Fungal Infection Identified by Pathogen Detection Array Technology

By LabMedica International staff writers
Posted on 09 Feb 2016

Image: Sporangiophores, columellae and primitive rhizoids of Rhizomucor spp., the zygomycetous fungus detected by the PathoChip, which has the ability to detect all known viruses, as well as a variety of bacteria, fungi, helminths, and protozoa (Photo courtesy of the University of Adelaide).

Image: Rhizomucor pusillus (Photo courtesy of the University of Adelaide).

Patients who are undergoing treatment for diseases such as cancer often face the added challenge of a compromised immune system, which can be challenging to both of their condition and the drugs used to treat it, leaving them vulnerable to various opportunistic infections.

A novel investigational technology has been developed that can rapidly identify elusive microorganisms which are not only life-threatening, but those caused by rare organisms are extremely difficult to isolate and identify.

Scientists at the University of Pennsylvania (Philadelphia, PA, USA) utilized a pathogen array technology referred to as PathoChip, comprised of oligonucleotide probes that can detect all the sequenced viruses as well as known pathogenic bacteria, fungi and parasites and family-specific conserved probes, thus providing a means for detecting previously uncharacterized members of a family. The technology contains 60,000 probes that simultaneously test for all known viruses, as well as a variety of bacteria, fungi, helminths, and protozoa.

The investigators applied the PathoChip test to tissue samples of a patient with relapsed acute myelogenous leukemia (AML). The patient, a middle-aged man, had undergone chemotherapy for the cancer, a treatment that is well known to weaken the immune system, increasing susceptibility to infection. As a result, he developed an unknown fungal infection. The team rapidly identified a zygomycetous fungus, Rhizomucor, an otherwise challenge for the clinical laboratories, predominantly in the patient with acute myelogenous leukemia.

Erle Robertson, PhD, a professor and vice-chair for research in Otorhinolaryngology, said, “We've run many tests to see if we could identify pathogens in the laboratory, just to see if the PathoChip has efficacy in identifying a variety of organisms, and we were able to identify all infectious agents tested, but this was the first time we actually looked directly at a patient sample to identify a pathogenic agent. With this technology, out of 60,000 possibilities and probes that we used, in a little over 24 hours we were able to identify this particular fungi.” The study was published originally online on November 20, 2015, in the journal Cancer, Biology & Therapy.

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