16SITS

16SITS is a term encountered in the microbiology literature referring to an integrated sequencing approach that combines analysis of the 16S ribosomal RNA gene with the internal transcribed spacer (ITS) regions surrounding rRNA operons. The aim is to improve taxonomic resolution in bacterial communities by leveraging the conserved 16S motif for broad classification while exploiting the higher variability of ITS to distinguish closely related taxa. There is no widely adopted standard for 16SITS, and the exact implementation can vary among studies, including primer sets, sequencing platforms, and data analysis pipelines.

In practice, 16SITS workflows may involve parallel or concatenated sequencing of 16S amplicons with ITS amplicons, followed by integrated taxonomic assignment using databases for both regions, and, in some cases, combining results with whole-genome data or multi-locus sequence typing (MLST).

Applications: used in microbiome research, clinical microbiology, environmental surveys where species-level resolution is needed; can help differentiate strains within a genus that are indistinguishable by 16S alone; used to study bacteria-yeast interactions or bacteria-fungi associations when both markers are present.

Limitations: ITS regions are highly variable in length and sequence across taxa; database coverage for bacterial ITS is inconsistent; primer design can be challenging; there is higher sequencing cost and analysis complexity.

History and reception: The term appears in a subset of studies in the 2010s and 2020s and is not a formal standard; its use reflects ongoing efforts to enhance taxonomic resolution in mixed-domain samples.

See also: 16S rRNA gene sequencing; ITS sequencing; MLST; metagenomics.