Incidence of Multidrug Resistance R-plasmids among Escherichia coli Causing Urinary Tract Infections: A Case Study from Nigeria

Aims: Study on the antimicrobial resistance pattern and plasmid screening of some clinical strains of Escherichia coli isolated from urine of some urinary tract infection out patients.
Study design: Cross-sectional study.
Place and Duration of Study: General hospital Lagos Island, Lagos, Nigeria, between March 2009 and August 2009.
Methodology: Fifty resistant strains of E. coli were isolated by standard procedures from 96 clinical specimens. Antimicrobial susceptibility testing and plasmid screening were done on the strains. Followed by plasmid isolation and gene transfer experiment. plasmid curing of the resistant plasmid was also carried out.
Results: Out of 96 samples screened only 50 (52.1%) yielded clinical isolates of E. coli. Among the various classes of antibiotic tested, high resistance was found with amoxycillin (100%), followed by tetracycline (98%), and augmentin (98%), while nitrofurantoin, ceftriaxone and ofloxacin being the most potent with (90%), (58%), (58%), sensitivity respectively. All the strains that were resistant to any antimicrobial agent were also resistant to amoxycillin. 34.4% of the isolates with multiple antimicrobial resistant haboured single plasmids ranging in sizes from 4.5kb to 4.8kb. Transformation experiment revealed that six of these resistant strains carried a common R-plasmid of size 4.8kb. Plasmid determined resistance to tetracycline was identified.

Conclusion: This study has highlighted the emergence of multidrug resistance R-plasmids among Escherichia coli causing urinary tract infections in Nigeria. There is a high level of resistance to many antimicrobials that are frequently used in Nigeria. The uncontrolled use of antibiotics has contributed largely to this situation. Thus the government should make considerable effort to establish an antibiotic policy for the country.