AIASSA VIRGINIA
Congresos y reuniones científicas
Título:
Effect of D-glucosamine and N-Acetylglucosamine on oxidative metabolism and biofilm formation of Staphylococcus epidermidis.
Autor/es:
AIASSA, V.; BARNES, A.I.; ALBESA I
Lugar:
Córdoba
Reunión:
Otro; 1° Reunión Internacional de Ciencias Farmacéuticas.; 2010
Institución organizadora:
Dpto. de Farmacia. Fac. de Cs. Qcas. UNC. Dpto de Farmacia. Fac. de Cs. Bioqcas y Farm. UNR
Resumen:
Introduction
Coagulase-negative staphylococci are important causes of infections associated with diverse biomaterials; biofilm-producing strains have emerged as important pathogens especially in patients with implanted devices (1). The formation of biofilm is not only an adhesive medium; it also affects the virulence of strains and enhances the resistance of bacteria against antibiotic treatments (2). The adherence to biomaterials and formation of biofilms is associated to less sensitivity to the stress caused by diverse agents (3) and it was proved that microorganisms suffer less oxidative stress in biofilms than planktonic bacteria during antibiotics treatment (4). The present study was designed to address the issue of S. epidermidis adhesion and inhibition of biofilm formation in relation to the generation of oxidative stress by D-Glucosamine (D-Glu) and N-acetylglucosamine (NAG) in order to find conditions that reduce the adhesion of the bacteria and consequently the biofilm formation.
Materials and methods Three clinical strains (848, 1569, 2786) were isolated from infected catheters, in Hospital Tránsito Cáceres de Allende, (Córdoba) to investigate the influence of glucose (Glu), D-Glu and NAG on bacterial adhesion by optical microscopy, quantification of biofilm on glass surfaces stained with crystal violet, and production of reactive oxygen species (ROS) by chemiluminiscence assay and by nitro blue tetrazolium reduction.
Results There was correlation between reduction of biofilm formation and oxidative stress. Glu incremented the adhesion whereas reduced the oxidative stress of all the strains. Inversely, D-Glu inhibited the adhesion and generated an increase of ROS at 0.05 mM in the three strains while NAG decreased the adhesion in less extent and required more concentration to cause oxidative stress, except in the strain that was more
sensitive (2786). Similar results were obtained during the biofilm quantification specifically; Glu
incremented the biofilm formation while D-Glu and NAG provoked decrease of biofilm.
Conclusions Since Glu reduced the production of ROS and favoured the biofilm formation, while D-Glu and NAG caused oxidative stress and decreased biofilm, therefore, it would be interesting to apply these hexosamines to enhance the antibacterial action of antibiotics by exploiting their ability to reduce adhesion and biofilm formation of S. epidermidis.
Acknowledgments The authors thank CONICET for the support to Virginia Aiassa as a postgraduate fellow. This work was supported by Agencia de Promoción Científica y Tecnológica, Agencia Córdoba de Promoción Científica y Técnica, and Secretaría de Ciencia y Técnica from Universidad Nacional de Córdoba.
References
1) Costerton JW, Lewandowski Z, Caldwell DE, Korber DR, Lappin-Scott HM. Microbial biofilms.
Annu Rev Microbiol. 1995;49:711-45.
2) Farber BF, Kaplan MH, Glogston AG. Staphylococcus epidermidis extracted slime inhibits the
antimicrobial action of glycopeptide antibiotics. J Infect Dis. 1990;161:37-40.
3) Brown MRW, Gilbert P. Sensitivity of biofilms to antimicrobial agents. J Appl Bacteriol.
1993;74:S87-S97.
4) Battán PC, Barnes AI, Albesa I. Resistance to oxidative stress caused by ceftazidime and piperacillin
in biofilm of Pseudomonas. Luminescence; 2004;19:265-270.
Coagulase-negative staphylococci are important causes of infections associated with diverse biomaterials; biofilm-producing strains have emerged as important pathogens especially in patients with implanted devices (1). The formation of biofilm is not only an adhesive medium; it also affects the virulence of strains and enhances the resistance of bacteria against antibiotic treatments (2). The adherence to biomaterials and formation of biofilms is associated to less sensitivity to the stress caused by diverse agents (3) and it was proved that microorganisms suffer less oxidative stress in biofilms than planktonic bacteria during antibiotics treatment (4). The present study was designed to address the issue of S. epidermidis adhesion and inhibition of biofilm formation in relation to the generation of oxidative stress by D-Glucosamine (D-Glu) and N-acetylglucosamine (NAG) in order to find conditions that reduce the adhesion of the bacteria and consequently the biofilm formation.
Materials and methods Three clinical strains (848, 1569, 2786) were isolated from infected catheters, in Hospital Tránsito Cáceres de Allende, (Córdoba) to investigate the influence of glucose (Glu), D-Glu and NAG on bacterial adhesion by optical microscopy, quantification of biofilm on glass surfaces stained with crystal violet, and production of reactive oxygen species (ROS) by chemiluminiscence assay and by nitro blue tetrazolium reduction.
Results There was correlation between reduction of biofilm formation and oxidative stress. Glu incremented the adhesion whereas reduced the oxidative stress of all the strains. Inversely, D-Glu inhibited the adhesion and generated an increase of ROS at 0.05 mM in the three strains while NAG decreased the adhesion in less extent and required more concentration to cause oxidative stress, except in the strain that was more
sensitive (2786). Similar results were obtained during the biofilm quantification specifically; Glu
incremented the biofilm formation while D-Glu and NAG provoked decrease of biofilm.
Conclusions Since Glu reduced the production of ROS and favoured the biofilm formation, while D-Glu and NAG caused oxidative stress and decreased biofilm, therefore, it would be interesting to apply these hexosamines to enhance the antibacterial action of antibiotics by exploiting their ability to reduce adhesion and biofilm formation of S. epidermidis.
Acknowledgments The authors thank CONICET for the support to Virginia Aiassa as a postgraduate fellow. This work was supported by Agencia de Promoción Científica y Tecnológica, Agencia Córdoba de Promoción Científica y Técnica, and Secretaría de Ciencia y Técnica from Universidad Nacional de Córdoba.
References
1) Costerton JW, Lewandowski Z, Caldwell DE, Korber DR, Lappin-Scott HM. Microbial biofilms.
Annu Rev Microbiol. 1995;49:711-45.
2) Farber BF, Kaplan MH, Glogston AG. Staphylococcus epidermidis extracted slime inhibits the
antimicrobial action of glycopeptide antibiotics. J Infect Dis. 1990;161:37-40.
3) Brown MRW, Gilbert P. Sensitivity of biofilms to antimicrobial agents. J Appl Bacteriol.
1993;74:S87-S97.
4) Battán PC, Barnes AI, Albesa I. Resistance to oxidative stress caused by ceftazidime and piperacillin
in biofilm of Pseudomonas. Luminescence; 2004;19:265-270.
