Influence of Taurine Haloamines (TauCl and TauBr) on the Development of Pseudomonas aeruginosa Biofilm: A Preliminary Study

Abstract

Biofilms are consortia of microorganisms (sessile cells) that form on various surfaces including mucosal membranes or teeth. Bacterial biofilms cause many human infections such as chronic sinusitis, acne vulgaris, periodontal diseases, and chronic wounds. These infections are persistent as they show increased resistance to antibiotics and host defense system. Taurine chloramine (TauCl) and taurine bromamine (TauBr) are the physiological products of activated neutrophils, resulting from the reaction between taurine with hypochlorous acid (HOCl) and hypobromous acid (HOBr), respectively. It has been shown in vitro that taurine haloamines exert antimicrobial properties against various pathogenic bacteria. Moreover, clinical studies have shown that both haloamines are effective in the local treatment of skin and mucose infections, including biofilm-related infections. Nevertheless, it has been not tested yet whether they can kill bacteria hidden in biofilm or disrupt biofilm structure. In this study we have investigated the capacity of TauCl and TauBr to inhibit in vitro the formation of P. aeruginosa biofilm. We have also tested their ability to destroy the mature biofilm. Our results suggest that TauBr is able to inhibit in vitro the formation of P. aeruginosa biofilm but cannot destroy the mature biofilm and effectively killed hidden bacteria. In further studies, the combined effect of TauBr and DNase, one of suggested biofilm inhibitors, was tested. Together, we conclude that TauBr is a better than TauCl candidate for local therapy of biofilm-related infections. However, a combined therapy, an application of TauBr together with other anti-biofilm agents (e.g., DNase), seems to be more promising.

Bactericidal Activity of N -Chlorotaurine against Biofilm-Forming Bacteria Grown on Metal Disks

“…In a recent study, low concentrations of NCT (300 and 1,000 M) inhibited the P. aeruginosa biofilm formation but did not destroy the biofilm or kill hidden bacteria (11). In millimolar concentrations, however, we found a time-and concentration-dependent antibiofilm activity at concentrations between 0.1% and 1% (5.5 to 55 mM).…”

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

“…As an active chlorine compound, it is microbicidal against bacteria, fungi, viruses, and protozoa, and it does not induce resistance because of the multiple target molecules in pathogens (18,24); this has been confirmed for NCT and its analogue dichlorodimethyltaurine in multiple-passage studies with bacteria (25,26). NCT is also effective against bacteria in biofilms (27)(28)(29).…”

Effect of selected biofilm inhibitors, N -acetylcysteine and DNase, on some biological properties of taurine haloamines (TauCl and TauBr)

“…TauBr, in contrast to TauCl, shows the microbicidal activity at very low concentrations < 10 µM, even as taurine monobromamine. Therefore, these results, together with our previous study [2,20], suggest that TauBr is a more promising candidate than TauCl for killing bacteria hidden in the biofilm matrix, but, as TauCl is a more stable molecule than TauBr, we were tempted to examine the effect of anti-biofilm agents on activity of both taurine haloamines.…”

“…Oral biofilm (dental plaque) is a polymicrobial biofilm growing on hard and soft dental surfaces and is considered the main etiological factor for gingivitis and periodontitis [17]. Among a variety of oral bacteria, streptococcus mutans and Porphyromonas gingivalis play a crucial role in the formation of dental plaque and in the pathogenesis of periodontal diseases, respectively [17,18,[20][21][22]. Modern concepts for the prevention and therapy of biofilm-associated infections are based on eradication of the biofilm by using antibiotics combined with adjuvant substances, capable of destroying biofilm matrix.…”