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principal investigator
Joerg Graf, PhD

We are interested in beneficial microbes, the evolution of microbe-host associations and the spread of antibiotic resistance. We use a range of techniques including genetics, microscopy, 16S rRNA tag sequencing, transcriptomics, metagenomics and comparative genomics to address these topics.

Our research focuses on investigating how bacteria colonize the digestive tract of animals without causing disease. This research is critical for understanding the differences betwen bacteria that cause disease and those that provide the host animal with a benefit. In addition, we will learn more about the benefits that the symbionts provide the animal. 

As a model for digestive-tract associations, we investigate the digestive-tract symbiosis of the medicinal leech, Hirudo verbanaWhile the digestive tract of most animals is colonized by a very complex microbial community, the digestive tract of the medicinal leech is colonized by an unusually simple microbioal community. This simplicity helps us to investigate the interaction between the symbionts and the host as well as between the two primary symbionts.

Lab Papers