Isolation and Characterization of Pseudomonas Strain That Inhibit Growth of Indigenous and Clinical Isolate

The use of microorganisms for biological purpose has become an effective alternative to control pathogens. Bacteria from marine environment are an underutilized source of novel antibiotics. A total of 100 bacteria were isolated from marine samples (Fish, Water and Crustaceans) of Baluchistan coast and screened for antagonistic interaction. Out of these 15 strains showed antibacterial activity. One strain designated as CMG1030 identified as Pseudomonas aeruginosa gave excellent antibacterial activity, capable of inhibiting growth of clinical isolates such as methicillin resistant Staphylococcus aureus. Escherichia coli, Salmonella typhi, Shigella flexnerie, Staphylococcus epidermidis, as well as indeginous marine bacteria such as Staphylococcus aureus, Shewanella putrifacians, Vibrio alginolyticus, Staphylococcus epidermidis, Micrococcus luteus, Bacillus subtilis. Inhibition did not involve living cells, which has suggested that at least a substantial portion of the anti microbial activity was due to the excretion of extra cellular compound but did not give activity against Streptococcus (group G), Candida albicans, Aspergillus niger Thin layer chromatography of crude extract of cells of Pseudomonas aeruginosa revealed one UV active fraction with biological activity. Microscopic examination of exponentially growing cells of S.aureus treated with crude extract of P.aeruginosa suggests cell lysis and some ghost cells and big cells were also observed.