Improving Understanding of Microbial Populations in Urinary Tract Infections to Better Treat these Hard to Eradicate Infections

Urinary tract infections (UTIs) are more prevalent in females and the chance of acquiring the UTI during her lifetime is 1 in 2 women with many experiencing repeated infection (rUTIs). Every year millions of females suffer from UTI which causes frequent painful urination, upper back and side pain, fever, nausea, and pelvic pressure, etc. The most common organism in uncomplicated UTIs is Escherichia coli followed by several gram-positive cocci and other Enterobacteriaceae. The UTI can be classified as urethra (urethritis), bladder (cystitis), or kidney (pyelonephritis).

In urethritis, bacteriuria (the presence of bacteria in the urine), doesn’t pose much risk in absence of symptoms. But in pregnant women, asymptomatic bacteriuria increases the risk of disease in kidney and is also associated with prematurity, low birth weight infants, and fetal mortality. Pyelonephritis during pregnancy is associated with bacteremia (bacteria in the blood), and severe illness which can be fatal to mother.

Among all hospital acquired infections UTIs are responsible for 40% of all cases. The majority are associated with catheterization and other manipulations of the urinary tract. Pathogenic bacteria present in the hospital environment may be introduced to the bladder during catheterization. The criteria for diagnosis includes multiple clinical parameters and laboratory tests, and the clinical suspicion of a UTI frequently triggers the prescription of broad spectrum antibiotics, with or without confirmation of the infecting organisms.

rUTIs do not respond well to treatment and are associated with considerable morbidity and health care. Most rUTIs are caused by the infection of the same organism, but in some cases a second bacterium can also cause infection. The emergence of resistance to antibiotics has stimulated research into alternative treatment and prevention methods, such as cranberry products and probiotics.

It has been observed that women with higher vaginal colonization of Lactobacillus have lower rates of UTI. Lactobacillus is the dominant organism in vagina and helps to inhibit pathogens by producing lactic acid and competing for nutrients. It has also been shown that reduction or absence of Lactobacillus in the vagina may lead to colonization by pathogenic bacteria, which can cause a UTI infection.

Next generation sequencing techniques create the possibility of investigating the microbial metagenome associated with infection and inflammation of the urinary tract. A comprehensive analysis of microbiota using next generation sequencing during UTI and recurrent UTI will help in generating new hypothesis for UTI infection. This hypothesis could ultimately lead to entirely new and safe prebiotic and probiotic preventive treatments to restore and protect the urinary tract microbiome from the establishment of UTI pathogens.

Funding