Waste Water Treatment Plants (WWTPs) have no way currently to eliminate antibiotics during the cleaning process of waste water. This has led to observable and well documented concentrations of antimicrobial in and around the effluent of WWTPs. One antimicrobial in particular that has been investigated is triclosan. Efflux pumps were thought to be the main mechanism that was being over expressed in the presence of triclosan, which enabled bacteria to overcome multiple mechanisms of actions. This study looks at the presence of triclosan in aquatic environments and bacteria that already possess resistance towards triclosan. Then examined the resistance these bacteria exhibited towards multiple classes of antibiotics. Bacteria was grown in the presence of antibiotics above MIC and were further isolated for 16sRNA identification. The bacteria in this study were mostly Pseudomonas aeruginosa and exhibited high levels of resistance towards beta-lactam antibiotics, and polyketides. DNA synthesis inhibition antibiotics such as ciprofloxacin did inhibit the growth of bacteria in this study. At the current time there is no direct mechanism to explain the link between the presence of triclosan and the exhibition of antibiotic resistance by bacteria. There is still no direct evidence as to what in the environment causes the activation of this over expression and the possible correlation to triclosan. Triclosan has been banned in the United States and European consumer market since the beginning of this study, on the grounds of its effect on microbial populations and concerns to human health.

Semester/Year of Award

Fall 2016


William J. Staddon

Mentor Professional Affiliation

Biological Sciences

Access Options

Restricted Access Thesis

Document Type

Bachelor Thesis

Degree Name

Honors Scholars

Degree Level



Biological Sciences