilins (CyPs) are proteins with enzymatic peptidyl-prolyl isomerase activity (PPIase), essential for protein folding in vivo. Cyclosporin A (CsA) has a high binding affinity for CyPs and inhibits their PPIase activity. CsA has proved to be a parasiticidal drug on some protozoa, including T. cruzi. In this review, we describe the T. cruzi cyclophilin gene family, that comprises 15 paralogues. Among the proteins isolated by CsA-affinity chromatography, we found orthologues of mammalian CyPs. TcCyP19, as the human CyPA, is secreted to the extracellular environment by all parasite stages and could be part of a complex interplay involving the parasite and the host cell. TcCyP22, an orthologue of mitochondrial CyPD, is involved in the regulation of parasite cell death. Our findings on T. cruzi cyclophilins will allow further characterization of these processes, leading to new insights into the biology, the evolution of metabolic pathways, and novel targets for anti-T. cruzi control.


Assuntos
Ciclofilinas/metabolismo , Parasitos/fisiologia , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/fisiologia , Sequência de Aminoácidos , Animais , Antiprotozoários/farmacologia , Doença de Chagas/parasitologia , Ciclofilinas/química , Parasitos/efeitos dos fármacos , Proteínas de Protozoários/química
20.
Rev Med Chil ; 146(2): 168-174, 2018 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-29999152

RESUMO

BACKGROUND: One in five deaths that occur in Chile can be attributed to smoking whose prevalence remains high, despite interventions aimed at reducing it. AIM: To compare the prevalence of smoking and its intensity among young adults born 15 years apart and determine their association with socioeconomic status (SES). MATERIAL AND METHODS: Two cohorts of young adults living in the Valparaiso Region of Chile were evaluated in the third decade of life. Cohort 1 was evaluated between 2000 and 2002 (n = 1232) and cohort 2 between 2014 and 2017 (n = 1078). RESULTS: In cohort 1, 57.5% (95% Confidence Interval (CI) 54.6-58.7) of the subjects reported smoking, with a median of 3 (Interquartile range (ICR:1-6) cigarettes/day. This percentage fell to 40.2% (CI: 37.5-43.1) with a similar median in cohort 2. Analyzing cohort 2, the odds ratio (OR) for smoking was 2.24 (CI 1.48-3.38) in the medium SES, compared with the medium high SES. The figures for low medium and low SES were 2.72 (CI: 1.85-3.99) and 3.01 (1.85-4.88). Similarly, in this cohort there was a significantly higher risk of being a heavy smoker in lower SES. No associations between smoking or its intensity and SES were observed in cohort 1. CONCLUSIONS: Smoking behavior has decreased among young adults evaluated at the same age in two generational cohorts in the third decade of life. In the most recent cohort analyzed, smoking and its intensity increase along with a decrease in SES.


Assuntos
Fumar/epidemiologia , Classe Social , Adulto , Chile/epidemiologia , Estudos de Coortes , Feminino , Humanos , Masculino , Prevalência , Fumar/tendências , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...