Zabidi, Muhammad AzrulYusoff, Narazah MohdKader, Zainoodin Sheik Abdul2012-10-162012-10-162012-01Zabidi Muhammad Azrul, Yusoff Narazah Mohd, Kader Zainoodin Sheik Abdul. Preliminary comparative analysis of antibacterial effects of activated and non-activated of expired platelet concentrate by disc diffusion method. Indian Journal of Pathology & Microbiology. 2012 Jan-Mar 55(1): 47-51.http://imsear.searo.who.int/handle/123456789/142175Background: Platelets release more than 30 cytokines to provide primary hemostatic function. In addition, platelets are also known to release antimicrobial peptides upon activation by thrombin. Materials and Methods: In this study, comparative analysis of antibacterial activity of activated and non-activated expired platelet concentrate was determined against Gram-positive and Gram-negative bacteria by Kirby-Bauer disk diffusion method. Thrombin was used to prepare activated platelet concentrate. Gram-positive bacteria tested in this study were S.aureus and S.pyogenes and Gram-negative bacteria were E.coli and K.oxytoca. All the bacteria used in this study were sensitive strains from clinical isolates. Activated and non-activated platelet showed no zone of inhibition against S.pyogenes and E.coli. Results: Activated platelet showed antibacterial activity against S.aureus and K.oxytoca with the zone of inhibition of 8.3 ± 0.6 mm and 7.7 ± 0.2 mm, respectively. Zone of inhibition observed in non-activated platelet against S.aureus and K.oxytoca were 7.8 ± 0.4 mm and 7.5 ± 0.3 mm, respectively. Conclusions: These findings showed that no significant differences in antibacterial activity produced by activated and non-activated platelet. However, zone of inhibition observed in activated and non-activated platelet indicate the presence of antibacterial property in expired platelet.enDisc diffusion assayexpired platelet concentrateplatelet microbicidal peptideAntimicrobial Cationic Peptides --metabolismAntimicrobial Cationic Peptides --pharmacologyBlood Platelets --chemistryGram-Negative Bacteria --drug effectsGram-Positive Bacteria --drug effectsHumansMicrobial Sensitivity TestsArticle