Research Paper Bactericidal activity of manganese (IV) complex of Bactericidal activity of manganese (IV) complex of Bactericidal activity of manganese (IV) complex of Bactericidal activity of manganese (IV) complex of Bactericidal activity of manganese (IV) complex of 2-methylamino-pyridine against 2-methylamino-pyridine against 2-methylamino-pyridine against 2-methylamino-pyridine against 2-methylamino-pyridine against Streptococcus pyogenes Streptococcus pyogenes Streptococcus pyogenes Streptococcus pyogenes Streptococcus pyogenes and and and and and Staphylococcus aureus Staphylococcus aureus Staphylococcus aureus Staphylococcus aureus Staphylococcus aureus S. El-Masry, I. H. El-Sayed, M. Lotfy, M. El-Shahat, S. A. Ali, W. A. Nasif ABSTRACT Objective: To investigate the bactericidal activity of manganese (IV) complex of 2- Molecular and Cellular methylamino-pyridine against Streptococcus pyogenes (S. pyogenes) and Staphylococcus Biology Department, aureus (S. aureus). Genetic Engineering and Materials and Methods: The inhibitory effect of the complex was studied on the molecular Biotechnology Research level and by turbidity measurement. Treatment of bacteria was carried out using 5, 10, 25, Institute, 50 and 100 μmol of the complex per ml of culture media. Minufiya University, Sadat City, Results: The results showed that the growth of S. pyogenes rapidly decreased with increas- Minufiya. Egypt ing concentrations of the complex. In contrast, the complex caused no significant decrease in the growth rate of S. aureus. The molecular level studies showed that four protein bands, Received: 27.10.2005 with apparent molecular weights of 19, 23, 30 and 54 Kda, respectively, increased in the Revised: 2.3.2006 protein pattern of the S. pyogenes extract after the complex treatment using silver stained Accepted: 8.3.2006 polyacrylamide gels, under reducing condition. However, there was no detectable change in the protein pattern of the S. aureus extract after the complex treatment. No DNA damage Correspondence to: was detected while using agarose gel electrophoresis and ethidium bromide staining in both Mahmoud Lotfy types of bacteria. E-mail: mlotfy2000@yahoo.com Conclusion: Manganese (IV) complex of 2-methylamino-pyridine showed an apparent anti- bacterial inhibitory effect against S. pyogenes, but S. aureus was apparently resistant. KEY WORDS: Free radicals, gram-positive cocci, metal complex, SOD. Introduction that grow in air and is toxic. Cells devoid of cytosolic SOD Gram-positive cocci are a heterogeneous collection of suffer enzyme inactivation, growth deficiencies and DNA approximately 21 genera that colonise humans. Among these, damage. It has been suggested that the scant superoxide, Streptococcus and Staphylococcus are important pathogens generated by aerobic metabolism, harms even cells that in humans. [1] S. pyogenes has demonstrated the ability to contain abundant SOD. The vulnerability of bacteria to develop drug resistance, particularly in patients with mixed increased intracellular superoxide explains the widespread use infections that involve S. aureus. The drug resistance in of superoxide-producing drugs as bactericidal weapons . [5] staphylococci is due to penicillinase and acquisition of the mec Extensive studies were conducted to address the A gene, which codes for a novel penicillin-binding protein, antibacterial activity for many compounds and metal PBP2. [1,2] complexes that were found to have redox-cycling or pro- Free radicals and, in particular, superoxide radical (O – 2 ) oxidative activity. [6-9] In a previous study, we found an cause cellular disruption due to peroxidation of membrane antitumour activity of some metal complexes having SOD-like lipids. Superoxide dismutase (SOD) is believed to be involved activity on Ehrlich ascites carcinoma cells. [10] The present study in all oxygen-metabolising cells. [3] Four different types of SOD aims to examine the antibacterial activity of one of these have been found, two of which have been found in eukaryotic complexes [Manganese (IV) complex of 2-methylamino- cells. A copper and zinc containing form is located in the pyridine, (MnL 2 O) 2 Cl 4 .2H 2 O where L is 2-methylamino-pyridine] cytosol; and a manganese containing form is located in the on S. aureus and S. pyogenes. The inhibitory effect of this mitochondria. [4] Its wide distribution among aerobic complex was studied on the molecular level and by turbidity organisms [3] suggests that superoxide is formed inside all cells measurement. Indian J Pharmacol | June 2006 | Vol 38 | Issue 3 | 177-80 177