Ciprofloxacin resistance in the faecal carriage of patients undergoing transrectal ultrasound-guided prostate biopsy

Authors


Urosepsis and UTIs after TRUS-guided biopsy of the prostate are becoming increasingly worrisome events. Initially, antimicrobial prophylaxis reduced infectious complications compared with placebo from ∼25% to 8%. [1-5] Currently, fluoroquinolones are most commonly used for prophylaxis. Worldwide, despite follow-up prophylaxis, ∼ 3–5% of men undergoing TRUS-guided biopsy of the prostate experience UTIs and urosepsis. Moreover, several recent studies have highlighted an increasing trend towards infectious complications attributable to fluoroquinolone-resistant organisms among men undergoing this procedure [6-11]. A number of studies, including the present one [12], have demonstrated fluoroquinolone resistance of ∼20% in men undergoing biopsies. About 25% of men with fluoroquinolone-resistant bowel flora, who receive fluoroquinolone prophylaxis, develop infectious complications. Consequently, the majority of infectious complications after TRUS-guided biopsy of the prostate are attributable to fluoroquinolone-resistant bacteria. Conversely, infectious complications are rare when fluoroquinolone prophylaxis is given to men with bowel flora presumed to be fluoroquinolone-sensitive. We developed a targeted prophylaxis approach wherein patients with ciprofloxacin-susceptible organisms received ciprofloxacin and those with ciprofloxacin-resistant organisms received directed prophylaxis, and the infection rate was reduced to zero [13]. Clearly, a larger study will be needed to confirm these observations.

The aforementioned approach brings with it some further challenges. Cultures need to be obtained 1 week before the biopsy so that the bacterial sensitivity data can be used to select the best antimicrobial prophylaxis. A slight cost (∼ US$30) is incurred for the cultures, but the cost is offset by the significant benefits of avoiding the morbidity and cost of septic complications. Thus, the overall cost to the healthcare community is reduced at a slight increase in cost to individual patients. In addition, only 38 men needed to undergo rectal swab and directed prophylaxis to prevent one potentially deleterious infectious complication.

A number of important points should be considered as we move forward:

  1. Antimicrobials can also have a lasting effect on bacterial resistance. Urologists should identify patients at increased risk, most notably patients who receive any antimicrobial therapy, and specifically fluoroquinolone treatment, within 1 year of the biopsy.
  2. Inappropriate use of antimicrobials. Treating patients with fluoroquinolones in an effort to reduce serum PSA levels is not a sound concept as it increases bacterial resistance and the risk of infection.
  3. Antimicrobial prophylaxis should be used appropriately, that is one dose 2 h before the biopsy and one dose 1 h after the biopsy. Increasing the duration of ‘prophylaxis’ is of no benefit and can lead to unnecessary development of antimicrobial resistance. For example, in the present study, patients received a dose of ciprofloxacin and then the rectal swab culture was obtained ∼20 h later. Approximately half of the swabs did not show gram-negative organisms, suggesting that the ciprofloxacin had a marked early impact on the faecal flora.
  4. Increasing the spectrum of antimicrobial prophylaxis will only provide short-term gains. Invariably more resistant bacteria will emerge and lead to a greater number and severity of infectious complications.

Directed prophylaxis is a reasonable course to take for monitoring faecal flora and reducing the infectious complications of transrectal prostate biopsy.

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