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Many strategies and technologies are available to improve blood culture (BC)-based diagnostics. The ideal approach to BCs varies between healthcare institutions. Institutions need to examine clinical needs and practices in order to optimize BC-based diagnostics for their site. Before laboratories consider offering rapid matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) or expensive rapid panel-based molecular BC diagnostics, they should optimize preanalytical, analytical, and postanalytical processes and procedures surrounding BC systems. Several factors need to be considered, including local resistance rates, antibiotic prescribing patterns, patient- and provider-types, laboratory staffing, and personnel available to liaise with clinicians to optimize antibiotic use. While there is much excitement surrounding new high-technology diagnostics, cost-neutral benefits can be realized by optimizing existing strategies and using available tools in creative ways. Rapid BC diagnostics should be implemented in a manner that optimizes impact. Strategies to optimize these BC diagnostics in individual laboratories are presented here. [ABSTRACT FROM AUTHOR]

Abstract: Granulicatella and Abiotrophia spp. were known as nutritionally variant streptococci (NVS). Such strains have caused major diagnostic difficulties due to fastidious culturing and unspecific colony morphology. The present study is aimed at comparing the performance of laboratory available diagnostic methods for NVS isolates and determining the antimicrobial susceptibility of these isolates. Fourteen clinical invasive isolates, consisting of 10 Granulicatella adiacens, 1 Granulicatella elegans, and 3 Abiotrophia defectiva were in parallel analyzed by 2 matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) systems, i.e., Bruker MS and Vitek MS, as well as Vitek 2 for the species determination. 16S rRNA gene sequencing was applied as a reference method. The Vitek MS gave correct identification for all 14 isolates. The Bruker MS could correctly identify 8/10 G. adiacens, 0/1 G. elegans, and 3/3 A. defectiva isolates at the first analysis occasion, and all 14 isolates became identifiable after repeated tests. The Vitek 2 system could identify 6/10 G. adiacens, 1/1 G. elegans, and 2/3 A. defectiva isolates at the species level. Antimicrobial susceptibilities of 11 antibiotics were determined by Etest. Resistance against ciprofloxacin, ceftriaxone, rifampicin, and tetracycline were observed in 4, 10, 4, and 1 isolates, respectively. In conclusion, MALDI-TOF MS is a useful tool for the rapid diagnosis of NVS. Phenotypic testing by Vitek 2 is only partially effective for the accurate identification of such strains. The emergence of resistant NVS isolates indicates the necessity of monitoring antimicrobial susceptibilities of such uncommon pathogens. [Copyright &y& Elsevier]

Abstract: In the present study we investigated transport times for blood cultures from three tertiary-care hospitals to Karolinska University Laboratory and identified predictors of long transport times. Concomitantly, consequences of delayed incubation on total detection time (TDT) were analyzed by in vitro sepsis models. A total of 909 blood cultures were studied. The median (interquartile range) transport time was 9 (3–15) h. The hospital accommodating the microbiology laboratory had the shortest transport time compared to the other two hospitals (P < 0.0001). Samples taken between 16:00–24:00 had longer transport times compared to samples taken between 8:00–16:00 and 24:00–08:00 (P < 0.0001). In vitro experiments showed that TDT was longer for samples pre-incubated at room temperature (RT) for 19 h compared to the ones pre-incubated for 2 h or 9.5 h (P < 0.0001). In conclusion, off-site location, time of sampling and number of transports per day were related to, and predictors of transport time. [Copyright &y& Elsevier]