Use of in vivo Microbial Antigen Detection (InMAD) with human biological fluids for detection of circulating antigens

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Diagnosis of an infection in a timely manner is essential for proper therapeutic administration and more effective treatments, especially for diseases with non-specific early symptoms. Acute infections are typically diagnosed by identifying microbial antigens directly from patient samples. However, microbes do not replicate to high levels in biological fluids, and the ability to detect trace amounts of microbial antigen within complex biological fluids, such as serum, is severely compromised. Researchers at the University of Nevada, Reno have developed a method to identify trace amounts of circulating microbial antigens that possess diagnostic potential.



Our researchers have developed a novel method for detecting the presence of microbial antigens circulating in human body fluids shed during an infection, termed “In vivo Microbial Antigen Discovery” (InMAD). This method is capable of identifying microbial antigens at low levels, and antigens different from those predicted to be shed or secreted by a pathogen. The identified antigens may then be used in immunoassays such as lateral flow immunoassays (LFIs). Improving our conventional InMAD technique where sera harvested from a laboratory animal infected with a particular pathogen is used to immunize a naïve laboratory animal, our method uses filtered human biological samples (e.g., urine and serum) to directly immunize such naïve animals for the production of antibodies specific to shed microbial antigens. The serum may then be used as probes for detection of bacterial antigens and be subjected to immunoblot/mass spectroscopy and proteome array analysis to identify candidate diagnostic antigens of a given disease.


Our method provides techniques for preparing a sample from an infected patient, immunizing mice, detecting shed microbial antigens, and for the use of immunoassays that can be applied in point-of-care (POC) analytical tests.  Our researchers have used this method for identifying a shed microbial antigen produced by Burkholderia pseudomallei, the causative agent of melioidosis, a disease causing an estimated 89,000 deaths worldwide per year.  This shed antigen is now the target of a soon to be FDA approved POC assay for diagnosis of melioidosis.



  • This method allows accurate identification of candidate diagnostic microbial antigens in human bodily fluids
  • Can identify low concentrations of microbial antigens, the proverbial “needle in the haystack”
  • This method can detect multiple diagnostic antigens in a biological sample







Patent Information:
For Information, Contact:
David Maine
Senior Licensing Associate
University of Nevada, Reno
David AuCoin
Thomas Kozel
Claire Smalley
Life Sciences