Antibiotic resistant bacteria are a worldwide health problem. Eschericia coli (E. coli) cause the majority of all urinary tract infections (UTI), so the emergence of antibiotic resistant E. coli presents a challenge for urinary tract health.
According to the Centers for Disease Control, the E. coli species contains a large number of different strains. Most of them are harmless, but a few can cause illness including diarrhea, urinary tract infections, and respiratory infections.
A recent study of college women at Duke University showed that 29.6% of the E. coli samples isolated from urine cultures were resistant to trimethoprim-sulfamethoxazole, which is a standard antibiotic combination used for UTI. The researchers note that this does not represent the entire population, since most UTI cases are diagnosed and treated based on the symptoms of urinary pain, burning, and frequency. Generally, the urine culture lab test is performed when the original treatment is unsuccessful.
Recurrent UTI is a major risk for antibiotic resistant infections. The Duke study found only 1.8% ciprofloxacin resistance in urine cultures of women with no prior UTI. This number rose to 11.8% for women with a history of UTI. A similar study in Taiwan found that prior exposure to ciprofloxacin raises the risk of resistance by a factor of 13. Ciprofloxacin is commonly used for UTI that do not respond to the standard sulfa drugs.
Prevention has never been more important. A Canadian study identified vaginal colonization by “bad” bacteria as a critical step in the development of UTI. “Good” bacteria in both the intestines and the vagina have potential for preventing UTI. Oral probiotics are popular for intestinal health, and may offer benefits for vaginal health as well. Probiotic vaginal suppositories are a more direct way to supply “good” bacteria to the vagina. I found one commercially available brand (see references), and I hope research and development efforts will continue.
Song S et al, “Antibiotic resistance mechanisms of Escherichia coli isolates from urinary specimens”, Korean J Lab Med. 2009 Feb;29(1):17-24.
Olson RP et al, “Antibiotic resistance in urinary isolates of Escherichia coli from college women with urinary tract infections”, Antimicrob Agents Chemother. 2009 Mar;53(3)1285-6.
Lin CY et al, “Risk factors of ciprofloxacin resistance in urinary Escherichia coli isolates”, J Microbiol Immunol Infect. 2008 Aug;41(4):325-31.
Shigemura K et al, “Significance of fluoroquinolone-resistant Escherichia coli in urinary tract infections”, Jpn J Infect Dis. 2008 May;61(3):226-8.
Nys S et al, “Trends in antimicrobial susceptibility of Escherichia coli isolates from urology services in the Netherlands”, J Antimicrob Chemother. 2008 Jul;62(1):126-32.
Centers for Disease Control information on E. coli:
Research on the connection between vaginal flora and urinary tract infection:
Probiotic vaginal suppositories:
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.