The inhibitory effects of zinc on autolysin activity and cell lysis of Clostridium perfringens

Nozomu Matsunaga, Seira Egusa, Riyo Aono, Yasuo Hitsumoto, Seiichi Katayama

The 13th International Conference on the Molecular Biology and Pathogenesis of the Clostridia（ClostPath 13)

The International Conference on the Molecular Biology and Pathogenesis of the Clostridia

Banff, Canada

Clostridium perfringens is an obligate anaerobe associated with food poisoning and gas gangrene. Acp, one of peptidoglycan hydrolases (PGHs) of C. perfringens, has been identified as a key player in regulating cell division. Acp-defective cells (strain 13 acp::erm) are unable to divide normally, and their morphology of cells is observed as a long chain [1]. This report suggested that Acp is required in the vegetative growth of C. perfringens cells. On the other hand, dysregulated activation of Acp under oxidative stress or exposure to bile salt leads to detrimental cell lysis. Therefore, the experimental handling of C. perfringens cells is needed for caution under normal atmospheric conditions. We investigated the influence of various metals on Acp activity using renaturing SDS-PAGEs (zymography), revealing the inhibitory effects of zinc on Acp activity. Our findings demonstrate that zinc at 0.25-10 mM exerts a significant reduction in cell lysis compared to the control under a normal atmosphere. Notably, 5-10 mM zinc concentrations achieve over 90% suppression of cell lysis. Interestingly, in GAM medium pre-supplemented with zinc (5-10 mM zinc-added), the cell lengths were significantly increased in each group relative to the control. These results elucidate the inhibitory effects of zinc on Acp activity within C. perfringens, resulting in diminished cell lysis under normal atmospheric conditions. Understanding the molecular mechanisms underlying Acp regulation and the impact of zincmediated modulation could provide valuable insights for the experimental handling of C. perfringens cells.