RESUMEN
Little is known about early plastic biofilm assemblage dynamics and successional changes over time. By incubating virgin microplastics along oceanic transects and comparing adhered microbial communities with those of naturally occurring plastic litter at the same locations, we constructed gene catalogues to contrast the metabolic differences between early and mature biofilm communities. Early colonization incubations were reproducibly dominated by Alteromonadaceae and harboured significantly higher proportions of genes associated with adhesion, biofilm formation, chemotaxis, hydrocarbon degradation and motility. Comparative genomic analyses among the Alteromonadaceae metagenome assembled genomes (MAGs) highlighted the importance of the mannose-sensitive hemagglutinin (MSHA) operon, recognized as a key factor for intestinal colonization, for early colonization of hydrophobic plastic surfaces. Synteny alignments of MSHA also demonstrated positive selection for mshA alleles across all MAGs, suggesting that mshA provides a competitive advantage for surface colonization and nutrient acquisition. Large-scale genomic characteristics of early colonizers varied little, despite environmental variability. Mature plastic biofilms were composed of predominantly Rhodobacteraceae and displayed significantly higher proportions of carbohydrate hydrolysis enzymes and genes for photosynthesis and secondary metabolism. Our metagenomic analyses provide insight into early biofilm formation on plastics in the ocean and how early colonizers self-assemble, compared to mature, phylogenetically and metabolically diverse biofilms.
Asunto(s)
Microbiota , Plásticos , Plásticos/química , Océanos y Mares , Biopelículas , MetagenomaRESUMEN
Purpose: The purpose of this study was to create an early childhood caries (ECC) risk-screening tool that fits into the primary care provider (PCP) well-child workflow. Methods: Integrated health records were employed to develop a predictive model for infants/toddlers at ECC risk; 2,009 patients with 12-, 15-, or 18-month well-child visits and at least one dental visit were used to develop a predictive model for ECC risk at the first dental visit. Independent model validation used 880 18- to 48-month-olds at their first dental appointment after at least one well-child visit. Results: Age at the first dental visit strongly predicted caries risk (odds ratio for one-year increase in age equals 2.11; 95 percent confidence interval equals 1.80 to 2.47). Three factors predicted high-caries risk: breast feeding status, preferred language not English, and no-show rates for pediatric clinic visits greater than 20 percent. All three non-age risk factors in well-child exams prior to 18 months predicted 42 percent probability of having caries if present for the first dental visit at 18 months. If that child was not seen until four years of age for the first dental visit, the probability of high caries risk increased to 83 percent. Model performance for independent validation was very close to expected performance. Conclusions: Existing clinical documentation plus a validated predictive model enables an effective caries risk assessment within well-child visits.