Life Sciences Commons^™

The Genesis Of Pathogenic E. Coli, Alan L. Gillen, Douglas Oliver

Faculty Publications and Presentations

Even though some strains are pathogenic, most E. coli strains still show evidence of being one of God’s “very good” creations.

Fig. 1. E. coli Gram stain (Wiki commons image). E. coli are Gram-negative bacteria, thus red or pink colored. The red color is due to a counterstain, called safranin.

Escherichia coli is frequently in the news (Fig. 1). E. coli often gets “bad press” for contaminating drinking water or causing a food-borne infection (via hamburgers, apple juice, spinach, or other foods). Recently a new strain (E. coli O145) has been implicated in contaminating lettuce in the U.S., while …

Escherichia Coli And Antibiotic Resistance To Tetracycline Antibiotics, Taylor L. Dodgen

Senior Honors Theses

Escherichia coli cells growing under ideal conditions are able to complete one reproduction cycle in as little as every twenty minutes. Since so many generations are able to be observed, one should theoretically be able to observe thousands of generations and determine evolution’s effects over a short period of time. In this experiment, E. coli K12 cells were cultured under ideal growth conditions but in the presence of antibiotics as a selective environmental stress in order to select for resistance. This was accomplished by serially passing colonies that were in close contact with two different, but similar antibiotics over a …