Urine Influences Growth and Virulence Gene Expressions in Uropathogenic E. coli: A Comparison with Nutrient Limited Medium

Objective: The interactions between environmental factors and microbial biological processes are well known. Urine provides host conditions probably affecting bacterial growth and gene expressions. The aim of this study was to detect the modulations of growth and gene expressions [sfa/foc, cnf1, usp and aer] of Uropathogenic E.coli (UPEC) strains in urine by comparing the results with serum supplemented standard American Petroleum Institute (SAPI) medium which is defined as host-like medium.

Methods: UPEC strains C7 and C149 were incubated at 37°C and growth alterations were detected by measuring the changes in the absorbance at 600 nm in four-, six – and 24 hours. Gene expression levels were analyzed by quantitative polymerase chain reaction (qPCR). Statistical analysis of fold changes in gene expression values and growths were calculated using one-way ANOVA unpaired t-test and Tukey’s post hoc test, respectively.

Results: The increase of bacterial growth in urine was found to be statistically significant (p<0.0001). The alterations of aer and sfa/foc expression levels were statistically significant (p0.05).

Conclusion: According to our results, urine as an environment in vivo affected both the growth and gene expression in UPEC.