Functional Insights into Struvite Formation in Cats and Dogs

Struvite urolithiasis in dogs are commonly associated with urease-producing Staphylococcus spp., unlike in cats. However, many different bacterial species have been associated with struvite formation in dogs and humans. Whether bacteria beyond Staphylococcus contribute to ammonia production, through other metabolic routes remains largely unexplored. Studies using 16S rRNA gene sequencing has been used most often to characterize the microbiome of body systems.  However, 16S rRNA gene sequencing, as an amplicon-based method, does not provide consistent species-level taxonomic resolution or biochemical pathway information, leaving a substantial gap in understanding the microbiome’s functional contribution to struvite formation
 
In this talk, we will begin to characterize the taxonomic composition and ammonia-producing metabolic activity of the microbial community within struvite uroliths from dogs and cats using deep-sequencing metatranscriptomics. In addition to urease, bacteria can generate ammonia through at least three other metabolic routes: arginine deiminase (ADI) pathway,   amino acid deamination , and dissimilatory nitrate reduction (DNRA) Each of these pathways operates under distinct physiological conditions and in different bacterial taxa.  Discussions regarding the role of microbiome in struvite uroliths from dogs and cats will be discussed as well as how the microbial subcommunities exhibit distinct c0-occurrence patterns.  Future directions of how microbes are associated with other mineral compositions such as calcium oxalate will also be reviewed