On April 28, researchers published new evidence suggesting that up to 30% of patients with suspected urinary tract infections (UTIs) are not treated with antibiotics due to insensitive bacterial culture diagnostics.

Using a more sensitive technique called quantitative polymerase chain reaction (qPCR), Dr. Heytons and colleagues at the University of Ghent diagnosed UTIs of bacterial origin in over 98.2% of female study participants presenting with symptoms. While this research study further supports the empirical management of UTIs with antibiotics, GlobalData notes that in an era of antibiotic resistance, it is of utmost importance to also properly utilize diagnostics to confirm a bacterial infection and help guide appropriate antibiotic selection.

In a clinical study involving 308 women, including 220 women with UTI-associated symptoms and 86 healthy volunteers, researchers assessed a total of 308 urine samples for the presence of Escherichia coli and Staphylococcus saprophyticus. Among the 220 women with UTI-associated symptoms, standard microbiological culture techniques identified bacteria in 80.9% of urine samples, whereas qPCR techniques detected E. coli in 95.9% and S. saprophyticus in 8.6% of all suspected urine samples, yielding an overall evidence for bacterial infections of 98.2%.

In healthy volunteers, standard microbiological culture techniques confirmed E. coli infection in 10.5%, compared with 11.6% detected by qPCR. The researchers cited asymptomatic bacteriuria as most likely explanation for the positive results in healthy volunteers.

The results of this study must be confirmed in cohorts before guidelines can change to recommend an antibiotic treatment in patients with symptomatic UTI and negative microbiological cultures. In particular, the researchers are planning to assess the potential of qPCR techniques in diagnosing UTIs that are caused by bacteria but are currently difficult to detect by culture-based detection methods.

However, GlobalData notes that the current results—a higher number of qPCR-positive E. coli urine samples than culture-positive E. coli samples—seem to suggest that screening for E. coli DNA by qPCR could be sufficient to detect bacterial origin of UTIs.

While the evidence from this study supports the more liberal use of empiric therapy in treating suspected UTIs, ultimately a balance needs to be achieved to avoid an increase in multidrug-resistant UTIs due to antibiotic resistance in the future.