Electrolyte Concentration in Urine and Urinary Infection-Is There Any Relation?

BACKGROUND

Sodium, potassium, chloride, calcium, and magnesium in urine are useful biomarkers and are commonly evaluated in patients with different conditions. Urinary tract infections are among the most common diseases worldwide. However, their treatment poses significant challenges, particularly in hospitals, primarily due to antibiotic resistance and recurrence.

OBJECTIVES

To evaluate the relationship between ion concentrations in urine and the presence of infection.

METHODS

A total of 175 random urine samples were collected from patients who had a request for urine culture at the Cova da Beira University Hospital Centre in Portugal. In vitro contamination was also conducted, in which ten negative urine cultures were contaminated with an Escherichia coli strain to evaluate the direct effect of its presence on the concentration of the ions.

RESULTS

In total, 61 samples were found to be positive, following a consensual quantitative definition. For Ca, there was a significant association between its concentrations in positive and negative cultures. In ten negative urine cultures experimentally contaminated with an Escherichia coli strain, bacterial growth did not seem to affect the concentration of ions. In vitro contaminated samples were also inoculated on MacConkey agar and incubated. The results showed that Gram-negative bacteria do not seem to proliferate in environments with low Ca concentrations.

CONCLUSIONS

The presence of higher concentrations of Ca may facilitate the multiplication of Gram-negative bacteria, which can potentially result in depletion of Ca in vivo to putatively potentiate an inflammatory response. The concentration of Na, K, Cl, and Mg does not seem to have any relationship with UTIs.