Routine Ertapenem Prophylaxis for Transrectal Ultrasound Guided Prostate Biopsy does Not Select for Carbapenem Resistant Organisms: A Prospective Cohort Study.

PURPOSE: Sepsis after transrectal ultrasound guided prostate biopsy is an increasing problem in this era of rising antibiotic resistance. Although ertapenem prophylaxis has proved effective at our institution to reduce this, it has raised local and regional antimicrobial stewardship concerns. We investigated the possible selective effect of single dose ertapenem prophylaxis on fecal colonization with carbapenem resistant Enterobacteriaceae. MATERIALS AND METHODS: Patients underwent a rectal swab prior to receiving prebiopsy ertapenem prophylaxis. A second swab was obtained at followup 4 to 6 weeks later. Swabs were screened for carbapenem resistant Enterobacteriaceae using an enhanced CDC (Centers for Disease Control) method. Prebiopsy swabs were also screened for extended spectrum ß-lactamase producing and ciprofloxacin resistant Enterobacteriaceae. Patients were monitored for post-biopsy sepsis. RESULTS: A total of 326 patients were enrolled in the study. At baseline 6.4% and 9.0% of patients had colonization with extended spectrum ß-lactamase producing and ciprofloxacin resistant Enterobacteriaceae, respectively. Carbapenem resistant Enterobacteriaceae were not detected at baseline or followup in any patients. Colonization with nonfermentative organisms with intrinsic ertapenem resistance was detected in 29.4% of patients at baseline and followup (p = 1.0). Three cases (0.9%, 95% CI 0.2-2.8) of probable post-biopsy sepsis were identified during the study period. None was bacteremic or required intensive care unit admission. CONCLUSIONS: Single dose ertapenem prophylaxis did not appear to have a significant selective effect on fecal colonization with carbapenem resistant Enterobacteriaceae or other ertapenem resistant gram-negative organisms in this outpatient group. It is highly effective prophylaxis for transrectal ultrasound guided prostate biopsy. In the right setting ertapenem may represent a useful prophylactic option to prevent post-transrectal ultrasound guided prostate biopsy sepsis.

Molecular testing for viral and bacterial enteric pathogens: gold standard for viruses, but don't let culture go just yet?

Contemporary diagnostic microbiology is increasingly adopting molecular methods as front line tests for a variety of samples. This trend holds true for detection of enteric pathogens (EP), where nucleic acid amplification tests (NAAT) for viruses are well established as the gold standard, and an increasing number of commercial multi-target assays are now available for bacteria and parasites. NAAT have significant sensitivity and turnaround time advantages over traditional methods, potentially returning same-day results. Multiplex panels offer an attractive 'one-stop shop' that may provide workflow and cost advantages to laboratories processing large sample volumes. However, there are a number of issues which need consideration. Reflex culture is required for antibiotic susceptibility testing and strain typing when needed for food safety and other epidemiological investigations. Surveillance systems will need to allow for differences in disease incidence due to the enhanced sensitivity of NAAT. Laboratories should be mindful of local epidemiology when selecting which pathogens to include in multiplex panels, and be thoughtful regarding which pathogens will not be detected. Multiplex panels may not be appropriate in certain situations, such as hospital-onset diarrhoea, where Clostridium difficile testing might be all that is required, and laboratories may wish to retain the flexibility to run single tests in such situations. The clinical impact of rapid results is also likely to be relatively minor, as infective diarrhoea is a self-limiting illness in the majority of cases. Laboratories will require strategies to assist users in the interpretation of the results produced by NAAT, particularly where pathogens are detected at low levels with uncertain clinical significance. These caveats aside, faecal NAAT are increasingly being used and introduce a new era of diagnosis of gastrointestinal infection.

Mortality in Clostridium difficile infection: a prospective analysis of risk predictors.

OBJECTIVES: To date, the vast majority of studies investigating risk factors for mortality in Clostridium difficile infection (CDI) have been based on retrospective, routinely collected data, and have not specifically tested the capacity of risk factors to predict outcome. We aimed to prospectively evaluate predictors of mortality in patients with CDI, utilizing established metrics of risk prediction to assess their ability to prognosticate. PATIENTS AND METHODS: We collected a cohort of all patients diagnosed with CDI at Addenbrooke's Hospital in 2010. Univariate associations between several parameters and all-cause 30-day in-hospital mortality were assessed, with statistically significant parameters entered into a Cox regression model. A backwards selection procedure was used to derive a final multivariate model. RESULTS: The cohort consisted of 131 patients. From the univariate analyses white blood cell count (WBC)>15×10/l, serum albumin <25 g/l, serum creatinine >200 µmol/l and C-reactive protein >100 nmol/l met criteria for entry into the multivariate model. WBC>15×10/l (hazard ratio 5.3, 95% confidence interval 1.7-16.8) and serum albumin level <25 g/l (hazard ratio 9.5, 95% confidence interval 1.2-74.5), were significantly associated with mortality in the final multivariate model. The model containing these variables had a C-index of 0.79, D-statistic of 2.1 and RD measure of 0.52. CONCLUSION: We have demonstrated in a prospective cohort of patients diagnosed with CDI that WBC and serum albumin, when used together, offer good risk predictive ability for mortality. Our results support the inclusion of these parameters in a clinically useful risk prediction model.