Extended Data Fig. 2: Reduced capsule and biofilm production in phage-resistant mutants.
From: Bacteriophage-resistant Acinetobacter baumannii are resensitized to antimicrobials
a, Microscopic inspection of capsule thickness in slides stained using the Maneval’s technique. Scale bars: 10 μm. b, Standard curve for the phenol-chloroform capsule quantification assay, calibrated with carbohydrate standards ranging from 0 to 300 μg/ml. OD490, optical density at 490 nm. c, Production of capsule polysaccharides (n = 3), for AB900 vs. øFG02-R AB900: 79 ± 1.7 μg/ml vs. 35.6 ± 8.8 μg/ml (mean ± s.d.), P = 0.001; and for A9844 vs. øCO01-R A9844: 179.9 ± 15.6 μg/ml vs. 58.1 ± 5.6 μg/ml; P = 0.0002. d,e, Repeatability of phage-resistance evolution was assessed by measuring capsule production of twelve independently-evolved phage-resistant strains from each of the wild type hosts (AB900 and A9844). Violin plots (n = 3) of surface polysaccharides produced by each strain compared between the wild type host and each of the additional phage-resistant mutants. f,g, Biofilm production on a polystyrene surface at 48 h, measured by absorbance of crystal-violet stained and ethanol-solubilized biofilm (n = 3); optical density of biofilm 1 ± 0.1 vs. 0.5 ± 0.1 (mean ± s.d.), P = 0.0038, for AB900 vs. øFG02-R AB900; and 1.3 ± 0.2 vs. 0.4 ± 0.03, P = 0.001, for A9844 vs. øCO01-R A9844. For panels C, D, E and G, wild type strains represented in red and (original) phage-resistant mutants in blue, bars represent medians, each point represents the average from three technical replicates, and P values pertain to unpaired t tests, two-tailed. ** = P < 0.005; n.s. = non-significant.
