New technologies in clinical microbiology

Rapid identification of microorganisms in the clinical microbiology laboratory can be of great value for selection of optimal patient management strategies for infections caused by bacteria, viruses, fungi, mycobac-teria, and parasites. Rapid identification of microorganisms in clinical samples enables expedient de-escala-tion from broad-spectrum agents to targeted antimicrobial therapy. The switch to tailored therapy minimizes risks of antibiotics, namely, disruption of normal flora, toxic side effects, and selective pressure. There is a critical need for new technologies in clinical microbiology, particularly for bloodstream infections, in which associated mortality is among the highest of all infections. Just as importantly, there is a need for the clinical laboratory community to embrace the practices of evidence-based interventional laboratory medicine and collaborate in translational research projects to establish the clinical utility, cost benefit, and impact of new technologies. The topic “new technologies ” described here was part of a group session entitled Clinical Microbiology in the Year 2015, part of the 2011 Camp Clin Micro meeting held in Houston, TX. The discussion focused on new and emerging laboratory methods, specifically those related to identification of blood

Evaluation of a multiplexed bead assay for assessment of Epstein-Barr virus immunologic status

Currently, serological assays using either indirect immunofluorescence assay or enzyme-linked immunosorbent assay (ELISA) are performed to evaluate the status of Epstein-Barr virus (EBV) infection in humans. Although these methods are reliable, they are limited to testing an antibody response to a single viral antigen per reaction, thus necessitating a panel of assays to complete the evaluation. In contrast, a new bead-based method (BioPlex 2200; Bio-Rad Laboratories, Hercules, Calif.) can analyze the humoral response to multiple antigens in a single tube. This approach potentially reduces overall cost, turnaround time, and sample volume. The aim of this study was to evaluate the multiplexed EBV serologic assays performed on the BioPlex 2200 platform compared to results of conventional heterophile and ELISA-based assays. A total of 167 nonconsecutive, stored serum samples from adult and pediatric patients submitted for EBV serologic studies were used in the evaluation. Concordance between results generated by the BioPlex 2200 system and conventional assays was calculated. The anti-EA-D assay had the lowest concordance at 91%. The BioPlex 2200 system showed 97% agreement with conventional heterophile and anti-nuclear antigen assays and 92% agreement with the anti-VCA IgG and immunoglobulin M assays. Agreement between the BioPlex 2200 system and conventional testing was 92% with respect to categorization of acute versus nonacute EBV disease. The correlation between these two systems with regard to assignment into one of four categories of EBV status was also good (82%). In summary, there is excellent correlation between contemporary EBV serologic testing and the BioPlex 2200 system

Evaluation of spectra VRE, a new chromogenic agar medium designed to screen for vancomycin-resistant Enterococcus faecalis and Enterococcus faecium

Spectra VRE (Remel, Lenexa, KS) is a chromogenic medium designed to recover and differentiate vancomycin-resistant Enterococcus faecium and Enterococcus faecalis (VRE). This medium was compared to bile esculin azide agar (BEAV) and was 98.2% sensitive and 99.3% specific compared to BEAV, which was 87.6% sensitive and 87.1% specific at 24 h