The molecular mechanisms of fluoroquinolone resistance found in rectal swab isolates of Enterobacterales from men undergoing a transrectal prostate biopsy: the rationale for targeted prophylaxis

Antimicrobial prophylaxis protocol based on rectal swab culture before prostate biopsy to prevent infectious complications: a prospective randomized comparative study

PURPOSE

To evaluate the benefit of targeted antibiotic prophylaxis (TAP) based on rectal swab culture in comparison with standard empiric antimicrobial prophylaxis in patients undergoing transrectal ultrasound-guided needle biopsy of the prostate (TRUS-BP), as well as to assess rate of fecal carriage of Fluoroquinolone-resistant Enterobacterales FQRE.

PATIENTS AND METHODS

We prospectively analyzed data that randomized 157 patients within two groups: (G1) TAP according to rectal swab performed 10 days before PB; (G2): empirical antibiotic prophylaxis with ciprofloxacin. Prevalence of FQRE digestive carriage and risk factors were investigated. Incidence of infectious complications after (TRUS-BP) in each group was compared.

RESULTS

G2 included 80 patients versus 77 in G1. There was no difference between the two groups regarding age, diabetes, prostate volume, PSA, number of biopsy cores, and risk factors for FQRE. In G2, the prevalence of FQRE digestive carriage was 56.3% all related to E. coli species. In the case of digestive carriage of FQRE, TAP according to the rectal swab culture with third-generation cephalosporins was performed in 73.3%. Patients with FQRE had history of FQ use within the last 6 months in 17.8% (p = 0.03). Rate of febrile urinary tract infection after PB was 13% in G1 and 3.8% in G2 (p = 0.02).

CONCLUSIONS

Incidence of FQ resistance in the intestinal flora of our local population was prevalent. Risk factor for resistance was the use of FQ within the last 6 months. TAP adapted to rectal swab, mainly with third-generation cephalosporins, significantly reduced the rate of infectious complications after (TRUS-BP).

Synthesis and antibacterial activity evaluation of N (7) position-modified balofloxacins

A series of small-molecule fluoroquinolones were synthesized, characterized by HRMS and NMR spectroscopy, and screened for their antibacterial activity against MRSA, P. aeruginosa, and E. coli as model G+/G− pathogens. Compounds 2-e, 3-e, and 4-e were more potent than the reference drug balofloxacin against MRSA and P. aeruginosa (MIC values of 0.0195 and 0.039 μg/ml for 2-e, 0.039 and 0.078 μg/ml for each of 3-e and 4-e, respectively). Analysis of the time-dependent antibacterial effect of compound 2-e toward MRSA showed that in the early logarithmic growth phase, bactericidal effects occurred, while in the late logarithmic growth phase, bacterial inhibition occurred because of concentration effects and possibly the development of drug resistance. Compound 2-e exhibited low toxicity toward normal mammalian cell lines 3T3 and L-02 and tumor cell lines A549, H520, BEL-7402, and MCF-7. The compound was not hemolytic. Atomic force microscopy (AFM) revealed that compound 2-e could effectively destroy the membrane and wall of MRSA cells, resulting in the outflow of the cellular contents. Docking studies indicated the good binding profile of these compounds toward DNA gyrase and topoisomerase IV. ADMET’s prediction showed that most of the synthesized compounds followed Lipinski’s “rule of five” and possessed good drug-like properties. Our data suggested that compound 2-e exhibited potent anti-MRSA activity and is worthy of further investigation.

Prevalence of Plasmid-Mediated Quinolone Resistance (PMQRs) Determinants and Whole Genome Sequence Screening of PMQR-Producing E. coli Isolated from Men Undergoing a Transrectal Prostate Biopsy

Fluoroquinolones (FQs) are recommended as prophylaxis for men undergoing transrectal prostate biopsy (TRUS-Bx). Recent studies suggest a significant share of FQ-resistant rectal flora in post-TRUST-Bx infections. Methods: 435 Enterobacterales isolates from 621 patients attending 12 urological departments in Poland were screened by PCR for PMQR genes. PMQR-positive isolates were tested for quinolone susceptibility and investigated by whole genome sequencing (WGS) methods. Results: In total, 32 (7.35%) E. coli strains with ciprofloxacin MIC in the range 0.125–32 mg/L harbored at least one PMQR gene. qnrS and qnrB were the most frequent genes detected in 16 and 12 isolates, respectively. WGS was performed for 28 of 32 PMQR-producing strains. A variety of serotypes and sequence types (STs) of E. coli was noticed. All strains carried at least one virulence gene. AMR genes that encoded resistance against different classes of antibiotics were identified. Additionally, five of 13 ciprofloxacin-susceptible E. coli had alterations in codon 83 of the GyrA subunits. Conclusion: This study provides information on the common presence of PMQRs among E. coli, which may explain the cause for development of post-TRUS-Bx infections. High numbers of virulence and antimicrobial resistance genes detected show a potential for analysed strains to develop infections.