Directed carbapenemase testing is no longer just for Enterobacterales: cost, labor, and workflow assessment of expanding carbapenemase testing to carbapenem-resistant P. aeruginosa.

Molecular carbapenem-resistance testing, such as for the presence of carbapenemases genes, is commonly implemented for the detection of carbapenemase-producing Enterobacterales. Carbapenemase-producing P. aeruginosa is also associated with significant morbidity and mortality, although; prevalence may be underappreciated in the United States due to a lack of carbapenemase testing. The present study sought to compare hands-on time, cost and workflow implementation of carbapenemase gene testing in Enterobacterales and P. aeruginosa isolates versus sending out isolates to a public health laboratory (PHL) for testing to assess if in-house can provide actionable results. The time to carbapenemase gene results were compared. Differences in cost for infection prevention measures were extrapolated from the time of positive carbapenemase gene detection in-house versus PHL. The median time to perform carbapenemase gene testing was 7.5 min (range 5-14) versus 10 min (range 8-22) for preparation to send isolates to the PHL. In-house testing produced same day results compared with a median of 6 days (range 3-14) to receive results from PHL. Cost of in-house testing and send outs were similar ($46.92 versus $40.53, respectively). If contact precautions for patients are implemented until carbapenemase genes are ruled out, in-house testing can save an estimated $76,836.60 annually. Extension of in-house carbapenemase testing to include P. aeruginosa provides actionable results 3-14 days earlier than PHL Standard Pathway testing, facilitating guided therapeutic decisions and infection prevention measures. Supplemental phenotypic algorithms can be implemented to curb the cost of P. aeruginosa carbapenemases testing by identifying isolates most likely to harbour carbapenemases.

Evaluation of the BacterioScan 216Dx for Standalone Preculture Screen of Preserved Urine Specimens in a Clinical Setting.

BACKGROUND: The BacterioScan 216Dx laser microbial growth monitoring system was evaluated as an option for preurine culture screening of preserved urine specimens at an acute care medical center. METHODS: The BacterioScan 216Dx system performance characteristics and the economic impact (cost effectiveness) for the laboratory were assessed. Urinalysis performance compared to urine culture was assessed if urinalysis was ordered as part of the patient care set. RESULTS: When compared to urine culture, the BacterioScan had an overall performance with corresponding 95% confidence intervals of 76% (68-83) sensitivity, 84% (80-87) specificity, 55% (48-63) positive predictive value, and 93% (90-95) negative predictive value for 610 randomly selected preserved urine specimens. Urinalysis compared to urine culture overall performance was 59% (48-69) sensitivity, 87% (83-90) specificity, 53% (43-63) positive predictive value, 89% (86-92) negative predictive value for 414 urine specimens. CONCLUSIONS: While the system did improve the turnaround time to a negative report, adoption of the BacterioScan system would increase the reagent budget for laboratory urine culture by 2.34 times the current cost, potentially making BacterioScan prohibitive in a budget restricted environment. Additionally, performance when compared to traditional urine culture was less than acceptable for a diagnostic laboratory to use as a stand-alone urinary tract infection screen.