IN VITRO ANTIBACTERIAL ACTIVITY AND PLASMID MEDIATED DRUG RESISTANCE IN METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS

The emergence of multidrug resistance of human pathogenic bacteria and many undesirable adverse effects of antibiotics has led to a search for new antimicrobial agents. In this study, to screen the Methicillin Resistant Staphylococcus aureus (MRSA) from clinical specimens, 58 samples were collected from the government and private hospitals in Namakkal District, Tamil Nadu, India. Among 58 samples, 42 were identified as genus Staphylococcus. Out of 42 isolates, 16 were Coagulase positive. Based on the selective medium, differential medium and biochemical characters, 4 isolates were confirmed as MRSA. The antibacterial activity of selected heavy metals and different antibiotics were carried out by Kirby-Bauer disc diffusion method. Among the tested 8 heavy metals, copper sulphate and mercury chloride showed resistance to all 4 MRSA. Out of 15 antibiotics tested Penicillin and Nalidixic acid are resistant to all four MRSA isolates. Tetracycline was resistant to MRSA01, Chloramphenicol was resistance to MRSA02 and Erythromycin resistant to MRSA03. The four isolates of MRSA were processed for the isolation of plasmid DNA. For testing the capability of spreading drug resistance in plasmid, done by transformation using five methicillin resistance genetic strains of Escherichia coli such as MTCC119, KRX, DH5α, HB101 and GJ1158. The methicillin resistance in plasmid was confirmed by DH5α and GJ1158 transformants. Keywords: Antibacterial Activity, Methicillin Resistance, Staphylococcus aureus, Plasmid DNA, Heavy Metal