Date of Award
Bachelor of Science
Dr. DeEtta K. Mills
Dr. Walter M. Goldberg
Bacteria can develop cross-resistance to more than one antibiotic after being exposed to other antimicrobial compounds such as triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy)phenol). This raises concern since it is found in many personal care products such as deodorants and body washes in addition to the environment due to its unregulated disposal. Therefore, this study examined the antibiotic resistance of microbial communities of the skin with different exposures to TCS-containing topical products, as well as microbes from soil and sediment. Healthy volunteers were screened and organized into groups based on the use of deodorants, antiperspirants, and body washes that contained TCS or did not. Skin swab samples as well as microbes from environmental samples were cultured and isolates selected for further studies. Isolates were Gram-stained and tested for antibiotic resistance using the Kirby-Bauer method. Their ribosomal internal transcribed spacer (ITS) regions were amplified and sequenced to obtain the taxonomic identities. The trend towards greater resistance was observed among isolates from TCS-exposed skin as well as those from soil and sediment. Four skin isolates were identified as three separate species known to be transients or commensals of the skin microbiota. Further sampling and testing is needed to better understand if TCS exposure is increasing resistance in these communities.
Fundora, Kevin A. and Mills, DeEtta K., "Evaluating triclosan resistance and impact on community structure in the human skin microbiome" (2017). Department of Biological Sciences - Undergraduate Honors Theses. 73.