Study of interactions of bacterial, fungal, parasitic, and viral pathogens with host organisms at the molecular, cellular, organismal, or population level is a major research focus at both UTSA and Texas Biomedical Research Institute.

Both beneficial and harmful interactions of between microbes and various host-species and methods to increase or limit such interactions are currently being pursued in several laboratories.

Several subdisciplines of research on host-pathogen interaction include microbial pathogenesis (ability of microbes to cause infection in a host and the process by which infection leads to disease), microbial physiology (how microbes survive and replicate within or outside of a host and how they respond to their host environment), and vector-borne diseases (infectious agents transmitted by blood-feeding vectors such as ticks and mosquitoes, among others).