Potential therapeutic applications of microbial surface-activecompounds

Numerous investigations of microbial surface-active compounds or biosurfactants over the past two decades have led to the discovery of many interesting physicochemical and biological properties including antimicrobial, anti-biofilm and therapeutic among many other pharmaceutical and medical applications. Microbial control and inhibition strategies involving the use of antibiotics are becoming continually challenged due to the emergence of resistant strains mostly embedded within biofilm formations that are difficult to eradicate. Different aspects of antimicrobial and anti-biofilm control are becoming issues of increasing importance in clinical, hygiene, therapeutic and other applications. Biosurfactants research has resulted in increasing interest into their ability to inhibit microbial activity and disperse microbial biofilms in addition to being mostly nontoxic and stable at extremes conditions. Some biosurfactants are now in use in clinical, food and environmental fields, whilst others remain under investigation and development. The dispersal properties of biosurfactants have been shown to rival that of conventional inhibitory agents against bacterial, fungal and yeast biofilms as well as viral membrane structures. This presents them as potential candidates for future uses in new generations of antimicrobial agents or as adjuvants to other antibiotics and use as preservatives for microbial suppression and eradication strategies

Effect of anti-microbial fiber and its interaction with gentamicin on Pseudomonas aeruginosa

"nBackground: Because of importance and extensive use of textile in clinical setting especially as bandage, so outbreak of nosocomial infections due to Bacteria resistance; nanobiotechnological advances in recent decade, achieved methods for fabrication antimicrobial effect in fibers that can satisfied the needs of patients in the wake of health and hygiene. "nMethods: The antimicrobial effect of special type of fibers produced in Isfahan Poly Acryl Plant on one resistant strain of Pseudomonas aeruginosa isolated from 54 wound samples of patients in Isabn e Maryam hospital and P.aeruginosa (PTCC1024) was studied by using shake flask method. In order to compare the effect of pure antimicrobial agent of the fiber with that of gentamicin, the minimal inhibitory concentration of these agents was tested on strains. The effect of the interaction of these two antimicrobial agents and their fractional inhibitory concentration on chosen strains was studied using checkerboard method. "nResults: The results show inefficient effect by antimicrobial fiber on P.aeruginosa strains after 24 hrs. But despite the high level MIC of gentamicin on these bacteria (1-3 µg/ml), the MIC of pure antimicrobial agent of fiber at a level of 10-3 µl/ml caused growth inhibition. The interaction of these antibacterial agents on the P.aeruginosa isolated from wound was evaluated as synergism. "nConclusions: According to this study the antimicrobial effect of the fiber on growth inhibition of P.aeruginosa strains is negative (despite of significant effect by pure antimicrobial agent used in produced the antimicrobial fiber on examined strains)

Surface conditioning with <em>Escherichia coli</em> cell wall components can reduce biofilm formation by decreasing initial adhesion

Bacterial adhesion and biofilm formation on food processing surfaces pose major risks to human health. Non-efficient cleaning of equipment surfaces and piping can act as a conditioning layer that affects the development of a new biofilm post-disinfection. We have previously shown that surface conditioning with cell extracts could reduce biofilm formation. In the present work, we hypothesized that <em>E. coli</em> cell wall components could be implicated in this phenomena and therefore mannose, myristic acid and palmitic acid were tested as conditioning agents. To evaluate the effect of surface conditioning and flow topology on biofilm formation, assays were performed in agitated 96-well microtiter plates and in a parallel plate flow chamber (PPFC), both operated at the same average wall shear stress (0.07 Pa) as determined by computational fluid dynamics (CFD). It was observed that when the 96-well microtiter plate and the PPFC were used to form biofilms at the same shear stress, similar results were obtained. This shows that the referred hydrodynamic feature may be a good scale-up parameter from high-throughput platforms to larger scale flow cell systems as the PPFC used in this study. Mannose did not have any effect on <em>E. coli</em> biofilm formation, but myristic and palmitic acid inhibited biofilm development by decreasing cell adhesion (in about 50%). These results support the idea that in food processing equipment where biofilm formation is not critical below a certain threshold, bacterial lysis and adsorption of cell components to the surface may reduce biofilm buildup and extend the operational time