Jonathan Kargas

The opportunistic, waterborne pathogen Legionella caused 9,933 cases of Legionnaires’ disease in 2018 in the United States (CDC.gov). The incidence of Legionnaires’ disease can be reduced by maintaining clean building water systems through water management programs (WMPs). WMPs often include validation testing to confirm the control of bacteria, but the traditional culture method for enumerating Legionella requires 10–14 days to obtain results. A rapid DNA extraction developed by Phigenics and a real-time PCR negative screen for the genus Legionella provided results the day after sampling. This study evaluated the Next Day Legionella PCR (Phigenics, LLC) compared with the traditional culture method (ISO 11731) on 11,125 building water samples for approximately 1 year. Two DNA extraction methods (Methods 1 and 2) were compared. The negative predictive value (NPV) of the Next Day Legionella PCR in comparison to traditional culture for Method 1 was 99.95%, 99.92%, 99.85%, and 99.17% at >10, >2, >1, and >0.1 CFU/ml limits of detection, respectively. The improved DNA extraction (Method 2) increased the NPV to 100% and 99.88% at >1 and >0.1 CFU/ml, respectively. These results demonstrate the reliability of the genus-level Legionella PCR negative screen to predict culture-negative water samples. 

Jonathan is a Product Manager for Phigenics Analytical Laboratory Services (PASL). In this role, he is responsible for the complete Phigenics testing product portfolio, including defining the product vision and developing training and resources for both for the Phigenics’ Sales Team and our clients. Jonathan has been with Phigenics for five years. He started in the laboratory, and then transitioned to technical sales where he worked as an Account Manager. In this role, he developed and implemented Water Management Programs (WMP) for clients across the U.S. and Canada.

Jonathan has over a decade of laboratory experience. Prior to Phigenics, he worked in both an analytical laboratory and an environmental chemistry laboratory. In these labs, he gained experience in molecular and serological techniques and ICP-OES and ICP-MS instruments. Jonathan has a BS in Biology from Holy Names University in Oakland, CA.