Some bacteria from UTIs in bladder cells

ST. LOUIS, Dec. 18 (UPI) -- U.S. scientists have found proof some bacteria that cause urinary tract infections can become entrenched inside human bladder cells.

Senior author Scott Hultgren of the Washington University School of Medicine in St. Louis used light and electron microscopy and immunofluoresence to examine urine samples from 100 women with either active or previous urinary infections and found signs of bladder cell infection in a significant portion of the samples from patients with active UTIs. These included cells enlarged by bacterial infection and shed from the lining of the bladder.

The findings support previous animal studies by Hultgren, which suggested bacteria can become firmly anchored in bladder cells by changing to form cooperative communities called biofilms.

Hultgren's experiments suggested some bacteria progress to a filament-like shape when exiting out of the biofilm and these were found in 41 percent of the samples from patients with symptomatic UTIs.

"Biofilm formation is generally an important strategy bacteria use to evade host responses and antibiotic therapies," lead study author David Rosen said in a statement. "Attacking biofilms is going to be a really important approach as we enter a new era of fighting infectious diseases."

The study is published in the journal Public Library of Science Medicine.