Antimicrobial resistance is increasing worldwide and is of particular concern in gram-negative bacilli where there is a paucity of new and effective antimicrobial agents. Pseudomonas aeruginosa infections are associated with increased mortality and morbidity, especially in immunocompromised and burn patients respectively. The organism is capable of developing resistance to practically most classes of antibiotics and has always been considered a difficult target for antimicrobial chemotherapy because of the ability of bacteria to form biofilm. A biofilm is a structured consortium of bacteria, embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Biofilm bacteria are a major concern in the treatment of infectious diseases. The objective of this work is to evaluate the efficacy of the combination of Tetracycline with different D-amino acids such as D-Leucine, D-Methionine, D-Tyrosine, and D-Tryptophan against P.aeruginosa biofilm. Sub-inhibitory concentrations of Tetracycline (0.5 MIC) along with different D-aminoacids were tested for its anti-biofilm activity. The validations of these results were done in in vitro wound dressing and ex vivo porcine skin models which shows that tetracycline-D-tryptophan combination could reduce biofilm formation. The studies using porcine skin explant confirms the efficacy of this combination for inhibiting the biofilm formation even in biological substances. The Hemocompatibility study shows no significant hemolysis by this combination. The results established the potential therapeutic application of D-aminoacids alone or in combination with tetracycline for treating biofilm associated clinical problems caused by P.aeruginosa.
Jayalekshmi H., Norin Mary G Victus, R. Anoop, T. M. Sarath, Sajin Sali, C. .Harikrishnan, N. Kaushik, Geetha B Kumar, and Dr. Bipin G. Nair, “Combinatorial effect of d-amino acids and tetracycline against pseudomonas aeruginosa biofilm”, International Journal of Pharmacy and Pharmaceutical Sciences, vol. 8, no. 11, pp. 216-220., 2016.