Distribution of signaling molecules in a section of P Distribution of signaling molecules in a section of P. aeruginosa-infected bronchus analyzed in positive-ion mode. Distribution of signaling molecules in a section of P. aeruginosa-infected bronchus analyzed in positive-ion mode. PQS (total cell count, 1.239 × 105) and NHQ (total cell count, 2.657 × 105) are shown in panels A and B, respectively. An ion representative of bronchial tissue is shown in white in panel C (m/z 88.01; total cell count, 2.621 × 106). The combined signal derived from PQS and NHQ is shown in red in panel D overlaid with m/z 88.01 in white. Sarah K. Davies et al. mSphere 2017; doi:10.1128/mSphere.00211-17