Real-time test developed to detect fungal meningitis pathogen
Researchers have developed a real-time assay for the rapid detection of Exserohilum rostratum, the mold pathogen largely responsible for the deadly outbreak of fungal meningitis associated with tainted vials of methylprednisolone. The real-time PCR assay is highly accurate and capable of detecting E. rostratum efficiently, according to study results.
“Fungal meningitis, like many acute life-threatening infections, requires a rapid identification of the source of disease to be able to manage it effectively,” David S. Perlin, PhD, executive director of the Public Health Research Institute at the University of Medicine and Dentistry of New Jersey, told Infectious Disease News.
David S. Perlin
The PCR assay uses molecular beacon technology, designed in this case to specifically detect E. rostratum.
Perlin and colleagues tested the accuracy of the assay on seven separate outbreak isolates of E. rostratum.
Study results indicated that E. rostratum was detected in amounts as small as 100 femtograms, even in the presence of large excess quantities of human DNA.The new assay is applicable to detect E. rostratum in human tissue for rapid diagnosis and to monitor cerebrospinal fluid samples of infected patients receiving antifungal therapy. The new assay may also be used for E. rostratum detection in medication vials, which potentially could allow health officials and drug manufacturers to screen for the pathogen and prevent future outbreaks.
Although the assay was specifically designed for E. rostratum, the researchers expect to detect the presence of three closely related species: E. longirostratum, E. mcginnisii and E. gedarefense because of genetic relatedness. Tests of samples containing medically-imporant fungal species produced negative results.
Perlin said the assay can be applied to a wide range of specimen types.
“The test can detect the presence of the mold in less than 2 hours, and it was designed to be readily adaptable for most clinical microbiology testing laboratories,” he said.
So far, infection associated with contaminated steroid injections has been indentified in 664 cases, resulting in 40 deaths across 19 states, according to the CDC. The current treatment recommendation is high dose (6 mg/kg) voriconazole, every 12 hours.
Disclosure: The researchers report no relevant financial disclosures.
David S. Perlin, PhD, can be reached at email@example.com.