A culture-free biphasic approach for sensitive and rapid detection of pathogens in dried whole-blood matrix.

Blood stream infections (BSIs) cause high mortality, and their rapid detection remains a significant diagnostic challenge. Timely and informed administration of antibiotics can significantly improve patient outcomes. However, blood culture, which takes up to 5 d for a negative result, followed by PCR remains the gold standard in diagnosing BSI. Here, we introduce a new approach to blood-based diagnostics where large blood volumes can be rapidly dried, resulting in inactivation of the inhibitory components in blood. Further thermal treatments then generate a physical microscale and nanoscale fluidic network inside the dried matrix to allow access to target nucleic acid. The amplification enzymes and primers initiate the reaction within the dried blood matrix through these networks, precluding any need for conventional nucleic acid purification. High heme background is confined to the solid phase, while amplicons are enriched in the clear supernatant (liquid phase), giving fluorescence change comparable to purified DNA reactions. We demonstrate single-molecule sensitivity using a loop-mediated isothermal amplification reaction in our platform and detect a broad spectrum of pathogens, including gram-positive methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria, gram-negative Escherichia coli bacteria, and Candida albicans (fungus) from whole blood with a limit of detection (LOD) of 1.2 colony-forming units (CFU)/mL from 0.8 to 1 mL of starting blood volume. We validated our assay using 63 clinical samples (100% sensitivity and specificity) and significantly reduced sample-to-result time from over 20 h to <2.5 h. The reduction in instrumentation complexity and costs compared to blood culture and alternate molecular diagnostic platforms can have broad applications in healthcare systems in developed world and resource-limited settings.

Expired Epinephrine Maintains Chemical Concentration and Sterility.

OBJECTIVES: Epinephrine shortages affect nearly all American emergency medical services (EMS) systems. Utilization of expired epinephrine could mitigate this situation in daily EMS operations. Concerns about using expired medications include sterility, potency, and potential harmful chemical decay byproducts. There are no cross-platform analyses of sterility and chemical purity of multiple samples of expired parenteral epinephrine. We hypothesized that epinephrine injections will remain sterile and will retain their active ingredient's content for more than 30 months past expiration. METHODS: Six parenteral epinephrine prefilled syringes, 1 mg/10 mL, with an expiration date of January 1, 2012 had been stored in the climate controlled setting of a hospital inpatient pharmacy where they remained until they were taken for chemical or microbial analysis 30 months after expiration. An unexpired parenteral epinephrine prefilled syringe content was used as a control. Contents of three separate syringes with expired content from the same lot and one control underwent ultra-high pressure liquid chromatography-mass spectrometry (UHPLC-MS) and nuclear magnetic resonance (NMR) to determine epinephrine content and stability. In parallel, contents of another three expired epinephrine syringes were analyzed for sterility by plating on aerobic, anaerobic, and fungal media in a hospital microbiology laboratory. The aerobic plates were checked for growth in 3 days, the anaerobic in 5 days, and the fungal in 28 days. RESULTS: UHPLC-MS and NMR showed that content of epinephrine present in the original sample remained unchanged compared to the control. There was no statistical difference in the UHPLC-MS and NMR signal amplitudes between the control and the expired samples. No chemical degradation byproducts were detected using NMR. There was no growth of any bacteria or fungus. CONCLUSION: Recurrent epinephrine shortages impact EMS and hospital operations in the United States. Individual administrators may be hesitant to authorize use of expired pharmaceuticals due to perceived potential complications or fear of litigation. This study shows that the original parenteral epinephrine remains sterile and detectably pure more than 2.5 years after expiration. Further study of the sterility and chemical integrity of expired medications that had been subjected to the conditions of EMS vehicles may be a future research endeavor based on the aforementioned paradigm.

First-Line Antimicrobial Resistance Patterns of Escherichia coli in Children With Urinary Tract Infection in Emergency Department and Primary Care Clinics.

OBJECTIVE: To identify risk factors for antibiotic resistance to Escherichia coli (E. coli) in children with urinary tract infections (UTIs) in emergency room and primary care clinics. METHOD: This is a cross-sectional study of children 0 to 18 years of age reported to have E coli-positive UTIs whose medical and laboratory records were systematically reviewed. RESULT: Compared with girls, boys were 2.29 times (confidence interval [CI] = 1.30-4.02) more likely to have E coli isolates resistant to ampicillin and 2 times more likely (CI = 1.13-3.62) to have isolates resistant to trimethoprim-sulfamethoxazole (TMP/SMX). Patients with genitourinary abnormalities were 1.57 times more likely to be resistant to ampicillin (CI = 1.03-2.41) and 1.86 times to TMP/SMX (CI = 1.18-2.94). CONCLUSION: Higher rates of ampicillin and TMP/SMX resistant urinary E coli isolates were observed among boys and children with a history of genitourinary abnormality. Age and recent antibiotic prescription are also potential risk factors for resistance.

Challenges in operationalizing the DSM-IV clinical significance criterion.

BACKGROUND: An explicit clinical significance (CS) criterion was added to many DSM-IV diagnoses in an attempt to more closely approximate the clinical diagnostic process and reduce the proportion of false positives in epidemiological studies. The American Indian Service Utilization, Psychiatric Epidemiology, Risk and Protective Factors Project (AI-SUPERPFP) offered a unique opportunity to examine the success of this effort. OBJECTIVE: To determine the impact of distress, impairment, and help-seeking reported in a lay structured interview on concordance with a clinical reappraisal. Further, to test the efficacy of 5 operationalizations of CS on the concordance and prevalence of DSM-IV lifetime disorders. DESIGN: Completed between 1997 and 2000, a cross-sectional probability sample survey with clinical reappraisal of approximately 10% of participants. SETTING: General community. PARTICIPANTS: A population-based sample of 3084 members of 2 American Indian tribal groups, who were between the ages of 15 and 54 years and resided on or near their home reservations, were randomly sampled from the tribal rolls and participated in structured psychiatric interviews. Clinical reappraisals were conducted with approximately 10% of the lay-interview participants. The response rate for the lay interview was 75%, and for the clinical reappraisal it was 72%. MAIN OUTCOMES MEASURES: The AI-SUPERPFP Composite International Diagnostic Interview (CIDI), a culturally adapted version of the CIDI, University of Michigan version. Adapted to assess DSM-IV diagnoses, questions assessing the CS criterion were inserted in all diagnostic modules. The Structured Clinical Interview for DSM-III-R (SCID) was used in the clinical reappraisal. RESULTS: Most participants who qualified as having AI-SUPERPFP CIDI lifetime disorders reported at least moderate levels of distress or impairment. Evidence of increased concordance between the CIDI and the SCID was lacking when more restrictive operationalizations of CS were used; indeed, the CIDI was very likely to underdiagnose disorders compared with the SCID (false negatives). Concomitantly, the CS operationalizations affected prevalence rates dramatically. CONCLUSION: The CS criterion, at least as operationalized to date, demonstrates little effectiveness in increasing the validity of diagnoses using lay-administered structured interviews.