Non-antibiotic compounds affecting the growth of urinary pathogens during urine culture: a preliminary in vitro study

Abstract

Introduction: Urine samples are one of the most frequently submitted samples for culture to clinical microbiology laboratories, exceeding the number of most of the other clinical sample types. Various non-antibiotic pharmaceutical compounds may have inhibitory properties on bacteria, as many of these agents accumlate in/eliminated through urine. Methods: Sixty (n=60) pharmacological agents were tested during our experiments. Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603 (ESBL-producing) and Staphylococcus aureus ATCC 29213 were the bacterial strains utilized in this study. Detection of inhibitory activity among the tested compounds was performed on Mueller-Hinton plates, using disk diffusion method. Results: Nineteen (n=19) compounds presented with various levels of inhibitory activity on the tested bacterial strains (four compounds for K. pneumoniae, seven compounds on E. coli and sixteen compounds on S. aureus). The compounds showed the highest levels of inhibitory activity on B. subtilis ATCC 6633, which is one of the main bacterial strains used for the screening of the ’intrinsic’ antibacterial activity of urine. Conclusion: Our results suggest that further experiments, involving additional pharmacological agents is warranted, to establish the full extent of their influence on the appropriate culture of urine samples.