Approach to antimicrobial prophylaxis for urology procedures in the era of increasing fluoroquinolone resistance

Antibiotic prophylaxis in urologic interventions: Who, when, where?

BACKGROUND

Periprocedural prophylaxis in medicine encompasses the set of measures (physical, chemical, and pharmacological) used to reduce the risk of infection. Antibiotic prophylaxis (AP) refers to the administration of a short-term regimen of antibiotics shortly before a medical procedure to reduce the risk of infectious complications that can result from diagnostic and therapeutic interventions. The outspreading growth of multidrug-resistant bacterial species and changes in the bacterial local ecosystem have impeded the development of a unique scheme of AP in urology.

OBJECTIVES

To review the literature and current guidelines regarding AP for urological diagnostic and therapeutic procedures, and to define agents, timing, and occasions when administering pharmacological prophylaxis. Secondly, according to current literature, to open new scenarios where AP can be useful or useless.

RESULTS

Major gaps in evidence still exist in this field. AP appears useful in many invasive procedures and some sub-populations at risk of infectious complications. AP is not routinely recommended for urodynamic exams, diagnostic cystoscopy, and extracorporeal shock-wave lithotripsy. The available data regarding the use of AP during the transperineal prostate biopsy are still unclear; conversely, in the case of the transrectal approach AP is mandatory. AP is still considered the gold standard for the prevention of postoperative infective complications in the case of ureteroscopy, percutaneous nephrolithotomy, endoscopic resection of bladder tumor, endoscopic resection of the prostate, and prosthetic or major surgery.

CONCLUSION

The review highlights the complexity of determining the appropriate candidates for AP, emphasizing the importance of considering patient-specific factors such as comorbidities, immunocompetence, and the nature of the urologic intervention. The evidence suggests that a one-size-fits-all approach may not be suitable, and a tailored strategy based on the specific procedure and patient characteristics is essential.

Antibiotic prophylaxis in flexible ureterorenoscopy with negative urine culture

Objective

To improve susceptibility profiles of nosocomial bacteria, identifying the difference between infectious complications in patients undergoing endoscopic flexible ureterolithotomy (fURS) with negative urine culture (UC) that received extended antibiotic prophylaxis (EP) compared with standard antibiotic prophylaxis (SP).

Methodology

This is a retrospective, observational, analytical cohort study, comparing infectious complications between patients undergoing fURS with negative UC who received EP versus SP. We include patients with susccessfull fURS, <20-mm stones and complete information.

Results

Overall, 10.3% of patients had complications, 7.2% of patients had postoperative urinary infection, 1.8% had upper urinary tract infection (UTI) and 1.4% had urinary sepsis. Lower UTI were significantly more likely in the extended prophylaxis group with 6.8% versus 2.7% (RR = 2.8; 95% CI: 1.10-7.37, p = 0.030). The risk of upper UTI and sepsis did not show significant differences. A total of 69% patients with postoperative infection had isolated multidrug-resistant bacteria (MDRB) in the UC, with a higher risk in patients with extended prophylaxis (RR = 3.1; 95% CI: 1.33-7.59, p = 0.009).

Conclusions

Patients with negative UC who underwent fURS using extended prophylaxis have two times higher risk of low UTI than patients with standard prophylaxis, without differences in the incidence of upper UTI or urinary sepsis. The risk of MDRB isolation in the postoperative UC is higher in the extended prophylaxis group, therefore we recommend the standard 60-min preoperative prophylaxis.

A role for the bacterial GATC methylome in antibiotic stress survival

Antibiotic resistance is an increasingly serious public health threat¹. Understanding pathways allowing bacteria to survive antibiotic stress may unveil new therapeutic targets^2–8. We explore the role of the bacterial epigenome in antibiotic stress survival using classical genetic tools and single-molecule real-time sequencing to characterize genomic methylation kinetics. We find that Escherichia coli survival under antibiotic pressure is severely compromised without adenine methylation at GATC sites. While the adenine methylome remains stable during drug stress, without GATC methylation, methyl-dependent mismatch repair (MMR) is deleterious, and fueled by the drug-induced error-prone polymerase PolIV, overwhelms cells with toxic DNA breaks. In multiple E. coli strains, including pathogenic and drug-resistant clinical isolates, DNA adenine methyltransferase deficiency potentiates antibiotics from the β-lactam and quinolone classes. This work indicates that the GATC methylome provides structural support for bacterial survival during antibiotics stress and suggests targeting bacterial DNA methylation as a viable approach to enhancing antibiotic activity.

Fluoroquinolone-based antimicrobial prophylaxis in patients undergoing transrectal ultrasound-guided prostate biopsy

The aim of this study was to establish the prevalence of resistance to fluoroquinolones in Escherichia coli strains isolated from patients undergoing transrectal ultrasound-guided prostate biopsy (TRUS-Bx) and to evaluate the incidence of possible infectious complications associated with this procedure. One hundred and four patients undergoing a TRUS-Bx in a single medical centre were prospectively enrolled in this study. In all patients, pre-biopsy rectal swabs were obtained. The analysis determined the antimicrobial susceptibility of E. coli strains to levofloxacin, ciprofloxacin and a panel of other antibiotics. Before biopsy, each of the men received a levofloxacin-based prophylaxis. Telephone follow-up was used to identify patients who had complications after TRUS-Bx. Fluoroquinolone-resistant strains were isolated from 9.62 % of the patients. In all cases, there were related to E. coli and all those strains were resistant to both levofloxacin and ciprofloxacin. Fluoroquinolones showed greater antimicrobial activity against E. coli (p < 0.05) than ampicillin, amoxicillin/clavulanate and cephalothin. Minor infectious complications occurred in three patients (2.91 %). The relation between the resistance of E. coli to fluoroquinolones and the risk of readmission, as well as infectious complications, was statistically significant (p < 0.05). Despite recent reports of increasing prevalence of fluoroquinolone-resistant E. coli and the associated increase of severe infectious complications, the presented results have not confirmed this phenomenon. Resistance to fluoroquinolones of E. coli strains isolated from rectal swab cultures prior to TRUS-Bx is the risk factor for readmission and infectious complications after this procedure.