Antibiotic Resistance Patterns in Escherichia coli Isolated from Urban Water Sources in the Northeastern United States

Antibiotic resistance in environmental bacteria represents a growing public health concern, particularly in densely populated urban areas where wastewater treatment may be incomplete. This study examines resistance patterns in Escherichia coli isolates obtained from urban water sources across three major cities in the northeastern United States. A total of 240 isolates were collected from 48 sampling sites over a six-month period and subjected to disk diffusion testing against twelve antibiotic agents spanning five drug classes. Results indicate that 67.4% of isolates exhibited resistance to at least one antibiotic, while multidrug resistance—defined as resistance to three or more drug classes—was detected in 23.8% of isolates. Resistance rates were significantly higher downstream of wastewater treatment plant outflows (p < 0.001) and in sampling sites adjacent to high-density residential zones (p = 0.004). These findings underscore the need for enhanced surveillance programs and improved wastewater treatment protocols in urban environments to mitigate the spread of antibiotic-resistant organisms through municipal water systems.