Quinolone-resistant E coli strain a major threat

August 15, 2005

One by one, drug-resistant microbes have weakened or destroyed the efficacy of established antimicrobials. The appearance of a strain of urinary tract infection-associated Escherichia coli that is resistant to ciprofloxacin (Cipro, Proquin) is not necessarily a surprise, but it is a significant concern, according to Anthony J. Schaeffer, MD, chairman of the department of urology, Northwestern School of Medicine, Chicago.

A study documenting this resistant strain was one of several presented at the AUA annual meeting that merited comment from Dr. Schaeffer. Others included findings that PSA can remain elevated for extended periods following acute prostatitis, reports of two new markers for chronic prostatitis, and a study relating nanobacteria to prostatic stones in men with chronic pelvic pain syndrome.

Ciprofloxacin-resistant E coli occur in 12% of UTIs overall, in only 2% of uncomplicated UTIs, but in 31% of all complicated UTIs. Risks for resistance are complicated UTI or previous exposure to quinolone antibiotics.

In nearly 80% of patients with acute prostatitis, PSA is elevated, and it can remain so for months.

Dr. Schaeffer cautioned that sustained elevated PSA levels following acute prostatitis should not be misinterpreted.

"Although acute prostatitis is a rare condition, it can cause marked symptoms and changes in the prostate which will be evidenced by a marked rise in PSA. These changes can persist and can mislead in the direction of other diagnoses. The take-home message is to monitor the PSA until is ceases to diminish. When it is stable for several months, establish that finding as the nadir and proceed from there," he advised.

A multicenter retrospective Korean study of 225 patients with acute prostatitis showed that high fever was the most common complaint, and that E coli was the most frequently found organism. PSA was elevated (mean 26.5 [4.2 to 163.0] ng/mL) in 78% of the patients and remained elevated in more than half the patients through 12 weeks of therapy.

New research shows evidence of biomarkers for chronic pelvic pain syndrome, or type III nonbacterial prostatitis.

A study from Dr. Schaeffer's own lab identified two new biomarkers in expressed prostatic secretions that appear not only to have a high degree of sensitivity and specificity for CPPS, but may also shed light on the pathogenesis of the disease. The cytokine macrophage inflammatory protein-1alpha (MIP-1α) has a sensitivity of 72.4% and a specificity of 69.2%; monocyte chemoattractant protein-1 (MCP-1) has a sensitivity of 83.9% and a specificity of 90%. Combined, the two have a sensitivity of 88.7% and a sensitivity of 80%.

"Men with CCPS frequently have prostatic inflammation. This study indicates that they also have these two elevated cytokines. These may, in fact, be biomarkers for the disease. Further study is needed to determine how these biomarkers are modulated during the course of the disease and if treatment with anti-cytokines might be warranted," Dr. Schaeffer said.