Multidrug Resistance Phenotype and Plasmid Profiling of Escherichia coli Isolates Causing Urinary Tract Infections in North East Part of Bangladesh

Aim: Urinary tract infections (UTIs) caused by Escherichia coli have become a significant worldwide public health concern and the situation is now worsening by the ability of bacteria to develop resistance to antimicrobial agents. The main aim of our study is to determine the probable link of antibiotic resistance patterns with plasmid profile of E. coli isolates causing Urinary tract infections (UTIs).

Study Design: The design of this study was to i) identify bacteria causing UTIs, ii) investigate antimicrobial susceptibility, iii) analyze plasmid profiling and iv) find possible link between of antimicrobial susceptibility and plasmid profile.

Place and Duration of Study: Genetic Engineering and Biotechnology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh, from January 2011 to January 2015.

Methods: Urine samples were collected from 94 patients suspected with UTI. Bacterial isolates from the infected urine samples were identified based on morphological, cultural and biochemical characteristics. Antibiogram of bacterial isolates was performed by standard disc diffusion method. Plasmid isolation of all E. coli isolates was done by mini alkalysis method. Plasmid profiling was visualized following agarose gel electrophoresis.

Results: Fifty patients of them were infected with UTI. Among the 50 UTI positive patients, 29 were infected with E. coli. All the E. coli isolates were resistant to amoxicillin and nalidixic acid. Overall resistant phenotype of E. coli isolates to cefixime, ciprofloxacin, ceftriaxone and azithromycin was 68.96%, 65.51%, 55.17% and 47.5% respectively. However, imipenem and gentamicin were found very effective as 96.55% and 82.75% of E. coli isolates were sensitive to these drugs, respectively. Approximately 90% of the E. coli isolates were resistant to three or more antibiotics and were defined as multidrug resistant (MDR). Plasmid profiling showed that multiple plasmids of different sizes between 24.5 and 0.5 kb were present in most of the MDR E. coli isolates. However, no plasmid was found in several MDR E. coli isolates.

Conclusion: Our data revealed that multidrug resistance pattern of E. coli isolates causing UTI was very alarming in Bangladesh and might be plasmid-mediated in most cases and also chromosomal DNA mediated in some cases.