Superior bactericidal activity ofN-bromine compounds compared to theirN-chlorine analogues can be reversed under protein load

Abstract

Aims: To investigate and compare the bactericidal activity (BA) of active bromine and chlorine compounds in the absence and presence of protein load. Methods and Results: Quantitative killing tests against Escherichia coli and Staphylococcus aureus were performed both in the absence and in the presence of peptone with pairs of isosteric active chlorine and bromine compounds: hypochlorous and hypobromous acid (HOCl and HOBr), dichloro-and dibromoisocyanuric acid, chlorantine and bromantine (1,3-dibromo-and 1,3 dichloro-5,5-dimethylhydantoine), chloramine T and bromamine T (N-chloroand N-bromo-4-methylbenzenesulphonamide sodium), and N-chloro-and N-bromotaurine sodium. To classify the bactericidal activities on a quantitative basis, an empirical coefficient named specific bactericidal activity (SBA), founded on the parameters of killing curves, was defined:SBA ¼ mean log reductions=ðmean exposure times  concentrationÞIn the absence of peptone, tests with washed micro-organisms revealed a throughout higher BA of bromine compounds with only slight differences between single substances. This was in contrast to chlorine compounds, whose killing times differed by a factor of more than four decimal powers. As a consequence, also the isosteric pairs showed according differences. In the presence of peptone, however, bromine compounds showed an increased loss of BA, which partly caused a reversal of efficacy within isosteric pairs. Conclusions: In medical practice, weakly oxidizing active chlorine compounds like chloramines have the highest potential as topical anti-infectives in the presence of proteinaceous material (mucous membranes, open wounds). Active bromine compounds, on the other hand, have their chance at insensitive body regions with low organic matter, for example skin surfaces. Significance and Impact of the Study: The expected protein load is one of the most important parameters for selection of a suited active halogen compound.

Bactericidal and Fungicidal Activity of N -Chlorotaurine Is Enhanced in Cystic Fibrosis Sputum Medium

“…In particular, transhalogenation from NCT to ammonium, which forms the more lipophilic, better penetrating, and stronger microbicidal monochloramine (NH 2 Cl), has been considered causative (22,46). As a first consequence, this remarkable increase in the microbicidal activity of NCT in human body fluids and exudates enables the clinical application of a mildly oxidizing compound, avoiding the irritative adverse effects of stronger reactive antiseptics (23,30,37). Moreover, the superior microbicidal activity of strong active halogen compounds, compared to NCT, has been found to be reversed in peptone solution, because of the high levels of halogen consumption of the former (37, 47).…”

“…Moreover, the superior microbicidal activity of strong active halogen compounds, compared to NCT, has been found to be reversed in peptone solution, because of the high levels of halogen consumption of the former (37, 47). Therefore, NCT seems to be more suitable for body fluids or exudates with high protein loads (23,37).…”

“…Generally, the activity of antiseptics is impaired in the presence of organic material, but NCT is an exception to this rule and generally caused more rapid killing of microorganisms in body fluids and proteinaceous solutions in previous studies (22,23,37).…”

N -Chlorotaurine Exhibits Fungicidal Activity against Therapy-Refractory Scedosporium Species and Lomentospora prolificans

“…The marked enhancement of activity in the presence of ammonium supports this intention. In human body fluids and exudates, ammonium is present and increases the killing activity exactly at the location of treatment (11,15,21,23,37,47,48). At the same time, the tolerability of NCT is high; therefore, it is of particular advantage for sensitive body regions, including body cavities (12).…”

Sensing and inactivation of Bacillus anthracis Sterne by polymer–bromine complexes

“…8). Hypobromous acid is highly unstable and is an active oxidizer used as a bleach, a deodorant, and a disinfectant capable of killing many pathogens (Gottardi et al 2014;Heeb et al 2014).…”