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The complex community of microbes residing in our gut, also known as the gut microbiota, is currently seen as an organ of vertebrate animals which has multiple functions such as contributing to food digestion and protecting the host from pathogens. Our lab is dedicated to the study of the commensal and pathogenic bacterial components of the gut microbiota, and their interactions with each other and the host. An important, secondary goal, is to utilize our knowledge to promote the wellbeing of humans and food animals, such as poultry.
The reproductive tract microbiome and vertical transmission of gut bacteria from hens to chicks
Early vertical transmission to the chick is theoretically beneficial for bacteria as it would allow access to an empty niche. It is also theoretically beneficial for the host as the microbiota supports a number of functions for the host, such as degradation of plant derived fiber and protection from pathogens. A main mechanism contributing to vertical transmission are the interactions between parents and their progeny. However, in the poultry industry fertilized eggs are separated from the hens immediately after being laid. Thus, the egg is the only connection between the chick and the hen in the poultry industry. Thus, we hypothesized that gut bacteria might utilize the egg for vertical transmission. Our published results show that most gut bacteria cannot utilize the egg as a transmission vehicle but some might. Two projects in this area of research are currently running in the lab. The first aims to characterize the culturable reproductive tract microbiota. The second is aimed at identifying when are chicks exposed to bacteria that would become their gut microbiome – does this happen already in the egg, when the chick pierces the air chamber, when they break out of the shell, or later.
Dissecting the roles of specific gut bacterial strains and designing a probiotic for chickens
Our published data shows the chicken is an excellent model to study host microbiota interactions as many single strains of bacteria can colonize newly hatched chicks which are raised conventionally, e.g. not germ free conditions. Current projects in this area of research running in the lab include a project aimed at identifying immune related phenotypes of gut colonization by bacteria and a project aimed at identifying symbiotic gut bacteria able to inhibit Salmonella infection of chicks. Successful completion of these projects might result in the development of a probiotic for chickens.
Salmonella sensing of the environment and the development of sensing based anti-bacterial compounds
Bacteria need to sense changes in their environment in order to survive and optimally utilize available resources. While we can easily identify in bacterial sequenced genomes a large number of environmental sensors, we know very little about what is sensed, how, and when during the life cycle of the bacteria. Understanding sensing will allow as to modal bacterial behavior, better understand the environment (such as the gut environment), develop whole cell biosensors, and develop new anti-bacterials that will work by manipulating bacteria, for example by exposing them to the immune system or to co-administrated antibiotics. A number of projects in this area of research are currently running in the lab. One project aims to identify yet uncharacterized signals sensed by Salmonella. Another project is aimed at characterizing the Salicylic acid sensing pathway. A third project, is aimed at characterizing signals in the context of Salmonella’s interaction with macrophages. Finally, a collaboration with Dr. Erik Petersen of ETSU is aimed at developing sensing based anti-Salmonella compounds for poultry associated environments.
