Comparative analytical evaluation of the respiratory TaqMan Array Card with real-time PCR and commercial multi-pathogen assays

•

Viral and bacterial real-time PCR oligonucleotides were spotted on TaqMan Array Cards.

•

Analytical sensitivity was compared with standalone laboratory PCR assays.

•

TaqMan Array Card sensitivity was generally one log lower.

•

Reproducibility across six independent testing sites was within one log.

In this study, a multicenter evaluation of the Life Technologies TaqMan^® Array Card (TAC) with 21 custom viral and bacterial respiratory assays was performed on the Applied Biosystems ViiA™ 7 Real-Time PCR System. The goal of the study was to demonstrate the analytical performance of this platform when compared to identical individual pathogen specific laboratory developed tests (LDTs) designed at the Centers for Disease Control and Prevention (CDC), equivalent LDTs provided by state public health laboratories, or to three different commercial multi-respiratory panels. CDC and Association of Public Health Laboratories (APHL) LDTs had similar analytical sensitivities for viral pathogens, while several of the bacterial pathogen APHL LDTs demonstrated sensitivities one log higher than the corresponding CDC LDT. When compared to CDC LDTs, TAC assays were generally one to two logs less sensitive depending on the site performing the analysis. Finally, TAC assays were generally more sensitive than their counterparts in three different commercial multi-respiratory panels. TAC technology allows users to spot customized assays and design TAC layout, simplify assay setup, conserve specimen, dramatically reduce contamination potential, and as demonstrated in this study, analyze multiple samples in parallel with good reproducibility between instruments and operators.

Development of a proficiency testing program for molecular diagnosis of influenza viruses

BACKGROUND

The Molecular Virology Proficiency Testing Program at the Wadsworth Center began the assembly and distribution of influenza virus panels to US public health labs (PHLs) in 2008. The program was created to assist PHLs in assessing their performance and in meeting CLIA regulations for mandated proficiency testing (PT).

OBJECTIVES

To design and distribute proficiency testing panels containing influenza A virus subtypes H1N1 and H3N2, and influenza B; when H1N1pdm09 emerged it also was incorporated into the panels. A secondary objective was to determine the best matrix for long term storage of the molecular PT samples.

STUDY DESIGN

Viruses were quantitated using TCID(50) and quantitative real-time RT-PCR. Reference laboratories were enlisted to verify viral identity in the panels and to help determine viral titers to be used in the PT panels sent to PHLs.

RESULTS AND CONCLUSIONS

Of the 29 laboratories that participated the first year, 27 were able to correctly identify all of the virus types in the panel. Fifty-one PHLs participated in the program the second year when pandemic H1N1 was added, and 45 were able to correctly detect, type and subtype all of the viruses in the panel. In the program's third year, 60 laboratories participated; 58 correctly detected and subtyped all of the viruses in the panel. Annual surveys of assay techniques showed that the PHLs had shifted their extraction methods and PCR-thermocycler instrumentation to meet FDA-approved methods. The degradation study revealed that frozen viral stocks were stable for at least 30months, thus allowing ample time to prepare and pre-test panels.