Abstract
Specimens of the isolated bacteria Klebsiella pneumoniae from various pathogenic cases in human (urine, pus, stool, sputum, cerebrospinal fluid) were studied. These specimence were classified into five groups of isolates according to their resistance to the antibiotics (ampicillin, tetracycline, chloramphenico, streptomycine, cephalexine). Some of the characters are studied for the plasmid DNA in these isolates, of these, the self-transmissible ability of the plasmid DNA molecules though conjugation.The plasmid DNA of the isolates (1, 2, 4) have the ability to transfer the antibiotic resistant genes to the laboratory strain of E. coli (JM83). Then the amplification of the plasmid DNA were studied in these isolates. Only the isolates (3, 5) have revealed high yield of purified plasmid DNA in the presence of chloramphenicol (100mg/ml).