Grant: CIHR Fellowship

Antibiotics are used to help combat infection with harmful bacteria. Unfortunately, antibiotics can also have off-target effects and kill helpful bacteria that reside in our gut. The community of bacteria in the gut, also called the microbiome, plays an important role in restricting the growth of harmful bacteria. This function is termed colonization resistance. Colonization resistance is reduced when antibiotics disrupt the microbiome. Klebsiella is a potentially harmful bacterium that can take advantage of reduced colonization resistance to expand to high levels in the gut following antibiotic treatment. This expansion is a significant clinical problem since having high levels of Klebsiella in the gut puts patients at an increased risk of both a dangerous spread of the bacteria into the body and pneumonia. The aim of this project is to study this process of Klebsiella's expansion in the gut by examining which bacteria are responsible for the colonization resistance, how our immune system responds to the expansion, and what strategies Klebsiella uses to expand and spread. Identifying these factors could lead to treatments that block the initial expansion of Klebsiella in the gut, or the increased risk of infection in other parts of the body that results from that expansion.