Biology subjects

Lluansi, A.

Publications and source records attributed to Lluansi, A..

3 recordsLinked to original sources

bioRxiv2025

Oral Microbiota Composition in Children and Adults During Spanish COVID-19 Lockdown: Impact of Home Self-Confinement and SARS-CoV-2 infection

BackgroundThe COVID-19 pandemic changed societys habits and customs due to the social restrictions and health measures imposed during the first half of 2020. This study analyzes the composition of the oral microbiota in relation to age, household cohabitation, SARS-CoV-2 infection, and COVID-19 severity among children and adults under home confinement in Barcelona, Spain. MethodsA prospective study conducted involving children and adults confined during the COVID-19 pandemic in the Barcelona Metropolitan Area between April and June 2020 included multiple cases of several participants living within the same family household. Saliva samples were collected from all participants, and microbiota composition was characterized through 16S rRNA gene sequencing. ResultsA total of 142 adults and 265 children living in 121 family households were included in the study. All 142 adults had a prior confirmed SARS-CoV-2 infection, and 20 (14.08%) of them had a history of severe COVID-19. SARS-CoV2 infection was detected in 58/265 (21.89%) of children; all of them were asymptomatic. Oral microbiota composition and diversity did not differ by SARS-CoV-2 infection status in children. In contrast, adults with severe COVID-19 exhibited lower microbiota diversity and distinct microbiota composition compared to those with mild disease symptoms. Age-related differences in oral microbiota composition were marked in the younger children groups. Additionally, cohabiting individuals shared more Amplicon Sequence Variants (ASVs) than non-cohabitants. ConclusionsAge and cohabitation strongly influenced oral microbial composition. Our study demonstrates that oral microbiota composition in adults varies according to COVID-19 severity, whereas such microbial shifts are not observed in asymptomatic pediatric populations, regardless of infection status.

microbiology↗

bioRxiv2025

The Multiomics Blueprint of Extreme Human Lifespan

The indexed individual, from now on termed M116, was the worlds oldest verified living person from January 17th 2023 until her passing on August 19th 2024, reaching the age of 117 years and 168 days (https://www.supercentenarian.com/records.html). She was a Caucasian woman born on March 4th 1907 in San Francisco, USA, from Spanish parents and settled in Spain since she was 8. A timeline of her life events and her genealogical tree are shown in Supplementary Fig. 1a-b. Although centenarians are becoming more common in the demographics of human populations, the so-called supercentenarians (over 110 years old) are still a rarity. In Catalonia, the historic nation where M116 lived, the life-expectancy for women is 86 years, so she exceeded the average by more than 30 years (https://www.idescat.cat). In a similar manner to premature aging syndromes, such as Hutchinson-Gilford Progeria and Werner syndrome, which can provide relevant clues about the mechanisms of aging, the study of supercentenarians might also shed light on the pathways involved in lifespan. To unfold the biological properties exhibited by such a remarkable human being, we developed a comprehensive multiomics analysis of her genomic, transcriptomic, metabolomic, proteomic, microbiomic and epigenomic landscapes in different tissues, as depicted in Fig. 1a, comparing the results with those observed in non-supercentenarian populations. The picture that emerges from our study shows that extremely advanced age and poor health are not intrinsically linked and that both processes can be distinguished and dissected at the molecular level. O_FIG O_LINKSMALLFIG WIDTH=156 HEIGHT=200 SRC="FIGDIR/small/639740v1_fig1.gif" ALT="Figure 1"> View larger version (63K): org.highwire.dtl.DTLVardef@1705be6org.highwire.dtl.DTLVardef@1a16e4borg.highwire.dtl.DTLVardef@15005f1org.highwire.dtl.DTLVardef@b6297b_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFig. 1C_FLOATNO Chromosomes and genes.a, Schematic representation of all -omics studied in the supercentenarian. b, Telomeres marked with Cy3 (yellow) in nuclei stained with DAPI (blue) observed in HT-qFISH from M116 and younger womens PBMCs. Scale bars: 20 {micro}m. c, Telomere length (Kb) calculation (left) and percentage of extremely short telomeres (below the 20th percentile) (right) in M116 (orange) using standard curve from samples previously analyzed (black) and control women (blue) (Online Methods). d, Circos plot with chromosomal alterations detected through optical genome mapping in supercentenarian. e, Variants of interest (VOI)-harboring genes found in supercentenarians genomic DNA contributing to immune function, cardiovascular health, neuroprotection, metabolism, and DNA dynamics. f, Significantly enriched functions of VOI-harboring genes in the supercentenarian. g, VOI-harbouring genes significantly contributing to enriched functions. h, VOI-harboring genes found in supercentenarians genomic and mitochondrial DNA contributing to mitochondrial function. i, Mean fluorescence intensity of TMRE (a marker of mitochondrial membrane potential) and SOX (a marker of mitochondrial superoxide ion) in PBMCs from the supercentenarian (orange) and healthy controls across various ages (gray). Unpaired t-test was used to statistically compare M116 to the mean of all control women. *p < 0.05. C_FIG

genomics↗

bioRxiv2025

Inhibitory effect of Dolosigranulum pigrum and Corynebacterium pseudodiphtheriticum on pneumococcal in vitro growth

BackgroundStreptococcus pneumoniae is a nasopharynx coloniser that can invade sterile tissues, causing Invasive Pneumococcal Disease (IPD). Dolosigranulum pigrum and Corynebacterium pseudodiphtheriticum are commensal bacteria commonly isolated from the nasopharynx of healthy children, potentially playing a protective role. This study aims to analyse the effects of D. pigrum and C. pseudodiphtheriticum on S. pneumoniae in vitro growth. MethodsPneumococcal strains were collected from IPD patients and healthy carriers in Catalonia (2016-2023). D. pigrum and C. pseudodiphtheriticum strains were isolated from a healthy childs nasopharynx. S. pneumoniae was co-cultured with each commensal bacterium in triplicate experiments. Pneumococcal growth was quantified using a real-time PCR assay targeting the lytA gene. The effect of commensal bacteria on pneumococcal growth was evaluated using a linear mixed-effect regression model. ResultsTwenty-eight pneumococcal strains expressing 24 different serotypes and 26 clonal types were analysed (18 isolated in blood and 10 in nasopharyngeal aspirate). Pneumococcal growth was decreased by D. pigrum ({beta} = -0.763, 95% CI: -0.94 to -0.59, p < 0.0001) and C. pseudodiphtheriticum ({beta} = -0.583, 95% CI: -0.76 to -0.41, p < 0.0001). The combined presence of both had a stronger inhibitory effect ({beta} = -0.971, 95% CI: -1.15 to -0.79, p < 0.0001). No association was found between isolation site or serotype with pneumococcal growth. ConclusionD. pigrum and C. pseudodiphtheriticum significantly reduced pneumococcal growth, with a synergic effect when combined. This antagonistic effect supports the potential protective factor of healthy nasopharyngeal microbiota against IPD and the development of these microorganisms as probiotics.

microbiology↗