Plasmids for Amoxicillin and Ciprofloxacin Resistance in Escherichia coli Isolate Causing Urinary Tract Infection

Background: Escherichia coli causes urinary tract infection (UTI), one of the most frequent bacterial infections in humans, shows resistance to various commonly prescribed antibiotics. This is termed as multi drug resistance, which is increasing among E. coli. The multi-drug resistant E. coli isolates harbor multiple plasmids that might be responsible for antibiotic resistance. The resistance can be transferred among bacteria through horizontal transfer of the genetic materials.

Objectives: We undertook this study 1) to find a link between antibiotic resistance and plasmid of E. coli from UTI patients of Sylhet region of Bangladesh 2) to analyze the spread of the plasmid mediated antibiotic resistant gene between E. coli isolates.

Methods: Conjugation experiment was carried out in Luria Broth with E. coli DH5α as recipient. For transformation, competent cells were prepared using E. coli DH5α. Plasmid isolation was done by mini alkaline lysis method and plasmid was extracted from agarose gel and transferred to the competent cell.

Results: After conjugation, the donor E. coli isolate that showed resistance to amoxicillin (AMX), ciprofloxacin (CIP) and ceftriaxone (CTR) tranferred its AMX and CIP resistance to the recipient E. coli DH5α, that was previously sensitive to all antibiotics. After transformation, the recipient E. coli DH5α became resistant to CIP and AMX, while the donor showed resistance to gentamycin (CN), ceftriaxone (CTR), amoxicillin (AMX), ciprofloxacin (CIP), cefixime CFM, and cotrimoxazole (COT). Plasmid extracted from the transformant revealed that, three genes (3 kb, 5 kb and 20 kb) have been transferred from the donor to recipient.

Conclusion: Plasmids responsible for amoxicillin and ciprofloxacin were transferred