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PLASMID BORNE ANTIBIOTIC RESISTANCE FACTORS AMONG INDIGENOUS KLEBSIELLA

SHEIKH AJAZ RASOOL, AFSHEEN AHMAD, SADIA KHAN  AND ABDUL WAHAB

Abstract: About fifty indigenous clinical Klebsiella were isolated and identified on the basis of morphology, growth, and biochemical characteristics. Fifty two percent were identified as K. oxytoca, 42% as K. pneumoniae and 6% as K. ozaenae. All the isolates offered different resistance patterns (determined by medium incorporation-replica method) against antibiotics including ampicillin, streptomycin, gentamicin, ofloxacin, tetracycline and chloramphenicol. Some of the representative isolates lost the antibiotic resistance after acridine orange mediated curing. Two methods (uninterrupted tube method and solid substrate mediated mating) were tried for in vivo gene transfer studies for determining the conjugative/ transferable nature of the drug resistance plasmid markers. In only one out of five mating (filter paper) experiments, chloramphenicol and ampicillin resistance markers were transferred to the recipient E. coli MD40 cells. The rest of the plasmid borne markers were non-conjugative/nontransferable. Conjugative plasmids carry a tremendous potential to disseminate resistance markers to distant recipient cells.  

Department of Microbiology, University of Karachi, Karachi, Pakistan.