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).

Virulence determinants, biofilm production and antimicrobial susceptibility in Staphylococcus aureus causing device-associated infections in a Tunisian hospital.

Staphylococcus aureus is a clinically relevant pathogen that causes device-related infections (DRI) driven by several virulence factors. This study characterized S. aureus isolates involved in DRI in Tunisian patients. Forty consecutive S. aureus strains causing DRI and 47 randomly selected S. aureus strains causing non-device-related infections (NDRI) were collected. All strains were screened phenotypically for antibiotic susceptibility and biofilm forming ability. They were investigated for accessory gene regulator (agr) types, biofilm encoding genes (icaADBC), adhesins, leukotoxins, toxic shock toxin, enterotoxins and exotoxins encoding genes by polymerase chain reaction. Meticillin-resistant S. aureus (MRSA) strains were further characterized by staphylococcal cassette chromosome mec (SCCmec) typing. MRSA rates among DRI and NDRI isolates were 23% and 49% (P=0.02), respectively. The DRI isolates formed biofilm more frequently (n=32) than the NDRI isolates (n=28) (P=0.04), with predominance of the moderate biofilm producer category (P=0.027). All biofilm-positive isolates except four harboured icaADBC genes. A significant difference was observed between DRI and NDRI isolates for fnbA (53-77%), spa (45-26%), sdrD (80-55%) and sen (33-11%) genes. DRI strains were agrI (48%) and agrII (30%) types, whereas NDRI strains were agrI (36%) and agrIII (43%) types. SCCmec type IV was carried by 50% of MRSA isolates. This study highlights the virulence potential displayed by S. aureus isolated from DRI in comparison with NDRI.