[ODP-071] Variety of fundamental cell morphology in Mycobacterium avium strains examined with cryo-TEM
Mycobacterium avium (MAV) is one of the pathogenic bacterial species belonging to the genus Mycobacterium, which contains M. tuberculosis and M. leprae as well. Under microscopical observation, MAV represents varied individual cell morphology between and within strains. In this study, a total of approximately 1000 fundamental cell morphologies of the 9 strains of MAV clinical isolates (M. avium Chester 1901, Riken BRM JCM strains) were analyzed through a whole-mount cryo-TEM examination. Cell diameter, length, perimeter, circularity, and aspect ratio were measured with Fiji/ImageJ. Among all comparisons, the average and the standard deviation of cell length, diameter, perimeter, circularity and aspect ratio were 0.59 ± 0.08, 1.49 ± 0.52, 3.62 ± 1.02, 0.76 ± 0.14, and 2.56 ± 1.02, respectively. Out of 180 comparisons, only 20% of comparisons were non-significant, the other comparisons between strains showed significant differences. In addition, the data were compared with previously published data of MAV type strain. It is revealed that the ratio of the longest (L) vs. the shortest (S) cell length (L/S ratio) differentiate the strains into two groups with the cut-off value of 3.3. The genetic background of morphological diversity in MAV strains should be revealed in future.