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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, sends 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.
Research team reviewed the behavior of bacteria during this period and what that may mean for antibiotic resistance, the 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- alkyl hydroxyquinoline (AQNO).
The team mapped production of each response spatially, and determined that P. aeruginosa is capable of producing PQS in small pockets at significantly higher concentrations than previously recorded. PQS and AQNO are independently regulated responses that are intentionally communicating different messages. This shows that bacteria type may have some capability to protect the colony from some external toxins while the bacteria are still in a colonizing phase.
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