Stable post-TRUS biopsy sepsis rates and antibiotic resistance over 5 years in patients from Newcastle, New South Wales

To the Editor: Sepsis after transrectal ultrasound (TRUS)-guided prostate biopsy is a potentially serious complication. Antibiotic prophylaxis reduces the risk of sepsis; however, practices are highly variable among urologists.

Several reports show increasing incidence of bacterial resistance in patients with sepsis after TRUS-guided biopsy.1-3 Preprocedure screening of high-risk patients using cultures from rectal swabs would allow targeted prophylaxis.4,5 We performed a retrospective audit of all men undergoing a TRUS-guided prostate biopsy by one of nine urologists in Newcastle, New South Wales, to assess the incidence of bacteraemia and changes in antimicrobial susceptibility.

Unique patient data were collected retrospectively from private and public hospital records, including data on positive blood cultures from Hunter Area, Douglass Hanly Moir, Laverty and Healthscope pathology services. Patient and pathology records were cross-referenced and data were analysed using Microsoft Excel. This clinical audit did not require ethics committee approval, in accord with the NSW Health policy on authorisation to commence human research in public health organisations.

From 2008 to 2012, 4218 men underwent a TRUS-guided prostate biopsy. Median age was 64 years. Of these men, 35 (0.8%) developed bacteraemia, with the annual incidence varying between 4/935 (0.4%) and 12/999 (1.2%) over the 5 years (non-significant differences). There were no recorded deaths from sepsis. Most of the cultures from men who developed bacteraemia (29/35) grew Escherichia coli. None grew Enterococcus species. The isolate cultured was resistant to at least one of the preprocedure prophylactic antibiotics given in 13 out of 35 cases.

Bacteraemia was uncommon, and the rates we found were comparable to previously reported ones.1,2 Antimicrobial resistance fluctuated (Box) without significant change.

Of note, we found quinolone resistance for cultures from 5/12 patients who developed bacteraemia in 2012. Worldwide emergence of multidrug-resistant E. coli sequence type 131 has coincided with a rising incidence of quinolone-resistant infection after TRUS-guided prostate biopsy in New Zealand.3

Only five isolates (out of 35) were resistant to both gentamicin and ciprofloxacin, while 12 were resistant to one of these, suggesting that a prophylactic combination remains superior to either agent alone. The low overall incidence of post-TRUS bacteraemia due to a pathogen with resistance to ciprofloxacin and gentamicin (5/4218; 0.1%) implies that there is no utility in screening with cultures from rectal swabs before TRUS biopsy in the population we studied. It remains essential to administer antibiotics prophylactically 1 hour before the procedure and at an appropriate dose to maximise sepsis prevention.