General mechanism for the bacterial toxicity of hypochlorous acid: abolition of ATP production

Abstract

The adenylate energy charges (EC) of Escherichia coli 25922, Pseudomonas aeruginosa 27853, and Streptococcus lactis 7962 rapidly fell in nutrient-rich media from values in excess of 0.9 to below 0.1 when the organisms were exposed to lethal levels of HOCl. The same cells maintained in energy-depleted states were incapable of attaining normal EC values necessary for biosynthesis and growth when challenged with nutrient energy sources after HOCl exposure. These changes correlated quantitatively with loss of replicative capabilities. Initial rates of transport of glucose, succinate, and various amino acids that act as respiratory substrates and the ATP hydrolase activity of the F1 complex from the ATP synthase of E. coli 25922 also declined in parallel with or preceded loss of viability. These results establish that cellular death is accompanied by complete disruption of bacterial ATP production by both oxidative and fermentative pathways as a consequence of inhibition of inner membrane bound systems responsible for these processes.

Evaluation of time-dependent antimicrobial effect of sodium dichloroisocyanurate (NaDCC) onEnterococcus faecalisin the root canal

“…The results are similar to those reported by Heling et al 6) . They evaluated MIC values of NaDCC and NaOCl for Streptococcus sobrinus, Streptococcus salivarius, Enterococcus faecalis, and Streptococcus mutans.…”

“…The antimicrobial ability of CRA results from the formation of hypochlorous acid (HOCl), when in contact with organic debris. HOCl has been found to disrupt oxidative phosphorylation and other membraneassociated activities of bacteria 6) . Also bacterial DNA synthesis (incorporation of [3H]-thymidine) was significantly decreased by exposure to HOCl 7) .…”

Myeloperoxydase Expression in The Pathogenesis of Nasal Polyps

“…In another similar study conducted by Morinaka et al, the polyp and inferior turbinate mucosas were compared and the ratio of neutrophils was found significantly higher in polyps [12]. MPO is an enzyme, which occurs as a result of neutrophil activation, may lead to the formation of FOR such as H 2 O 2 , NO and especially, HOCL with other enzymes [13,14]. Several studies were performed to investigate the relationship of MPO with chronic sinusitis, role of FOR in the development of nasal polyps and the effects of antioxidant agents on the development of nasal polyps [7,15,16].…”

Protein Synthesis and the Stress Response

“…This condition can be met when production of or exposure to oxidative species is increased, such as when bacterial cells are attacked by the immune system of a host [4][5][6][7] or when oxygen reactive species (ROS) are generated in cyanobacteria as a byproduct of photosystem II irradiation with strong light [8]. Also, "normal" ROS levels can cause oxidative stress when there is a lower level of protective enzymes as when bacteria pass from an anaerobic environment to another with oxygen [9].…”

“…Part of this inhibition might be due to the oxidative inactivation of several enzymes involved in the metabolism of energy and amino acid synthesis [7,11,12,28,29] both of which are essential for protein synthesis. Also, several macromolecules that participate in translation have been found to be a target of oxidation in in vivo or in vitro experiments indicating that translation is directly targeted by oxidative species.…”