MedicalResearch.com Interview with: Dr. Daria Van Tyne, PhD The Gilmore Lab Department of Ophthalmology Harvard Medical School Massachusetts Eye and Ear Infirmary Boston, Massachusetts MedicalResearch.com: What is the background for this study? What are the main findings? Response: A specific clone of E. coli, type ST131, which produces an extended-spectrum beta-lactamase (ESBL – an enzyme that inactivates many penicillin-type antibiotics), has rapidly spread around the globe to become the leading cause of multidrug-resistant, non-intestinal E. coli infection. Despite this, E. coli is a rare cause of infection of the cornea. A patient was recently seen at the Massachusetts Eye and Ear Infirmary with a severe E. coli infection of the cornea, and the large number of antibiotic resistances of this strain tipped us off to the possibility that it might be the highly virulent ST131 ESBL type. By sequencing the DNA of its genome, we found that it was indeed ST131 ESBL E. coli. Moreover, we discovered a new mutation in this strain that allows it to produce a slimy outer coating on its surface. This slime layer, or capsule, makes the bacteria more resistant to removal by phagocytic cells of the immune system. The slime layer also makes these particular colonies appear different on a special type of agar that contains the dye Congo Red. (more…)