FIG. 3.

M. alligatoris cell-associated sialidase activity. Colonies (upper center plate) and aliquots of cell-free culture supernatant (lower center plate) were overlaid with top agar containing the fluorogenic sialidase substrate MUAN (Sigma) and illuminated with short-wave UV light for comparison to M. crocodyli (right plates) and the negative control M. pulmonis (left plates). The plates in the foreground were positive (type VI C. perfringens neuraminidase [Sigma]) (left plate) and negative (PBS) (right plate) sialidase controls.