Fig. 1

SEM images of the external morphology of different AFBs analysed by the current study: a. an apical form and beaded AFB from patient N1, b. cylindrical and spherical forms from an AFB from patient S1, c. an elliptical form from an AFB from patient N1, d. a carrot form from an AFB from patient N1, e. a dumbbell form from an AFB from patient S1 and f. a plot of average AFB form width against AFB length. A typical length and width measurement are shown in f., with the width and length being taken along the longest dimensions. The circle in d. highlights the sphere or elliptical-like components that form the AFB coats, with this particular component being 120 nm by 220 nm in diameter. N1 and N2 are non-smoking patient 1 and 2 and S1 and S2 are smoking patient 1 and 2, respectively