STUDY: New methods needed

JOURNAL: Science

AUTHORS: Dr. Joseph J. Palermo, Gregory G. Anderson

ABSTRACT: A germ that causes stubborn urinary tract infections may be resistant to antibiotics because it invades the bladder cells and builds a fort-like colony that is impervious to drugs and attack from the body's own immune system.

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COMMENTARY: E. coli bacteria form a biofilm inside cells of the bladder cells of mice. This biofilm is composed of bacteria unified into a colony to resist attack, said Dr. Joseph J. Palermo, a Washington University researcher and a co-author of the study. "The bacteria rest in a matrix like eggs in a carton," said Palermo.

He said this is the first time that a biofilm structure has been found within a cell, and the discovery explains why many patients are unable to ever become completely free of urinary tract infections.

"In a biofilm, thousands and thousands of bacteria work together as sort of a multicellular organism," said Gregory G. Anderson, a co-author of the study. Anderson said the biofilm "is a slimy type of mesh" similar to the slick coating often found on submerged rocks in a stream or pool of water.

If biofilm formation is confirmed in humans, she said, then it adds a new sense of urgency to the need to develop alternate ways to treat stubborn urinary tract infections.

The Washington University researchers said their studies show that individual E. coli bacteria assume different roles within the biofilm, acting like members of a multi-cell organism. Bacteria on the edge of the biofilm can burst out of the host cell and colonize other cells within the bladder wall.

Because the bacteria are within the cells of the bladder, they often are not detected by routine medical tests.

When you check a urine sample for the presence of bacteria, all you are looking for are free floating bacteria.

If there are bacteria in the bladder tissue itself, you are not going to pick them up. Having sterile urine doesn't really give you a picture of what the bacteria state of the bladder is. It makes diagnosis more difficult.

Recurring or highly resistant urinary tract infections are a major medical problem, particularly among women. The infections cause frequent and painful urination, fever and can lead to more dangerous kidney infections.

About 8 million urinary tract infections are diagnosed annually, second only to respiratory infections in the United States. Antibiotics usually knock out the infections, but for many it becomes a problem returning time after time.