Epidemiology and Resistance Levels of Enterobacteriaceae Isolates from Urinary Tract Infections Expressed as Multiple Antibiotic Resistance (MAR) Indices

Aims: To assess the epidemiology of UTIs affecting inpatients and outpatients and the antibiotic resistance levels, expressed as multiple antibiotic resistance (MAR) indices from the isolated species at a tertiary-care hospital in Hungary, during a 10-year study period.

Study Design: Retrospective microbiological study.

Place and Duration of Study: 1st of January 2008 - 31st of December 2017 at the University of Szeged, which is affiliated with the Albert Szent-Györgyi Clinical Center, a primary- and tertiary-care teaching hospital in the Southern Great Plain of Hungary.

Methodology: Antimicrobial susceptibility testing (AST) was performed using disk diffusion method and when appropriate, E-tests on Mueller–Hinton agar (MHA) plates. The multiple antibiotic resistance (MAR) index of the isolates was determined.

Results: During the 10-year study period, the Institute of Clinical Microbiology received 21,150 urine samples from outpatient clinics and 19,325 samples from inpatient departments that turned out to be positive for a significant urinary pathogen. Out of the positive urine samples, E. coli represented the overwhelming majority of all positive urine samples. The resistance levels in inpatient isolates were higher than in the outpatient isolates (average MAR indices: 0.347 vs. 0.410, 0.267 vs. 0.435 and 0.318 vs. 0.473 for the E. coli/Klebsiella, CES and Proteae group, respectively).

Conclusion: As the therapeutic options are becoming increasingly limited in the current antibiotic resistance climate, more effort should be put into the prudent use of antibiotics and the development of novel antimicrobial agents.