ABSTRACT
BACKGROUND: Epstein-Barr Virus (EBV) is one of the most prevalent causes of viral infection in humans. EBV infection stage (acute, past, or absent infection) is typically determined using a combination of assays that detect EBV-specific markers, such as IgG and IgM antibodies against the EBV viral capsid antigen (VCA) and IgG antibodies against the EBV nuclear antigen (EBNA). We compared the diagnostic performance and agreement of results between three commercial EBV antibody assays using an EBV performance panel (SeraCare Life Science, Milford, MA, USA) as a reference. METHODS: EBV antibody tests of EBV VCA IgM, VCA IgG, and EBNA IgG antibodies were performed by the Architect (Abbott Diagnostics, Wiesbaden, Germany), Liaison (DiaSorin, Saluggia, Italy), and Platelia (Bio-Rad, Marnes-la-Coquette, France) assays. Agreement between the three assays was evaluated using 279 clinical samples, and EBV DNA and antibody test results were compared. RESULTS: The three EBV antibody assays showed good diagnostic performance with good and excellent agreement with the performance panel (kappa coefficient, >0.6). The overall VCA IgM positivity rate was higher in EBV DNA-positive samples than in EBV DNA-negative samples for all three EBV antibody assays (P=0.02). The three EBV antibody assays exhibited good agreement in results for the clinical samples. CONCLUSIONS: The diagnostic performance of the three EBV antibody assays was acceptable, and they showed comparable agreement in results for the clinical samples.
Subject(s)
Humans , Antibodies , Biological Science Disciplines , Capsid , DNA , Epstein-Barr Virus Infections , Herpesvirus 4, Human , Immunoglobulin G , Immunoglobulin M , ImmunoglobulinsABSTRACT
BACKGROUND: Early and appropriate antibiotic treatment improves the clinical outcome of patients with septicemia; therefore, reducing the turn-around time for identification (ID) and antimicrobial susceptibility test (AST) results is essential. We established a method for rapid ID and AST using short-term incubation of positive blood culture broth samples on solid media, and evaluated its performance relative to that of the conventional method using two rapid ID systems and a rapid AST method. METHODS: A total of 254 mono-microbial samples were included. Positive blood culture samples were incubated on blood agar plates for six hours and identified by the MicroFlex LT (Bruker Daltonics) and Vitek-MS (bioMeriéux) systems, followed by AST using the Vitek2 System (bioMeriéux). RESULTS: The correct species-level ID rates were 82.3% (209/254) and 78.3% (199/254) for the MicroFlex LT and Vitek-MS platforms, respectively. For the 1,174 microorganism/antimicrobial agent combinations tested, the rapid AST method showed total concordance of 97.8% (1,148/1,174) with the conventional method, with a very major error rate of 0.5%, major error rate of 0.7%, and minor error rate of 1.0%. CONCLUSIONS: Routine implementation of this short-term incubation method could provide ID results on the day of blood culture-positivity detection and one day earlier than the conventional AST method. This simple method will be very useful for rapid ID and AST of bacteria from positive blood culture bottles in routine clinical practice.
Subject(s)
Humans , Agar , Bacteria , Methods , SepsisABSTRACT
Bacillus cereus is a widespread organism in nature and a member of the B. cereus group of catalasepositive, aerobic, spore-forming, Gram-positive bacilli. B. cereus found in blood is often dismissed as a contaminant in the absence of repeated isolation from multiple cultures. Soft tissue and bone infection due to B. cereus have been associated with trauma, intravenous drug use, and an immunocompromised state. We report a very late prosthetic joint infection of the hip joint and consequent bacteremia caused by B. cereus, which occurred 13 years after total hip replacement surgery in the absence of recent trauma or intervention.
Subject(s)
Arthritis , Arthroplasty, Replacement, Hip , Bacillus cereus , Bacillus , Bacteremia , Hip Joint , Hip , Joints , Pathology , Prostheses and ImplantsABSTRACT
No abstract available.
Subject(s)
Humans , Male , Middle Aged , Base Sequence , Bone Marrow/pathology , Fusion Proteins, bcr-abl/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis , Real-Time Polymerase Chain ReactionABSTRACT
BACKGROUND: Epstein-Barr virus (EBV) is known to be the causative agent of infectious mononucleosis and EBV-related malignancies. In this study, we compared the results of three real-time PCR kits for EBV DNA assays. METHODS: A total of 300 whole blood samples submitted for quantitative EBV PCR between January 2013 and September 2014 at Severance Hospital were included. The samples were tested by using the Artus EBV RG PCR Kit (Qiagen, Germany), AccuPower EBV Quantitative PCR Kit (Bioneer, Korea), and Real-Q EBV Kit (BioSewoom, Korea). Samples with discordant results between the three kits were confirmed by direct sequencing. RESULTS: The result concordance rate and kappa coefficient (K) were 86.3% and 0.69 for Artus-AccuPower, 93.3% and 0.85 for Artus-Real-Q, and 92.3% and 0.83 for AccuPower-Real-Q, respectively. The correlations between the three kits were found to be significant, with a correlation coefficient of r=0.854 for Artus-AccuPower, -0.802 for Artus-Real-Q, and -0.977 for AccuPower-Real-Q, respectively (P<0.0001). If the real-time PCR concordant results of 258 samples and the direct sequencing results of 42 real-time PCR discordant samples were assumed to be true, the sensitivity/specificity values were 0.921/0.976 for Artus, 0.902/0.965 for AccuPower, and 0.967/1.000 for Real-Q. CONCLUSIONS: The three real-time PCR kits showed excellent sensitivities and specificities. All these kits would be acceptable for clinical and therapeutic management of EBV. However, some discordant results between the kits indicate the need for caution in clinical diagnosis and staging. Further implementation of standardized methodology would be needed for EBV DNA assays.