Effect of Antibiotics and Antibiofilm Agents in the Ultrastructure and Development of Biofilms Developed by Nonpigmented Rapidly Growing Mycobacteria

Abstract

We analyze the effect of amikacin, ciprofloxacin, and clarithromycin, alone and associated with N-acetylcysteine (NAC) and Tween 80, at different times and concentrations in nonpigmented rapidly growing mycobacteria (NPRGM) biofilms. For this purpose, confocal laser scanning microscopy and image analysis were used to study the development and behavior of intrinsic autofluorescence, covered area, thickness, and cell viability in NPRGM biofilms after adding antibiotics alone and associated with antibiofilm agents. In this study, ciprofloxacin is the most active antibiotic against this type of biofilm and thickness is the most affected parameter. NAC and Tween 80 combined with antibiotics exert a synergistic effect in increasing the percentage of dead bacteria and also reducing the percentage of covered surface and thickness of NPRGM biofilms. Tween 80 seems to be an antibiofilm agent more effective than NAC due to its higher reduction in the percentage of cover surface and thickness. In conclusion, the results obtained in this work show that phenotypic parameters (thickness, percentage of covered surface, autofluorescence, percentage of live/dead bacteria) are affected by combining antibiotics and antibiofilm agents, ciprofloxacin and Tween 80 being the most active agents against NPRGM biofilms.

N‐acetylcysteine eradicates Pseudomonas aeruginosa biofilms in bone cement

“…In this study, we manifested the antimicrobial and antibiofilm effects of NAC and ciprofloxacin, each alone and in combination in bone cement against P. aeruginosa . Although there are some studies indicating antimicrobial and antibiofilm effects of that agents (Dinicola et al ., ; Munoz‐Egea et al ., ), to our knowledge, there are no studies demonstrating those effects on P. aeruginosa biofilms in bone cement. Furthermore, quantitative evaluation of bone cement samples using SEM also is the first approach in the literature.…”

Mycobacterium Biofilms

“…Muñoz-Egea et al found differences between the MIC and minimum biofilm eradication concentration (MBEC) in 4 species of RGM, ranging between <100-fold in the case of Mycobacterium mucogenicum exposed to ciprofloxacin, and >100,000-fold in the case of M. abscessus and Mycobacterium peregrinum exposed to clarithromycin (Muñoz-Egea et al, 2015 ); ciprofloxacin was the most active antibiotic against these biofilms, compared with clarithromycin or amikacin. Further studies have shown the effect of antibiotic therapy in different stages of biofilm development (Muñoz-Egea et al, 2015 , 2016b ). In these studies, treatment of the biofilm was more effective when antibiotics are added in the early stage of biofilm development, probably because the phenotype of the cells is not fully adapted to biofilm growth.…”

“…Tween 80 alters the structural integrity of the membrane, lipids, and proteins (Teixeira et al, 2007 ), while NAC acts on the polysaccharide matrix of the biofilm, breaking disulfide bridges that link the polysaccharide fibers (Olofsson et al, 2003 ). Due to the high lipid content of the mycobacterial cell wall and the significant presence of lipids in the extracellular matrix, Tween 80 is more active against mycobacterial biofilm than NAC (Muñoz-Egea et al, 2016b ). An increase in antibacterial activity was observed when NAC and Tween 80 were combined with ciprofloxacin, clarithromycin, and amikacin.…”

“…The ultrastructure of biofilms in M. fortuitum, M. chelonae, M. abscessus , and M. smegmatis is also affected by ciprofloxacin, clarithromycin, and amikacin combined with antibiofilm agents. In fact, the percentage of dead bacteria is higher with a combination of antibiotics and antibiofilm agents than with antibiotics only (Muñoz-Egea et al, 2016b ). This synergistic effect is potentially useful in the prophylaxis or treatment of infections associated with mycobacterial biofilms.…”

Pulmonary non-tuberculous mycobacterial infections: current state and future management

“…A study by Ortíz-Pérez et al (2011) on biofilm-producing RGM treated with antibiotics showed that biofilms are resistant to AMK, CLR and ciprofloxacin (CIP) [363]. Among these three antibiotics, CIP is the most active drug affecting the thickness of the biofilms and its combination with anti-biofilm agents such as N-acetylcysteine (NAC) and Tween 80 have resulted in higher bacterial death [364].…”