Rectal E. coli above ciprofloxacin ECOFF associate with infectious complications following prostate biopsy

Fluoroquinolone-resistant Escherichia coli among the rectal flora is the predominant risk factor for severe infection after transrectal ultrasound-guided prostate biopsy: a prospective observational study

BACKGROUND

Infection of the prostate gland following biopsy, usually with Escherichia coli, is a common complication, despite the use of antimicrobial prophylaxis. A fluoroquinolone (FQ) is commonly prescribed as prophylaxis. Worryingly, the rate of fluoroquinolone-resistant (FQ-R) E. coli species has been shown to be increasing.

OBJECTIVE

This study aimed to identify risk factors associated with infection after transrectal ultrasound-guided prostate biopsy (TRUS-Bx).

METHODS

This was a prospective study on patients undergoing TRUS-Bx in southeast Sweden. Prebiopsy rectal and urine cultures were obtained, and antimicrobial susceptibility and risk-group stratification were determined. Multivariate analyses were performed to identify independent risk factors for post-biopsy urinary tract infection (UTI) and FQ-R E. coli in the rectal flora.

RESULTS

In all, 283 patients were included, of whom 18 (6.4%) developed post-TRUS-Bx UTIs. Of these, 10 (3.5%) had an UTI without systemic inflammatory response syndrome (SIRS) and 8 (2.8%) had a UTI with SIRS. Being in the medium- or high-risk groups of infectious complications was not an independent risk factor for UTI with SIRS after TRUS-Bx, but low-level FQ-resistance (minimum inhibitory concentration (MIC): 0.125-0.25 mg/L) or FQ-resistance (MIC > 0.5 mg/L) among E. coli in the faecal flora was. Risk for SIRS increased in parallel with increasing degrees of FQ-resistance. Significant risk factor for harbouring FQ-R E.coli was travelling outside Europe within the previous 12 months.

CONCLUSION

The predominant risk factor for UTI with SIRS after TRUS-Bx was FQ-R E. coli among the faecal flora. The difficulty in identifying this type of risk factor demonstrates a need for studies on the development of a general approach either with rectal swab culture for targeted prophylaxis, or prior rectal preparation with a bactericidal agent such as povidone-iodine before TRUS-Bx to reduce the risk of FQ-R E. coli-related infection.

Fosfomycin Trometamol for the Prevention of Infectious Complications After Prostate Biopsy: A Consensus Statement by an International Multidisciplinary Group

CONTEXT

Transrectal ultrasound-guided prostate biopsy (TRPB) has been a standard of care for diagnosing prostate cancer but is associated with a high incidence of infectious complications.

OBJECTIVE

To achieve an expert consensus on whether fosfomycin trometamol provides adequate prophylaxis in TRPB and discuss its role as prophylaxis in transperineal prostate biopsy (TPPB).

EVIDENCE ACQUISITION

An international multidisciplinary group of experts convened remotely to discuss how to best use fosfomycin in various clinical settings and patient situations. Six statements related to prostate biopsy and the role of fosfomycin were developed, based on literature searches and relevant clinical experience.

EVIDENCE SYNTHESIS

Consensus was reached for all six statements. The group of experts was unanimous regarding fosfomycin as a preferred candidate for antimicrobial prophylaxis in TRPB. Fosfomycin potentially also meets the requirements for empiric prophylaxis in TPPB, although further clinical studies are needed to confirm or refute its utility in this setting. There is a risk of bias due to sponsorship by a pharmaceutical company.

CONCLUSIONS

Antimicrobial prophylaxis is mandatory in TRPB, and fosfomycin trometamol is an appropriate candidate due to low rates of resistance, a good safety profile, sufficient prostate concentrations, and demonstrated efficacy in reducing the risk of infectious complications following TRPB.

PATIENT SUMMARY

Patients undergoing transrectal ultrasound-guided prostate biopsy (TRPB) have a high risk of infectious complications, and antimicrobial prophylaxis is mandatory. However, increasing antimicrobial resistance, as well as safety concerns with fluoroquinolones, has restricted the number of antimicrobial options. Fosfomycin trometamol meets the requirements for a preferred antimicrobial in the prophylaxis of TRPB.

Infectious complications after transrectal MRI-targeted and systematic prostate biopsy

PURPOSE

To compare infectious complications after transrectal systematic prostate biopsy (SB) and magnetic resonance imaging (MRI)-targeted biopsy (TB) in a large retrospective cohort to assess whether one technique is superior to the other regarding infectious complications.

METHODS

A total of 4497 patients underwent 5288 biopsies, 2875 (54%) SB and 2413 (46%) MRI-TB only. On average, 12 SB cores and 3.7 MRI-TB cores were taken per biopsy session during the study period. Infection-related complications within 30 days were compared. The primary endpoint was a positive urine culture. Secondary endpoints were positive blood cultures, urine tests with elevated leukocytes ≥ 100 E6/L and elevated C-reactive protein (CRP) ≥ 100 mg/L. Chi-square test was used to compare the cohorts.

RESULTS

Positive urine cultures were found in 77 (2.7%) after SB and in 42 (1.7%) after MRI-TB (p = 0.022). In total, 46 (0.9%) blood culture positive infections were found, 23 (0.9%) occurred after SB and 23 (1.0%) after MRI-TB, (p = 0.848). Urine tests with elevated leukocytes ≥ 100 E6/L were found in 111 (3.9%) after SB and in 61 (2.5%) after MRI-TB (p = 0.006). Elevated CRP ≥ 100 mg/L was found in 122 (4.2%) after SB and in 72 (3.0%) after MRI-TB (p = 0.015). Blood cultures were drawn more often after SB than after MRI-TB, but the difference was not statistically significant. However, urine cultures and CRP were taken more often after SB than MRI-TB.

CONCLUSION

Blood culture positive infections were equally rare after SB and MRI-TB. However, all other infectious complications were more common after SB than MRI-TB.

Does Protocol Make a Difference? Comparison of Two Prostate Cancer Active Surveillance Cohorts: A Non-protocol-based Follow-up and a Protocol-based Contemporary Follow-up

Background

Active surveillance (AS) is the preferred option for initial management for low-risk prostate cancer (PC). Although many AS protocols exist, there is little evidence to support one over another.

Objective

To assess whether there is difference in overall (OS), prostate cancer–specific (CSS), metastasis-free (MFS), or treatment-free (TFS) survival between a strict (Prostate cancer Research International: Active Surveillance [PRIAS]) and a loose (European Randomized study of Screening for Prostate Cancer [ERSPC]) AS protocol.

Design, setting, and participants

This study included two cohorts of men (n = 518) with low-risk, localized, Gleason score ≤7 PC. The ERSPC cohort included 241 men followed for 9.5 yr (median) with a non–protocol-based follow-up. The PRIAS cohort included 277 men followed for 5 yr (median) with a strict protocol.

Outcome measurements and statistical analysis

OS, CSS, MFS, and TFS were compared by the Kaplan-Meier method, competing risk analysis, and Cox proportional hazard regression.

Results and limitations

As expected, due to the difference in median follow-up time between the cohorts, a difference in the absolute number of events was seen. However, no difference in any of the survival outcomes was evident in the Kaplan-Meier or competing risks analysis. Furthermore, in Cox proportional hazard regression analysis, cohort (ERSPC vs PRIAS) was not associated with any of the outcomes. Results are limited by the retrospective study design, limited statistical power, and inability to match the cohorts for predictive factors.

Conclusions

There was no difference in survival outcomes between a non–protocol-based follow-up and a protocol-based contemporary AS follow-up of patients with low-risk PC. However, a longer follow-up is needed.

Patient summary

We compared survival outcomes of two cohorts of patients with low-risk prostate cancer: a strict and a loose follow-up protocol. We found no differences in survival measures between the cohorts.

Phenotypic screening for quinolone resistance in Escherichia coli

Recent studies show that rectal colonization with low-level ciprofloxacin-resistant Escherichia coli (ciprofloxacin minimal inhibitory concentration (MIC) above the epidemiological cutoff point, but below the clinical breakpoint for resistance), i.e., in the range > 0.06-0.5 mg/L is an independent risk factor for febrile urinary tract infection after transrectal ultrasound-guided biopsy (TRUS-B) of the prostate, adding to the other risk posed by established ciprofloxacin resistance in E. coli (MIC > 0.5 mg/L) as currently defined. We aimed to identify the quinolone that by disk diffusion best discriminates phenotypic wild-type isolates (ciprofloxacin MIC ≤ 0.06 mg/L) of E. coli from isolates with acquired resistance, and to determine the resistance genotype of each isolate. The susceptibility of 108 E. coli isolates was evaluated by ciprofloxacin, levofloxacin, moxifloxacin, nalidixic acid, and pefloxacin disk diffusion and correlated to ciprofloxacin MIC (broth microdilution) using EUCAST methodology. Genotypic resistance was identified by PCR and DNA sequencing. The specificity was 100% for all quinolone disks. Sensitivity varied substantially, as follows: ciprofloxacin 59%, levofloxacin 46%, moxifloxacin 59%, nalidixic acid 97%, and pefloxacin 97%. We suggest that in situations where low-level quinolone resistance might be of importance, such as when screening for quinolone resistance in fecal samples pre-TRUS-B, a pefloxacin (S ≥ 24 mm) or nalidixic acid (S ≥ 19 mm) disk, or a combination of the two, should be used. In a setting where plasmid-mediated resistance is prevalent, pefloxacin might perform better than nalidixic acid.