Fig. 3

Adhesion of labeled B. pertussis Tohama I on A549 cells. a A549 cells were infected for 1 h with serially diluted labeled bacteria starting from an optical density (OD₆₀₀) of 0.2. After washes, cell-associated bacteria were quantified by fluorescence reading at Ex/Em 485/535 nm. b After fluorescence reading, infected cells were treated with 1 % saponin, and lysates were serially diluted and plated for CFU counting of adhering bacteria (). Aliquots of serially diluted bacterial suspensions used for infection were also plated () c A549 cells were infected with unlabeled and labeled B. pertussis Tohama I at OD₆₀₀ 0.2 for 1 h. Adhering bacteria were quantified by CFU counting as described before. Results represent mean ± SD from one out of the three representative experiments performed in triplicates