Bacteria of healthy periodontal tissues as candidates of probiotics: a systematic review.

OBJECTIVES: The use of probiotics could promote the balance of the subgingival microbiota to contribute to periodontal health. This study aimed to identify the potential of bacteria commonly associated with healthy periodontal tissues as probiotic candidates. MATERIAL AND METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the PubMed, Scopus, Science Direct, ProQuest, and Ovid databases as well as the combination of Medical Subject Headings (MeSH) and non-MeSH terms. Based on the selection criteria, original studies published in English and identifying the microorganisms present in the periodontium of healthy individuals and patients with periodontitis using the high-throughput 16S ribosomal gene sequencing technique were included. RESULTS: Out of 659 articles, 12 met the criteria for this review. These articles were published from 2012 to 2020 and mainly originated from the United States, China, and Spain. Most of these studies reported adequate criteria for selecting participants, using standardized clinical criteria, and compliance with quality based on the tools used. In periodontal healthy tissue were identified species like Actinomyces viscosus, Actinomyces naeslundii, Haemophilus parainfluenzae, Rothia dentocariosa, Streptococcus sanguinis, Streptococcus mitis, Streptococcus oralis, Streptococcus gordonii, Streptococcus intermedius, and Prevotella nigrescens which have recognized strains with a capacity to inhibit periodontopathogens. CONCLUSIONS: S. sanguinis, S. oralis, S. mitis, and S. gordonii are among the bacterial species proposed as potential probiotics because some strains can inhibit periodontopathogens and have been reported as safe for humans.

Percepciones sobre la importancia de las ciencias básicas en estudiantes de odontología y medicina / Perceptions of the importance of basic sciences in odontology and medical students

Introducción: El aprovechamiento de los cursos de ciencias básicas puede depender de las percepciones estudiantiles sobre la importancia de estos en su vida profesional, por lo que se hace necesario determinar el grado de importancia que los estudiantes le confieren a este tipo de cursos. Materiales y métodos: Se presentó un cuestionario con 9 declaraciones a 54 estudiantes de odontología y medicina. Las respuestas se pasaron a una escala numérica para su análisis. Se usó una prueba de U de Mann-Whitney con el fin de evaluar diferencias entre estudiantes de ambas facultades. Resultados: Los estudiantes en conjunto mostraron tener una buena opinión de la importancia de las ciencias básicas en la práctica clínica. Se observó también que es mayor la proporción de estudiantes de odontología que consideran que la investigación básica no es útil para su práctica clínica. Conclusión: Los estudiantes consideran las ciencias básicas necesarias para un buen desempeño profesional.

Introduction: The benefit of basic science courses may depend on students' perceptions of the importance of these courses in their professional life, therefore, it's necessary to determine the degree of importance that students give to this type of courses. Materials and methods: A questionnaire with 9 statements was presented to 54 dental and medical students. The responses were converted to a numerical scale for analysis. Using a Mann-Whitney U test, differences between students from both faculties were evaluated. Results: The students showed a good opinion of the importance of basic sciences in clinical practice. It was also observed that the proportion of dental students who consider that basic research is not useful for their clinical practice is higher. Conclusion: Students consider the basic sciences necessary for good professional performance.

Oral manifestations in patients with coronavirus disease 2019 (COVID-19) identified using text mining: an observational study.

Text mining enables search, extraction, categorisation and information visualisation. This study aimed to identify oral manifestations in patients with COVID-19 using text mining to facilitate extracting relevant clinical information from a large set of publications. A list of publications from the open-access COVID-19 Open Research Dataset was downloaded using keywords related to oral health and dentistry. A total of 694,366 documents were retrieved. Filtering the articles using text mining yielded 1,554 oral health/dentistry papers. The list of articles was classified into five topics after applying a Latent Dirichlet Allocation (LDA) model. This classification was compared to the author's classification which yielded 17 categories. After a full-text review of articles in the category "Oral manifestations in patients with COVID-19", eight papers were selected to extract data. The most frequent oral manifestations were xerostomia (n = 405, 17.8%) and mouth pain or swelling (n = 289, 12.7%). These oral manifestations in patients with COVID-19 must be considered with other symptoms to diminish the risk of dentist-patient infection.

Does high sugar intake really alter the oral microbiota?: A systematic review.

OBJECTIVES: Diet is one of the main factors influencing the diversity and interactions of the oral microbiota. The purpose of this study is to determine the impact of sugar intake on the microbial diversity and bacteria that predominate under these conditions. MATERIAL AND METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guide, using the PubMed, Scopus, and Science Direct databases and combinations of the words "microbiota," "microbiology," "bacteria," "sugars," "dysbiosis," "caries," "microbiome," "oral microbial," and "oral microbiota profile pattern." The selection criteria included year, language, type of publication, comparison of microbiota during low and high sugar intake, and bacterial identification by molecular sequencing of the 16S subunit of ribosomal RNA. RESULTS: Out of a total of 374 papers that came up after the initial search, 8 met the criteria for this review. The papers included research on populations comprising children, young adults, and adults, with most of the studies reporting selection criteria for the participants and using validated instruments to determine sugar intake. Apart from one study, all others reported for high sugar intake conditions a significant decrease in microbial diversity of the oral microbiome and the predominance of several bacterial genera or species, including Streptococcus, Scardovia, Veillonella, Rothia, Actinomyces, and Lactobacillus. CONCLUSIONS: Sugar-rich diets have a significantly unfavorable effect on the diversity and balance of oral microbiota; however, further studies are required to determine the exact role of sugar in microbial interactions.

Presence of periodontal pathogenic bacteria in blood of patients with coronary artery disease.

It has been hypothesised that oral bacteria can migrate, through the blood, from the mouth to the arterial plaques, thus exacerbating atherosclerosis. This study compared bacteria present in the peripheral blood of individuals with and without coronary artery disease (CAD). RNA sequences obtained from blood were downloaded from GEO (GSE58150). Eight patients with coronary artery calcification (CAC) scoring > 500 and eight healthy individuals were analysed. After conducting quality control, the sequences were aligned to the hg38 reference genome using Hisat2. Bacterial taxa were analysed by inputting the unmapped sequences into Kraken. Ecological indices were calculated using Vegan. The package DESeq2 was used to compare the counts of bacteria per standard rank between groups. A total of 51 species were found only in patients with CAD and 41 were exclusively present in healthy individuals. The counts of one phylum, one class, three orders, two families and one genus were significantly different between the analysed groups (p < 0.00032, FDR < 10%), including the orders Cardiobacteriales, Corynebacteriales and Fusobacteriales. Twenty-three bacterial species belonging to the subgingival plaque bacterial complexes were also identified in the blood of individuals from both the groups; Fusobacterium nucleatum was significantly less frequent in patients with CAD (p = 0.0012, FDR = 4.8%). Furthermore, the frequency of another 11 bacteria differed significantly among patients with CAD than that among healthy individuals (p < 0.0030, FDR < 10%). These bacteria have not been previously reported in patients with atherosclerosis and periodontitis. The presence of members of the subgingival plaque bacterial complexes in the blood of patients with CAC supports the hypothesis that the periodontopathogens can be disseminated through the blood flow to other body parts where they may enhance inflammatory processes that can lead to the development or exacerbation of atherosclerosis.

Genetic variants in the G gamma-globin promoter modulate fetal hemoglobin expression in the Colombian population.

Fetal hemoglobin (HbF) is a determining factor for the development of sickle cell anemia. High HbF levels lower the intensity of symptoms of this disease. HbF levels can vary in patients with sickle cell anemia and individuals without the disease. The purpose of this study was to identify the genetic variants in the G gamma-globin gene promoter that can modulate HbF expression in patients with sickle cell anemia and healthy individuals from Colombia. In total, 413 bp of the G gamma-globin gene promoter were sequenced in 60 patients with sickle cell anemia and 113 healthy individuals. The allelic and genotype frequencies of the identified variants were compared between individuals with low and high HbF for both patients and healthy individuals. In total, we identified 15 variants in both groups, only three of which were shared between patients and healthy individuals. In healthy individuals, sites -16 and -309 (rs112479156) exhibited differences in allele frequencies. The mutant allele of -16 lowered the production of HbF, whereas the mutant allele of -309 increased its production. These results reveal the presence of different mechanisms of HbF regulation between patients with sickle cell and healthy individuals.

Presence of Non-African Haplotypes Increase Genetic Diversity in Sickle Cell Anemia Patients in Colombia / Presencia de haplotipos no africanos incrementa la diversidad genética en pacientes con anemia falciforme en colombia

RESUMEN El objetivo de este estudio fue identificar la frecuencia de haplotipos dentro del cluster de Beta globina presente en pacientes con anemia falciforme en Colombia, establecer la presencia de haplotipos no africanos en esta población, así como verificar variaciones en el patrón de desequilibrio de ligamiento dentro del cluster de Beta globina. Se analizaron 83 individuos con anemia falciforme, los haplotipos se formaron utilizando cinco sitios de restricción dentro del cluster de Beta globina, se estableció la frecuencia de haplotipos, se calculó el grado de desequilibrio de ligamiento entre los sitios de restricción, así como la similitud genética de esta población con otra de afectados en América. Los haplotipos más frecuentes en la población fueron Benin (35,1 %) y Bantú (26, 5 %), ambos africanos. Sin embargo, haplotipos presentes en poblaciones indígenas americanas y europeas alcanzaron frecuencias entre el 2 - 10 %, así como haplotipos que no han sido reportados en otras poblaciones. Los sitios de restricción presentaron bajo o nulo desequilibrio de ligamiento entre ellos. Al compararse con otras poblaciones, la población colombiana presentó mayor similitud con la población de Venezuela en donde Benin y Bantú son también predominantes. Nuestros resultados muestran que el mestizaje ha facilitado el paso de la mutación para la anemia falciforme a un contexto genético no africano (amerindio y europeo). Además, el mestizaje también ha alterado el patrón de desequilibrio de ligamiento dentro del cluster de Beta globina generando modificaciones que pueden tener influencia en estudios de asociación dentro de esta población de afectados.

ABSTRACT The objective of this study was identify the frequency of Beta globin cluster's haplotypes present in sickle cell anemia patients in Colombia, to establish the presence of non-African haplotypes in this population, to verify variations in the pattern of linkage disequilibrium in the Beta globin cluster. It was analyzed 83 individuals affected with sickle cell anemia, the haplotypes were formed using five restriction sites into Beta globin cluster. The haplotype frequency was calculated, as well as the linkage disequilibrium among restriction sites, the genetic similarity among Colombian population and other affected American population was determined. The haplotypes most frequent were Benin (35.1 %) and Bantu (26.5 %), both African. However, haplotypes present in American indigenous and European populations got frequency between two to ten percent, as well as haplotypes not reported in others population were observed in our population. The restriction sites showed low or null linkage disequilibrium. When compare with other populations, the Colombian population showed higher similarity with Venezuelan population where Benin and Bantu are predominant too. Our results showed that admixture has facilitated the move of sickle cell mutation to a non-African genetic context (Amerindian and European). Further, the admixture has also modified the pattern of linkage disequilibrium into the Beta globin cluster generating modifications that could have influence in association studies in this affected population.

Genetic variants associated with fetal hemoglobin levels show the diverse ethnic origin in Colombian patients with sickle cell anemia / Las variantes genéticas asociadas con niveles de hemoglobina fetal señalan diversos orígenes étnicos en pacientes colombianos con anemia falciforme.

Introduction: Fetal hemoglobin is an important factor in modulating the severity of sickle cell anemia. Its level in peripheral blood underlies strong genetic determination. Associated loci with increased levels of fetal hemoglobin display population-specific allele frequencies. Objective: We investigated the presence and effect of known common genetic variants promoting fetal hemoglobin persistence (rs11886868, rs9399137, rs4895441, and rs7482144) in 60 Colombian patients with sickle cell anemia. Materials and methods: Four single nucleotide polymorphisms (SNP) were genotyped by restriction fragment length polymorphisms (RFLP) and the use of the TaqMan procedure. Fetal hemoglobin (HbF) from these patients was quantified using the oxyhemoglobin alkaline denaturation technique. Genotype frequencies were compared with frequencies reported in global reference populations. Results: We detected genetic variants in the four SNPs, reported to be associated with higher HbF levels for all four SNPs in the Colombian patients. Genetic association between SNPs and HbF levels did not reach statistical significance. The frequency of these variants reflected the specific ethnic make-up of our patient population: A high prevalence of rs7482144-'A' reflects the West-African origin of the sickle cell mutation, while high frequencies of rs4895441-'G' and rs11886868-'C' point to a significant influence of an Amerindian ethnic background in the Colombian sickle cell disease population. Conclusion: These results showed that in the sickle cell disease population in Colombia there is not a unique genetic background, but two (African and Amerindian). This unique genetic situation will provide opportunities for a further study of these loci, such as fine-mapping and molecular-biological investigation. Colombian patients are expected to yield a distinctive insight into the effect of modifier loci in sickle cell disease.

Introducción. La hemoglobina fetal es un importante factor modulador de la gravedad de la anemia falciforme, cuya expresión está muy condicionada por el factor genético. Los loci asociados con el incremento de la hemoglobina fetal pueden presentar frecuencias alélicas específicas para cada población. Objetivo. Investigar la presencia y el efecto de las variantes genéticas rs11886868, rs9399137, rs4895441 y rs7482144 asociadas con la persistencia de hemoglobina fetal, en 60 pacientes colombianos con anemia falciforme. Materiales y métodos. Se hizo la genotipificación de los polimorfismos de nucleótido simple ( Single Nucleotide Polymorphisms, SNP) mediante la técnica de polimorfismos de longitud de fragmentos de restricción ( Restriction Fragment Length Polymorphisms, RFLP) y el procedimiento TaqMan. La hemoglobina fetal (HbF) se cuantificó utilizando la técnica de desnaturalización alcalina de la oxihemoglobina. Las frecuencias genotípicas se compararon con las reportadas en poblaciones de referencia global. Resultados. Se observaron variantes genéticas ya reportadas para aumento de HbF en los cuatro SNP. La asociación genética entre los SNP y el incremento de la HbF no alcanzó significancia estadística. La frecuencia de estos alelos reflejó la siguiente composición específica en esta muestra de pacientes colombianos: una gran prevalencia de rs7482144-'A', lo que indica que el origen de la mutación para la anemia falciforme es África occidental, y una gran frecuencia de rs4895441-'G' y rs11886868-'C', lo que denota la influencia significativa del origen genético amerindio. Conclusión. Los resultados evidenciaron que la población con anemia falciforme de Colombia no tiene un único origen genético, sino que existen dos (africano y amerindio). Esta situación genética única ofrece la oportunidad de llevar a cabo un estudio más amplio de estos loci a nivel molecular. Se espera que el estudio de pacientes colombianos permita una visión diferente del efecto de los loci modificadores en esta enfermedad.

Genetic variants associated with fetal hemoglobin levels show the diverse ethnic origin in Colombian patients with sickle cell anemia.

INTRODUCTION: Fetal hemoglobin is an important factor in modulating the severity of sickle cell anemia. Its level in peripheral blood underlies strong genetic determination. Associated loci with increased levels of fetal hemoglobin display population-specific allele frequencies. OBJECTIVE: We investigated the presence and effect of known common genetic variants promoting fetal hemoglobin persistence (rs11886868, rs9399137, rs4895441, and rs7482144) in 60 Colombian patients with sickle cell anemia. MATERIALS AND METHODS: Four single nucleotide polymorphisms (SNP) were genotyped by restriction fragment length polymorphisms (RFLP) and the use of the TaqMan procedure. Fetal hemoglobin (HbF) from these patients was quantified using the oxyhemoglobin alkaline denaturation technique. Genotype frequencies were compared with frequencies reported in global reference populations. RESULTS: We detected genetic variants in the four SNPs, reported to be associated with higher HbF levels for all four SNPs in the Colombian patients. Genetic association between SNPs and HbF levels did not reach statistical significance. The frequency of these variants reflected the specific ethnic make-up of our patient population: A high prevalence of rs7482144-'A' reflects the West-African origin of the sickle cell mutation, while high frequencies of rs4895441-'G' and rs11886868-'C' point to a significant influence of an Amerindian ethnic background in the Colombian sickle cell disease population. CONCLUSION: These results showed that in the sickle cell disease population in Colombia there is not a unique genetic background, but two (African and Amerindian). This unique genetic situation will provide opportunities for a further study of these loci, such as fine-mapping and molecular-biological investigation. Colombian patients are expected to yield a distinctive insight into the effect of modifier loci in sickle cell disease.

Frequency and origin of haplotypes associated with the beta-globin gene cluster in individuals with trait and sickle cell anemia in the Atlantic and Pacific coastal regions of Colombia.

Sickle cell anemia is a genetic disease with high prevalence in people of African descent. There are five typical haplotypes associated with this disease and the haplotypes associated with the beta-globin gene cluster have been used to establish the origin of African-descendant people in America. In this work, we determined the frequency and the origin of haplotypes associated with hemoglobin S in a sample of individuals with sickle cell anemia (HbSS) and sickle cell hemoglobin trait (HbAS) in coastal regions of Colombia. Blood samples from 71 HbAS and 79 HbSS individuals were obtained. Haplotypes were determined based on the presence of variable restriction sites within the ß-globin gene cluster. On the Pacific coast of Colombia the most frequent haplotype was Benin, while on the Atlantic coast Bantu was marginally higher than Benin. Eight atypical haplotypes were observed on both coasts, being more diverse in the Atlantic than in the Pacific region. These results suggest a differential settlement of the coasts, dependent on where slaves were brought from, either from the Gulf of Guinea or from Angola, where the haplotype distributions are similar. Atypical haplotypes probably originated from point mutations that lost or gained a restriction site and/or by recombination events.

EFECTO DE DENSIDAD POBLACIONAL DE HUEVOS SOBRE VIABILIDAD Y TIEMPO DE DESARROLLO DE Drosophila melanogaster (DROSOPHILIDAE) / Effect Of Eggs Population Density On Viability And Time Of Development Of Drosophila melanogaster (Drosophilidae)

Para estimar el efecto de la densidad poblacional de huevos sobre la viabilidad huevoadulto de Drosophila melanogaster se realizaron tres tratamientos en frascos con medio de cultivo agar-banano: a densidad de 10, 50 y 90 huevos. La variable de respuesta fue la proporción de individuos adultos emergidos desde la aparición del primer imago hasta 15 días después de la siembra. Las viabilidades huevo-adulto promedio fueron 0,320, 0,338 y 0,328 para las densidades de 10, 50 y 90 huevos respectivamente. No se evidenciaron diferencias significativas entre los tres tratamientos (p>0.05). Por lo tanto, no se detectó en este estudio influencia de la densidad poblacional de huevos sobre la viabilidad huevo-adulto. Probablemente debido a que la proporción entre el número de huevos y la cantidad de medio fue suficientemente alta para no generar competencia en otros estadios del desarrollo huevo/adulto.

For estimating the effect from population density of eggs over viability egg-adult in Drosophila melanogaster, it was made three treatments in flasks with agar-banana culture media: densities of 10, 50 and 90 eggs. The effect evaluated was the adult’s proportion that emerged after 15 days of planting. The mean proportions of viability egg-adult were 0.32, 0.338 and 0.328 for the density of 10, 50 and 90 eggs respectively. Significant differences in viability were not evident (p>0.05). Consequently, it was not found effects from the eggs densities in the present study over egg-adult viability. These results probably were due to that the relation among number of eggs and quantity of culture media was not enough of a high for generate competition at another stadiums through the egg-adult development.