Rapid Identification of Rectal Multidrug-resistant Escherichia coli Before Transrectal Prostate Biopsy

Abstract

Objective To develop and evaluated a rapid multiplex-qPCR to identify fecal carriers of multi-drug resistant extra-intestinal pathogenic E. coli clonal groups. Methods Men presenting for transrectal prostate biopsy (TPB) at the San Diego Veterans Affairs Medical Center underwent rectal culture immediately prior to TPB. Rectal swabs were streaked ciprofloxacin-supplemented (4 mg/L) MacConkey agar plates, identified, and susceptibility tested. The same swab was sent to the University of Washington for qPCR test (EST200) targeting two major MDR-ExPEC clonal groups – ST131 and ST69 that combined were expected to represent majority of fluoroquinolone as well as trimethoprim-sulfamethoxazole resistant E. coli. We calculate test characteristics including the area under the receiver operative curve (AUC). Results We enrolled 104 men from 11/5/2013 to 6/10/2014. Fluoroquinolone - resistant E. coli were cultured from 19.2% (20/104) of rectal swabs and 26% (27/104) of all swabs were positive for EST200 by PCR. The test characteristics comparing the EST200 to the culture-based detection of fluoroquinolone-resistance were 75%, 86%, 94%, and 56%, respectively. The AUC was 0.84 for the EST200 to detect fluoroquinolone resistance prior to TPB. Conclusions Compared to the reference standard rectal culture, EST200 was able to detect majority of fluoroquinolone resistant E. coli on rectal swabs prior to prostate biopsy.

The role of targeted prophylactic antimicrobial therapy before transrectal ultrasonography‐guided prostate biopsy in reducing infection rates: a systematic review

“…at initial clinic attendance) provides concordant results compared with testing immediately before biopsy . Rapid testing methods employing PCR may allow culture results to be available with much shorter intervals . There will need to be significant patient pathway changes introduced, with reliance placed on staff to check results and prescribe targeted antimicrobial agents.…”

Urinary Tract Infection: Pathogenesis and Outlook

“…For example, if sample preparation challenges could be circumvented, direct mass spectrometry on infected urine might be useful, detecting bacteria promptly in urine without the need to wait for growth on solid media [115]. Alternatively, rapid molecular identification of E. coli at the substrain level, as well as prediction of antibiotic resistances, might enable more efficient selection of antibiotics for treatment [116, 117]. Ultimately, improved and accurate diagnostics for UTI should translate into more satisfying care for patients, less frustration and speculation on the part of providers, and an overall reduction in antibiotic use.…”

Impact of selective media for detecting fluoroquinolone‐insusceptible/extended‐spectrum beta‐lactamase‐producing Escherichia coli before transrectal prostate biopsy

“…According to the American Urological Association Best Practice Policy Statement, it is recommended that FQs and cephems be prophylactically administered before prostate biopsy. However, an increasing incidence of rectal colonization of FQ‐resistant E. coli and ESBL‐producing E. coli has been reported …”

“…However, an increasing incidence of rectal colonization of FQ-resistant E. coli and ESBL-producing E. coli has been reported. [3][4][5][6][7][8] Previous studies showed that rectal swabs and resistance profiles of the rectal flora are effective for targeting antibiotic prophylaxis and preventing post-transrectal prostate biopsy infections. 9,10 These findings led some groups to adopt rectal culture and directed prophylactic therapy before transrectal prostate biopsy.…”