Infectious disease specialists are raising the alarm over a variant of the e.coli bacteria that is resistant to most of the antibiotics used to treat bladder infections and could be responsible for more than 3,000 deaths a year.
E.coli ST131, an aggressive strain of multi-drug-resistant e.coli bacteria, may be responsible for as many as 1 million bladder infections a year, according to a recent study conducted by Dr. James Johnson, an infectious disease expert at the Veterans Affairs Medical Center in Minneapolis.
E.coli ST131 is one resistance gene away from being untreatable, Johnson warns. “I think it’s high time to worry. Before, resistant strains were wimpy. Now, we have a winner,” he says.
Although e.coli is best known as the intestinal bacteria that causes diarrhea when people eat tainted meat or vegetables, such as spinach, it actually occurs more often outside the intestines, causing far more infection and death. Extra-intestinal e.coli is responsible for about 80 percent to 90 percent of the urinary tract infections that occur annually.
Most e.coli variants respond to common treatments: guzzling gallons of water, swilling quarts of cranberry juice, and, if all else fails, heading to the doctor for a quick course of antibiotics. However, Dr. Johnson’s study determined that although the e.coli ST131 strain accounted for only about 17 percent of e.coli isolates overall, it accounted for more than 50 percent of bacteria resistant to more than one antibiotic, including the top two types used to treat most urinary tract infections, or UTIs, and also was responsible for nearly 70 percent of resistance to the biggest guns of mainline UTI treatment, fluoroquinolones and extended-spectrum cephalosporins.
E.coli ST131 probably caused the most significant multi-drug resistant e.coli infections in the U.S. in 2007, the year Johnson studied, constituting a serious public health threat.
Dr. Johnson’s findings add to the growing concerns about drug-resistance in common infections such as UTIs. New UTI guidelines that will restrict the use of fluoroquinolones for large infections are expected to be issued by the Infectious Diseases Society of America this fall.