Extended-spectrum ß-lactamase in the rectal flora of patients undergoing transrectal prostate biopsy: a study of the prevalence in a major metropolitan hospital.

OBJECTIVES: To determine the prevalence of extended-spectrum ß-lactamase (ESBL) in patients undergoing transrectal prostate biopsy, to assess the incidence of postoperative sepsis, to correlate the development of sepsis with the presence of preoperative ESBL on rectal swabs, and to assess the adequacy of prophylactic antibiotic guidelines in the context of local ESBL prevalence. METHODS: Patients undergoing transrectal ultrasonography (TRUS)-guided biopsy at the Royal Melbourne Hospital between January 2012 and July 2016 had rectal swabs taken immediately prior to TRUS with specific cultures to identify the presence of ESBL. Patients were given a prophylactic antibiotic, 500 mg oral ciprofloxacin, 1 h before the TRUS procedure. Data were collected prospectively, with retrospective review of all readmitted patient files and audit data to ensure complete capture of events. RESULTS: A total of 387 TRUS-guided biopsy procedures were performed. Rectal swabs were correctly collected in 352 patients (91%). The median patient age was 65 years. In all, 25 (7%) ESBL-positive swabs were identified. Most ESBL were Escherichia coli. Half (50%) of ESBL were resistant to ciprofloxacin and all were sensitive to meropenem. A small increase in ESBL prevalence over time was not significant (R2 = 0.35). Four patients (1.1%) were readmitted with sepsis; ESBL Pseudomonas had previously grown in one patient, but sepsis was attributable to non-ESBL E. coli. In one of the readmitted patients ESBL E. coli was present, but this patient did not have ESBL preoperatively. There were no deaths or high-dependency/intensive care unit admissions. CONCLUSIONS: This study represents the largest Australian series to investigate ESBL prevalence, and reveals a rate lower than that of many other nations. Our sepsis rate is lower than many international series, perhaps because of our low ESBL rate and strict antibiotic prophylaxis. Preoperative swab results did not predict postoperative sepsis, and the process was therefore not useful for guiding antibiotic therapy. In this patient population, TRUS biopsy, with ciprofloxacin prophylaxis, remains a safe option for diagnostic prostate biopsy.

Health service impact of testing for respiratory pathogens using cartridge-based multiplex array versus molecular batch testing.

There is increasing demand for access to rapid microbiological testing, with a view to improving clinical outcomes. The possibility of rapid testing has been facilitated by development of cartridge-based random access molecular technologies that are now widely available. Whether the expense of cartridge-based assays is justified in terms of clinical or laboratory cost savings is controversial. This prospective study evaluated the impact of the Biofire FilmArray Respiratory Panel ('FilmArray'), a cartridge-based random access molecular test, compared with standard batched molecular testing using an 'in-house' respiratory polymerase chain reaction (PCR) on laboratory and health service outcomes for adult patients at a tertiary-level adult hospital in Melbourne, Australia. Laboratory result turnaround time was significantly reduced with the FilmArray (median 4.4 h) compared to a standard validated in-house respiratory PCR assay (median 21.6 h, p < 0.0001) and there was a significant increase in diagnostic yield with the Filmarray (71/124, 57.3%) compared to in-house PCR (79/200; 39.5%; p = 0.002). Despite improved result turnaround time and increased diagnostic yield from testing, there was no corresponding reduction in hospital length of stay or use of isolation beds. Although cartridge-based molecular testing reduced turnaround time to result for respiratory pathogen testing, it did not impact on health service outcomes such as hospital length of stay. Further work is warranted to determine whether cartridge-based tests at the point of care can improve clinical and health service impacts.

An Australian case of Streptococcus suis toxic shock syndrome associated with occupational exposure to animal carcasses.

Streptococcus suis is known to cause sporadic infections in people who have occupational exposure to pigs and pig meat. A large outbreak occurred in China in 2005, where there was 62% mortality among those who developed toxic shock syndrome. Despite S. suis being common in pigs, this is the first published report of a human case of S. suis toxic shock syndrome in Australia.