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Biology subjects

Huang, B. C.

Publications and source records attributed to Huang, B. C..

3 recordsLinked to original sources

Metatranscriptomic Profiling Reveals Species-Level Microbial Shifts and Metabolic Remodeling in Feline Oral Inflammatory Disease

Progressive oral mucosal inflammatory diseases are common among mammals. Cats are a valuable natural model for these conditions because they frequently develop oral diseases with varying severity, yet causative microbes remain unidentified in part because longitudinal studies are challenging and sampling is difficult. The lack of individual pathobionts suggests community-scale taxonomic and functional remodeling of the microbiome may be a contributor to oral disease. This study evaluated the microbiome composition and function of 33 cats across three cohorts with different levels of inflammation: healthy, aggressive periodontitis, and feline gingivostomatitis. Ultradeep metatranscriptomic sequencing was used to assign microbial taxonomy and examine functional changes via differential gene expression analysis to reveal genera that maintained stable relative abundance across all three disease states, including Porphyromonas and Treponema, while others had more subtle shifts in species activity, including multiple members of Moraxella and Mycoplasmopsis. Disease status was marked by co-occurring changes in low activity species accompanied by microbiome-level changes in protein, arginine, and nitrogen metabolism. Cats with aggressive periodontitis and gingivostomatitis displayed microbiome shifts in species that correlated to disease state. Microbial differential expression analysis revealed induction of stress-related genes and metabolic genes involved in amino acid metabolism, polyamine production, and nitric oxide production. Together, species identification and functional profiling suggest oral inflammation was correlated to shifts in the activity of multiple species that were involved with NO and polyamines. These coordinated metabolic signatures represent potential diagnostic targets for feline oral inflammatory disease.

microbiology↗

Monitoring the microbiome for food safety and quality using deep shotgun sequencing

In this work, we hypothesized that shifts in the food microbiome can be used as an indicator of unexpected contaminants or environmental changes. To test this hypothesis, we sequenced total RNA of 31 high protein powder (HPP) samples of poultry meal pet food ingredients. We developed a microbiome analysis pipeline employing a key eukaryotic matrix filtering step that improved microbe detection specificity to >99.96% during in silico validation. The pipeline identified 119 microbial genera per HPP sample on average with 65 genera present in all samples. The most abundant of these were Bacteroides, Clostridium, Lactococcus, Aeromonas, and Citrobacter. We also observed shifts in the microbial community corresponding to ingredient composition differences. When comparing culture-based results for Salmonella with total RNA sequencing, we found that Salmonella growth did not correlate with multiple sequence analyses. We conclude that microbiome sequencing is useful to characterize complex food microbial communities, while additional work is required for predicting specific species viability from total RNA sequencing.

microbiology↗

Genomic characterization of a diazotrophic microbiota associated with maize aerial root mucilage

A geographically isolated maize landrace cultivated on nitrogen-depleted fields without synthetic fertilizer in the Sierra Mixe region of Oaxaca, Mexico utilizes nitrogen derived from the atmosphere and develops an extensive network of mucilage-secreting aerial roots that harbors a diazotrophic microbiota. Targeting these diazotrophs, we selected nearly 600 microbes from a collection isolated from these plants and confirmed their ability to incorporate heavy nitrogen (15N2) metabolites in vitro. Sequencing their genomes and conducting comparative bioinformatic analyses showed that these genomes had substantial phylogenetic diversity. We examined each diazotroph genome for the presence of nif genes essential to nitrogen fixation (nifHDKENB) and carbohydrate utilization genes relevant to the mucilage polysaccharide digestion. These analyses identified diazotrophs that possessed canonical nif gene operons, as well as many other operon configurations with concomitant fixation and release of >700 different 15N labeled metabolites. We further demonstrated that many diazotrophs possessed alternative nif gene operons and confirmed their genomic potential to derive chemical energy from mucilage polysaccharide to fuel nitrogen fixation. These results confirm that some diazotrophic bacteria associated with Sierra Mixe maize were capable of incorporating atmospheric nitrogen into their small molecule extracellular metabolites through multiple nif gene configurations while others were able to fix nitrogen without the canonical (nifHDKENB) genes. Data SummaryGenetic resources, including biological materials and nucleic acid sequences, were accessed under an Access and Benefit Sharing (ABS) Agreement between the Sierra Mixe community and the Mars Corporation, and with authorization from the Mexican government. An internationally recognized certificate of compliance has been issued by the Mexican government under the Nagoya Protocol for such activities (ABSCH-IRCC-MX-207343-3). Any party seeking access to the nucleic acid sequences underlying the analysis reported here is subject to the full terms and obligations of the ABS agreement and the authorization from the government of Mexico. Individuals wishing to access nucleic acid sequence data for scientific research activities should contact Mars Incorporated Chief Science Officer at CSO@effem.com.

genomics↗