Publication Date

Spring 2011


School of Health Sciences




Biology | Medical Sciences


Antibiotic resistance is a growing problem that has rendered many antibiotics ineffective. Bacteria can gain resistance through spontaneous mutations and horizontal gene transfer. A better understanding of the overarching effects of antibiotic resistance on resistant strains is necessary when considering possible solutions to this issue. Tetracycline and doxycycline resistant strains of E. coli were compared to a wild type K-12 strain to determine if resistance engenders any fitness costs. The different strains were compared using antibiotic sensitivity tests, growth rate analysis and metabolic tests. The resistant strains actually grew at a slightly faster rate than the wild type strain. However, the metabolic test revealed that, unlike the wild type strain, the resistant strains were unable to ferment dulcitol. Thus, there may be a slight fitness cost associated with the resistant strains method of antibiotic resistance.