This on-demand webinar discusses a metagenomic assay to identify viruses and other pathogenic microorganisms in human tumor samples, with the aim of gaining a more comprehensive understanding of the role of the microbiome in cancer development and treatment. 

Erle Robertson, a professor of Microbiology at the University of Pennsylvania's Perelman School of Medicine, discusses the PathoChip, a 60,000-probe comparative genomic hybridization microarray that was developed to target viral, prokaryotic, and eukaryotic genomes. 

Dr. Robertson and his colleagues recently used the PathoChip technology to identify viruses, bacteria, fungi, and parasites associated with triple negative breast cancer. The study used formalin-fixed paraffin embedded archival tissues and the results were validated by PCR and next-generation sequencing. Hierarchical clustering analysis identified two signature patterns, one predominantly bacteria and parasites and the other predominantly viruses. 

The contribution of these microbial signatures has yet to be determined. It's possible that the microbes play a causative role, contributing something to the cellular microenvironment that helps damaged cells become malignant, or they may just find tumor tissue to be a favorable environment. Nevertheless, their association with the disease indicates that they may have diagnostic potential. 

Dr. Robertson also discusses how his team used the PathoChip to rapidly identify a zygomycetous fungi, Rhizomucor pusilla, in a case of a patient with acute myelogenous leukemia, highlighting the value of the chip as a tool to identify microorganisms to the species level, especially those that are difficult to identify for most microbiology laboratories.