Browsing by Author "León, R."

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    Comparative 16S rRNA gene sequencing study of subgingival microbiota of healthy subjects and patients with periodontitis from four different countries
    (2023) Arredondo, A.; Álvarez, G.; Isabal, S.; Teughels, W.; Laleman, I.; Contreras, M. J.; Isbej Esposito, Lorena Pilar; Huapaya, E.; Mendoza, G.; Mor, C.; Nart, J.; Blanc, V.; León, R.
    Aim: To investigate the differences between the subgingival microbiota of healthy subjects (HS) and periodontitis patients (PP) from four different countries through a metagenomic approach. Materials and Methods: Subgingival samples were obtained from subjects from four different countries. Microbial composition was analysed through high-throughput sequencing of the V3–V4 region of the 16S rRNA gene. The country of origin, diagnosis and clinical and demographic variables of the subjects were used to analyse the microbial profiles. Results: In total, 506 subgingival samples were analysed: 196 from HS and 310 from patients with periodontitis. Differences in richness, diversity and microbial composition were observed when comparing samples pertaining to different countries of origin and different subject diagnoses. Clinical variables, such as bleeding on probing, did not significantly affect the bacterial composition of the samples. A highly conserved core of microbiota associated with periodontitis was detected, while the microbiota associated with periodontally HS was much more diverse. Conclusions: Periodontal diagnosis of the subjects was the main variable explaining the composition of the microbiota in the subgingival niche. Nevertheless, the country of origin also had a significant impact on the microbiota and is therefore an important factor to consider when describing subgingival bacterial communities.
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    Cross-sectional comparative shotgun metagenomic analysis of the subgingival resistome in healthy subjects and patients with periodontitis from four countries
    (2026) Arredondo, A.; Àlvarez, G.; Isabal, S.; Teughels, W.; Laleman, I.; Contreras Rebollo, María José; Isbej Esposito, Lorena Pilar; Huapaya, E.; Mendoza, G.; Mor, C.; Nart, J.; Blanc, V.; León, R.
    Background The oral cavity is a known reservoir of antibiotic resistance genes (ARGs), but little is known about their subgingival distribution across health states and regions. Objective This study aimed to characterize and compare the subgingival resistome and mobile genetic elements (MGEs) in healthy subjects (HS) and periodontitis patients (PP) from Belgium, Chile, Peru and Spain. Design Subgingival samples pooled from the deepest site of each quadrant of 40 HS and 40 PP were analyzed via shotgun metagenomic sequencing. After human DNA depletion, the microbial composition was assessed with MetaPhlAn 4.0; ARGs were identified using MEGAHIT and AMRFinderPlus; and MGEs with MGEfinder. Results ARG richness was significantly higher in PP (mean 3.98) than in HS (2.15). PP from Peru showed more ARGs than HS from Chile and Spain. In total, 28 ARGs were found, conferring resistance to eight antibiotic classes. β-lactam, tetracycline and aminoglycoside resistance were more abundant in PP. Macrolide resistance was lower in Chilean samples than in Peruvian and Spanish ones. Additionally, 99 MGE-associated genes were detected, with 16 differing by diagnosis and 78 by country. Conclusions Subgingival resistome profiles vary significantly by periodontal status and geography, underscoring the influence of clinical and regional factors on antimicrobial resistance in the oral microbiome.
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    Divergent molecular and growth responses of young "Cabernet Sauvignon" (Vitis vinifera) plants to simple and mixed infections with grapevine rupestris stem pitting-associated virus
    (2020) Tobar, M.; Fiore, N.; Pérez Donoso, Alonso Gastón; León, R.; Rosales V., Marlene; Gambardella C., Marina