Antibiotic resistance is a global public health threat, resulting in increasing numbers of infections that do not respond to conventional antibiotic therapies. While early studies focused primarily on hospital acquitted infections, it is becoming increasingly clear that commensal and environmental bacteria are playing a role in the spread of antibiotic resistance. When the human gut microbiome is expose to antibiotics, this selects for resistance in diverse bacteria that can then be transmitted to other community members through fecal-oral transmission or through the environment through numerous pathways. One such method of transmission is passage via wastewater into freshwater environments used for farm irrigation and recreation. As a result, microbial communities in surface water are essential to understand in order to predict transmission patterns and mitigate the spread of antibiotic resistance. This work presents three investigations spanning the human-environment continuum. In Chapter 2, we present a study of ESBL Enterobacteriaceae in the human gut, in which we found that 4.5% of the southeastern US population that participated in the study, asymptomatically carried ESBL-E bacteria and that 64% of those remain colonized after 3 months. In Chapter 3, we present an undergraduate teaching module to isolate and characterize ESBL-E from freshwater streams where students develop microbiology skills and improve awareness of the antibiotic resistance in the environment. In Chapter 4, we present a study examining how the metabolic activity of bacterioplankton predict their abundance or success downstream the creek. Together, the work presented here aims to advance the understanding of microbial community ecology and the ecology of antibiotic resistance in the freshwater environments and the human gut.