Antimicrobial resistance (AMR) is a global health crisis with previous reports stating 70% of Hospital Acquired Infections (HAIs) are directly linked to Antimicrobial Resistance (AMR). In Ireland, the rates of AMR associated HAIs increase annually with Escherichia coli and Staphylococcus aureus the most frequent causative agents. The theory of hospital sanitary ware acting as reservoirs for these AMR pathogens has been previously described throughout Europe. The first part of the following thesis investigated Irish hospital sanitary ware for the presence of these persistent AMR pathogens with a specific focus on extended-spectrum-beta lactamase (ESBL) and carbapenemase (CP) producing bacteria. Beta-lactams, particularly, carbapenems and third generation cephalosporins, are broad-spectrum antimicrobials used to treat dangerous infections. Pin-pointing the location of AMR pathogens resistant to these life-saving antimicrobials are a top priority within clinical environments. The findings of this section highlight these reservoirs and discuss the microbial populations within. The second part of the following thesis characterises and compares eighty bloodstream infection (BSI) isolates collected from patients at three Irish hospitals. This section uncovered resistant mechanisms of ESBL and CP Enterobacterales, MRSA, and VREfm. These mechanisms included the presence of blaCTX-M-15, blaOXA-48, within Enterobacterales, mecA genes within MRSA isolates, and the vanA operon reported in VREfm isolates. One finding of this study underlines the movement of different plasmid replicon types not only between the bacteria as species but between different species sequence types across all three hospitals. Other findings highlight species relatedness and similarities by using phylogenetic and distancing analysis.