Plasmid Diversity and Transferable Antimicrobial Drug Resistance, in E.coli Isolates from Calf Diarrhoea

E.coli is one of the serious pathogen that can cause tremendous therapeutic problem by developing resistance against antibiotics. The drug resistance in bacterial population is may be due to a genetic and non genetic mechanism (Choudhary 1988). Regarding genetic mechanism most drug resistant microbes emerged as a result of genetic changes and subsequent processes by antimicrobial drugs. The drug resistance may be chromosomal DNA or plasmid DNA mediated. The plasmid mediated drug resistance is caused due to the presence of drug resistance gene(s) harboring on the plasmid DNA. These genes confer the drug resistant phenomenon in the host organism (Meyer s et al.1976).Transferable multiple drug resistance has been reported among the E.coli isolated from disease outbreaks. This character is mostly coded by auto transferable plasmids. Plasmid associated resistance genes have been discovered for a majority of known antimicrobials including the quinolones and fluroquinolones ( Hawkey, 2003; Neu, H.C. 1992) and it is not uncommon for a single plasmid to simultaneously mediate resistance to five or six antimicrobials. This ability to sequester multiple resistance genes is of particular concern to modern medicine. The present ISSN: 2319-7706 Volume 3 Number 9 (2014) pp. 474-480 http://www.ijcmas.com