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BACKGROUND: Early diagnosis of candidemia is critical for the correct management and treatment of patients. AIMS: To test the efficacy of different blood culture bottles in the growth of Candida strains. METHODS: We compared the performance of BD BACTEC™ Plus Aerobic/F (Aero) culture bottles with the specific BD BACTEC™ Mycosis IC/F Lytic (Myco) culture bottles using the BD BACTEC™ FX 40 automated blood culture system to determine the mean time-to-detection (TTD) in Candida species. One isolate each of six Candida species was inoculated into blood culture bottles (final concentration, 1-5CFUml-1) and incubated at 37°C until automated growth detection. RESULTS: Candida albicans and Nakaseomyces glabratus (Candida glabrata) were detected earlier in the specific culture bottle, whereas Candida tropicalis was detected earlier in the nonspecific bottle; Candida parapsilosis, Pichia kudriavzevii (Candida krusei), and Meyerozyma guilliermondii (Candida guilliermondii) presented similar TTD in both bottles. CONCLUSIONS: Our study suggests the suitability of using both bottles in clinical laboratories for a faster diagnosis and prompt starting of any treatment.

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In this article, we demonstrate a rapid sterility testing method for non-filterable cell-based preparations and its in-process control media/buffers. The selected rapid sterility test (RST) in this work is based on the ScanRDI® system, which detects fluorescently labeled microorganisms with solid-phase cytometry. ScanRDI® has been chosen due to its sensitivity for detecting viable microorganisms down to one microbial cell with a shorter time to detection compared with the compendial sterility test (CST) method. The RST was validated for a CAR-T cell-therapy product with 4 days of time to detection (TTD) and evaluated for in-process control of media/buffers with real-time detection method success according to USP <1223>, Ph. Eur. 5.1.6, and PDA Technical Report No. 33. The validation parameters included limit of detection and equivalence in routine operations, specificity, robustness, ruggedness, and repeatability. For the validation, a combination of pharmacopoeial ATCC strains as well as in-house isolates were used. In addition, the evaluation study of this RST for in-process control of media/buffers was assessed by performing the limit of detection and equivalence with four representative microorganisms. Where applicable, results were statistically evaluated to demonstrate equivalence and no significant difference of the rapid method as compared with the CST method have been detected. All acceptance criteria have been met, and the solid-phase cytometry technology was successfully validated as an alternative sterility test for cell-based preparations and for its in-process control of media/buffer.

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OBJECTIVES: Time-to-detection (TTD) in culture on liquid media is inversely correlated to bacillary load and should be a contributing factor for assessing tuberculosis transmission. We wanted to assess if TTD was a better alternative than smear status to estimate transmission risk. METHODS: From October 2015 to June 2022, we retrospectively studied a cohort of index cases (IC) with pulmonary tuberculosis (tuberculosis disease [TD]) from which samples were culture-positive before treatment. We studied the correlation between TTD and contact-positivity (CP) of IC contacts: CP was defined as CP = 1 (CP group) in case of TD or latent tuberculosis infection (LTI) in at least one screened contact of an IC, and CP = 0 otherwise (contact-negativity [CN] group). Univariate and multivariable analyses (logistic regression) were done. RESULTS: Of the 185 IC, 122 were included, generating 846 contact cases of which 705 were assessed. A transmission event (LTI or TD) was identified in 193 contact cases (transmission rate: 27%). At day 9, 66% and 35% of the IC had their sample positive in culture for CP and CN groups, respectively. Age and TTD ≤9 days were independent criteria of CP (odds ratio 0.97, confidence interval [0.95-0.98], P = 0.002 and odds ratio 3.52, confidence interval [1.59-7.83], P = 0.001, respectively). CONCLUSION: TTD was a more discriminating parameter than smear status to evaluate the transmission risk of an IC with pulmonary tuberculosis. Therefore, TTD should be considered in the contact-screening strategy around an IC.

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INTRODUCTION: Candidemia is a severe condition associated with high mortality, and fungi are often not covered by empiric antimicrobial regimes for sepsis. Therefore, the shortest possible time to detection of yeast in the blood is of the essence. MATERIALS AND METHODS: We performed a cohort study of blood culture flasks drawn from patients aged 18 or older in the capital region of Denmark. In 2018 a blood cultures set consisted of two aerobic and two anaerobic flasks. This was changed in 2020 to two aerobic, one anaerobic, and one mycosis flask. We used time-to-event statistics to model time to positivity and compared 2018 with 2020; further, we stratified analyses on the blood culture system used (BacTAlert™ vs. BACTEC™) and high-risk vs. low-risk departments. RESULTS: We included 175,416 blood culture sets and 107,077 unique patients. We found an absolute difference in the likelihood of identifying fungi in a blood culture set of 1.2 (95% CI: 0.72; 1.6) pr. 1.000 blood culture sets corresponding to the number needed to treat 853 (617; 1382). In high-risk departments, the absolute difference was profound, whereas it was negligible and statistically non-significant in low-risk departments 5.2 (95% CI: 3.4; 7.1) vs. 0.16 (-0.17; 0.48) pr. 1.000 blood culture sets. CONCLUSIONS: We found that including a mycosis flask in a blood culture set increases the likelihood of identifying candidemia. The effect was mainly seen in high-risk departments.

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Bloodstream infections are associated with high rates of morbidity and mortality. Blood culture remains the gold standard for the diagnosis of BSIs. We report a prospective crossover diagnostic clinical trial comparing the performances of two blood culture incubation systems: Virtuo and Bactec FX. The primary outcome was the time to detection (TTD) (from the loading of the sample into the incubator to the positivity signal). Patients over 16 years old suspected of having bacteremia/fungemia were included. They were divided into two strata with a total of 9,957 blood extractions. Initially, each stratum was randomly assigned to one of the incubators and then alternated every 2 weeks for 6 months. Each sample was inoculated into an aerobic bottle and an anaerobic bottle. All bottles were processed equally according to the laboratory's standard procedures after they were flagged positive. We analyzed 4,797 samples in the Virtuo system and 5,160 in the Bactec FX system. The median TTD was significantly lower for the Virtuo group (Virtuo, 15.2 h; Bactec FX, 16.3 h [P < 0.0001]). The turnaround time (TAT) (from sample loading to the Gram stain report) was also reduced with Virtuo (Virtuo, 26.2 h; Bactec FX, 28.3 h [P < 0.004]). When considering only samples from patients with antimicrobial treatment prior to blood culture extraction, the TTD was shorter for Virtuo (median differences in the TTD of 4.5 h for all bottles and 8.7 h for aerobic bottles only [P = 0.0001]). In conclusion, virtuo provided shorter TTD and TAT than Bactec FX. The difference in the median TTD was increased when considering samples incubated in aerobic bottles from patients with antimicrobial treatment. This could have an important effect on the faster diagnosis of BSIs. IMPORTANCE Bloodstream infections are associated with high rates of morbidity and mortality. Blood culture remains the gold standard for its diagnosis. While the identification of the pathogen and its antibiotic susceptibility is required to confirm the optimal antimicrobial regimen, reductions in the times to the detection of positivity and reporting of Gram stain results may be important and time-saving to reduce inappropriate antimicrobial use, improve patient outcomes, and decrease health care costs. We report the first clinical diagnostic study of this scale in a "real-world" setting with a crossover design, comparing two automatic blood culture incubators using samples from patients with a suspected diagnosis of bacteremia/sepsis, as opposed to spiked vials. Our study design mimics that of clinical trials performed for drug marketing authorization, but patient randomization was replaced with the crossover design. A shorter time to detection could have an important effect on the faster identification of causative microorganisms of BSIs and antimicrobial stewardship.

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The time taken to detect a species during site occupancy surveys contains information about the observation process. Accounting for the observation process leads to better inference about site occupancy. We explore the gain in efficiency that can be obtained from time-to-detection (TTD) data and show that this model type has a significant benefit for estimating the parameters related to detection intensity. However, for estimating occupancy probability parameters, the efficiency improvement is generally very minor. To explore whether TTD data could add valuable information when detection intensities vary between sites and surveys, we developed a mixed exponential TTD occupancy model. This new model can simultaneously estimate the detection intensity and aggregation parameters when the number of detectable individuals at the site follows a negative binomial distribution. We found that this model provided a much better description of the occupancy patterns than conventional detection/nondetection methods among 63 bird species data from the Karoo region of South Africa. Ignoring the heterogeneity of detection intensity in the TTD model generally yielded a negative bias in the estimated occupancy probability. Using simulations, we briefly explore study design trade offs between numbers of sites and surveys for different occupancy modeling strategies.

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Surveys aimed at finding threatened and invasive species can be challenging due to individual rarity and low and variable individual detection rates. Detection rate in plant surveys typically varies due to differences among observers, among the individual plants being surveyed (targets), and across background environments. Interactions among these 3 components may occur but are rarely estimated due to limited replication and control during data collection. We conducted an experiment to investigate sources of variation in detection of 2 Pilosella species that are invasive and sparsely distributed in the Alpine National Park, Australia. These species are superficially similar in appearance to other yellow-flowered plants occurring in this landscape. We controlled the presence and color of flowers on target Pilosella plants and controlled their placement in plots, which were selected for their variation in cover of non-target yellow flowers and dominant vegetation type. Observers mimicked Pilosella surveys in the plots and reported 1 categorical and 4 quantitative indicators of their survey experience level. We applied survival analysis to detection data to model the influence of both controlled and uncontrolled variables on detection rate. Orange- and yellow-flowering Pilosella in grass- and heath-dominated vegetation were detected at a higher rate than nonflowering Pilosella. However, this detection gain diminished as the cover of other co-occurring yellow-flowering species increased. Recent experience with Pilosella surveys improved detection rate. Detection experiments are a direct and accessible means of understanding detection processes and interpreting survey data for threatened and invasive species. Our detection findings have been used for survey planning and can inform progress toward eradication. Interaction of target and background characteristics determined detection rate, which enhanced predictions in the Pilosella eradication program and demonstrated the difficulty of transferring detection findings into untested environments.

Un Experimento de Campo que Caracteriza las Tasas Variables de Detección en los Censos de Plantas Resumen Los censos enfocados en encontrar especies amenazadas e invasoras pueden ser un reto debido a la rareza individual y las tasas bajas y variables de detección individual. Las tasas de detección en los censos botánicos varían comúnmente por las diferencias entre los observadores, entre las plantas individuales que se están censando (objetivo de búsqueda) y en el entorno ambiental. La interacción entre estos tres componentes puede ocurrir, pero rara vez se calcula debido a la replicación y control limitados durante la recolección de datos. Realizamos un experimento para investigar el origen de las variaciones en la detección de dos especies de Pilosella que son invasoras y están distribuidas escasamente en el Parque Nacional Alpino en Australia. Estas especies son superficialmente similares en apariencia a otras plantas de flores amarillas que habitan este paisaje. Controlamos la presencia y el color de las flores en las plantas de Pilosella, así como su colocación en lotes, los cuales fueron seleccionados por su variación en la cobertura de flores amarillas y tipos de vegetación circundantes. Los observadores imitaron los censos de Pilosella en los lotes y reportaron un indicador categórico y cuatro cuantitativos de su nivel de experiencia en censos. Aplicamos el análisis de supervivencia a los datos de detección para modelar la influencia de las variables controladas y no controladas sobre la tasa de detección. Las plantas de Pilosella con flores amarillas y anaranjadas en la vegetación dominada por pastos y brezales fueron detectadas con una tasa mayor que las plantas de Pilosella sin flores. Sin embargo, esta ganancia en la detección disminuyó conforme incrementó la cobertura de otras plantas con flores amarillas. La experiencia reciente de los observadores con censos de Pilosella aumentó la tasa de detección. Los experimentos de detección son un medio directo y accesible para entender los procesos de detección e interpretar los datos de los censos de especies amenazadas e invasoras. Nuestros resultados en la detección han sido utilizados para la planeación de censos y pueden guiar el progreso hacia la erradicación. La interacción de las características diana y del entorno determinaron la tasa de detección, la cual mejoró las predicciones en el programa de erradicación de Pilosella y demostró la dificultad de transferir los resultados de detección hacia ambientes sin ensayos.

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BACKGROUND: To evaluate the performance of BACTEC FX, BacT/ALERT 3D, and VIRTUO systems using simulated blood culture (BC). METHODS: Two experimental designs based on 'with' or 'without' added trough antibiotic concentrations in bottles were implemented. RESULTS: For the experiment A, A shorter time to detection (TTD) was observed for most of organisms (17/22) in VIRTUO system. VIRTUO system was also faster than 3D and FX systems no matter in aerobic and anaerobic bottles. The anaerobic bottles had faster detection than aerobic bottles in 3D system (13.68 h vs 15.36 h, P < 0.001) and VIRTUO system (10.30 h vs 12.46 h, P = 0.001) but not in FX system (P = 0.38). When antibiotics were present, the bacterial recovery rate (RR) of FX, 3D and VIRTUO systems were 64.10% (50/78), 58.97% (46/78) and 43.59% (34/78), respectively (P = 0.027). the bacterial RR of various bottles were as follows: BPA vs. FA vs. SA [84.44%(38/45) vs. 55.56%(25/45) vs. 42.22(19/45), P < 0.001]; BFN vs. FN vs. SN [36.36%(12/33) vs. 63.64%(21/33) vs.45.45%(15/33), P = 0.078]. CONCLUSIONS: The VIRTUO system allowed faster growth detection for most of organisms compared with FX and 3D systems. When antibiotics were present, the bottles containing antibiotic-binding agent showed better bacterial RR, especially in BACTEC Plus Aerobic/F bottles.

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Background: Diagnosis of Mycobacterium tuberculosis (MTB) infection can be confirmed by Xpert assays within hours. However, when sample size does not allow performing both culture and Xpert, or if Xpert is negative, then formal diagnosis of MTB relies on culture and time to detection of growth (TDG) becomes critical for clinical management. Objectives: To determine TDG in Xpert negative samples, or in samples in which Xpert could not be performed, in a low-incidence area for MTB. Methods: Retrospective analysis (2015-2020) of a database including all cultures for mycobacteria in a University Hospital covering approximately 500'000 inhabitants. Analysis was restricted to culture positive (C+) samples for MTB for which 1/Xpert was negative or could not be performed because of limited sample volume, and 2/collected from subjects treated less than 24 hours. TDG was analyzed according to microscopy, origin of sample (pulmonary or not) and presence of cavitation. Results: Among 837 C+ samples for MTB, 236 samples (80% of respiratory origin) from 147 patients fulfilled study criteria; 78 samples (49 patients, 33%) were acid-fast bacilli (AFB) positive. Median (IQR) TDG was 25 (17; 40) days for all samples. TDG exceeded 28 days in 43% of samples and was significantly shorter in AFB+ vs AFB- samples, and samples from cavitary vs non cavitary or extra-thoracic disease. Conclusions: In Xpert negative samples, or samples for which Xpert could not be performed, TDG exceeded 4 weeks in 43% of samples. AFB+ and samples from cavitary lung disease had a significantly shorter TDG.

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Bread and intermediate moisture bakery products are mainly spoiled by yeasts and filamentous fungi. The inoculum load and preservation system used determines their shelf life. To extend the shelf life of such commodities, the use of chemical preservatives is the most common way to try and control the initiation of mold spoilage of bread. This study has utilized a rapid turbidimetric assay system (Bioscreen C) to examine the temporal efficacy of calcium propionate (CP) and potassium sorbate (PS) for controlling the growth of important bread spoilage fungi. The objectives were to compare the temporal growth of strains of three important spoilage fungi Hyphopichia burtonii (HB17), Paecilomyces variotii (PV11), and Penicillium roqueforti (PR06) isolated from visibly molded bread to (a) different concentrations of CP and PS (0-128 mM), (b) temperatures (25°C, 30°C), (c) water activity (aw; 0.95, 0.97), and (d) pH (5.0, 5.5). All three abiotic factors, pH, aw, and temperature, and preservative concentrations influenced the relative growth of the species examined. In general, PS was more effective than CP in inhibiting the growth of the strains of these three species. In addition, the Time to Detection (TTD) for the efficacy of the preservatives under the interacting abiotic factors was compared. The strain of Paecilomyces variotii (PV10) was the most tolerant to the preservatives, with the shortest TTD values for both preservatives. P. roqueforti was the most sensitive with the longest TTD values under all conditions examined. These results are discussed in the context of the evolution of resistance to food-grade preservatives by such spoilage fungi in bakery products.

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BACKGROUND: Even though antiretroviral therapy access for HIV infected children increased dramatically, anemia have been continued as a challenge regardless of a cluster of differentiation (CD4) count and viral load. Hence, this study aimed to assess the time to detection of anemia and its predictors among children living with HIV at Debre Tabor and university of Gondar compressive specialized hospital, 2020. METHODS: A retrospective follow-up study was conducted from January 2010 to December 2018. A total of 372 children under the age of 15 who had received ART were included in the study. Data were collected from children's medical charts and ART registration logbook using a standard checklist. Besides, the data were entered into Epi data 4.2.2 and then exported to Stata 14.0 for further analysis. The Cox regression model, the variables having P-value ≤.05 with 95% CIs in multivariable analysis were declared as statistically significant for anemia. RESULT: The mean (±SD) of follow-up periods were 56.6 ± 1.7 SD months. The overall median survival time free from anemia was 137 months, and the incidence rate of anemia was 6.9 per 100 PYO (95% CI: 5.3, 7.8). Moreover, WHO clinical staging of III/IV [AHR: 4.2, 95% CI: 1.80, 11.1], low CD4 count below threshold [AHR: 1.9, 95% CI: 1.09, 3.37], cotrimoxazole preventive therapy non-users, and poor level of adherence [(AHR: 2.4, 95% CI: 1.20, 4.85] were the main predictors of the time to detection of anemia. CONCLUSION: The incidence rate of anemia in our retrospective cohort was high. The risk of anemia is present in children living with HIV infection but the risk for anemia is increased based on (WHO clinical staging III and IV, CD4 count below the threshold level, CPT non-users, and poor level of adherence). Since many of these risk factors are present routinely, even within one single patient, our clinical monitoring for anemia quarterly was fully justified as was our routine switch from standard therapies such as AZT to another regimen upon lab confirmation of anemia. Additional methods to improve cotrimoxazole preventative therapy and level of adherence are also needed.

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Infectious disease outbreaks can have significant impact on individual health, national economies, and social well-being. Through early detection of an infectious disease, the outbreak can be contained at the local level, thereby reducing adverse effects on populations. Significant time and funding have been invested to improve disease detection timeliness. However, current evaluation methods do not provide evidence-based suggestions or measurements on how to detect outbreaks earlier. Key conditions for earlier detection and their influencing factors remain unclear and unmeasured. Without clarity about conditions and influencing factors, attempts to improve disease detection remain ad hoc and unsystematic. Methods: We developed a generic five-step disease detection model and a novel methodology to use for data collection, analysis, and interpretation. Data was collected in two workshops in Southeast Europe (n = 33 participants) and Southern and East Africa (n = 19 participants), representing mid- and low-income countries. Through systematic, qualitative, and quantitative data analyses, we identified key conditions for earlier detection and prioritized factors that influence them. As participants joined a workshop format and not an experimental setting, no ethics approval was required. Findings: Our analyses suggest that governance is the most important condition for earlier detection in both regions. Facilitating factors for earlier detection are risk communication activities such as information sharing, communication, and collaboration activities. Impeding factors are lack of communication, coordination, and leadership. Interpretation: Governance and risk communication are key influencers for earlier detection in both regions. However, inadequate technical capacity, commonly assumed to be a leading factor impeding early outbreak detection, was not found a leading factor. This insight may be used to pinpoint further improvement strategies.

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Large-scale protracted outbreaks can be prevented through early detection, notification, and rapid control. We assessed trends in timeliness of detecting and responding to outbreaks in the African Region reported to the World Health Organization during 2017-2019. We computed the median time to each outbreak milestone and assessed the rates of change over time using univariable and multivariable Cox proportional hazard regression analyses. We selected 296 outbreaks from 348 public reported health events and evaluated 184 for time to detection, 232 for time to notification, and 201 for time to end. Time to detection and end decreased over time, whereas time to notification increased. Multiple factors can account for these findings, including scaling up support to member states after the World Health Organization established its Health Emergencies Programme and support given to countries from donors and partners to strengthen their core capacities for meeting International Health Regulations.

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OBJECTIVE: We aimed to investigate risk factors related to remnant gallbladder (RGB) stones. METHODS: This retrospective study included 73 patients with RGB, in groups with and without RGB calculi. Univariate analyses were used to identify nine variables associated with RGB calculi: sex, age, body mass index (BMI), time to detection, surgical method, length of RGB, angle of RGB and common hepatic duct (CHD), choledocholithiasis, and remnant cholecystitis. Multivariate logistic regression was performed to assess independent predictors of RGB stones. A receiver operating characteristic (ROC) curve was used to estimate model accuracy and determine cut-off values of independent predictors. RESULTS: We enrolled 73 patients, 33 with and 40 without RGB stones. Univariate analyses showed that age, BMI, time to detection, length of RGB, angle of RGB and CHD were predictors for RGB calculi. Multivariate analyses indicated that time to detection, length of RGB, and angle of RGB and CHD were independent predictors for RGB calculi. The area under the ROC curve of the model was 0.940. Cut-off values of the three indicators were 1.5 years, 2.25 cm, and 22.5°, respectively. CONCLUSION: Time to detection, length of RGB, and angle of RGB and CHD were independent predictors of RGB calculi.

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Cutibacterium acnes is a major etiologic agent of orthopaedic implant-associated infections (IAIs) and requires up to 14 days of incubation in an anaerobic atmosphere for growth detection. As blood culture (BC) systems are increasingly being used to monitor the growth of IAI specimens, we compared different BC media for growth detection of C. acnes. Non-duplicate C. acnes isolates (n = 99) obtained from sonicate-fluid cultures of orthopaedic IAIs from Slovenia (n = 54), conventional tissue samples of monomicrobial orthopaedic IAIs from France (n = 43) and two reference strains were inoculated to anaerobic BC bottles of two major BC systems and 3 conventional culture media types (thioglycolate broth, Schaedler and chocolate agar). Growth and time-to-detection (TTD) were recorded. Only Lytic (BACTEC) and SN (BacT/ALERT) bottles consistently detected growth of C. acnes within 14 days with 94% (n = 93) and 92% (n = 91) detection rates, respectively (p = 0.79). Lytic was superior to Plus BACTEC medium (p < 0.001), while SN was superior to all other BacT/ALERT media (p < 0.001). Mean TTD was 128 ± 43 h (61-336 h) for Lytic and 158 ± 65 h (77-336 h) for SN medium. Among the conventional media, 99% (n = 98) of the isolates grew on Schaedler agar, 96% (n = 95) in thioglycolate broth and 74% (n = 73) on chocolate agar. Inconsistent growth of C. acnes in different BC media can critically influence the detection of this major IAI pathogen. Only Lytic (BACTEC) and SN (BacT/ALERT) BC media types were consistently able to detect C. acnes within 14 days of incubation. However, visible growth was observed faster in thioglycolate broth and Schaedler agar media.

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CONTEXT: Time to detection (TTD) given by continuous monitoring automated blood culture systems (CMABS) have been found to be a predictor of clinical outcome, drug resistance and type of microorganism in cases of bacteremia but the studies evaluating TTD with respect to fungemia are scarce especially from India. AIMS: To evaluate TTD for yeast isolates in fungal bloodstream infections with respect to the type of yeast isolates, risk factors and outcome and to study yeast susceptibility and distribution of yeast isolates with respect to patient population. MATERIALS AND METHODS: All blood culture specimens were processed in CMABS. The TTD for yeast isolates were recorded. The identification of yeast and susceptibility testing was done by automated methods. A correlation of TTD was done with respect to prior/concurrent yeast isolates, use of antifungal, risk factors and clinical outcome. RESULTS: Out of 80 yeast isolates, the maximum was C. parapsilosis (26.25%) followed by C. albicans (16.25%) and C. tropicalis (13.75%). A statistically significant difference in the occurrence of yeasts with early TTD (TTD < = 48 hours) and late TTD (TTD > 48 hours) was found. TTD of C. glabrata was significantly longer (p = 0.002) while TTD of C. tropicalis was significantly shorter (p = 0.013). There was an observable favorable outcome in shorter TTD (< = 48 hours). C. albicans and C. tropicalis depicted 100% susceptibility for Azoles, Amphotericin B and Echinocandins. CONCLUSION: TTD may be used as both diagnostic and prognostic adjunct in fungal bloodstream infections. This study is a step towards this novel approach. We also emphasize on the importance of speciation of yeast isolates and susceptibility testing. HOW TO CITE THIS ARTICLE: Butta H, Sardana R, Mendiratta L, Sibal A, Gupta V, Chawla R, Jafri AA. Time to Detection of Yeast Isolates in Pediatric and Adult Patients with Fungemia and its Relevance to Clinical Profile and Outcome. Indian Journal of Critical Care Medicine, January 2019;23(1):27-30.

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The diagnosis of bloodstream infection requires the optimum combination of media in an automated blood culture system for maximum recovery of pathogens with the earliest time to detection. In a previous work, we showed that for patients admitted to the Emergency Department of our hospital, the combination of BACTEC lytic anaerobic and BACTEC aerobic vials was more efficient than BACTEC anaerobic and BACTEC aerobic vial. In this study, we extended the work including a broader patient population, representative of all hospital. A total of 8629 cultures were collected during the pre-lytic phase, from 01 July 2013 to 30 June 2014 and 7940 cultures during the post-lytic phase, ranged from 01 July 2015 to 30 June 2016. The number of positive blood cultures was higher during the post-lytic phase (19.74%) than in the pre-lytic phase (17.52%), particularly for Escherichia coli, Staphylococcus spp., Enterococcus spp., and anaerobes. We also observed a significant decreased of the time to detection, with the mean and median in the post-lytic phase of 17.68 and 13.05 h compared with 19.49 and 14.47 h in the pre-lytic phase. Whereas the time to detection was the same for organisms recovered in the aerobic Plus bottles for both time periods, time to detection for the anaerobic lytic bottles was significantly faster than with the anaerobic Plus bottles. This study carried out on a long time observation reported that a simple modification of composition of blood culture set could lead to better results in bloodstream infection detection.

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BACKGROUND: BacT/Alert Virtuo (BioMérieux, Durham, NC, USA) is a recently developed blood culture system that includes functions of automatic registration, loading, and unloading of the blood culture bottles, as well as measurement of blood volume. We compared the performances between the BacT/Alert Virtuo and 3D (BioMérieux) blood culture systems. METHODS: A total of 952 patients (1,904 sets) visiting an university-affiliated hospital in Korea for blood cultures were enrolled. Five milliliters of blood was added into each of the two aerobic (FA Plus) and two anaerobic (FN Plus) bottles of the Virtuo and 3D systems for a single set. Positive rate and time to detection (TTD) were compared between the two systems. RESULTS: The positive rates were 8.3% and 8.4% in FA Plus bottles and 7.8% and 8.3% in FN Plus bottles, in the Virtuo and 3D systems, respectively (P>0.05). Median TTDs were shorter in the Virtuo than in the 3D system for all isolates (11.5 hours [N=305] vs 11.8 hours [N=318], P<0.001), Staphylococcus aureus (N=38; 14.3 hours vs 16.0 hours, P=0.021), and Escherichia coli (N=117; 10.4 hours vs 11.0 hours, P<0.001). CONCLUSIONS: The Virtuo has the potential to detect pathogens early in all bottle types. This might improve the prognosis of sepsis by allowing for implementation of expeditious management.

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Staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus (S. aureus) are the cause of Saphylococcal food poisoning (SFP) outbreaks. Thus, estimation of the time to detection (TTD) of SEs, that is, the time required to reach the SEs detection limit, is essential for food preservation and quantitative risk assessment. This study was conducted to explore an appropriate method to predict the TTD of SEs in cooked chicken product under variable environmental conditions. An S. aureus strain that produces staphylococcal enterotoxin A (SEA) was inoculated into cooked chicken meat. Initial inoculating concentrations (approximately 102, 103, 104 CFU/g) of S. aureus and incubation temperatures (15 ± 1, 22 ± 1, 29 ± 1, and 36 ± 1°C) were chosen as environmental variables. The counting of S. aureus colonies and the detection of SEA were performed every 3 or 6 h during the incubation. The TTD of SEA was considered a response of S. aureus to environmental variables. Linear polynomial regression was used to model the effects of environmental variables on the TTD of SEA. Result showed that the correlation coefficient (R2) of the regressed equation is higher than 0.98, which means the obtained equation was reliable. Moreover, the minimum concentration of S. aureus for producing a detectable amount of SEA under various environmental conditions was approximately 6.32 log CFU/g, which was considered the threshold for S. aureus to produce SEA. Hence, the TTD of SEA could be obtained by calculating the time required to reach the threshold by using an established S. aureus growth predictive model. Both established methods were validated through internal and external validation. The results of graphical comparison, RMSE, SEP, Af , and Bf showed that the accuracy of both methods were acceptable, and linear polynomial regression method showed more accurately.

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BACKGROUND: BRCA carrier identification offers opportunities for early diagnoses, targeted treatment and cancer prevention. We evaluate BRCA- carrier detection rates in general and Ashkenazi Jewish (AJ) populations across Greater London and estimate time-to-detection of all identifiable BRCA carriers. METHODS: BRCA carrier data from 1993 to 2014 were obtained from National Health Service genetic laboratories and compared with modelled predictions of BRCA prevalence from published literature and geographical data from UK Office for National Statistics. Proportion of BRCA carriers identified was estimated. Prediction models were developed to fit BRCA detection rate data. BRCA carrier identification rates were evaluated for an 'Angelina Jolie effect'. Maps for four Greater London regions were constructed, and their relative BRCA detection rates were compared. Models developed were used to predict future time-to-identify all detectable BRCA carriers in AJ and general populations. RESULTS: Until 2014, only 2.6% (3072/111 742 estimated) general population and 10.9% (548/4985 estimated) AJ population BRCA carriers have been identified in 16 696 608 (AJ=190 997) Greater London population. 57% general population and 54% AJ mutations were identified through cascade testing. Current detection rates mirror linear fit rather than parabolic model and will not identify all BRCA carriers. Addition of unselected ovarian/triple-negative breast cancer testing would take >250 years to identify all BRCA carriers. Doubling current detection rates can identify all 'detectable' BRCA carriers in the general population by year 2181, while parabolic and triple linear rates can identify 'detectable' BRCA carriers by 2084 and 2093, respectively. The linear fit model can identify 'detectable' AJ carriers by 2044. We did not find an Angelina Jolie effect on BRCA carrier detection rates. There was a significant difference in BRCA detection rates between geographical regions over time (P<0.001). CONCLUSIONS: The majority of BRCA carriers have not been identified, missing key opportunities for prevention/earlier diagnosis. Enhanced and new strategies/approaches are needed.

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