Search

UTI-lizer is a recent digital format for easy-to-use culture-based detection, preliminary identification, and quantification of bacteria in urine at the point of care (PoC). This study aimed to evaluate the diagnostic accuracy of UTI-lizer tests for detection of bacteriuria caused by five common bacterial species: Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, Proteus mirabilis, and Staphylococcus saprophyticus. We evaluated the accuracy of UTI-lizer tests by comparing test results of UTI-lizer with those of current standard bacterial culture-based diagnostics in clinical microbiology laboratories in a retrospective and a prospective study. Comparator methods were classical bacterial culture in combination with matrix-assisted laser desorption/ionization-time of flight mass spectrometry mediated bacterial identification. In the retrospective study, we tested 104 urine samples with in-panel microorganisms, plain urethral microbiota, and culture-negative samples. In the prospective study, we used 137 urine samples within 10 hours of their collection at general practitioner clinics. The retrospective study demonstrated 100% sensitivity and specificity in the detection of bacteriuria, and 98.6% sensitivity and 96.8% specificity in identifying primary pathogens with UTI-lizer when compared to clinical standards. S. saprophyticus and E. coli could not be distinguished. The combined nitrite and esterase test predicted the presence of bacteriuria in only 36.5% of cases. The prospective study demonstrated 100% sensitivity and 89.6% specificity in the detection of significant bacteriuria for in-panel microorganisms with a coverage rate of 88.3% (121/137). This study indicates that digital dipsticks are a promising alternative for the detection of the five main pathogens that cause the vast majority of urinary tract infections (UTIs). The results demonstrate that digital dipsticks have the potential to uniquely provide—in primary care or at the point of care—a, QC 20231218

Objectives The performance of blood cultures (BC) relies on optimal sampling. Sepsis guidelines do not specify which sampling protocol to use, but recommend two sets of BC bottles, each set containing one aerobic and one anaerobic bottle. For the single-site sampling (SSS) protocol, only one venipuncture is performed for all four bottles. The predominating multi-site sampling (MSS) protocol implies that BC bottles are collected from two separate venipuncture sites. The aim of this study was to compare SSS and MSS. Primary outcomes were number of BC sets collected, sample volume and diagnostic performance. Methods This was a retrospective clinical study comparing BC results in an emergency department before and after changing the sampling protocol to SSS from MSS. All BC samples were incubated in the BacT/ALERT BC system. Results The analysis included 5,248 patients before and 5,364 patients after the implementation of SSS. There was a significantly higher proportion of positive BCs sampled with SSS compared to MSS, 1,049/5,364 (19.56%) and 932/5,248 (17.76%) respectively (P=0.018). This difference was due to a higher proportion of solitary BC sets (two BC bottles) in MSS. Analyzing only patients with the recommended four BC bottles, there was no difference in positivity. SSS had a higher proportion of BC bottles with the recommended sample volumes of 8-12 ml than MSS (P<0.001). Conclusions Changing the sampling protocol to SSS from MSS resulted in higher positivity rates, higher sample volume and fewer solitary BC sets. These advantages of SSS should be considered in future sepsis guidelines., Correction for Ekwall-Larson et al., “Single-Site Sampling versus Multisite Sampling for Blood Cultures: a Retrospective Clinical Study”. Journal of Clinical Microbiology, vol. 60(9), e01180-22. DOI 10.1128/jcm.01180-22

Blood culture (BC) often fails to detect bloodstream microorganisms in sepsis. However, molecular diagnostics hold great potential. The molecular method PCR/electrospray ionization-mass spectrometry (PCR/ESI-MS) can detect DNA from hundreds of different microorganisms in whole blood. The aim of the present study was to evaluate the performance of this method in a multicenter study including 16 teaching hospitals in the USA (n=13) and Europe (n=3). First, on 2,754 contrived whole blood samples, with or without spiked microorganisms, PCR/ESI-MS produced 99.1% true positive and 97.2% true negative results. Secondly, among 1,460 patients with suspected sepsis (sepsis-2 definition), BC and PCR/ESI-MS on whole blood were positive in 14.6% and 25.6% of cases, respectively, with the following result combinations: BC+/PCR/ESI-MS-, 4.3%; BC+/PCR/ESI-MS+, 10.3%; BC-/PCR/ESI-MS+, 15.3%; and BC-/PCR/ESI-MS-, 70.1%. Compared with BC, PCR/ESI-MS showed the following sensitivities (coagulase-negative staphylococci not included): Gram-positive bacteria, 58%; Gram-negative bacteria, 78%; and Candida species, 83%. The specificities were > 94% for all individual species. Patients treated with prior antimicrobial medications (n=603) had significantly increased PCR/ESI-MS positivity rates compared with patients without prior antimicrobial treatment, 31% vs 22% (p<0.0001), with pronounced differences for Gram-negative bacteria and Candida species. In conclusion, PCR/ESI-MS showed excellent performance on contrived samples. On clinical samples, it showed high specificities, moderately high sensitivities for Gram-negative bacteria and Candida species, and elevated positivity rates during antimicrobial treatment. These promising results encourage further development of molecular diagnostics on whole blood for detection of bloodstream microorganisms in sepsis., Funding Agencies:Ibis Biosciences, a division of Abbott Abbott LaboratoriesCepheid ContraFect Nabriva Therapeutics AG Lajolla Pharmaceuticals Alere Corporation Spectral Diagnostics Ferring Pharmaceuticals Inflammix VICTASm Sanofi Pasteur Inc. Curetis GmbH PfizerMerck & CompanyCidara Therapeutics Inc. Shire Aridis Pharmaceuticals Inc. Epigenomics Inc. Roche Holding GenentechFinch Therapeutics Seres Therapeutics Inc. Diasorin Molecular Janssen Research and Development NeuMoDx Molecular Iterum Therapeutics International

Blood volume is the most important variable, for detection of microorganisms in blood cultures (BC). Most standards recommend 40-60 ml blood, collected in several BC bottles filled up to 10 ml. We measured blood volume in individual BC bottles, and analysed the association of hospital, bottle type, day of the week, daily sampling time, and age and gender of the patient, with sampling volume and BC result. The variation in blood volume per BC bottle was analysed in a mixed linear model using hospital, bottle type, weekday, sampling time, age and gender as fixed factors, and patient ID and episode as random factors to control for repetitive sampling of individual patients. Only 18 % of all bottles were filled with the recommended 8-10 ml, and 47 % were filled with less than 8 ml. The mean (±SE) volume was larger in positive 9.09 (±0.15) compared to negative bottles 8.47 (±0.07) (p<0.001). Blood volume was larger in BacT/ALERT-FA Plus than in -FN Plus BC bottles (p<0.001). There was significantly lower volumes collected during the night (p<0.001). The volume of blood collected decreased significantly with increasing patient age (p<0.001). Larger volumes were collected from males compared to females, 8.78 (±0.06) vs. 8.36 (±0.06) ml (mean ± SE) respectively (p<0.001). The odds of detecting a positive patient increases with 13 % for each additional ml blood drawn. Our results show that we need to work actively with development of blood sampling routines to overcome age and gender effects, and to optimize blood sampling volumes.

The usefulness of pneumococcal urinary antigen tests (UATs) in severe pneumococcal infection relies heavily on the performance in bacteremic patients. Fluorescence technology and automatic reading of test results may improve UAT performance. We evaluated the automatically read Sofia S. pneumoniae FIA for diagnosing pneumococcal bloodstream infection (BSI) in hospitalized adult patients. First, the Sofia FIA was evaluated on 97 patients with pneumococcal (n = 47) and nonpneumococcal (n = 50) BSI and compared with results by the visually read BinaxNOW S. pneumoniae immunochromatographic test (ICT) and ImmuView S. pneumoniae and Legionella pneumophila ICT. In four cases (4.1%), the Sofia FIA showed invalid test results, three of which showed invalid results by the ImmuView ICT previously. Based on 93 valid cases, the Sofia FIA showed similar sensitivity (for both comparisons: 68% versus 62%; P = 0.45) and specificity (for both comparisons: 91% versus 93%; P = 1.00) as the visually read UATs. Second, the Sofia FIA was prospectively evaluated on 82 consecutive nonfrozen urine samples, detecting pneumococcal antigen in 10 of 14 (sensitivity, 71%) pneumococcal BSI patients, similarly to the visually and automatically read BinaxNOW ICT (both 12 of 14; sensitivity, 86%; P = 0.50). Of five nonpneumococcal BSI cases, the Sofia FIA showed an invalid test result in one case, but no positive UAT results were obtained. Thus, the sensitivity and specificity of the Sofia FIA were similar to the performance rates of other UATs in patients with BSI, but invalid test results are of concern for the usefulness in pneumococcal BSI., Funding Agency:Region Örebro County Council Research Committee OLL-723721