Tic-Tac-Toe with Multi-drug Resistant Bacteria

Date Posted: 2011-08-22

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Karen Mruk (upper left), Denice O’Connell (upper center), and Dr. Jessica Rocheleau (lower center)

In the August issue of The Journal of General Physiology (JGP), Denice O’Connell (Animal Medicine) and Karen Mruk and Dr. Jessica Rocheleau in the Kobertz Lab reveal that many Xenopus laveis harbor multi-drug resistant bacteria, which live on and kill the oocytes extracted from the animals. These bacteria are the bane of many electrophysiologists who use Xenopus laevis oocytes to study the proteins responsible for generating action potentials in brain, heart and muscles. These infections decrease the number of successful experiments and introduce variability in apparently successful ones. In the JGP communication, O’Connell et al. (2011) examine the effectiveness of 25 different antibiotics in treating the infections and establish an antibiotic cocktail protocol that maximizes oocyte quality. The cover illustrates that antibiotic resistance is a game of tic-tac-toe that cannot be won, but with judicious antibiotic usage can eliminate the oocyte-damaging bacteria without evolving newer antibiotic resistant strains of Pseudomonas fluorescens, Pseudomonas putida, and Stenotrophomonas maltophilia. X’s and O’s are high-resolution EM pictures of the rod-shaped bacteria on the oocyte’s surface and the visibly damaged oocytes (black dots) caused by the multi-drug–resistant bacteria, respectively.