Molecular Diagnostics in the Public Health Laboratories

Deborah Josko

doi:10.29074/ascls.23.4.242

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Deborah Josko, PhD, M(ASCP)^CM, MLT,SM⇑
1. University of Medicine and Dentistry of New Jersey, Scotch Plains, NJ

Address for correspondence: Deborah Josko, PhD, M(ASCP)^CM, MLT,SM, associate professor, Department of Clinical Laboratory Sciences, Medical Laboratory Science Program, University of Medicine and Dentistry of New Jersey, 1776 Raritan Road, Scotch Plains, NJ 07076. (908) 889-2422. joskotda{at}umdnj.edu.

Discuss various molecular viral assays performed at the public health laboratory.
Describe West Nile virus surveillance protocols.
Explain Qiagen QIAmp BioRobot 9604 methodology.
Compare and contrast Applied Biosystems 7900HT and 7500 Fast real-time PCR systems.
Describe protocols utilized to identify rabies.
Discuss the principle of PFGE in the identification of enteric organisms.
State the principle of the Bactec MGIT 960 Mycobacterial Detection System.
List select and non-select agents identified in the bioterrorism and molecular detection services laboratory.

Extract

This article will give a brief overview of some of the molecular methodologies and assays performed at the New Jersey State Department of Health and Senior Services laboratory in Trenton, NJ. Assays to be discussed include influenza A, swine flu, West Nile virus, rabies, Salmonella and Shigella, Mycobacterium tuberculosis, and Streptococcus pneumoniae. Methodologies such as real-time PCR, pulsed field gel electrophoresis (PFGE) and multiplex PCR will also be discussed.

Introduction Samples for viral testing are sent to the public health laboratory for identification and confirmation. If a medical laboratory scientist identifies an unsubtypable strain of type A influenza virus, they send the isolate to the public health laboratory for confirmation. If the public health lab confirms the type A unsubtypable influenza strain, an influenza 2009 A (H1N1)pdm² (formerly “swine flu”) confirmation test is ordered.¹ Screening, routine flu surveillance, and confirmation testing are done using real-time polymerase chain reaction (PCR), however when confirming, a different set of probes and primers is used in the master mix than those used for screening and surveillance.

Human specimens for suspected West Nile virus (WNV) are sent to the public health laboratory since most clinical laboratories do not test for WNV or do not have the volume to justify keeping identification kits on hand. Specimens go to the public health serology department where enzyme immunoassay testing is performed on serum. Specimens such as mosquitoes and birds are analyzed using real-time PCR.¹ ELISA is the method of choice for human specimens since the…

ABBREVIATIONS: AFB = acid-fast bacilli; CDC = Centers for Disease Control and Prevention; CSF = cerebrospinal fluid; DFA = direct fluorescent antibody; DNA = deoxyribonucleic acid; ELISA = enzyme-linked immunosorbent assay; FITC = fluorescein isothiocyanate; GIS = Geographical Information System; H1N1 = influenza A virus; LRN = Laboratory Response Network; MDS = Molecular Detection Services; MGIT = mycobacteria growth indicator tube; MTB = Mycobacterium tuberculosis; PCR = polymerase chain reaction; PFGE = pulsed field gel electrophoresis; RNA = ribonucleic acid; STEC = shiga-toxin producing Escherichia coli; TB = tuberculosis; WHO = World Health Organization; WNV = West Nile virus

Discuss various molecular viral assays performed at the public health laboratory.
Describe West Nile virus surveillance protocols.
Explain Qiagen QIAmp BioRobot 9604 methodology.
Compare and contrast Applied Biosystems 7900HT and 7500 Fast real-time PCR systems.
Describe protocols utilized to identify rabies.
Discuss the principle of PFGE in the identification of enteric organisms.
State the principle of the Bactec MGIT 960 Mycobacterial Detection System.
List select and non-select agents identified in the bioterrorism and molecular detection services laboratory.