Brandi Klingerman | May 3, 2018
In a new study published in the Journal of Biological Chemistry (JBC), researchers from the University of Notre Dame and the University of Illinois at Urbana-Champaign have found that the bacterium Pseudomonas aeruginosa, a pathogen that causes pneumonia, sepsis and other infections, communicates distress signals within a group of bacteria in response to certain antibiotics. This communication was found to vary across the colony and suggests that this bacterium may develop protective behaviors that contribute to its ability to tolerate some antibiotics.
“There is a general lack of understanding about how communities of bacteria, like the opportunistic pathogen P. aeruginosa, respond to antibiotics,” said Nydia Morales-Soto, senior research scientist in civil and environmental engineering and earth sciences (CEEES) at the University of Notre Dame and lead author of the paper. “Most of what we know is from studies about stationary biofilm communities, whereas less is known about the process beforehand when bacteria are colonizing, spreading and growing. In this study, our research team specifically reviewed the behavior of bacteria during this period and what that may mean for antibiotic resistance.”
The reported behavior was caused by tobramycin, an antibiotic commonly used in clinical settings, and resulted in a dual signal response. As this antibiotic was applied to a colony of P. aeruginosa, the bacteria produced a signal to a localized area of the colony — a Pseudomonas quinolone signal (PQS) that is known to occur — as well as a second, community-wide response, known as the alkyl hydroxyquinoline (AQNO).