N-acetylcysteine inhibit biofilms produced by Pseudomonas aeruginosa

Abstract

BackgroundPseudomonas aeruginosa is a common pathogen in chronic respiratory tract infections. It typically makes a biofilm, which makes treatment of these infections difficult. In this study, we investigated the inhibitory effects of N-acetylcysteine (NAC) on biofilms produced by P. aeruginosa.ResultsWe found that minimum inhibitory concentrations (MICs) of NAC for most isolates of P. aeruginosa were 10 to 40 mg/ml, the combination of NAC and ciprofloxacin (CIP) demonstrated either synergy (50%) or no interaction (50%) against the P. aeruginosa strains. NAC at 0.5 mg/ml could detach mature P. aeruginosa biofilms. Disruption was proportional to NAC concentrations, and biofilms were completely disrupted at 10 mg/ml NAC. Analysis using COMSTAT software also showed that PAO1 biofilm biomass decreased and its heterogeneity increased as NAC concentration increased. NAC and ciprofloxacin showed significant killing of P. aeruginosa in biofilms at 2.5 mg/ml and > 2 MIC, respectively (p < 0.01). NAC-ciprofloxacin combinations consistently decreased viable biofilm-associated bacteria relative to the control; this combination was synergistic at NAC of 0.5 mg/ml and CIP at 1/2MIC (p < 0.01). Extracellular polysaccharides (EPS) production by P. aeruginosa also decreased by 27.64% and 44.59% at NAC concentrations of 0.5 mg/ml and 1 mg/ml.ConclusionsNAC has anti-bacterial properties against P. aeruginosa and may detach P. aeruginosa biofilms. Use of NAC may be a new strategy for the treatment of biofilm-associated chronic respiratory infections due to P. aeruginosa, although it would be appropriate to conduct clinical studies to confirm this.

Does Dithiothreitol Improve Bacterial Detection from Infected Prostheses? A Pilot Study

“…Sonication was capable of detaching more bacteria than the NAC and scraping methods, thus confirming the usefulness of this method reported in clinical studies [4,12,23,[28][29][30]. Some studies [2,10,16,26,33] have shown that NAC alone or in combination with other compounds has strong activity against bacterial biofilm, and the mechanism involving the disruption of biofilm may induce the susceptibility of bacteria during antibiotic Fig. 9A-H Confocal laser scanning microscopy shows the formation and removal of biofilms on prosthetic materials for S aureus on PE discs (Stains: bacteria were stained green by Syto-9, the biofilm matrix was stained red by FilmTracer TM SYPRO Ruby Matrix Stain; original magnification, x 3000).…”

“…Sonication of explanted implants has notably improved sensitivity of microbiologic diagnosis of PJIs by dislodging bacteria from biofilm adhered to prosthetic surfaces, as documented in numerous studies [1,4,12,13,23,[28][29][30]. Since NAC exerts activity against bacterial biofilms [2,10,16,26,33], we presumed NAC and DTT could be used to remove bacteria from a prosthetic biofilm. We asked the following questions: (1) Do DTT and NAC remove bacteria from biofilm formed on prosthetic materials?…”

Combining biofilm matrix measurements with biomass and viability assays in susceptibility assessments of antimicrobials against Staphylococcus aureus biofilms

“…For characterizing anti-biofilms activity, the most common practice has been to use a single type of assay that measures reduction of total biomass or cellular viability 4,5 with less emphasis put into combining the three assays. 6 One likely explanation is that, to measure the EPS content, most of the available methods depend on the extraction of polysaccharides, 7,8 which makes them more laborious and time-consuming for anti-biofilm susceptibility studies.…”

Evidence-Based Treatment of Acute Respiratory Infections in Children

“…Препарат приводит к уменьшению образования биопленок грам-положительными и грамотрицательными бактериями и грибами; уменьшает продукцию экстрацеллюлярного полисахаридного матрикса, что способствует разруше-нию зрелых биопленок [43][44][45]. Видимо, ацетилцистеин может разрушать дисульфидные связи бактериальных энзимов, воздействуя на главный компонент матрикса биопленки -экзополисахариды, участвующие в их обра-зовании или экскреции, и благодаря антиоксидантным свойствам, влиянию на метаболизм бактериальных кле-ток может нарушать функционирование адгезивных про-теинов бактерий [44], что подтверждено культуральным методом и электронной микроскопией [45].…”