TY - JOUR
T1 - Quantitative single-cell characterization of bacterial interactions reveals type VI secretion is a double-edged sword
AU - LeRoux, Michele
AU - De Leon, Justin A.
AU - Kuwada, Nathan J.
AU - Russell, Alistair B.
AU - Pinto-Santini, Delia
AU - Hood, Rachel D.
AU - Agnello, Danielle M.
AU - Robertson, Stephen M.
AU - Wiggins, Paul A.
AU - Mougous, Joseph D.
PY - 2012/11/27
Y1 - 2012/11/27
N2 - Interbacterial interaction pathways play an important role in defining the structure and complexity of bacterial associations. A quantitative description of such pathways offers promise for understanding the forces that contribute to community composition. We developed time-lapse fluorescence microscopy methods for quantitation of interbacterial interactions and applied these to the characterization of type VI secretion (T6S) in Pseudomonas aeruginosa. Our analyses allowed a direct determination of the efficiency of recipient cell lysis catalyzed by this intercellular toxin delivery pathway and provided evidence that its arsenal extends beyond known effector proteins. Measurement of T6S apparatus localization revealed correlated activation among neighboring cells, which, taken together with genetic data, implicate the elaboration of a functional T6S apparatus with a marked increase in susceptibility to intoxication. This possibility was supported by the identification of T6S-inactivating mutations in a genome-wide screen for resistance to T6S-mediated intoxication and by time-lapse fluorescence microscopy analyses showing a decreased lysis rate of recipient cells lacking T6S function. Our discoveries highlight the utility of single-cell approaches for measuring interbacterial phenomena and provide a foundation for studying the contribution of a widespread bacterial interaction pathway to community structure.
AB - Interbacterial interaction pathways play an important role in defining the structure and complexity of bacterial associations. A quantitative description of such pathways offers promise for understanding the forces that contribute to community composition. We developed time-lapse fluorescence microscopy methods for quantitation of interbacterial interactions and applied these to the characterization of type VI secretion (T6S) in Pseudomonas aeruginosa. Our analyses allowed a direct determination of the efficiency of recipient cell lysis catalyzed by this intercellular toxin delivery pathway and provided evidence that its arsenal extends beyond known effector proteins. Measurement of T6S apparatus localization revealed correlated activation among neighboring cells, which, taken together with genetic data, implicate the elaboration of a functional T6S apparatus with a marked increase in susceptibility to intoxication. This possibility was supported by the identification of T6S-inactivating mutations in a genome-wide screen for resistance to T6S-mediated intoxication and by time-lapse fluorescence microscopy analyses showing a decreased lysis rate of recipient cells lacking T6S function. Our discoveries highlight the utility of single-cell approaches for measuring interbacterial phenomena and provide a foundation for studying the contribution of a widespread bacterial interaction pathway to community structure.
KW - Imaging
KW - Peptidoglycan
KW - Polymicrobial
KW - Protein secretion
UR - http://www.scopus.com/inward/record.url?scp=84870354045&partnerID=8YFLogxK
U2 - 10.1073/pnas.1213963109
DO - 10.1073/pnas.1213963109
M3 - Article
C2 - 23150540
AN - SCOPUS:84870354045
SN - 0027-8424
VL - 109
SP - 19804
EP - 19809
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 48
ER -